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Sample records for conch strombus gigas

  1. Growth and survival of juvenile queen conch, Strombus gigas fed artificial diets containing varying levels of digestible protein and energy

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    Aquaculture methods for queen conch, Strombus gigas, have been established for several decades. However, there is a need to improve husbandry techniques for the growout of juveniles. The purpose of this study was to determine growth and survival of juvenile queen conch fed artificial diets with incr...

  2. Use of nanoindentation technique for a better understanding of the fracture toughness of Strombus gigas conch shell

    Energy Technology Data Exchange (ETDEWEB)

    Romana, L., E-mail: laurence.romana@univ-ag.fr [Groupe de Technologie des Surfaces et des Interfaces, Université des Antilles et de la Guyane, 97 159 Pointe à Pitre, French West Indies, Guadeloupe (France); Thomas, P.; Bilas, P. [Groupe de Technologie des Surfaces et des Interfaces, Université des Antilles et de la Guyane, 97 159 Pointe à Pitre, French West Indies, Guadeloupe (France); Mansot, J.L. [Groupe de Technologie des Surfaces et des Interfaces, Université des Antilles et de la Guyane, 97 159 Pointe à Pitre, French West Indies, Guadeloupe (France); Centre Commun de Caractérisation des Matériaux, 97 159 Pointe à Pitre, French West Indies, Guadeloupe (France); Merrifiels, M. [Groupe de Technologie des Surfaces et des Interfaces, Université des Antilles et de la Guyane, 97 159 Pointe à Pitre, French West Indies, Guadeloupe (France); Bercion, Y. [Centre Commun de Caractérisation des Matériaux, 97 159 Pointe à Pitre, French West Indies, Guadeloupe (France); Aranda, D. Aldana [CINVESTAV IPN Unidad Merida, Recursos del Mar, Laboratorio de Biología y Acuacultura de Moluscos, Km 6 antigua Carretera a Progreso, Cp 97310 Cordemex (Mexico)

    2013-02-15

    In this work the nanochemical properties of the composite organomineral biomaterial constituting Strombus gigas conch shell are studied by means of dynamic mechanical analyses associated to nanoidentation technique. The measurements are performed on shell samples presenting different surface orientations relative to the growth axis of the conch shell. The influence of the organic component of the biomaterial on its nanomechanical properties is also investigated by studying fresh and dried S. gigas conch shells. Monocrystalline aragonite is used as a reference. For the understanding of nanochemical behaviour, special attention is paid to the pop in events observed on the load/displacement curves which results from nanofractures' initiation and propagation occuring during the load process. In order to better understand the mechanical properties systematic studies of the structure and morphology are performed using scanning electron microscopy, atomic force microscopy and X-ray diffractometry. The hardness and Young's modulus values measured on bio aragonite samples are close to those of the aragonite mineral standard. This surprising result shows that, H and E values are not related to the bio composition and lamellar structure of the bio aragonite. However, it was found that the organic layer and the micro architecture strongly influence the nanofracture initiation and propagation processes in the samples. Statistic study of the pop-in events can help to predict the macroscopic mechanical behaviour of the material. - Highlights: ► Nanomechanical properties of Strombus gigas conch shell ► Low influence of the crossed lamellar structure on H and E values at the nano scale ► Strong influence of the crossed lamellar on nanocracks initiation ► Correlation between mechanical behaviors at the macro and nano scales.

  3. Queen conch (Strombus gigas testis regresses during the reproductive season at nearshore sites in the Florida Keys.

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    Daniel J Spade

    Full Text Available BACKGROUND: Queen conch (Strombus gigas reproduction is inhibited in nearshore areas of the Florida Keys, relative to the offshore environment where conchs reproduce successfully. Nearshore reproductive failure is possibly a result of exposure to environmental factors, including heavy metals, which are likely to accumulate close to shore. Metals such as Cu and Zn are detrimental to reproduction in many mollusks. METHODOLOGY/PRINCIPAL FINDINGS: Histology shows gonadal atrophy in nearshore conchs as compared to reproductively healthy offshore conchs. In order to determine molecular mechanisms leading to tissue changes and reproductive failure, a microarray was developed. A normalized cDNA library for queen conch was constructed and sequenced using the 454 Life Sciences GS-FLX pyrosequencer, producing 27,723 assembled contigs and 7,740 annotated transcript sequences. The resulting sequences were used to design the microarray. Microarray analysis of conch testis indicated differential regulation of 255 genes (p<0.01 in nearshore conch, relative to offshore. Changes in expression for three of four transcripts of interest were confirmed using real-time reverse transcription polymerase chain reaction. Gene Ontology enrichment analysis indicated changes in biological processes: respiratory chain (GO:0015992, spermatogenesis (GO:0007283, small GTPase-mediated signal transduction (GO:0007264, and others. Inductively coupled plasma-mass spectrometry analysis indicated that Zn and possibly Cu were elevated in some nearshore conch tissues. CONCLUSIONS/SIGNIFICANCE: Congruence between testis histology and microarray data suggests that nearshore conch testes regress during the reproductive season, while offshore conch testes develop normally. Possible mechanisms underlying the testis regression observed in queen conch in the nearshore Florida Keys include a disruption of small GTPase (Ras-mediated signaling in testis development. Additionally, elevated tissue

  4. IDENTIFICACIÓN MOLECULAR DE POBLACIONES BACTERIANAS ASOCIADAS AL CARACOL PALA (Strombus gigas DEL CARIBE COLOMBIANO Molecular Identification Of Bacterial Populations Associated To Queen Conch (Strombus gigas From Colombian Caribbe

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    EDINSON ANDRÉS ACOSTA

    Full Text Available El caracol Pala, Strombus gigas (Strombidae, es de gran importancia ecológica y socioeconómica en el área caribeña colombiana. Sin embargo, es una especie catalogada como "vulnerable" y existe muy poca información referente a las especies bacterianas asociadas al caracol que puedan ser importantes para el desarrollo, manejo productivo y de seguridad acuícola de estos gastrópodos. En este trabajo, nosotros empleamos un estudio microbiológico y molecular de la región intergénica entre los genes 16S y 23S rDNA, análisis del gen rDNA 16S y secuenciación, para analizar las bacterias asociadas al caracol Pala (S. gigas. La composición de bacterias cultivables asociadas fue evaluada por su capacidad para crecer en agar marino y en medios de cultivos selectivos. De un total de 28 muestras analizadas encontramos que el número de bacterias cultivadas en condiciones aerobias fue de alrededor 10(6 ufc mL-1 donde las bacterias pertenecientes a la familia Vibrionacea fueron las más abundantes, cerca de >10(5 ufc mL-1. El análisis molecular de la región intergénica entre los genes 16S y 23S rDNA de las diferentes muestras, reveló una gran complejidad bacteriana asociada a S. gigas. Las secuencias de los amplificados del gen rDNA 16S identificó Pseudoalteromonas sp., Halomonas sp., Psycrobacter sp., Cobetia sp., Pseudomonas sp. y Vibrios sp. Nuestros resultados podrían sugerir un rol importante de estas bacterias como componentes de la comunidad asociada al S. gigas. Esta información puede complementar los estudios que se están implementando en los procesos para la conservación y repoblamiento de las poblaciones de S. gigas en Colombia.The Queen Conch, Strombus gigas (Strombidae, is a species of great ecological and socioeconomic importance in the Caribbean area of Colombia. However, it is currently catalogued as "vulnerable"; there is limited information concerning the bacterial species associated with conch and important in the

  5. Gene expression profiling in the ovary of Queen conch (Strombus gigas) exposed to environments with high tributyltin in the British Virgin Islands

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    Titley-O' Neal, Cassander P. [Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5 (Canada); Spade, Daniel J. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Zhang, Yanping [Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32611 (United States); Kan, Rosalinda; Martyniuk, Christopher J. [Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5 (Canada); Denslow, Nancy D. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); MacDonald, Bruce A., E-mail: bmacdon@unbsj.ca [Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5 (Canada)

    2013-04-01

    Queen conch (Strombus gigas) are listed in CITES Appendix II. Populations may be declining due to anthropogenic inputs that include pollutants from boating activity. In the British Virgin Islands (BVI), some conch exhibit imposex, a condition in which male external genitalia are present in female conch. Previous studies suggest that tributyltin (TBT), an antifouling chemical used in boat paint, is correlated to increased incidence of imposex although the mechanisms leading to imposex are not known. The present study utilized a Queen conch microarray to measure the response of the ovarian transcriptome in conch inhabiting polluted environments with high TBT levels in the BVI. The polluted sites, Road Harbour (RH) and Trellis Bay (TB), are areas with high boating activity while the reference sites, Guana Island (GI) and Anegada (AN), are areas with low boating activity. There were 754 and 898 probes differentially expressed in the ovary of conch collected at RH and TB respectively compared to conch collected at GI. Of the genes that were differentially expressed at both sites, > 10% were shared suggesting that these sites have additional environmental factors influencing gene expression patterns. Functional enrichment analysis showed that the biological processes of cell proliferation, translation, and oxidative stress were over-represented in the polluted sites. Gene set enrichment analysis revealed that transcripts involved in the biological processes of general metabolism, immune, lipid metabolism, and stress were affected in conch from polluted environments. Interestingly, altered stress genes appeared to be more prevalent in conch collected from RH than TB, corresponding to the higher TBT load at RH compared to TB. Our study shows that stress pathways are affected in conch ovary in environments that experience heavy boating activity in the BVIs, although we are unable to directly link changes at the transcriptomics level to high TBT levels. Highlights:

  6. Sclerochronology - a highly versatile tool for mariculture and reconstruction of life history traits of the queen conch, textit{Strombus gigas} (Gastropoda)

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    Radermacher, Pascal; Schöne, Bernd R.; Gischler, Eberhard; Oschmann, Wolfgang; Thébault, Julien; Fiebig, Jens

    2010-05-01

    The shell of the queen conch Strombus gigas provides a rapidly growing palaeoenvironmental proxy archive, allowing the detailed reconstruction of important life-history traits such as ontogeny, growth rate and growth seasonality. In this study, modern sclerochronological methods are used to cross-date the palaeotemperatures derived from the shell with local sea surface temperature (SST) records. The growth history of the shell suggests a bimodal seasonality in growth, with the growing season confined to the interval between April and November. In Glovers Reef, offshore Belize, the queen conch accreted shell carbonate at rates of up to 6 mm day-1 during the spring (April-June) and autumn (September-November). However a reduced period of growth occurred during the mid-summer months (July-August). The shell growth patterns indicate a positive response to annual seasonality with regards to precipitation. It seems likely that when precipitation levels are high, food availability is increased as the result of nutrient input to the ecosystem in correspondence with an increase in coastal runoff. Slow growth rates occur when precipitation, and as a consequence riverine runoff, is low. The SST however appears to influence growth only on a secondary level. Despite the bimodal growing season and the winter cessation in growth, the growth rates reconstructed here from two S. gigas shells are among the fastest yet reported for this species. The S. gigas specimens from Belize reached their final shell height (of 22.7 and 23.5 cm in distance between the apex and the siphonal notch) at the transition to adulthood in just 2 years. The extremely rapid growth as observed in this species permits detailed, high-resolution reconstructions of life-history traits where sub-daily resolutions can be achieved with ease. The potential for future studies has yet to be further explored. Queen conch sclerochronology provides an opportunity to recover extremely high-resolution palaeotemperature

  7. Geographical variation in the genetic diversity and composition of the endangered Queen Conch Strombus gigas (Mesogastropoda: Strombidae from Yucatán, México

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    Ricardo Pérez-Enriquez

    2011-09-01

    Full Text Available In Mexico and elsewhere in the Caribbean, the queen conch Strombus gigas is an endangered species. Understanding the genetic connectivity of their populations will support management strategies for long term conservation of the species. Genetic diversity and population differentiation was assessed from samples collected at Banco Chinchorro and Isla Cozumel in the Mexican Caribbean and at Arrecife Alacranes in the Gulf of Mexico. Samples were obtained from the commercial capture at Banco Chinchorro (n=50 and Isla Cozumel (n=40 on March 2004. On November 2004, a non-invasive method for the Arrecife Alacranes sampling was applied, taking the hemolymph of live animals (n=65 and releasing them to the wild. The mitochondrial DNA variation at two genes (COI and Cyt-b was analyzed. Genetic diversity at the three locations ranged between 0.55-0.65 in COI and 0.87-0.94 in Cyt-b, showing no bottleneck evidences. A non-significant fixation index (F ST=0.019, p=0.161 and a Maximum Parsimony Network tree that did not show particular clades associated with any of the geographical locations, suggested a lack of statistically significant genetic differentiation among populations. Nevertheless, the cline patterns observed in both genetic diversity and haplotypic frequencies from Banco Chinchorro through Arrecife Alacranes, and the larger genetic distance between these locations from those between Isla Cozumel, Banco Chinchorro and Arrecife Alacranes, suggest the possibility of a pattern of isolation-by distance. The role of the main current systems over the potential genetic differences in S. gigas populations along the Mexican Caribbean, and the conservation management of S. gigas at these locations as discrete units is discussed. Rev. Biol. Trop. 59 (3: 1115-1126. Epub 2011 September 01.

  8. Growth and population assessment of the queen conch Strombus gigas (Mesogastropoda: Strombidae by capture mark-recapture sampling in a natural protected area of the Mexican Caribbean

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    Joanne Rebecca Peel

    2012-03-01

    Full Text Available The Inlet of Xel-Ha is used as a park for ecotourism, representing a sanctuary for the conservation of Pink Queen Conch. Increasing fishing pressure has led to the inclusion of the species in CITES. Most knowledge about the growth of the queen conch was generated through aquaculture, ocean enclosures or obtained using estimates derived from population dynamics. In this study we estimated the growth rate of juvenile S. gigas in a natural protected area by direct methods, during the period of April 2009 to January 2011. Data was obtained by capture-mark-recapture sampling. 1418 individuals were tagged and growth of 714 conchs was analyzed. Population size and density was estimated using Schnabel’s method. The average density was estimated at 0.1694 ± 0.0996ind. m-2, while the highest density was estimated for September 2010 (0.3074ind. m-2. The highest growth rate (0.27 ± 0.10mm day-1 was detected in juveniles with an initial size between 100-149mm, followed by conch 200mm (0.08 ± 0.07mm day-1. Variability in growth rate was high in conch 100-149mm and showed seasonal differences, with the highest growth rate in May 2010. Recruitment of juveniles was highest in October 2009 and February 2010. The population of Xel-Ha has grown in size and more large and juvenile conch could be found than in previous studies, indicating that Xel-ha park is working as a sanctuary for the conservation of the queen conch in Mexico’s Riviera Maya. The growth rate of juvenile conch in Xel-Ha is high and exhibits large variations in individuals, reflecting the natural conditions of foraging and aggregation. Seasonal differences in growth rate may be associated with water quality and availability of nutrients for primary production. We conclude that the direct method is useful for the assessment of growth in juvenile S. gigas and that growth in natural conditions may be higher than in aquaculture systems. This information may be applied to fishery management as

  9. Declining densities and reproductive activities of the queen conch Strombus gigas (Mesogastropoda: Strombidae in Banco Chinchorro, Eastern Caribbean, Mexico

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    Alberto De Jesús Navarrete

    2013-12-01

    Full Text Available Queen conch is a gastropod inhabiting the Caribbean Sea, it represents the second largest fishery after the spiny lobster, but it has been extensively captured in the area. In order to know its population status in Chinchorro Bank, we determined conch density changes and its effects on reproductive activities, between July and November 2009. For this, data on conch density, morphology and reproductive activities were obtained from 15 sites within three fishing zones, and compared with previously collected data (1990, 1992, 1994, and 1997. Data showed that adult density decreased with time, from 10 700ind./ha in 1990, to 198ind./h in 2009. Neither egg masses nor spawns were found and mating was only observed once in July 2009. In July, adult (lip>4mm density in the Southern zone was 23ind./ha whereas in the Northern zone and Central zone densities were 15 and 9ind./ha respectively. In November, density was somewhat higher: Southern zone 96ind./ha; Central zone 39ind./ha and Northern zone had 38ind./ha. In July, mean shell length was 170.80±46.28mm, with a higher median abundance at 180-189mm. In November, higher frequency was 187.63±45.14mm, maximum at 210-219mm interval. For the last 10 years period, mean adult conch densities have diminished in each zone, which might be the main cause of decreased reproductive activities of the conch at Banco Chinchorro. It is therefore an immediate need to analyse the management plan for this species in this Reserve and perhaps to promote a re-population of queen conch and culture activities. Rev. Biol. Trop. 61 (4: 1671-1679. Epub 2013 December 01.

  10. Geographical variation in the genetic diversity and composition of the endangered Queen Conch Strombus gigas (Mesogastropoda: Strombidae from Yucatán, México

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    Ricardo Pérez-Enriquez

    2011-09-01

    Full Text Available In Mexico and elsewhere in the Caribbean, the queen conch Strombus gigas is an endangered species. Understanding the genetic connectivity of their populations will support management strategies for long term conservation of the species. Genetic diversity and population differentiation was assessed from samples collected at Banco Chinchorro and Isla Cozumel in the Mexican Caribbean and at Arrecife Alacranes in the Gulf of Mexico. Samples were obtained from the commercial capture at Banco Chinchorro (n=50 and Isla Cozumel (n=40 on March 2004. On November 2004, a non-invasive method for the Arrecife Alacranes sampling was applied, taking the hemolymph of live animals (n=65 and releasing them to the wild. The mitochondrial DNA variation at two genes (COI and Cyt-b was analyzed. Genetic diversity at the three locations ranged between 0.55-0.65 in COI and 0.87-0.94 in Cyt-b, showing no bottleneck evidences. A non-significant fixation index (F ST=0.019, p=0.161 and a Maximum Parsimony Network tree that did not show particular clades associated with any of the geographical locations, suggested a lack of statistically significant genetic differentiation among populations. Nevertheless, the cline patterns observed in both genetic diversity and haplotypic frequencies from Banco Chinchorro through Arrecife Alacranes, and the larger genetic distance between these locations from those between Isla Cozumel, Banco Chinchorro and Arrecife Alacranes, suggest the possibility of a pattern of isolation-by distance. The role of the main current systems over the potential genetic differences in S. gigas populations along the Mexican Caribbean, and the conservation management of S. gigas at these locations as discrete units is discussed. Rev. Biol. Trop. 59 (3: 1115-1126. Epub 2011 September 01.El caracol rosado Strombus gigas es una especie amenzada en México y otros sitios del Caribe. Su conservación a largo plazo requiere la comprensión de la conectividad entre

  11. Mitochondrial genome of the endangered marine gastropod Strombus gigas Linnaeus, 1758 (Mollusca: Gastropoda).

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    Márquez, Edna J; Castro, Erick R; Alzate, Juan F

    2016-01-01

    The queen conch Strombus gigas is an endangered marine gastropod of significant economic importance across the Greater Caribbean region. This work reports for the first time the complete mitochondrial genome of S. gigas, obtained by FLX 454 pyrosequencing. The mtDNA genome encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of gastropods.

  12. IDENTIFICACIÓN MOLECULAR DE POBLACIONES BACTERIANAS ASOCIADAS AL CARACOL PALA (Strombus gigas DEL CARIBE COLOMBIANO

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    ROMERO MAGALLY

    2009-08-01

    Full Text Available RESUMEN

    El caracol Pala, Strombus gigas (Strombidae, es de gran importancia ecológica y socioeconómica en el área caribeña colombiana. Sin embargo, es una especie catalogada como “vulnerable” y existe muy poca información referente a las especies bacterianas asociadas al caracol que puedan ser importantes para el desarrollo, manejo productivo y de seguridad acuícola de estos gastrópodos. En este trabajo, nosotros empleamos un estudio microbiológico y molecular de la región intergénica entre los genes 16S y 23S rDNA, análisis del gen rDNA 16S y secuenciación, para analizar las bacterias asociadas al caracol Pala (S. gigas. La composición de bacterias cultivables asociadas fue evaluada por su capacidad para crecer en agar marino y en medios de cultivos selectivos. De un total de 28 muestras analizadas encontramos que el número de bacterias cultivadas en condiciones aerobias fue de alrededor 106 ufc mL-1 donde las bacterias pertenecientes a la familia Vibrionacea fueron las más abundantes, cerca de >105 ufc mL-1 . El análisis molecular de la región intergénica entre los genes 16S y 23S rDNA de las diferentes muestras, reveló una gran complejidad bacteriana asociada a S. gigas. Las secuencias de los amplificados del gen rDNA 16S identificó Pseudoalteromonas sp., Halomonas sp., Psycrobacter sp., Cobetia sp., Pseudomonas sp. y Vibrios sp. Nuestros resultados podrían sugerir un rol importante de estas bacterias como componentes de la comunidad asociada al S. gigas. Esta información puede complementar los estudios que se están implementando en los procesos para la conservación y repoblamiento de las poblaciones de S. gigas en Colombia.

    Palabras clave: Strombus gigas, Caracol pala, Bacteria, Región intergénica 16S-23S, rDNA 16S.

    ABSTRACT

    The Queen Conch, Strombus gigas (Strombidae, is a species of great ecological and socioeconomic importance in the Caribbean area of Colombia

  13. Photothermal characterization of thermally treated shells of Strombus Gigas

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    Hernández-Ayala, A.; Quintana, P.; Alvarado-Gil, J. J.; Aldana, D.

    2005-06-01

    The thermal properties of the marine shells of the mollusk Strombus gigas are studied using photoacoustic techniques. In order to generate changes in the layered structure of the shells, they were thermally treated in the range from ambient temperature up to 400ºC. Our results show that the thermal diffusivity and conductivity have a maximum at 200ºC due to the degradation of the organic matrix. At higher temperatures the thermal diffusivity and conductivity decrease due to the calcium carbonate structural phase transition from aragonite to calcite.

  14. [Genetic diversity in two populations of the snail Strombus gigas (Gastropoda: Strombidae) from Yucatan, Mexico, using microsatellite].

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    Zamora-Bustillos, Roberto; Rodríguez-Canul, Rossanna; García de León, Francisco J; Tello Cetina, Jorge

    2011-09-01

    The pink conch Strombus gigas is an important fisheries resource in the Caribbean region, including the Yucatán Peninsula. We analyzed the genetic diversity and genetic structure of two populations (Alacranes Reef and Chinchorro Bank) with the use of five microsatellite molecular markers. The results indicate that the two populations are in the same rank of genetic diversity (He), from 0.613 to 0.692. Significant deviation from H-WE was observed in the both populations due to deficit to heterozygotes, this was attributed to inbreeding as a consequence of over-fishing; nevertheless, other possible causes considered are mixing of individuals from two or more populations, and the existence of null alleles. Levels of genetic differentiation indicated the existence of a single homogenous population in the Yucatan Peninsula (F(ST) de 0.003, p = 0.49), which fits with highest levels of gene flow is significant (2.3 individuals) between both populations. Results from this study support the hypothesis that S. gigas is part of a single panmictic population in the Yucatan Peninsula; therefore, this fishery resource should be regulated the same way for both areas.

  15. Impact of minimum catch size on the population viability of Strombus gigas (Mesogastropoda: Strombidae inQuintana Roo, Mexico

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    Joanne R. Peel

    2014-12-01

    Full Text Available The queen conch Strombus gigas represents one of the most important fishery resources of the Caribbean but heavy fishing pressure has led to the depletion of stocks throughout the region, causing the inclusion of this species into CITES Appendix II and IUCN’s Red-List. In Mexico, the queen conch is managed through a minimum fishing size of 200mm shell length and a fishing quota which usually represents 50% of the adult biomass. The objectives of this study were to determine the intrinsic population growth rate of the queen conch population of Xel-Ha, Quintana Roo, Mexico, and to assess the effects of a regulated fishing impact, simulating the extraction of 50% adult biomass on the population density. We used three different minimum size criteria to demonstrate the effects of minimum catch size on the population density and discuss biological implications. Demographic data was obtained through capture-mark-recapture sampling, collecting all animals encountered during three hours, by three divers, at four different sampling sites of the Xel-Ha inlet. The conch population was sampled each month between 2005 and 2006, and bimonthly between 2006 and 2011, tagging a total of 8 292 animals. Shell length and lip thickness were determined for each individual. The average shell length for conch with formed lip in Xel-Ha was 209.39±14.18mm and the median 210mm. Half of the sampled conch with lip ranged between 200mm and 219mm shell length. Assuming that the presence of the lip is an indicator for sexual maturity, it can be concluded that many animals may form their lip at greater shell lengths than 200mm and ought to be considered immature. Estimation of relative adult abundance and densities varied greatly depending on the criteria employed for adult classification. When using a minimum fishing size of 200mm shell length, between 26.2% and up to 54.8% of the population qualified as adults, which represented a simulated fishing impact of almost one

  16. Impact of minimum catch size on the population viability of Strombus gigas (Mesogastropoda: Strombidae) in Quintana Roo, Mexico.

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    Peel, Joanne R; Mandujano, María del Carmen

    2014-12-01

    The queen conch Strombus gigas represents one of the most important fishery resources of the Caribbean but heavy fishing pressure has led to the depletion of stocks throughout the region, causing the inclusion of this species into CITES Appendix II and IUCN's Red-List. In Mexico, the queen conch is managed through a minimum fishing size of 200 mm shell length and a fishing quota which usually represents 50% of the adult biomass. The objectives of this study were to determine the intrinsic population growth rate of the queen conch population of Xel-Ha, Quintana Roo, Mexico, and to assess the effects of a regulated fishing impact, simulating the extraction of 50% adult biomass on the population density. We used three different minimum size criteria to demonstrate the effects of minimum catch size on the population density and discuss biological implications. Demographic data was obtained through capture-mark-recapture sampling, collecting all animals encountered during three hours, by three divers, at four different sampling sites of the Xel-Ha inlet. The conch population was sampled each month between 2005 and 2006, and bimonthly between 2006 and 2011, tagging a total of 8,292 animals. Shell length and lip thickness were determined for each individual. The average shell length for conch with formed lip in Xel-Ha was 209.39 ± 14.18 mm and the median 210 mm. Half of the sampled conch with lip ranged between 200 mm and 219 mm shell length. Assuming that the presence of the lip is an indicator for sexual maturity, it can be concluded that many animals may form their lip at greater shell lengths than 200 mm and ought to be considered immature. Estimation of relative adult abundance and densities varied greatly depending on the criteria employed for adult classification. When using a minimum fishing size of 200 mm shell length, between 26.2% and up to 54.8% of the population qualified as adults, which represented a simulated fishing impact of almost one third of the

  17. Variación estacional de lípidos en varios tejidos del cambute Strombus gigas (Mesogastropoda: Strombidae, en Quintana Roo, México

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    Nancy Brito Manzano

    1998-09-01

    Full Text Available Se determinó la variación mensual de lípidos en varios tejidos del cambute Strombus gigas (L., en Banco Chinchorro, Quintana Roo, México durante un año. La longitud de la heliconcha fue 209 ± 1 mm, la del cuerpo 137 ± 1 mm, la de la espira 100 ± 1 mm y el peso húmedo total 1 826 ± 7 g. La media del contenido de lípidos en la gónada-glándula digestiva fue 4.27 g% (machos 4.01 g% y hembras 4.50 g%. El contenido de lípidos en gónada-glándula digestiva mostró diferencias sexuales significativas (p Strombus gigas samples were collected in Banco Chinchorro, Quintana Roo, Mexico (18°47'-18°23' N; 87°14' W. Shell, body and spire lenght were measured. Fat content of gonad, digestive gland and meat of male and female conchs, was analyzed by the standard and microsoxhlet methods on a monthly basis for a year. Mean lenght for shell, body and spire were 209 ± 1 mm, 137 ±1 mm and 100 ± 1 mm, respectively. Total wet weigth was 1 826 ± 7 g. Fat content in gonad-digestive gland was 1.27-9.33 g% with a mean of 4.27 g% and in meat 0.41-5.03 g% with a mean of 2.15 g%. Fat content in female gonad-digestive gland was 1.27 g% at 8.57 g% with a mean of 4.50 g%; in male: 1.87 g% at 9.33 g% with a mean of 4.01 g%. Sexes differed (t student P < 0.05. Mean fat content in meat was 2.15 g%, (males 1.97 g%, females 2.3 g%. There was not significant sexual difference for meat fat content. There was a difference between gonad-digestive gland and meat (t student P < 0.05. However, from February to September meat lipid content exceeds the percentage recommended for human consumption by the FAO.

  18. IDENTIFICACIÓN MOLECULAR DE POBLACIONES BACTERIANAS ASOCIADAS AL CARACOL PALA (Strombus gigas DEL CARIBE COLOMBIANO

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    EDINSON ANDRÉS ACOSTA

    2009-01-01

    Full Text Available El caracol Pala, Strombus gigas (Strombidae, es de gran importancia ecológica y so- cioeconómica en el área caribeña colombiana. Sin embargo, es una especie catalogada como "vulnerable" y existe muy poca información referente a las especies bacterianas asociadas al caracol que puedan ser importantes para el desarrollo, manejo productivo y de seguridad acuícola de estos gastrópodos. En este trabajo, nosotros empleamos un estudio microbiológico y molecular de la región intergénica entre los genes 16S y 23S rDNA, análisis del gen rDNA 16S y secuenciación, para analizar las bacterias asociadas al caracol Pala (S. gigas. La composición de bacterias cultivables asociadas fue evaluada por su capacidad para crecer en agar marino y en medios de cultivos selectivos. De un total de 28 muestras analizadas encontramos que el número de bacterias cultivadas en condiciones aerobias fue de alrededor 106 ufc mL-1 donde las bacterias pertenecientes a la familia Vibrionacea fueron las más abundantes, cerca de >105 ufc mL-1 . El análisis molecular de la región intergénica entre los genes 16S y 23S rDNA de las diferentes muestras, reveló una gran complejidad bacteriana asociada a S. gigas. Las secuencias de los amplificados del gen rDNA 16S identificó Pseudoalteromonas sp., Halomonas sp., Psycrobacter sp., Cobetia sp., Pseudomonas sp. y Vibrios sp. Nuestros resultados podrían sugerir un rol importante de estas bacterias como componentes de la comunidad asociada al S. gigas. Esta información puede complementar los estudios que se están implementando en los procesos para la conservación y repoblamiento de las poblaciones de S. gigas en Colombia.

  19. Abundancia y distribución de larvas de Strombus gigas (Mesogastropoda: Strombidae durante el período reproductivo de la especie en el Caribe Mexicano Abundance and distribution of Strombus gigas (Mesogastropoda: Strombidae larvae during their reproductive period in the Mexican Caribbean

    Directory of Open Access Journals (Sweden)

    José Francisco Chávez Villegas

    2012-03-01

    Full Text Available El caracol rosa (Strombus gigas, Linnaeus, 1758 es una especie de importancia económica en el Mar Caribe, por lo cual, en la década de 1980 representó la segunda pesquería después de la langosta espinosa, razón por la que actualmente se encuentra en estado de sobrepesca. Con el objetivo de determinar la variación en la abundancia de larvas durante la época reproductiva, cuatro localidades del Caribe Mexicano “CM” (México: Puerto Morelos, Sian Ka’an, Mahahual; Belice: San Pedro fueron muestreadas. Mensualmente, de mayo a octubre del 2008, se realizaron arrastres de plancton en cada localidad empleando una red cónica (300μm. Temperatura (°C, salinidad (ppm y oxígeno disuelto (mg L-1 fueron registrados para cada sitio. Una densidad media larval de 0.34±0.87 larvas•10m-3 fue registrada entre localidades, con un pico de abundancia entre agosto y septiembre (0.82±1.00 y 0.76±1.68 larvas 10m-3, respectivamente. La densidad larval tuvo una correlación del 60% con la salinidad (r=0.6063, p0.05. El 100% de las larvas capturadas corresponden al estadio I definido por Davis et al (1993, mostrando actividad reproductiva local, de esta manera, se considera que los sitios muestreados en el CM son fuente de larvas para la especie S. gigas.Abundance and distribution of Strombus gigas (Mesogastropoda: Strombidae larvae during their reproductive period in the Mexican Caribbean. The Queen Conch (Strombus gigas Linnaeus, 1758 is a species of economic importance in the Caribbean Sea, which, in the 1980’s represented the second fishery after de spiny lobster, reason that is currently in a state of overfishing. In order to determine the larval abundance variation during the reproductive season, four locations of the Mexican Caribbean “MC” (Mexico: Puerto Morelos, Sian Ka’an, Mahahual; Belize: San Pedro were sampled. Monthly, from May to October 2008, planktonic net drags (300μm were carried out at each location. Temperature (

  20. Non-Detriment Finding Regarding the Export of Queen conch (Lobatus gigas) from St Eustatius (Caribbean Netherlands)

    NARCIS (Netherlands)

    Graaf, de M.; Meijer zu Schlochteren, M.; Boman, E.

    2014-01-01

    Queen conch (Lobatus gigas (Strombidae; Gastropoda) is a large, long-lived marine gastropod that is widely distributed throughout the coastal zones of the Wider Caribbean region. Because of concern for its future the species was listed in Appendix II of the Convention on International Trade in Endan

  1. Non-Detriment Finding Regarding the Export of Queen conch (Lobatus gigas) from St Eustatius (Caribbean Netherlands)

    NARCIS (Netherlands)

    Graaf, de M.; Meijer zu Schlochteren, M.; Boman, E.

    2014-01-01

    Queen conch (Lobatus gigas (Strombidae; Gastropoda) is a large, long-lived marine gastropod that is widely distributed throughout the coastal zones of the Wider Caribbean region. Because of concern for its future the species was listed in Appendix II of the Convention on International Trade in

  2. [Density, size structure and reproductive activity of the pink conch Eustrombus gigas (Mesogastropoda: Strombidae) in Banco Chinchorro, Mexico].

    Science.gov (United States)

    Cala, Yuself R; Navarrete, Alberto de Jesús; Ocaña, Frank A; Rivera, José Oliva

    2013-12-01

    The pink conch Eustrombus gigas is an important fisheries resource. At the regional level in the Caribbean, over-exploitation and habitat destruction have caused a decrease in the abundance of this resource. In order to provide necessary information for the species management in Mexico, this work aimed to analyze the total density, adult density, size structure and reproductive behavior of pink conch population at Banco Chinchorro during 2009-2010. Data from three seasons were obtained (rainy, dry and cold fronts periods) in three areas: Norte (North), Centro (Center) and Sur (South). The organisms were separated into two groups: (a) the criteria based upon legal harvest in Mexico: legal size conchs (siphonal length > 200 mm) and illegal size conchs (siphonal length or = 15 mm as adult conch. Copulation, spawning, egg masses and aggregations were evaluated as reproductive evidences. The highest total density was observed during the dry season with 384ind./ha, and the lowest during the rainy season with 127ind./ha. The highest density was reported at Sur (385ind./ha) and the lowest at Norte (198ind./ ha). The highest adult density was observed during the rainy season (8.33ind./ha), and the lowest occurred in the dry season (6.1 ind./ha). Adult density values were 5.55, 7.05 and 8.33ind./ha for Centro, Sur and Norte areas, respectively. Adult densities were lower than the threshold needed for reproduction, and 42% of the population may be vulnerable to fishing, as they had the minimum size for catch (Lsi 200 mm). Furthermore, only 2.2% of the population reached a Gl > 15 mm as sexual maturity indicator. During the study period, only six evidences of reproductive activity were observed. The smaller densities reported at Banco Chinchorro may cause reproduction events to be almost absent which in turn is sufficient evidence to show that the Allee Effect is acting on the queen conch population and there is an urgent need of fishery closure. Three important points were

  3. Connectivity and genetic structure of the queen conch on the Mesoamerican Reef

    Science.gov (United States)

    Machkour-M'Rabet, Salima; Cruz-Medina, Jorge; García-De León, Francisco J.; De Jesús-Navarrete, Alberto; Hénaut, Yann

    2017-06-01

    The queen conch ( Strombus gigas) is a commercially important marine invertebrate that is widely distributed throughout the western Atlantic, from Bermuda to Brazil. Intense exploitation has resulted in a decrease in population numbers of this species, which is listed as protected from commercial exploitation under IUCN and CITES. Previous studies on population genetics have demonstrated contrasting results in terms of the population structure of S. gigas. This research analyzed the genetic connectivity of the queen conch over a wide area of the Mesoamerican Reef System to determine whether S. gigas presents one panmictic population or a more complex structure. Furthermore, we evaluated the risk of local extinction by establishing the genetic diversity of the studied populations. High resolution was obtained for the five ISSR markers used for a total of 190 individuals, from seven localities along the Mesoamerican Reef. Our results reject the panmictic structure hypothesis for the queen conch in the study area and demonstrate genetic patchiness, indicating general homogeneity among localities that present an isolation-by-distance pattern. However, some genetic temporal variation was confirmed for the Cozumel locality. Furthermore, our results reveal self-recruitment for the Alacranes Reef aggregation and suggest sufficient connectivity with localities on the Caribbean coast to maintain high genetic diversity. With regard to genetic diversity, the results demonstrate that the queen conch is not genetically threatened in the study area. This is probably due to high annual recruitment within Caribbean queen conch aggregations, and suggests that S. gigas is a highly resilient organism. We advocate that the appropriate management of S. gigas (fishing quota and/or closed season) must be followed to attain a rapid recovery of queen conch populations. This study represents a fundamental step in the understanding of the dynamic population structure of S. gigas in the

  4. Organogénesis larvaria de Strombus gigas (Mesogastropoda: Strombidae) en el arrecife alacranes durante el periodo máximo de su época reproductiva

    OpenAIRE

    Brito-Manzano, N.; Aldana-Aranda, D.; E de la Cruz Lázaro; Ma Estrada-Botello

    2006-01-01

    Con el fin de describir el desarrollo ontogen´etico de las larvas de Strombus gigas se recolectaron masas de huevos del medio natural y se cultivaron bajo condiciones de laboratorio durante mayo, junio y julio, correspondientes al m´aximo de la ´epoca reproductiva en el arrecife Alacranes, durante 1997, 1998, 1999 y 2000. La misma t´ecnica de cultivo experimental fue empleada: incubaci´on por cinco d´ #305;as en contenedores de 19 l, alimentaci´on con Tetraselmis suecica a una concentraci´on ...

  5. Crecimiento del caracol Strombus gigas (Gastropoda: Strombidae en cuatro ambientes de Quintana Roo, México

    Directory of Open Access Journals (Sweden)

    Alberto de Jesús Navarrete

    2001-03-01

    Full Text Available Se estudió la tasa de crecimiento de caracoles cultivados en corrales en cuatro ambientes diferentes. El cultivo se realizó de octubre de 1993 a marzo de 1994. 16 corrales de 50 m² de área cada uno, cuatro por ambiente, fueron colocados en los siguientes ambientes: Thalassia, Thalassia-arena, Arena y Coral, todos dentro de la laguna arrecifal en Punta Gavilán y Banco Chinchorro. En cada ambiente se introdujeron 20 caracoles de las siguientes tallas: 1 100-120, 2 120-140, 3 140-160 y 4 160-180 mm de longitud de concha. Los caracoles se midieron mensualmente con un vernier con una precisión de un mm. El crecimiento se evaluó por dos métodos: a el incremento marginal promedio de la concha y por el método de Gulland-Holt. En el primer método, el ambiente Arena mostró el mayor crecimiento (3.21 + 0.26 mm/mes en Punta Gavilán, mientras que en Banco Chinchorro, el mayor crecimiento ocurrió en coral (2.31 + 0.44 mm/mes. Con el segúndo método la mayor longitud asintótica en Punta Gavilán se midió en Thalassia-arena (287.5 mm, mientras que en Banco Chinchorro, la mayor longitud asintótica se midió en Arena (318.1 mm. Existieron diferencias significativas en el crecimiento entre los sitios y eso muestra que el crecimiento de los juveniles se relaciona con la cantidad de alimento disponible el cual fue mayor en Thalassia y Thalassia-arena. Sin embargo se requiere evaluar la cantidad de alimento, principalmente microfitobentos en los ambientes sin vegetación como Arena y Coral.The growth rate of queen conch cultured in pens was studied from October 1993 to March 1994. Sixteen pens (50 m² each, four pens per environment, were set in four environments: Thalassia, Thalassia-sand, Sand and Coral within a reef lagoon on Punta Gavilan and Banco Chinchorro. Twenty conchs were introduced in each pen (sizes: 100-120, 120-140, 140-160 and 160-180 mm shell length and measured monthly to the nearest mm. Growth rate was assessed by two methods: a

  6. Density and reproduction of the Queen Conch EUSTROMBUS gigas (Mesogastropoda: Strombidae) at Cabo Cruz, Desembarco del Granma National Park, Cuba.

    Science.gov (United States)

    Cala, Yuself R; de Jesús-Navarrete, Alberto; Ocaña, Frank A; Oliva-Rivera, José

    2013-06-01

    The queen conch Eustrombus gigas is an important fisheries resource in the Caribbean region. In Cuba Island the studies about this resource are very scarce and particularly in the Southeastern regions of the country. With the aim to get important fishery information about this gastropod, adult Queen Conch density and frequency of reproductive activity were evaluated in Cabo Cruz, Cuba, during 2009-2010. Data from three seasons were obtained (rainy, dry and cold fronts periods) from three different areas: Farito, Guafe and Laguna. The highest density was observed in cold fronts season (468.5 ind./ha) and the lowest occurred during the dry season (268.5 ind./ha). The highest density was reported at Laguna (520.4 ind./ha) and the lowest at Farito (290.9ind./ha). In total, 158 reproductive events were observed. The highest frequency was reported in rainy season (36%), followed by dry (9%) and cold fronts (5%) seasons. Reproductive behavior (mating and egg laying) was related to temperature and photoperiod. Reproductive activity was observed during the whole year, which suggests the existence of an important Queen Conch reserve in the Southeastern region of Cuba and an apparently self-sufficient population for recruitment. From our results we may conclude that, the population's sustainable exploitation is viable if the following management measures are observed: functional zoning within the area, rotation of fishing areas and a closed season. We recommend that the Laguna site should be protected as a reproduction zone and banned for fishing activities.

  7. Conch, Cooperatives, and Conflict: Conservation and Resistance in the Banco Chinchorro Biosphere Reserve

    Directory of Open Access Journals (Sweden)

    David M Hoffman

    2014-01-01

    Full Text Available In theory, biosphere reserves link biodiversity conservation with development, primarily through sustainable resource utilisation, and alternative, conservation-compatible economies in the buffer and transition zones outside the core area. Successful management should reduce pressure on natural resources within its core area as well as enable local communities to participate in the management of buffer zone resources in a sustainable manner. The Banco Chinchorro Biosphere Reserve was declared in 1996 to protect coral reefs and marine biodiversity, while also enabling fishing cooperatives to maintain their livelihoods based upon the sustainable extraction of lobster, conch, and scalefish. In 2004, eight years after the Reserve′s declaration, Mexican authorities struggled to control marine resource use in the reserve, especially the extraction of queen conch (Strombus gigas. This article provides an overview of the long struggle to conserve queen conch populations in the area. Particular attention is paid to describing the various forms of resistance fishermen employed to counter the increasing regulation and vigilance that accompanied the creation of the Banco Chinchorro Biosphere Reserve. This case chronicles the resistance to regulation and interpersonal violence that erupts when entrenched attitudes and practices are confronted with increasing surveillance. Thus, what was observed in the Banco Chinchorro Biosphere Reserve parallels other research that depicts the forms of resistance to conservation that local people enact when confronted with conservation interventions. Finally, the plight of queen conch in the Banco Chinchorro Biosphere Reserve clearly reflects the conflicts and difficulties found across Mexico in the implementation of the biosphere reserve model.

  8. Conched out: Total reconstructed fisheries catches for the Turks and Caicos Islands uncover unsustainable resource usage

    Directory of Open Access Journals (Sweden)

    Aylin eUlman

    2016-05-01

    Full Text Available The Turks and Caicos Islands’ total marine fisheries catches were estimated for 1950-2012 using a catch reconstruction approach, estimating all removals, including reported catch destined for export, and unreported domestic artisanal and subsistence catches. Total reconstructed catch for the period is approximately 2.8 times that reported by Turks and Caicos to the FAO, and 86% higher than the export-adjusted national reported baseline. The pattern of total catches (strong decline to 1970, followed by gradual increase differs distinctly from that shown by data reported to FAO. Reported landings show a steady increase from less than 1,000 t∙year-1 in the 1950s to around 6,000 t∙year-1 in the 2000s. In contrast, the total reconstructed catches suggest declines in total catches from around 20,000 t in 1950 to a low of about 5,000 t in 1970, before gradual increases to about 12 500 t·year-1 in the late 2000s. Major discrepancies between reported and reconstructed data are under-reported artisanal catches in the early decades (accounting for 86% of total catches, and the absence of subsistence catches (14% of total catches in reported data. Queen conch (Strombus gigas and Caribbean spiny lobster (Panulirus argus dominate reconstructed catches. No discards were estimated as fishing has been highly selective, carried out by hand collection (conch, trap or hook (lobster, or hook and line (finfish. New data published here from local seafood consumption surveys demonstrates that the total local consumption of conch equates to almost the entire total allowable catch, before exported amounts are even factored. Policy-makers in the Turks and Caicos need to act if the sustainability of the fisheries stock and fishing industry is to be ensured.

  9. Conching Chocolate

    Science.gov (United States)

    Hunter, Gary L.; Chaikin, Paul; Blanco, Elena; Poon, Wilson

    2014-03-01

    ``Conching'' is an intermediate step in the processing of chocolate where hydrophilic solid particles, such as sugar and milk proteins, are aggressively mixed into a fatty, fluid phase containing emulsifier, e.g. molten cocoa butter with lecithin. During conching, the system evolves from a fine powder to a coarser granulated material and ultimately into a thick cohesive paste. Our goal is to better understand the evolution of chocolate during conching and the transition from an effectively dry to a wet or immersed granular material. In particular, we focus on how mixing times change in response to variations in solid particle volume fractions and emulsifier concentration. As a function of volume fraction, mixing times are well-described by a conventional form that diverges at a finite volume fraction. Furthermore, mixing times can be collapsed onto a universal curve as a function of mixing speed and emulsifier concentration.

  10. Genética poblacional del caracol rosado Strombus gigas en la Península de Yucatán: Implicaciones para su manejo y pesquería

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Se determinó la estructura genética poblacional del caracol rosado Strombus gigas en la Península de Yucatán, México, mediante la expresión de isoenzimas en geles de poliacrilamida. Se utilizaron muestras de músculo de 50 organismos, capturados en cada uno de los cuatro sitios de la Península de Yucatán seleccionados, para caracterizar la expresión genotípica revelada por la expresión de 55 loci en 30 sistemas enzimáticos. Se utilizó el programa TFPGA versión 1.3 para procesar los datos de frecuencias génicas de aloenzimas de las poblaciones en estudio. Los parámetros determinados fueron: estadística descriptiva, estadística F, distancias genéticas, equilibrio de Hardy-Weinberg, UPGMA y el número de migrantes como indicador del flujo de genes. Los valores de heterocigosis, en un rango de 0.3240 para OCTDH 2 hasta 0.0440 para FUM y promedio de 0.0366, los de Fis, con un rango de 0.0835 para OCTDH 2 hasta 0.3600 para la FUM y promedio de –0.0492, y los de Fst, con un rango de 0.0082 para LAP 2 hasta 0.1967 para MDH 2 y promedio de 0.1039, indican una deficiencia de heterocigotos. El número de migrantes derivado de la ecuación de Slatkin resultó de 2.156 por generación, lo que en forma global indica un cierto grado de variabilidad entre las poblaciones y es consistente con los bajos valores de distancia genética de Nei encontrados, particularmente en el nodo que sugiere la separación de la población de Alacranes de las otras poblaciones estudiadas, con un valor obtenido de 0.0053. Por los resultados, se concluye que las poblaciones de S. gigas en el Caribe mexicano presentan niveles de variabilidad genética que no reflejan fragilidad para su subsistencia.

  11. Características poblacionales del cambute, Strombus galeatus (Gastropoda: Strombidae) en el Parque Marino Ballena, Pacífico, Costa Rica (1999-2003)

    OpenAIRE

    Arroyo-Mora, Daisy

    2016-01-01

    Population characteristics of the cambute, Strombus galeatus at the Ballena Marine Park, Central Pacific, Costa Rica (1999-2003). Marine parks and reserves are important for biodiversity conservation and as sustainable places for recovery of fishery resources, especially for those species of economic importance such as the Pacific conch Strombus galeatus. Independent surveys, from 1999 to 2003 were done in three areas in the park, by snorkeling and/or scuba diving. A total of 168 live snails ...

  12. Density and reproduction of the Queen Conch Eustrombus gigas (Mesogastropoda: Strombidae at Cabo Cruz, Desembarco del Granma National Park, Cuba Densidad y reproducción de la concha reina Eustrombus gigas (Mesogastropoda: Strombidae en Cabo Cruz, Parque Nacional Desembarco del Granma, Cuba

    Directory of Open Access Journals (Sweden)

    Yuself R. Cala

    2013-06-01

    Full Text Available The queen conch Eustrombus gigas is an important fisheries resource in the Caribbean region. In Cuba Island the studies about this resource are very scarce and particularly in the Southeastern regions of the country. With the aim to get important fishery information about this gastropod, adult Queen Conch density and frequency of reproductive activity were evaluated in Cabo Cruz, Cuba, during 2009-2010. Data from three seasons were obtained (rainy, dry and cold fronts periods from three different areas: Farito, Guafe and Laguna. The highest density was observed in cold fronts season (468.5ind./ha and the lowest occurred during the dry season (268.5ind./ha. The highest density was reported at Laguna (520.4ind./ha and the lowest at Farito (290.9ind./ha. In total, 158 reproductive events were observed. The highest frequency was reported in rainy season (36%, followed by dry (9% and cold fronts (5% seasons. Reproductive behavior (mating and egg laying was related to temperature and photoperiod. Reproductive activity was observed during the whole year, which suggests the existence of an important Queen Conch reserve in the Southeastern region of Cuba and an apparently self-sufficient population for recruitment. From our results we may conclude that, the population’s sustainable exploitation is viable if the following management measures are observed: functional zoning within the area, rotation of fishing areas and a closed season. We recommend that the Laguna site should be protected as a reproduction zone and banned for fishing activities.El Eustrombus gigas es un recurso pesquero importante en la región del Caribe. En Cuba, los estudios acerca de este recurso son muy escasos y en la zona Sur-oriental del país son casi nulos. En este trabajo se evalúa la densidad de adultos y frecuencia de la evidencia reproductiva de Eustrombus gigas Linneus 1758 en Cabo Cruz, Cuba, en el periodo 2009-2010. Se obtuvieron datos de tres períodos (lluvias, seca

  13. Spatial distribution, abundance and relationship to habitat features of the queen conch Eustrombus gigas (Linnaeus) (Mollusca: Strombidae) in Nuestra Señora del Rosario archipelago, Caribbean coast of Colombia

    OpenAIRE

    Gómez-Campo, Kelly; Rueda, Mario; García-Valencia, Carolina

    2010-01-01

    Se evaluó la densidad poblacional y distribución espacial de Eustrombus gigas (Linnaeus) en el archipiélago Nuestra Señora del Rosario, así como su asociación a diferentes hábitats, a partir del muestreo sistemático de 184 estaciones en dos épocas climáticas, húmeda (mayo-noviembre) y seca (diciembre-abril) que coinciden con el período reproductivo de la especie. En cada estación se contaron y midieron los individuos presentes en un área circular de 1256.6 m2 ...

  14. Synthetic Multi-Functional Materials for Structural + Ballistic and Blast Protection

    Science.gov (United States)

    2005-03-01

    Meyers, M.A. Meyers, and K.S. Vecchio, "Quasi-Static and dynamic mechanical response of Strombus gigas (conch) shells", Mater. Sci. & Eng., A297 (2001...Mater. Sci. & Eng., 2001. A297 : p. 203-211. 28. Menig, R., M.H. Meyers, M.A. Meyers and K.S. Vecchio, Quasi-static and Dynamic mechanical response

  15. Bird communities of contrasting semi-natural habitats of Lac bay, Bonaire, during the fall migration season, 2011

    NARCIS (Netherlands)

    Debrot, A.O.; Bemmelen, van R.S.A.; Ligon, J.

    2013-01-01

    The mangrove and seagrass lagoon of Lac Bay on Bonaire covers an area of roughly 700 ha. It is home to endangered green sea turtles, Chelonia mydas, and the Caribbean queen conch, Strombus gigas, and is a roosting and breeding area for several birds. Based on its nature values this 7 km2 bay has bee

  16. Recovery of Queen Conch in the U. S. Virgin Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The queen conch is an important cultural component and an extremely valuable coral reef fishery resource throughout the Caribbean, historically second only to the...

  17. Preparation, Characterization and Performance of Conch Ceramics Added With Shell

    Directory of Open Access Journals (Sweden)

    Wang Qingyu

    2016-01-01

    Full Text Available The conch ceramics bodies with different ratios were prepared by compression moulding technology using shell, kaolin, and calcium oxide etc. as the raw materials, and then calcined at the high temperature to obtain the conch ceramics. The effects of raw material ratios and calcination temperatures on the performance of conch ceramics were investigated by rotational viscometer, vernier caliper, digital display whiteness meter, thermal analyzer, and Fourier transform infrared spectrometer(FT-IR. The results indicated that the viscosity, line shrinkage rate, and whiteness of the conch ceramics were 1.29 Pa·s, 17.9%, and 54.1%, respectively, when the content of the shell powder was 20 wt% and kaolin was 65 wt%. The density of the conch ceramics was the largest (3.8 g/cm3 when calcination temperature was 1200 °C. The results of FT-IR spectrum showed that the addition of the shell powders changed the structure of the ceramic body, which improved the performance of the conch ceramics.

  18. GigaDB: announcing the GigaScience database

    Directory of Open Access Journals (Sweden)

    Sneddon Tam P

    2012-07-01

    Full Text Available Abstract With the launch of GigaScience journal, here we provide insight into the accompanying database GigaDB, which allows the integration of manuscript publication with supporting data and tools. Reinforcing and upholding GigaScience’s goals to promote open-data and reproducibility of research, GigaDB also aims to provide a home, when a suitable public repository does not exist, for the supporting data or tools featured in the journal and beyond.

  19. GigaDB: announcing the GigaScience database.

    Science.gov (United States)

    Sneddon, Tam P; Li, Peter; Edmunds, Scott C

    2012-07-12

    With the launch of GigaScience journal, here we provide insight into the accompanying database GigaDB, which allows the integration of manuscript publication with supporting data and tools. Reinforcing and upholding GigaScience's goals to promote open-data and reproducibility of research, GigaDB also aims to provide a home, when a suitable public repository does not exist, for the supporting data or tools featured in the journal and beyond.

  20. [Identication of pearl powder and conch powder from different origins by differential scanning calorimetry].

    Science.gov (United States)

    Chen, Jia; Li, Ming-hua; Yu, Kun-zi; Dong, Ya-juan; Zhang, Nan-ping; Hu, Xiao-ru; Wei, Feng; Ma, Shuang-cheng

    2015-04-01

    The paper is aimed to establish a methods for identication of pearl powder and conch powder from different origins. Hermetic aluminum pan was used to encapsulate samples. The optimal testing conditions were: heating rate 10 degrees C x min(-1), sample weight 3 mg and nitrogen gas flow rate 40 mL x min(-1). The enthalpy values of pearl powder and conch powder was obvious different. Identication of pearl powder and conch powder by DSC is a practical method for its accuracy, convenience and practificality.

  1. Inactivation of Salmonella during cocoa roasting and chocolate conching.

    Science.gov (United States)

    Nascimento, Maristela da Silva do; Brum, Daniela Merlo; Pena, Pamela Oliveira; Berto, Maria Isabel; Efraim, Priscilla

    2012-10-15

    The high heat resistance of Salmonella in foods with low water activity raises particular issues for food safety, especially chocolate, where outbreak investigations indicate that few colony-forming units are necessary to cause salmonellosis. This study evaluated the efficiency of cocoa roasting and milk chocolate conching in the inactivation of Salmonella 5-strain suspension. Thermal resistance of Salmonella was greater in nibs compared to cocoa beans upon exposure at 110 to 130°C. The D-values in nibs were 1.8, 2.2 and 1.5-fold higher than those calculated for cocoa beans at 110, 120 and 130°C. There was no significant difference (p>0.05) between the matrices only at 140°C. Since in the conching of milk chocolate the inactivation curves showed rapid death in the first 180 min followed by a lower inactivation rate, and two D-values were calculated. For the first time interval (0-180 min) the D-values were 216.87, 102.27 and 50.99 min at 50, 60 and 70°C, respectively. The other D-values were determined from the second time interval (180-1440 min), 1076.76 min at 50°C, 481.94 min at 60°C and 702.23 min at 70°C. The results demonstrated that the type of matrix, the process temperature and the initial count influenced the Salmonella resistance.

  2. Fishery-independent Surveys of Queen Conch in St. Croix 2010-2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We examined queen conch populations on the northeastern coast of St. Croix, U.S. Virgin Islands, using a radial survey sampling technique with sample sites...

  3. Effects of Alkali Concentration and Conching Temperature on Flavour, Hardness and Colour of Chocolate

    Directory of Open Access Journals (Sweden)

    Misnawi Jati

    2006-05-01

    Full Text Available Alkalization is an addition of alkali into cocoa mass to improve product quality in terms of flavour and colour appearance. Sodium bicarbonate and potassium bicarbonate are usual to be added into cocoa cotyledon prior to roasting. A study has been carried out to evaluate the effects of alkalization proceeded upon conching on chocolate sensory properties, hardness and colour. Re sponse Surface Methodology design at alkali concentrations of 1—15 g kg -1 and conching temperature of 40—80 oC have been used in the study. Parameters evaluated were sensory properties, particle size, hardness and colour. Results of the study showed that alkali concentration significantly influenced aroma, overall preference, particle size and hardness; meanwhile, conching temperature showed significant influence on aroma, taste, appearance, overall preference and texture of chocolate. Alkali concentration and conching temperature showed interactively influence on aroma and overall preference. A good quality of chocolate could be found at the alkali concentration of 8—15 g kg -1 and conching temperature of 74—80 oC. Key words: cocoa bean, chocolate, flavour, conching, alkalization, colour, particle size, texture.

  4. 77 FR 51763 - Endangered and Threatened Wildlife; 90-Day Finding on a Petition To List the Queen Conch as...

    Science.gov (United States)

    2012-08-27

    ... scale poaching by foreigners (CITES, 2003, 2005). The review also found that intensive fishing pressure.... The petition cites several peer-reviewed publications and research studies that show queen conch in... only to the status of the queen conch throughout its range. Peer Review On July 1, 1994, NMFS,...

  5. 76 FR 82413 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-12-30

    ... Part 622 Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants... Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and... the FMP for the Spiny Lobster Fishery of Puerto Rico and the U.S. Virgin Islands (Spiny Lobster...

  6. 76 FR 59377 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-09-26

    ..., Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates Fishery Management... Fishery Management Plans (FMPs) for Reef Fish Resources, Spiny Lobster, Queen Conch, and Coral and Reef... (AMs) if ACLs should be exceeded for selected reef fish, spiny lobster, and aquarium trade...

  7. The impact of Dictyota spp. on Halimeda populations of Conch Reef, Florida Keys

    NARCIS (Netherlands)

    Beach, K; Walters, L; Borgeas, H; Coyer, J; Vroom, P

    2003-01-01

    Species of the brown alga Dictyota dominate the reef tract in the Florida Keys. In surveys during summer and fall months between 1994 and 2001, Dictyota occupied as much as 70% of the benthos on Conch Reef Dictyota spp. were found growing epiphytically on Halimeda tuna, Halimeda opuntia, Lobophora v

  8. Variability in the ecophysiology of Halimeda spp. (Chlorophyta, Bryopsidales) on Conch Reef, Florida Keys, USA

    NARCIS (Netherlands)

    Beach, K; Walters, L; Vroom, P; Coyer, J; Hunter, C

    2003-01-01

    The photosynthetic performance, pigmentation, and growth of a Halimeda community were studied over a depth gradient on Conch Reef, Florida Keys, USA during summer-fall periods of 5 consecutive years. The physiology and growth of H. tuna (Ellis & Solander) Lamouroux and H. opuntia (L.) Lamouroux on t

  9. 76 FR 59375 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and...

    Science.gov (United States)

    2011-09-26

    ..., Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and Reef Fish Fishery Management.... In contrast, the wenchman is presently included as a member of Snapper Unit 2 but clusters...

  10. 76 FR 66675 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and...

    Science.gov (United States)

    2011-10-27

    ..., Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and Reef Fish Fishery Management... poverty rates, and low median household incomes. Moreover, commercial fishermen of St. Croix and St...

  11. Laser-induced breakdown spectroscopy detection of heavy metal in water based on graphite conch method

    Science.gov (United States)

    Wang, Chunlong; Liu, Jianguo; Zhao, Nanjing; Shi, Huan; Liu, Lituo; Ma, Mingjun; Zhang, Wei; Chen, Dong; Liu, Jing; Zhang, Yujun; Liu, Wenqing

    2012-10-01

    The laser-induced breakdown spectroscopy emission characteristics of trace heavy metal lead in water is studied based on graphite conch method, with a 1064nm wavelength Nd: YAG laser as excitation source, the echelle spectrometer and ICCD detector are used for spectral separation and high sensitive detection with high resolution and wide spectral range. The delay time 900ns and gate time 1600ns are determined in the experiment. The calibration curve of Pb is plotted based on the different concentration measurement results, and a limit of detection of 0.0138mg / L is obtained for Pb in water. Graphite conch method effectively overcomes the current problems on laser-induced breakdown spectroscopy detection of heavy metal in water. The detection limits and stability are improved. The reference data is provided for further study on the fast measurement of trace heavy metals in water by laser induced breakdown spectroscopy technique.

  12. Seven 365-Million-Year-Old Trilobites Moulting within a Nautiloid Conch

    Science.gov (United States)

    Zong, Rui-Wen; Fan, Ruo-Ying; Gong, Yi-Ming

    2016-01-01

    A nautiloid conch containing many disarticulated exoskeletons of Omegops cornelius (Phacopidae, Trilobita) was found in the Upper Devonian Hongguleleng Formation of the northwestern margin of the Junggar Basin, NW China. The similar number of cephala, thoraces and pygidia, unbroken thoraces, explicit exuviae, and lack of other macrofossils in the conch, indicate that at least seven individual trilobites had moulted within the nautiloid living chamber, using the vacant chamber of a dead nautiloid as a communal place for ecdysis. This exuvial strategy manifests cryptic behaviour of trilobites, which may have resulted from the adaptive evolution induced by powerful predation pressure, unstable marine environments, and competition pressure of organisms occupying the same ecological niche in the Devonian period. The unusual presence of several trilobites moulting within a nautiloid conch is possibly associated with social behaviours in face of a serious crisis. New materials in this study open a window for understanding the survival strategy of marine benthic organisms, especially predator-prey interactions and the behavioural ecology of trilobites in the middle Palaeozoic.

  13. Multiscale hierarchical assembly strategy and mechanical prowess in conch shells (Busycon carica).

    Science.gov (United States)

    Li, Haoze; Xu, Zhi-Hui; Li, Xiaodong

    2013-12-01

    Seashells are natural body armors with superior mechanical strength and ultra-high toughness compared with their major constituent counterparts. What building blocks and architecture render seashells such mechanical prowess? In this study, micro/nanoscale structural and mechanical characterization of conch shells (Busycon carica) has been carried out. Here we show direct evidence that the previously claimed single-crystal third-order lamellae--the basic building blocks in conch shells are essentially assembled with aragonite nanoparticles of the size ranging from 20 to 45 nm. The nanoparticle-constructed third-order lamellae are not brittle, but ductile. The three-order crossed-lamellar architecture interlocks cracks via crack deflection along the interfaces in a three-dimensional manner, thus confining the damage in a small region. The findings advance the understanding of the mystery of conch shell's mechanical robustness, provide additional design guidelines for developing bioinspired nanomaterials, and lay a constitutive foundation for modeling the deformation behavior of seashells.

  14. Seven 365-Million-Year-Old Trilobites Moulting within a Nautiloid Conch

    Science.gov (United States)

    Zong, Rui-Wen; Fan, Ruo-Ying; Gong, Yi-Ming

    2016-10-01

    A nautiloid conch containing many disarticulated exoskeletons of Omegops cornelius (Phacopidae, Trilobita) was found in the Upper Devonian Hongguleleng Formation of the northwestern margin of the Junggar Basin, NW China. The similar number of cephala, thoraces and pygidia, unbroken thoraces, explicit exuviae, and lack of other macrofossils in the conch, indicate that at least seven individual trilobites had moulted within the nautiloid living chamber, using the vacant chamber of a dead nautiloid as a communal place for ecdysis. This exuvial strategy manifests cryptic behaviour of trilobites, which may have resulted from the adaptive evolution induced by powerful predation pressure, unstable marine environments, and competition pressure of organisms occupying the same ecological niche in the Devonian period. The unusual presence of several trilobites moulting within a nautiloid conch is possibly associated with social behaviours in face of a serious crisis. New materials in this study open a window for understanding the survival strategy of marine benthic organisms, especially predator-prey interactions and the behavioural ecology of trilobites in the middle Palaeozoic.

  15. Lobster and Conch Fisheries of Belize: a History of Sequential Exploitation

    Directory of Open Access Journals (Sweden)

    Miriam Huitric

    2005-06-01

    Full Text Available This article presents a historical review of the lobster and conch fisheries in Belize, Central America. In terms of yield and value, these are the main wild-caught targets of the national fisheries, a small-scale commercial fishery of around 3000 fishermen. Data were collected during interviews with key informants involved with the fisheries and through literature and archive research. The goal was to study how the fishing industry has responded to environmental signals from these resources and from their ecosystems and ecosystem dynamics. National yields for both lobster and conch have been relatively stable, however, individuals’ yields have been declining despite increased effort since the 1980s. This study concludes that the use of fossil fuel-based technology and organizational change, with the establishment of fishermen's cooperatives, have masked environmental signals. This masking, together with economic incentives, has led to the “pathology of resource use.” As a symptom of this pathology, four forms of sequential exploitation in these fisheries were identified. A major conclusion is that social resilience may not confer ecological resilience. The development of the cooperatives was needed in order to improve equity in the industry. Before their impacts could be assessed, this organizational change, together with new technology, led to very important and rapid changes in the industry. Together with existing regulations that allow de facto open access to lobster and conch, these changes resulted in a short-term boom that has resulted in the pathology of resource use, with over-capitalization and dependence on maintained yields, regardless of environmental feedback.

  16. Bio-assembled nanocomposites in conch shells exhibit giant electret hysteresis

    KAUST Repository

    Yao, Yingbang

    2012-10-23

    Giant electric polarization (2000-4000 μC cm-2) is observed in natural conch shells. The nanolaminas and biopolymer layers of their unique hierarchical microstructures exhibit ferroelectret behavior and account for the observed polarization. Such huge polarization leads to extremely high pyroelectric coefficients, 2-3 orders of magnitude larger than those of conventional ferroelectric materials. The possibility of tailoring the giant polarization for various applications is considered. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Proximate response of fish, conch, and sea turtles to the presence of the invasive seagrass Halophila stipulacea in Bonaire

    NARCIS (Netherlands)

    Becking, L.E.; Bussel, T.; Engel, M.S.; Christianen, M.; Debrot, A.O.

    2014-01-01

    In this report we examined the proximate response of fish assemblages, queen conch, and sea turtles on H. stipulacea meadows in Lac Bay, Bonaire, Caribbean Netherlands. Here we primarily focused on the differences between the invasive species H. stipulacea and the principal species of native sea gra

  18. Proximate response of fish, conch, and sea turtles to the presence of the invasive seagrass Halophila stipulacea in Bonaire

    NARCIS (Netherlands)

    Becking, L.E.; Bussel, T.; Engel, M.S.; Christianen, M.; Debrot, A.O.

    2014-01-01

    In this report we examined the proximate response of fish assemblages, queen conch, and sea turtles on H. stipulacea meadows in Lac Bay, Bonaire, Caribbean Netherlands. Here we primarily focused on the differences between the invasive species H. stipulacea and the principal species of native sea gra

  19. [Composition, abundance and distribution of populations of commercially important gastropods in La Guajira, Colombian Caribbean].

    Science.gov (United States)

    Nieto-Bernal, Ramón; Luis, Chasqui; Rodriguez, Angélica María; Castro, Erick; Gil-Agudelo, Diego L

    2013-06-01

    In the continental Colombian Caribbean the conch resource exploitation and the status of snails populations has been poorly studied, which are reflected in the lack of fisheries management. This study assesses composition, population density and distribution of the gastropods species that make conch resource in La Guajira region. Underwater visual censuses for snails were performed between September-November 2009 in 145100x4m (400m2) transects, spanning a total area of 56920m2 between Riohacha and Cabo de la Vela. The study was complemented with the evaluation of composition, abundance and size of gastropods conch found in the discarded-by-fishermen shell mounds in 13 beaches. In October 2010 another 40 transects were evaluated (16 000 m2) from the Southern of Riohacha to the Camarones village (La Guajira). We found a total of 9911 snails belonging to 12 species, the most abundant being Strombus pugilis with 8 912 individuals and an average density of 1 538.4 +/- 3 662.6 ind./ha, followed by Vasum muricatum with 374 individuals and an average density of 51.8 +/- 91.2 ind./ha. Calculating the importance value index (IVI) for both living organisms as the empty shells on beaches, shows that Turbinella angulata is the most used species by artisanal fishermen in the region. Cassis madagascariensis and Cassis tuberosa are also important snail resources in the region (as suggested by the number of empty shells found in beaches), but its densities were low. Strombus gigas, with only three living organisms found in the area, presented the lowest abundance ever found in the Colombian Caribbean (0.52 +/- 3.6 ind./ha), showing that queen conch population in La Guajira cannot support commercial exploitation. The abundance of discarded S. gigas shells on beaches suggests resource exploitation in the recent past. Results remarks the urgency of implementing management plans for snail fisheries in the region.

  20. The Giga View Multiprocessor Multidisk Image Server

    Directory of Open Access Journals (Sweden)

    B. A. Gennart

    1996-01-01

    Full Text Available Professionals in various fields such as medical imaging, biology, and civil engineering require rapid access to huge amounts of pixmap image data. Multimedia interfaces further increase the need for large image databases. To fulfill these requirements, the GigaView parallel image server architecture relies on arrays of intelligent disk nodes, each disk node being composed of one processor and one disk. This contribution reviews the design of the GigaView hardware and file system, compares it to other storage servers available on the market, and evaluates fields of applications for the architecture.

  1. Distribución, abundancia y morfometrÍa de Strombus costatus, Turbinella angulata, Busycon contrarium y Pleuroploca gigantea(Mesogasteropoda: Strombidae, Thrbinellidae, Neptuneidae y Fasciolaridae) en Yucatán, México

    OpenAIRE

    Pérez Pérez, Manuel; Aldana Aranda, Dalila

    2015-01-01

    Se analizó la distribución, abundancia y morfometría de Strombus costatus, Turbinella angulata, Busycon contrarium y Pleuroploca gigantea en Dzilam de Bravo, Yucatán, México. La toma de datos se realizó con buceo libre mediante el método de cuadrantes de 100 m de longitud por 300 m de ancho (31 cuadrantes en un área de 930 000 m2) entre agosto y septiembre de 1994. De 896 individuos, las especies más abundantes fueron Strombus coslatus (44.42%) y Turbinella angulala (42.75%), Bus)'con conlrar...

  2. Antihypertensive activity of polysaccharide from Crassostrea gigas.

    Science.gov (United States)

    Wang, Ting; Ding, Jie; Li, Haibo; Xiang, Jingjing; Wen, Ping; Zhang, Qin; Yin, Linliang; Jiang, Wei; Shen, Caie

    2016-02-01

    Water-soluble polysaccharide was extracted from Crassostrea gigas by hydrolysis with flavourzyme and filtered, ultrafiltered and precipitated using absolute ethanol. Sugar composition analysis performed on the C. gigas polysaccharide (CGP) by high performance liquid chromatography indicated that it was comprised primarily of glucose, and its molecular weight was determined using a TSK-GEL G5000PW column to be ∼3.413×10(6) Da. Next, the antihypertensive activity of CGP was evaluated in rats. Hypertension model Wistar rats were divided into three groups and intragastrically treated with physiological saline (negative control group), CGP (treatment group), and captopril (positive control group). CGP treatment led to significant decrease in both systolic and diastolic pressures in the hypertension model Wistar rats. Furthermore, the antihypertensive effect of CGP was comparable with that of captopril. Thus, CGP has antihypertensive effects and can potentially be used as a therapeutic agent for hypertension. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Rheological of chocolate-flavored, reduced-calories coating as a function of conching process.

    Science.gov (United States)

    Medina-Torres, Luis; Sanchez-Olivares, Guadalupe; Nuñez-Ramirez, Diola Marina; Moreno, Leonardo; Calderas, Fausto

    2014-07-01

    Continuous flow and linear viscoelasticity rheology of chocolate coating is studied in this work using fat substitute gums (xanthan, GX). An alternative conching process, using a Rotor-Estator (RE) type impeller, is proposed. The objective is to obtain a chocolate coating material with improved flow properties. Characterization of the final material through particle size distribution (PSD), differential scanning calorimetry (DSC) and proximal analysis is reported. Particle size distribution of the final material showed less polydispersity and therefore, greater homogeneity; fusion points were also generated at around 20 °C assuming crystal type I (β'2) and II (α). Moreover, the final material exhibited crossover points (higher structure material), whereas the commercial brand chocolate used for comparison did not. The best conditions to produce the coating were maturing of 36 h and 35 °C, showing crossover points around 76 Pa and a 0.505 solids particle dispersion (average particle diameter of 0.364 μm), and a fusion point at 20.04 °C with a ΔHf of 1.40 (J/g). The results indicate that xanthan gum is a good substitute for cocoa butter and provides stability to the final product.

  4. Systems Harmonization and Convergence - the GIGAS Approach

    Science.gov (United States)

    Marchetti, P. G.; Biancalana, A.; Coene, Y.; Uslander, T.

    2009-04-01

    0.1 Background The GIGAS1 Support Action promotes the coherent and interoperable development of the GMES, INSPIRE and GEOSS initiatives through their concerted adoption of standards, protocols, and open architectures. 0.2 Preparing for Coordinated Data Access The GMES Coordinated Data Access System is under design and implementation2. This objective has motivated the definition of the interoperability standards between the contributing missions. The following elements have been addressed with associated papers submitted to OGC: The EO Product Metadata has been based on the OGC Geographic Markup Language, addressing sensor characteristics for optical, radar and atmospheric products. Collection and service discovery: an ISO extension package for CSW ebRim has been proposed. Catalogue Service (CSW): an Earth Observation extension package of the CSW ebRim has been proposed. Feasibility Analysis and Order: an Order interface control document and an Earth Observation profile of the Sensor Planning Service have been proposed. Online Data Access: an Earth Observation profile of the Web Map Services (WMS) for visualization and evaluation purposes has been proposed. Identity (user) management: the objective in the long term is to allow for a single sign-on to the Coordinated Data Access system by users registered in the various Earth Observation ground segments by providing a federated identity across participating ground segments, exploiting OASIS standards. 0.3 The GIGAS proposed harmonization approach The approach proposed by GIGAS is based on three elements: Technology watch Comparative analysis Shaping of initiatives and standards This paper concentrates on the methodology for technology watch and comparative analysis. The complexity of the GIGAS scenario involving huge systems (i.e. GEOSS, INSPIRE, GMES etc.) entails the interaction with different heterogeneous partners, each with a specific competence, expertise and know-how. 0.3.1 Technology watch The methodology

  5. Obtención de masas ovígeras del caracol lancetilla, Strombus pugilis (Mesogastropoda: Strombidae en condiciones de laboratorio

    Directory of Open Access Journals (Sweden)

    Andrés Martín Góngora Gómez

    2007-03-01

    Full Text Available Se determinó la supervivencia, reproducción y el desarrollo embrionario del caracol Strombus pugilis, por un periodo de diez meses en condiciones de laboratorio. Siete progenitores fueron recolectados en Isla Contoy, Quintana Roo, México y posteriormente trasladados al laboratorio donde fueron colocados en acuarios de 80 l con agua de mar y alimentados con alimento granulado. Un total de 30 masas ovígeras fueron recolectadas, lográndose un aumento en el número de masas de huevos en abril. La longitud total estimada de una sola masa ovígera fue de 11.24 m, el número promedio de embriones encontrados en 2 cm fue de 264, obteniéndose un total de 157 500 embriones en toda la masa de huevos. Los resultados promedio de los parámetros físico-químicos a lo largo del periodo de estudio fueron los siguientes: salinidad de 37.5±0.5 ‰, pH 7.5±0.5 y temperatura de 28±0.2 °C. Con los datos aportados en este estudio se infiere que este sistema de mantenimiento y recirculación de los progenitores es excelente tanto para la reproducción como para la obtención de las masas ovígeras en condiciones controladas.Obtaining of egg masses of the snail, Strombus pugilis (Mesogastropoda: Strombidae under laboratory conditions. The survival, reproduction and embryonic development of Strombus pugilis, were determined during a period of ten months under laboratory conditions. Seven progenitors were collected in Contoy Island, Quintana Roo, Mexico and later transferred to the laboratory, where they were placed in aquarium with 80 l of sea water and fed with "pellets". A total of 30 egg masses were collected, one on September and the other on April. The estimated total length of one egg mass was 11.24 m; the mean number of embryos obtained per 2 cm was 264, obtaining an estimated total of 157 500 embryos in the egg mass. The means of the physical-chemical parameters during the study were: salinity 37.6±0.5 ‰, pH 7.5±0.5 and temperature 28±0.2

  6. GigaDB: promoting data dissemination and reproducibility.

    Science.gov (United States)

    Sneddon, Tam P; Zhe, Xiao Si; Edmunds, Scott C; Li, Peter; Goodman, Laurie; Hunter, Christopher I

    2014-01-01

    Often papers are published where the underlying data supporting the research are not made available because of the limitations of making such large data sets publicly and permanently accessible. Even if the raw data are deposited in public archives, the essential analysis intermediaries, scripts or software are frequently not made available, meaning the science is not reproducible. The GigaScience journal is attempting to address this issue with the associated data storage and dissemination portal, the GigaScience database (GigaDB). Here we present the current version of GigaDB and reveal plans for the next generation of improvements. However, most importantly, we are soliciting responses from you, the users, to ensure that future developments are focused on the data storage and dissemination issues that still need resolving. Database URL: http://www.gigadb.org.

  7. Composición químico-nutricional en diferentes tallas y sexos del cambute, Strombus gracilior (Mesogastropoda: Strombidae) de Playa Panamá, Costa Rica

    OpenAIRE

    Jiménez-Arce, G.

    2016-01-01

    Se obtuvieron 74 ejemplares de cambute (Strombus gracilior) de Playa Panamá (lOO 35' 45" N, 840 40' 09" W), Costa Rica. La proporción de sexos fue de 1:1 y el ámbito de talla 70- 80mm (longitud total). El rendimiento promedio fue de 80% de carne comestible. Los valores promedio de los macronutrientes para ambas tallas fueron: humedad 72.6% machos y 70.9% hembras. proteínas 19.09g% machos y 26.89g% hembras; carbohidratos 1.85g% machos y 1.35g% hembras; fibra cruda O.44g% machos y hembras. Las ...

  8. Anesthesia in Pacific oyster, Crassostrea gigas

    OpenAIRE

    Suquet, Marc; De Kermoysan, Goulwen; Araya, Ricardo Gonzalez; Queau, Isabelle; Lebrun, Luc; Le Souchu, Pierrick; Mingant, Christian

    2009-01-01

    Un protocole complet d'anesthésie chez les huîtres creuses devrait faciliter l'échantillonnage successif des mêmes animaux, sans les sacrifier, favorisant notamment l'étude de la gamétogenèse. Cette étude a pour but de définir des conditions fiables d'anesthésie adaptées à l'huître creuse, Crassostrea gigas. Trois groupes de 10 huîtres chacun (poids moyen $\\pm $ écart-type, 32,1 $\\pm $ 9,0 g) ont été anesthésiés dans des récipients de 5 L. Parmi les différents anesthésiants testés : benzocaïn...

  9. Moderate establishment success of Pacific oyster, Crassostrea gigas, on a sheltered intertidal mussel bed

    DEFF Research Database (Denmark)

    Holm, M.W.; Davids, J.K.; Dolmer, Per;

    2015-01-01

    The Pacific oyster (Crassostrea gigas Thunberg 1793) is introduced into marine ecosystems worldwide. In Denmark, C. gigas was introduced into the micro tidal Limfjord, around 1972 for aquaculture. This study describes the population structure of C. gigas at Agger Tange in 2007, 2009, 2010 and 2011...

  10. Modeling complex and multi-component food systems in molecular dynamics simulations on the example of chocolate conching.

    Science.gov (United States)

    Greiner, Maximilian; Sonnleitner, Bettina; Mailänder, Markus; Briesen, Heiko

    2014-02-01

    Additional benefits of foods are an increasing factor in the consumer's purchase. To produce foods with the properties the consumer demands, understanding the micro- and nanostructure is becoming more important in food research today. We present molecular dynamics (MD) simulations as a tool to study complex and multi-component food systems on the example of chocolate conching. The process of conching is chosen because of the interesting challenges it provides: the components (fats, emulsifiers and carbohydrates) contain diverse functional groups, are naturally fluctuating in their chemical composition, and have a high number of internal degrees of freedom. Further, slow diffusion in the non-aqueous medium is expected. All of these challenges are typical to food systems in general. Simulation results show the suitability of present force fields to correctly model the liquid and crystal density of cocoa butter and sucrose, respectively. Amphiphilic properties of emulsifiers are observed by micelle formation in water. For non-aqueous media, pulling simulations reveal high energy barriers for motion in the viscous cocoa butter. The work for detachment of an emulsifier from the sucrose crystal is calculated and matched with detachment of the head and tail groups separately. Hydrogen bonding is shown to be the dominant interaction between the emulsifier and the crystal surface. Thus, MD simulations are suited to model the interaction between the emulsifier and sugar crystal interface in non-aqueous media, revealing detailed information about the structuring and interactions on a molecular level. With interaction parameters being available for a wide variety of chemical groups, MD simulations are a valuable tool to understand complex and multi-component food systems in general. MD simulations provide a substantial benefit to researchers to verify their hypothesis in dynamic simulations with an atomistic resolution. Rapid rise of computational resources successively

  11. Top, GigaZ, MegaW

    Energy Technology Data Exchange (ETDEWEB)

    Heinemeyer, S. [Instituto de Fisica de Cantabria, Santander (Spain); Weiglein, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-08-15

    We review the physics potential of top mass measurements and the GigaZ/MegaW options of the International Linear Collider (ILC) for probing New Physics models and especially the Minimal Supersymmetric Standard Model (MSSM). We demonstrate that the anticipated experimental accuracies at the ILC for the top-quark mass, mt, the W boson mass, M{sub W}, and the effective leptonic weak mixing angle, sin{sup 2} {theta}{sub eff}, will provide a high sensitivity to quantum effects of New Physics. In particular, a new and more precise measurement of sin{sup 2} {theta}{sub eff}, for which the experimental central value is currently obtained from an average where the most precise single measurements differ by more than three standard deviations, could lead to a situation where both the Standard Model and the MSSM in its most general form are ruled out. Alternatively, the precision measurements may resolve virtual effects of SUSY particles even in scenarios where the SUSY particles are so heavy that they escape direct detection at the LHC and the first phase of the ILC. (orig.)

  12. The NA62 GigaTracker

    CERN Document Server

    Aglieri Rinella, G; Arcidiacono, R; Biino, C; Bonacini, S; Ceccucci, A; Chiozzi, S; Cortina Gil, E; Cotta Ramusino, A; Degrange, J; Fiorini, M; Gamberini, E; Gianoli, A; Kaplon, J; Kluge, A; Mapelli, A; Marchetto, F; Minucci, E; Morel, M; Noël, J; Noy, M; Perktold, L; Perrin-Terrin, M; Petagna, P; Petrucci, F; Poltorak, K; Romagnoli, G; Ruggiero, G; Velghe, B; Wahl, H

    2016-01-01

    The GigaTracker is a hybrid silicon pixel detector built for the NA62 experiment aiming at measuring the branching fraction of the ultra-rare kaon decay K+→π+νν¯ at the CERN SPS. The detector has to track particles in a beam with a flux reaching 1.3 MHz/mm2 and provide single-hit timing with 200 ps RMS resolution for a total material budget of less than 0.5% X0 per station. The tracker comprises three 60.8 mm×27 mm stations installed in vacuum (∼10$^{−6}$mbar) and cooled with liquid C6F14 circulating through micro-channels etched inside a few hundred micron thick silicon plates. Each station is composed of a 200 μm thick silicon sensor read out by 2×5 custom 100 μm thick ASICs, called TDCPix. Each chip contains 40×45 asynchronous pixels, 300 μm×300 μm each and is instrumented with 100 ps bin time-to-digital converters. In order to cope with the high rate, the TDCPix is equipped with four 3.2 Gb/s serialisers sending out the data. We will describe the detector and the results from the 2014 an...

  13. The NA62 GigaTracker

    CERN Document Server

    Perrin-Terrin, Mathieu

    2015-01-01

    The GigaTracker is an hybrid silicon pixel detector built for the NA62 experiment aiming at measuring the branching fraction of the ultra-rare kaon decay K + ! p + n ̄ n at the CERN SPS. The detector has to track particles in a beam with a flux reaching 1.3 MHz/mm 2 and provide single-hit timing with 200ps RMS resolution for a total material budget of less than 1.5 X 0 . The tracker comprises three 60.8mm 27mm stations installed in vacuum ( 10$^{-6}$ mbar) and cooled with liquid C 6 F 14 circulating through micro-channels etched inside few hundred of microns thick silicon plates. Each station is composed of a 200 m m thick silicon sensor readout by 2 x 5 cus- tom 100 m m thick ASIC, called TDCPix. Each chip contains 40 x 45 asynchronous pixels, each 300 m m x 300 m m and is instrumented with 100ps bin time-to-digital converters. In order to cope with the high rate, the TDCPix is equipped with four 3.2Gb/s serialisers sending out the data. We will describe the detector and the results from the 2014 NA62 ru...

  14. Stochasticity of convection in Giga-LES data

    Science.gov (United States)

    De La Chevrotière, Michèle; Khouider, Boualem; Majda, Andrew J.

    2016-09-01

    The poor representation of tropical convection in general circulation models (GCMs) is believed to be responsible for much of the uncertainty in the predictions of weather and climate in the tropics. The stochastic multicloud model (SMCM) was recently developed by Khouider et al. (Commun Math Sci 8(1):187-216, 2010) to represent the missing variability in GCMs due to unresolved features of organized tropical convection. The SMCM is based on three cloud types (congestus, deep and stratiform), and transitions between these cloud types are formalized in terms of probability rules that are functions of the large-scale environment convective state and a set of seven arbitrary cloud timescale parameters. Here, a statistical inference method based on the Bayesian paradigm is applied to estimate these key cloud timescales from the Giga-LES dataset, a 24-h large-eddy simulation (LES) of deep tropical convection (Khairoutdinov et al. in J Adv Model Earth Syst 1(12), 2009) over a domain comparable to a GCM gridbox. A sequential learning strategy is used where the Giga-LES domain is partitioned into a few subdomains, and atmospheric time series obtained on each subdomain are used to train the Bayesian procedure incrementally. Convergence of the marginal posterior densities for all seven parameters is demonstrated for two different grid partitions, and sensitivity tests to other model parameters are also presented. A single column model simulation using the SMCM parameterization with the Giga-LES inferred parameters reproduces many important statistical features of the Giga-LES run, without any further tuning. In particular it exhibits intermittent dynamical behavior in both the stochastic cloud fractions and the large scale dynamics, with periods of dry phases followed by a coherent sequence of congestus, deep, and stratiform convection, varying on timescales of a few hours consistent with the Giga-LES time series. The chaotic variations of the cloud area fractions were

  15. The invasive Pacific oyster, Crassostrea gigas, in Scandinavia coastal waters

    DEFF Research Database (Denmark)

    Dolmer, Per; Holm, Mark Wejlemann; Strand, Åsa;

    A massive invasion of the Pacific oyster, Crassostrea gigas , has occurred in Scandinavia during the last decade. The introduction and dispersal was described through collaboration between scientists from Sweden, Denmark and Norway. This work has been followed up by national activities that clearly...... presented in this report is based on available scientific literature, expert judgments and data collected during a Nordic collaboration project on Pacific oysters in 2011 – 2013....

  16. Amylase polymorphism affects growth in the cupped oyster Crassostrea gigas

    OpenAIRE

    Huvet, Arnaud; Samain, Jean-francois; Boudry, Pierre; Bedier, Edouard; Ropert, Michel; Van Wormhoudt, A

    2005-01-01

    The better understanding of physiological and environmental factors that determine optimal food conversion efficiencies is of major interest for the cupped oyster Crassostrea gigas for which the strong increase of aquaculture has been correlated in France with a decrease in productivity due to competition between aquatic species for limited food supplies at grow-out sites. To investigate the non-neutrality of the polymorphism of amylase, a key enzyme for carbohydrate assimilation, in oyster p...

  17. Identification of the Molecular Clockwork of the Oyster Crassostrea gigas

    Science.gov (United States)

    Perrigault, Mickael; Tran, Damien

    2017-01-01

    Molecular clock system constitutes the origin of biological rhythms that allow organisms to anticipate cyclic environmental changes and adapt their behavior and physiology. Components of the molecular clock are largely conserved across a broad range of species but appreciable diversity in clock structure and function is also present especially in invertebrates. The present work aimed at identify and characterize molecular clockwork components in relationship with the monitoring of valve activity behavior in the oyster Crassostrea gigas. Results provided the characterization of most of canonical clock gene including clock, bmal/cycle, period, timeless, vertebrate-type cry, rev-erb, ror as well as other members of the cryptochrome/photolyase family (plant-like cry, 6–4 photolyase). Analyses of transcriptional variations of clock candidates in oysters exposed to light / dark regime and to constant darkness led to the generation of a putative and original clockwork model in C. gigas, intermediate of described systems in vertebrates and insects. This study is the first characterization of a mollusk clockwork. It constitutes essential bases to understand interactions of the different components of the molecular clock in C. gigas as well as the global mechanisms associated to the generation and the synchronization of biological rhythms in oysters. PMID:28072861

  18. Population Dynamics Modeling of Arapaima gigas Modelagem da dinâmica populacional de Arapaima gigas

    Directory of Open Access Journals (Sweden)

    Eliane dos Santos de Souza Coutinho

    2010-01-01

    Full Text Available Pirarucu (Arapaima gigas has been of the most important natural fishing resources of the Amazon region. Due to its economic importance, and the necessity to preserve the species hand, field research concerning the habits and behavior of the pirarucu has been increasing for the last 20 years. The aim of this paper is to present a mathematical model for the pirarucu population dynamics considering the species peculiarities, particularly the male parental care over the offspring. The solution of the dynamical systems indicates three possible equilibrium points for the population. The first corresponds to extinction; the third corresponds to a stable population close to the environmental carrying capacity. The second corresponds to an unstable equilibrium located between extinction and full use of the carrying capacity. It is shown that lack of males’ parental care closes the gap between the point corresponding to the unstable equilibrium and the point of stable non-trivial equilibrium. If guarding failure reaches a critical point the two points coincide and the population tends irreversibly to extinction. If some event tends to destabilize the population equilibrium, as for instance inadequate parental care, the model responds in such a way as to restore the trajectory towards the stable equilibrium point avoiding the route to extinction. The parameters introduced to solve the system of equations are partially derived from limited but reliable field data collected at the Mamirauá Sustainable Development Reserve (MSDR in the Brazilian Amazonian Region.Pirarucu (Arapaima gigas tem sido um dos mais importantes recursos pesqueiros naturais da Amazônia. Devido à sua importância econômica, por um lado, e a necessidade de preservar a espécie, por outro lado, o domínio da investigação relativa a hábitos e comportamento do pirarucu tem sido crescente nos últimos 20 anos. O objetivo deste trabalho é apresentar um modelo matemático para a din

  19. A glycoprotein in shells of conspecifics induces larval settlement of the Pacific oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Hebert Ely Vasquez

    Full Text Available Settlement of larvae of Crassostrea gigas on shell chips (SC prepared from shells of 11 different species of mollusks was investigated. Furthermore, the settlement inducing compound in the shell of C. gigas was extracted and subjected to various treatments to characterize the chemical cue. C. gigas larvae settled on SC of all species tested except on Patinopecten yessoensis and Atrina pinnata. In SC of species that induced C. gigas larvae to settle, settlement was proportionate to the amount of SC supplied to the larvae. When compared to C. gigas SC, all species except Crassostrea nippona showed lower settlement inducing activities, suggesting that the cue may be more abundant or in a more available form to the larvae in shells of conspecific and C. nippona than in other species. The settlement inducing activity of C. gigas SC remained intact after antibiotic treatment. Extraction of C. gigas SC with diethyl ether (Et2O-ex, ethanol (EtOH-ex, and water (Aq-ex did not induce larval settlement of C. gigas larvae. However, extraction of C. gigas SC with 2N of hydrochloric acid (HCl-ex induced larval settlement that was at the same level as the SC. The settlement inducing compound in the HCl-ex was stable at 100°C but was destroyed or degraded after pepsin, trypsin, PNGase F and trifluoromethanesulfonic acid treatments. This chemical cue eluted between the molecular mass range of 45 and 150 kDa after gel filtration and revealed a major band at 55 kDa on the SDS-PAGE gel after staining with Stains-all. Thus, a 55 kDa glycoprotein component in the organic matrix of C. gigas shells is hypothesized to be the chemical basis of larval settlement on conspecifics.

  20. Thermal biology of prey (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya from the Yucatan Peninsula.

    Science.gov (United States)

    Noyola Regil, Javier; Mascaro, Maite; Díaz, Fernando; Denisse Re, Ana; Sánchez-Zamora, Adolfo; Caamal-Monsreal, Claudia; Rosas, Carlos

    2015-10-01

    On the Yucatan Peninsula there is an upwelling which allows access to a body of cold water that controls temperature in this area. This modulates the ecology and distribution of organisms that inhabit the continental shelf. The objective of this study was to determine the effect of different acclimation temperatures on the thermal biology of prey as mollusc, crustacean (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators as fish (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya. Octopus prey preferred temperatures between 23.5°C and 26.0°C, while predators preferred temperatures 26.4-28.5°C. The species with largest thermal windows were M. corona bispinosa (328.8°C(2)), C. similis (322.8°C(2)), L. dubia (319.2°C(2)), C. undecimalis (288.6°C(2)), O. chrysurus (237.5°C(2)), while the smallest thermal window was for S. pugilis (202.0°C(2)). The acclimation response ratios (ARR) estimated for prey ranged from 0.24-0.55 in animals exposed to CTMax and 0.21-0.65 in those exposed to CTMin. Amongst predators, ARR ranged from 0.30 to 0.60 and 0.41 to 0.53 for animals exposed to CTMax and CTMin, respectively. Correlating the optimal temperature limits of prey and predators with surface temperatures on the continental shelf and those 4m deep showed that the main prey, Callinectes similis and L. dubia, shared a thermal niche and that an increase in temperature could force these species to migrate to other sites to find optimal temperatures for their physiological functions. As a consequence the continental shelf community would undergo a structural change. Predators were found to be near their optimal temperatures in surface temperatures on the continental shelf. We conclude that they would remain in the area in a warming scenario. The size of the thermal window was related to the type of ecosystem inhabited by these species. These ARR intervals allowed us to categorize the species as temperate or tropical

  1. Dynamics and ecology of an Indo-Pacific conch,Conomurex persicus (Mollusca: Gastropoda in southeastern Turkey

    Directory of Open Access Journals (Sweden)

    Erhan Mutlu

    2006-03-01

    Full Text Available Conomurex persicus, one of the tropical conchs, has been introduced to one of the subtropical regions, the northeastern Mediterranean Sea, and invaded sandy bottoms between 1 and 10 m deep. Population dynamics were studied from specimens collected with a standard dredge (60 x 15 cm mouth opening, 0.5 x 0.5 cm eye opening of net. Samples of C. persicus were collected monthly along the 5 and 10 m depth contours off Erdemli, Mersin, Turkey, in February and May 2000. Intra-annual density depended on salinity levels, while inter-annual density was correlated with bottom water temperature. Specimens underwent spring emergences and winter burial and sheltering (disappearance. Emergence took place in March when temperatures rose and the disappearance occurred in October-November when temperatures dropped. Adults live at 10 m, juveniles are recruited at a 5 m depth. Recruitment began in April and continued for the next 6 months. In contrast to shell width or shell lip thickness, shell length was not a convenient index for estimation of growth parameters. Annual production and mortality were calculated to be 7.86 g m-2 and 3.80 g m-2, respectively, in April-November. Rev. Biol. Trop. 54 (1: 117-129. Epub 2006 Mar 31.El gastrópodo tropical Conomurex persicurs, ha sido introducido a una región subtropical, el noreste del Mar Mediterráneo, y ha invadido los fondos arenosos en un rango de profundidad de 1 a 10 m. Se estudiarion las dinámicas poblacionales a partir de especímenes recolectados mediante un dragado estándard (60 x 15 cm de apertura de entrada y 0.5 x 0.5 cm de tramado. Muestras de C. persicus fueron recolectadas mensualmente a produndidades de 5 y 10 m en las cercanías de Erdemil, Mersin, Turkey, en los meses de febrero y mayo del año 2000. La densidad dentro de un mismo año depende de los niveles de salinidad, mientras que al comparar años distintos está correlacionada con la temperatura del agua.

  2. GigaTracker, the NA62 Beam Tracker

    CERN Document Server

    Velghe, Bob; Bonacini, Sandro; Ceccucci, Augusto; Degrange, Jordan; Kaplon, Jan; Kluge, Alexander; Mapelli, Alessandro; Morel, Michel; Noël, Jérôme; Noy, Matthew; Perktold, Lukas; Petagna, Paolo; Poltorak, Karolina; Riedler, Petra; Romagnoli, Giulia; Chiozzi, Stefano; Ramusino, Angelo Cotta; Fiorini, Massimiliano; Gianoli, Alberto; Petrucci, Ferruccio; Wahl, Heinrich; Arcidiacono, Roberta; Jarron, Pierre; Marchetto, Flavio; Gil, Eduardo Cortina; Nuessle, Georg; Szilasi, Nicolas

    2015-01-01

    The GigaTracker measures the momentum, the direction and the crossing time of all the NA62 secondary beam particles. It is composed of three hybrid silicon pixel stations and four achromatic magnets. All the stations have a rate capability above 750 MHz, a single hit time resolution better than 200 ps and a thickness less than 0.5 % of X = X 0 . The stations’ sensor is read out by ten custom TDCpix ASICs. An innovative microchannel cooling solution is used to keep the sensor temperature below 0 °C. The stations are operated in vacuum and are easily swappable

  3. Lepton flavor violating Z-boson decays at GigaZ as a probe of supersymmetry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper briefly reviews the lepton flavor violating Z-decays at GigaZ as a probe of supersymmetry by focusing on Z → i j in two representative supersymmetric models: the minimal supersymmetric model without R-parity and the supersymmetric seesaw model.The work concludes that under the current experimental constraints from LEP and i → j γ,these rare decays can still be enhanced to reach the sensitivity of the GigaZ.Therefore,supersymmetry can be probed via these decays at GigaZ.

  4. GigaTracker, a Thin and Fast Silicon Pixels Tracker

    CERN Document Server

    Velghe, Bob; Bonacini, Sandro; Ceccucci, Augusto; Kaplon, Jan; Kluge, Alexander; Mapelli, Alessandro; Morel, Michel; Noël, Jérôme; Noy, Matthew; Perktold, Lukas; Petagna, Paolo; Poltorak, Karolina; Riedler, Petra; Romagnoli, Giulia; Chiozzi, Stefano; Cotta Ramusino, Angelo; Fiorini, Massimiliano; Gianoli, Alberto; Petrucci, Ferruccio; Wahl, Heinrich; Arcidiacono, Roberta; Jarron, Pierre; Marchetto, Flavio; Gil, Eduardo Cortina; Nuessle, Georg; Szilasi, Nicolas

    2014-01-01

    GigaTracker, the NA62’s upstream spectrometer, plays a key role in the kinematically constrained background suppression for the study of the K + ! p + n ̄ n decay. It is made of three independent stations, each of which is a six by three cm 2 hybrid silicon pixels detector. To meet the NA62 physics goals, GigaTracker has to address challenging requirements. The hit time resolution must be better than 200 ps while keeping the total thickness of the sensor to less than 0.5 mm silicon equivalent. The 200 μm thick sensor is divided into 18000 300 μm 300 μm pixels bump-bounded to ten independent read-out chips. The chips use an end-of-column architecture and rely on time-over- threshold discriminators. A station can handle a crossing rate of 750 MHz. Microchannel cooling technology will be used to cool the assembly. It allows us to keep the sensor close to 0 C with 130 μm of silicon in the beam area. The sensor and read-out chip performance were validated using a 45 pixel demonstrator with a laser test setu...

  5. Ontogenetic changes in feeding and food preferences of the dog conch Laevistrombus canarium Linnaeus 1758 (Mollusca: Gastropoda) from Merambong shoal, Malaysia

    Science.gov (United States)

    Husna, Wan Nurul Wan Hassan; Mazlan, Abd Ghaffar; Cob, Zaidi Che

    2017-09-01

    Laevistrombus canarium is one of the marine gastropod mollusks that have high commercial value, particularly in the aquaculture sector in Malaysia. This study was conducted to determine the feeding and food items of L. canarium at different ontogenetic stages (juveniles, sub-adults and adults) from Merambong shoals, Malaysia. Field observations on feeding activity were conducted, followed by detailed laboratory analysis on the stomach content. Five-minutes observations on randomly selected individuals were conducted at the field sampling site and their feeding activities were recorded with reference to age stage. Various shell sizes from each ontogenetic stage were randomly collected and quickly anaesthetized with ice and preserved in 10% formalin before being transported to the laboratory for stomach content analyses. Field observations showed that L. canarium mainly grazed on epiphytes occurring on seagrass (46.67%), followed by sediment surface (40%) and epiphytes occurring on macroalgae (13.33%). Stomach content analyses showed a significant difference ( P Food items found in the conch stomach include diatoms, detritus, foraminifera, seagrass and macroalgae fragments, sand particles and shell fragments. The Index of Relative Importance (%IRI) indicates three main types of food dominated the three ontogenetic stages namely diatoms, sand particles and detritus. However, no significant difference ( P >0.05) was detected between the three main food items (diatoms, sand particles and detritus) among the ontogenetic stages. Therefore, feeding activity revealed the role of the dog conch in the marine food network. While, classification of the types of food consumed by L. canarium through stomach content analysis determines the particular position of the gastropod in the food chain. Further studies are needed to provide a better insight between trophic relationships of L. canarium with marine ecosystem.

  6. Ontogenetic changes in feeding and food preferences of the dog conch Laevistrombus canarium Linnaeus 1758 (Mollusca: Gastropoda) from Merambong shoal, Malaysia

    Science.gov (United States)

    Husna, Wan Nurul Wan Hassan; Mazlan, Abd Ghaffar; Cob, Zaidi Che

    2016-10-01

    Laevistrombus canarium is one of the marine gastropod mollusks that have high commercial value, particularly in the aquaculture sector in Malaysia. This study was conducted to determine the feeding and food items of L. canarium at different ontogenetic stages (juveniles, sub-adults and adults) from Merambong shoals, Malaysia. Field observations on feeding activity were conducted, followed by detailed laboratory analysis on the stomach content. Five-minutes observations on randomly selected individuals were conducted at the field sampling site and their feeding activities were recorded with reference to age stage. Various shell sizes from each ontogenetic stage were randomly collected and quickly anaesthetized with ice and preserved in 10% formalin before being transported to the laboratory for stomach content analyses. Field observations showed that L. canarium mainly grazed on epiphytes occurring on seagrass (46.67%), followed by sediment surface (40%) and epiphytes occurring on macroalgae (13.33%). Stomach content analyses showed a significant difference (P Food items found in the conch stomach include diatoms, detritus, foraminifera, seagrass and macroalgae fragments, sand particles and shell fragments. The Index of Relative Importance (%IRI) indicates three main types of food dominated the three ontogenetic stages namely diatoms, sand particles and detritus. However, no significant difference (P >0.05) was detected between the three main food items (diatoms, sand particles and detritus) among the ontogenetic stages. Therefore, feeding activity revealed the role of the dog conch in the marine food network. While, classification of the types of food consumed by L. canarium through stomach content analysis determines the particular position of the gastropod in the food chain. Further studies are needed to provide a better insight between trophic relationships of L. canarium with marine ecosystem.

  7. Energy source in the developing eggs of the Indian horseshoe crab, Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Aguiar, Q.; Saldanha, C.

    Wet weight, dry weight, water content, ash weight, soluble and insoluble proteins, carbohydrates, lipids, and glycogen were determined from 0 to 40th day after fertilization of the developing eggs of the Indian horseshoe crab, Tachypleus gigas...

  8. Feeding behaviour and food selection in the horseshoe crab, Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A; Mishra, J.K.; Parulekar, A

    The Indian horseshoe crab, Tachypleus gigas, is a benthic feeder which subsists mainly on molluscs, decayed organic matter and polychaetes, in order of prevalence. A strong and positive preference was recorded for molluscs over other food organisms...

  9. Spawning migration of the horseshoe crab, Tachypleus gigas (Muller), in relation to lunal cycle

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Rathod, V.; Parulekar, A.H.

    Effects of lunar phases and tidal height on the spawning migration of the horseshoe crab, Tachypleus gigas, along the northeastern coast of India were studied. Mature pairs of crabs migrate towards the shore and build their nests in sandy beaches...

  10. Habitat suitability and conservation of the giant gartersnake (Thamnophis gigas) in the Sacramento Valley of California

    Science.gov (United States)

    Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2010-01-01

    Resource managers often have little information regarding the habitat requirements and distribution of rare species. Factor analysis-based habitat suitability models describe the ecological niche of a species and identify locations where these conditions occur on the landscape using existing occurrence data.We used factor analyses to assess the suitability of habitats for Thamnophis gigas (Giant Gartersnake), a rare, threatened species endemic to the Central Valley of California, USA, and to map the locations of habitat suitable for T. gigas in the Sacramento Valley. Factor analyses indicated that the niche of T. gigas is composed of sites near rice agriculture with low stream densities. Sites with high canal densities and near wetlands also appeared suitable, but results for these variables were sensitive to potential sampling bias. In the Sacramento Valley, suitable habitats occur primarily in the central portion of the valley floor. Based upon the results of the factor analyses, recovery planning for T. gigas will require an on-the-ground assessment of the current distribution and abundance of T. gigas, maintaining the few remaining natural wetlands and the practice of rice agriculture in the Sacramento Valley, and studying the effects of agricultural practices and land use changes on populations of T. gigas.

  11. Adult Pacific Oyster (Crassostrea gigas May Have Light Sensitivity.

    Directory of Open Access Journals (Sweden)

    Changlu Wu

    Full Text Available Light-sensitivity is an important aspect of mollusk survival as it plays a vital role in reproduction and predator avoidance. In the Pacific oyster Crassostrea gigas light sensitivity has been demonstrated in the larval stage but has not yet been conclusively demonstrated in adult oysters. In this paper we describe an experiment which was undertaken to determine if adult Pacific oysters were sensitive to light. One LED flashlight was used to shine light onto adult oysters while they were filtering seawater through their shell openings. We found that the degree of opening increased gradually during the light period but rapidly decreased when the flashlight was turned off in the treated group but not in the control group. These results suggest that adult Pacific oyster may be sensitive to light.

  12. GigaGauss magnetic fields in under-dense plasma

    CERN Document Server

    Lecz, Zsolt; Seryi, Andrei; Andreev, Alexander

    2016-01-01

    Magnetic fields have a crucial role in physics at all scales, from synchrotrons and laser-driven plasma accelerators to astrophysics and nanotechnology. Large field strengths, beside the guiding of relativistic particles along a shorter curvature, allows the investigation of material in extreme conditions existing only in exotic astro-objects like neutron stars or pulsars. Here we propose a method for generating magnetic field on the GigaGauss level in under-dense plasma using high intensity laser pulses with azimuthally non-uniform intensity distribution. The interaction is studied with the help of three-dimensional particle-in-cell plasma simulation code. Beside the standard wake-field and bubble generation, such laser beam induces the rotational motion of electrons at the edge of evacuated plasma region. The combined axial magnetic and electric fields form a compact source of both high frequency radiation, due to coherent synchrotron emission, and low emittance, high density relativistic electron bunches. ...

  13. The Trilogy is Complete - GigaGalaxy Zoom Phase 3

    Science.gov (United States)

    2009-09-01

    The third image of ESO's GigaGalaxy Zoom project has just been released online, completing this eye-opening dive into our galactic home in outstanding fashion. The latest image follows on from views, released over the last two weeks, of the sky as seen with the unaided eye and through an amateur telescope. This third instalment provides another breathtaking vista of an astronomical object, this time a 370-million-pixel view of the Lagoon Nebula of the quality and depth needed by professional astronomers in their quest to understand our Universe. The newly released image extends across a field of view of more than one and a half square degree - an area eight times larger than that of the full Moon - and was obtained with the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. This 67-million-pixel camera has already created several of ESO's iconic pictures. The intriguing object depicted here - the Lagoon Nebula - is located four to five thousand light-years away towards the constellation of Sagittarius (the Archer). The nebula is a giant interstellar cloud, 100 light-years across, where stars are forming. The scattered dark patches seen all over the nebula are huge clouds of gas and dust that are collapsing under their own weight and which will soon give birth to clusters of young, glowing stars. Some of the smallest clouds are known as "globules" and the most prominent ones have been catalogued by the astronomer Edward Emerson Barnard. The Lagoon Nebula hosts the young open stellar cluster known as NGC 6530. This is home for 50 to 100 stars and twinkles in the lower left portion of the nebula. Observations suggest that the cluster is slightly in front of the nebula itself, though still enshrouded by dust, as revealed by reddening of the starlight, an effect that occurs when small dust particles scatter light. The name of the Lagoon Nebula derives from the wide lagoon-shaped dark lane located in the middle of the

  14. GaN Initiative for Grid Applications (GIGA)

    Energy Technology Data Exchange (ETDEWEB)

    Turner, George [MIT Lincoln Lab., Lexington, MA (United States)

    2015-07-03

    For nearly 4 ½ years, MIT Lincoln Laboratory (MIT/LL) led a very successful, DoE-funded team effort to develop GaN-on-Si materials and devices, targeting high-voltage (>1 kV), high-power, cost-effective electronics for grid applications. This effort, called the GaN Initiative for Grid Applications (GIGA) program, was initially made up of MIT/LL, the MIT campus group of Prof. Tomas Palacios (MIT), and the industrial partner M/A Com Technology Solutions (MTS). Later in the program a 4th team member was added (IQE MA) to provide commercial-scale GaN-on-Si epitaxial materials. A basic premise of the GIGA program was that power electronics, for ubiquitous utilization -even for grid applications - should be closer in cost structure to more conventional Si-based power electronics. For a number of reasons, more established GaN-on-SiC or even SiC-based power electronics are not likely to reach theses cost structures, even in higher manufacturing volumes. An additional premise of the GIGA program was that the technical focus would be on materials and devices suitable for operating at voltages > 1 kV, even though there is also significant commercial interest in developing lower voltage (< 1 kV), cost effective GaN-on-Si devices for higher volume applications, like consumer products. Remarkable technical progress was made during the course of this program. Advances in materials included the growth of high-quality, crack-free epitaxial GaN layers on large-diameter Si substrates with thicknesses up to ~5 μm, overcoming significant challenges in lattice mismatch and thermal expansion differences between Si and GaN in the actual epitaxial growth process. Such thick epilayers are crucial for high voltage operation of lateral geometry devices such as Schottky barrier (SB) diodes and high electron mobility transistors (HEMTs). New “Normally-Off” device architectures were demonstrated – for safe operation of power electronics circuits. The trade-offs between lateral and

  15. Development and Commissioning of the GigaTracker Data Acquisition and Control Systems for the NA62 Experiment at CERN

    CERN Document Server

    AUTHOR|(CDS)2090267

    This thesis presents the results of years of work dedicated to the development, commissioning and testing of the NA62 GigaTracker data acquisition and control systems as well as analysis of the data for alignment and quality checking. The GigaTracker beam detector is part of the NA62 experiment at CERN-SPS.

  16. The GigaFitter: Performance at CDF and Perspectives for Future Applications

    Science.gov (United States)

    Amerio, S.; Annovi, A.; Bettini, M.; Bucciantonio, M.; Catastini, P.; Crescioli, F.; Dell'Orso, M.; Giannetti, P.; Lucchesi, D.; Nicoletto, M.; Piendibene, M.; Volpi, G.

    2010-04-01

    The Silicon Vertex Trigger (SVT) is a processor developed at CDF experiment to perform online fast and precise track reconstruction. SVT is made of two pipelined processors, the Associative Memory, finding low precision tracks, and the Track Fitter, refining the track quality whith high precision fits. We will describe the architecture and the performances of a next generation track fitter, the GigaFitter, developed to reduce the degradation of the SVT efficiency due to the increasing instantaneous luminosity. The GigaFitter reduces the track parameter reconstruction to a few clock cycles and can perform many fits in parallel, thus allowing high resolution tracking at very high rate. The core of the GigaFitter is implemented in a modern Xilinx Virtex-5 FPGA chip, rich in powerful DSP arrays. The FPGA is housed on a mezzanine board which receives the data from a subset of the tracking detector and transfers the fitted tracks to a Pulsar motherboard for the final corrections. Instead of the current 12 boards, one per sector of the detector, the final system will be much more compact, consisting of a single GigaFitter Pulsar board equipped with four mezzanine cards receiving the data from the entire tracking detector. Moreover, the GigaFitter modular structure is adequate to scale for much better performances and is general enough to be easily adapted to future High Energy Physics (HEP) experiments and applications outside HEP.

  17. Phylogeny of forkhead genes in three spiralians and their expression in Pacific oyster Crassostrea gigas

    Science.gov (United States)

    Yang, Mei; Xu, Fei; Liu, Jun; Que, Huayong; Li, Li; Zhang, Guofan

    2014-11-01

    The Fox genes encode a group of transcription factors that contain a forkhead domain, which forms a structure known as a winged helix. These transcription factors play a crucial role in several key biological processes, including development. High-degree identity in the canonical forkhead domain has been used to divide Fox proteins into 23 families (FoxA to FoxS). We surveyed the genome of three spiralians, the oyster Crassostrea gigas, the limpet Lottia gigantea, and the annelid Capitella teleta. We identified 25 C. gigas fox genes, 21 L. gigantea fox genes, and 25 C. teleta fox genes. The C. gigas fox and L. gigantea fox genes represented 19 of the 23 families, whereas FoxI, Q1, R, and S were missing. The majority of the Fox families were observed within the C. teleta fox genes, with the exception of FoxR and S. In addition, the foxAB-like gene, foxY-like gene, and foxH gene were also present in the three genomes. The conserved FoxC-FoxL1 cluster, observed in mammals, was also found in C. gigas. The diversity of temporal expression patterns observed across the developmental process implies the C. gigas fox genes exert a wide range of functions. Further functional studies are required to gain insight into the evolution of Fox genes in bilaterians.

  18. Somatosensory cortical representation in the Australian ghost bat, Macroderma gigas.

    Science.gov (United States)

    Wise, L Z; Pettigrew, J D; Calford, M B

    1986-06-08

    Bats of the two suborders Microchiroptera and Megachiroptera have a modified hand in which the digits of the forelimb are caudally oriented to form the wing. In a previous study of a megachiropteran species, this modification of body plan was found to be reflected in the somatosensory cortical representation such that the orientation of the digit representation was reversed compared with walking mammals. This finding suggests that the precise details of arrangement of topographical maps are functionally significant and do not merely reflect an order imposed by peripheral innervation. Recent evidence for separate origins of Microchiroptera and Megachiroptera raises the question of whether the cortical somatosensory representation in Microchiroptera will also have a reversal of digit orientation compared with walking mammals. We recorded multiunit activity from the somatosensory cortex of a microchiropteran bat, Macroderma gigas. We found two orderly representations of the body surface, SI and SII, in both of which the digit orientation was opposite to the head orientation in accordance with adaptation for flight, and reversed with respect to equivalent maps in other mammals. We also found minor variations in body surface representation compared with Megachiroptera, in line with their proposed independent evolution.

  19. Characteristic crystal orientation of folia in oyster shell, Crassostrea gigas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Woo [Department of Chemical and Biomolecular Engineering, Sogang University, Seoul (Korea, Republic of); Kim, Gyeung Ho [Nano-Materials Reserch Center, Korea Institute of Science and Technology, Seoul (Korea, Republic of); Choi, Cheong Song [Department of Chemical and Biomolecular Engineering, Sogang University, Seoul (Korea, Republic of)], E-mail: cschoi@sogang.ac.kr

    2008-03-10

    The thin sheets of calcite, termed folia, that make up much of the shell of an oyster are composed of foliated lath. Folia of the giant Pacific oyster (Crassostrea gigas) were examined using TEM (transmission electron microscopy) and tested using microindentation and nanoindentation techniques. Analysis of the Kikuchi patterns obtained from the folia showed that there are two types (type I and type II) of preferred orientation, with an angle of around 70{sup o} between them. Nanoindentation tests showed that the folia exhibit a hardness of about 3 GPa and elastic modulus of about 73 GPa. Microcracks were generated using a microindenter in order to study the fracture mechanisms of the folia. Following on from these investigations, fracture mechanisms are discussed in conjunction with the correlation between preferred orientation and structural characteristics during cracking of the folia. Comparing the morphology and the polymorphism with nacre (also known as mother of pearl), the advantages of the relatively fast crystal growth and less amount of organic matrix in folia may have interesting implications for the development of sophisticated synthetic materials.

  20. Giga-bit optical data transmission module for Beam Instrumentation

    CERN Document Server

    Roedne, L T; Cenkeramaddi, L R; Jiao, L

    Particle accelerators require electronic instrumentation for diagnostic, assessment and monitoring during operation of the transferring and circulating beams. A sensor located near the beam provides an electrical signal related to the observable quantity of interest. The front-end electronics provides analog-to-digital conversion of the quantity being observed and the generated data are to be transferred to the external digital back-end for data processing, and to display to the operators and logging. This research project investigates the feasibility of radiation-tolerant giga-bit data transmission over optic fibre for beam instrumentation applications, starting from the assessment of the state of the art technology, identification of challenges and proposal of a system level solution, which should be validated with a PCB design in an experimental setup. Radiation tolerance of 10 kGy (Si) Total Ionizing Dose (TID) over 10 years of operation, Bit Error Rate (BER) 10-6 or better. The findings and results of th...

  1. Study of D~0-D~0 mixing at a giga-Z linear collider

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The possibility of studying D 0-D 0 mixing at a giga-Z linear collider "Z factory" where 10 9 hadronic Z 0 decays can be accumulated is examined.We discuss the sensitivity for the measurements of neutral D mixing parameters.These results are compared to those attainable at B factories.We find that the typical decay length of the neutral D mesons at Z factory is about 10 times larger than that at B factory.In addition,the resolution of the vertex detector of a giga-Z factory is 2-3 times better than that of B factory.The proper time resolution at Z factory is about 20-30 times better than that at B factory.Therefore the determination of the mixing parameters at a giga-Z factory is more precise.

  2. High Infestation by Dawestrema cycloancistrioides in Arapaima gigas Cultured in the Amazon Region, Peru

    Directory of Open Access Journals (Sweden)

    Patrick D. Mathews

    2014-01-01

    Full Text Available The aim of this study was to evaluate the presence of Dawestrema cycloancistrioides in semi-intensive fish farming of fingerlings of Arapaima gigas. Between September and November 2013, 60 individuals of A. gigas born in captivity, were collected in three concrete ponds, from a semi-intensive fish farm in the Peruvian Amazon. For the study of sclerotized structures, parasites were fixed in a solution of ammonium picrate glycerine and mounted in Canada balsam. To visualize internal structures, parasites were fixed in hot formaldehyde solution (4% for staining with Gomori’s trichrome. The parasitic indexes calculated were prevalence, mean intensity, and mean abundance. This study identified a high infestation of a monogenean D. cycloancistrioides in gills of A. gigas. The prevalence was 100%. The mean intensity and mean abundance of the parasite were 144.9 of parasites per individual. This study confirms the necessity of constant monitoring of fish in order to reduce fish mortality.

  3. The biology and ecology of the jumbo squid Dosidicus gigas (Cephalopoda in Chilean waters: a review

    Directory of Open Access Journals (Sweden)

    Christian M Ibáñez

    2015-07-01

    Full Text Available ABSTRACT. The jumbo squid Dosidicus gigas is the most abundant cephalopod species in the southeastern Pacific Ocean, which supports the biggest cephalopod fishery in the world. Due to its growing economic importance, the population growth and distributional expansion of this squid is being increasingly studied. Nevertheless, some basic features of the biology of D. gigas are still unknown or have been poorly investigated. In this review we summarize the known information regarding the biology and ecology of this species in the southeastern Pacific Ocean; we focus on the Chilean region in order to propose hypotheses and research lines for a better understanding the life history of this organism. Available data on the size structure, reproduction and genetics of D. gigas allows us to propose hypotheses related to the squid's life history traits. Based on the current literature and publications of colleagues, we propose two hypotheses regarding the effect of spatial variation on the life history of D. gigas. Hypothesis 1: Squids mature at large sizes and spawn in oceanic waters with warm temperatures where paralarvae and juveniles develop. Immature squids migrate near shore to feed, grow and mature, and then return to the offshore sites to spawn. Hypothesis 2: Alternatively, juvenile D. gigas in the oceanic zone do not migrate to coastal waters and mature at small sizes compared to individuals living near the coast that mature at larger size and migrate to oceanic waters to spawn. We provide background information about the feeding behavior and parasitism of this species, suggesting that D. gigas is an important trophic link in the southeastern Pacific marine ecosystem. However, more studies on the feeding habits, reproduction and parasite load are needed not only to test hypotheses proposed in this study, but also to advance the overall knowledge of this species.

  4. Feeding traits of the European flat oyster, Ostrea edulis, and the invasive Pacific oyster, Crassostrea gigas

    DEFF Research Database (Denmark)

    Nielsen, Mette; Hansen, Benni Winding; Vismann, Bent

    2016-01-01

    Two oysters, the native flat oyster, Ostrea edulis, and the non-indigenous Pacific oyster, Crassostrea gigas, have partially overlapping distributions in European waters. Relatively little is known about particle selection by O. edulis, and the goal of the present study was to establish baselines...... °C and a salinity of 25. The CR of O. edulis was one to three times lower than that of C. gigas for the three smaller algal species (5−15 µm) but not different for the two larger algae. Algae in the size range 7−32 µm were retained with 100% RE by both oysters, but the smallest alga was retained...

  5. Heavy metal complexation in polluted molluscs. II. Oysters (Ostrea edulis and Crassostrea gigas)

    Energy Technology Data Exchange (ETDEWEB)

    Howard, A.G.; Nickless, G.

    1977-06-01

    Cadmium, zinc and copper, accumulated from polluted habitats by the oysters Ostrea edulis and Crassostrea gigas, were studued. Three distinct low molecular weight (less than 3000 daltons) zinc complexes were separated from highly contaminated C. gigas, one of which may be a complex with the amino acid taurine. Only one of these zinc complexes was present in less contaminatd specimens of O. edulis. On gel permeation chromatography of oyster extracts, copper was eluted together with amino acids (principally taurine) and the betaine homarine. No evidence of metallothionein type proteins was found.

  6. Literature review of giant gartersnake (Thamnophis gigas) biology and conservation

    Science.gov (United States)

    Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2015-08-03

    This report reviews the available literature on giant gartersnakes (Thamnophis gigas) to compile existing information on this species and identify knowledge gaps that, if addressed, would help to inform conservation efforts for giant gartersnakes.  Giant gartersnakes comprise a species of semi-aquatic snake precinctive to wetlands in the Central Valley of California.  The diversion of surface water and conversion of wetlands to agricultural and other land uses resulted in the loss of more than 90 percent of natural giant gartersnake habitats.  Because of this habitat loss, giant gartersnakes are now listed by the United States and California Endangered Species Acts as Threatened.  Most extant populations occur in the rice-growing regions of the Sacramento Valley, which comprises the northern portion of the giant gartersnake’s former range.  The huge demand for water in California for agriculture, industry, recreation, and other human consumption, combined with periodic severe drought, places remaining giant gartersnake habitats at increased risk of degradation and loss.  This literature review summarizes the available information on giant gartersnake distribution, habitat relations, behavior, demography, and other aspects of its biology relevant to conservation.  This information is then compiled into a graphical conceptual model that indicates the importance of different aspects of giant gartersnake biology for maintaining positive population growth, and identifies those areas for which important information relevant for conservation is lacking.  Directing research efforts toward these aspects of giant gartersnake ecology will likely result in improvements to conserving this unique species while meeting the high demands for water in California.

  7. Food competition between Crassostrea gigas and Mytilus edulis in the Oosterschelde estuary

    NARCIS (Netherlands)

    Stehouwer, P.P.

    2006-01-01

    The Pacific oyster (Crassostrea gigas) is an invasive species in the Oosterschelde estuary. It was originally brought there to replace the native flat oyster Ostrea edulis which had been greatly reduced in numbers due to diseases and parasites. Because of some hot summers the pacific oyster could sp

  8. Histone H3 gene in the Pacific oyster, Crassostrea gigas Thunberg, 1793: molecular and cytogenetic characterisations

    Directory of Open Access Journals (Sweden)

    Karine Bouilly

    2010-12-01

    Full Text Available The Pacific oyster, Crassostrea gigas Thunberg, 1793 (2n = 20 is an economically important mollusc species cultured throughout the world. The most frequently used technique for molecular cytogenetic studies is fluorescence in situ hybridisation which offers new opportunities for the identification of oyster chromosomes. In oysters, it has been used to locate telomeric sequences, satellite DNA, simple sequence repeats, ribosomal RNA genes, and bacteriophage P1 clones. However, regarding chromosome identification, no study has been done with histone H3 gene. Histone H3 is among the most conserved eukaryotic proteins. Most histone H3 genes are repeatedly organised into clusters, which make them an ideal chromosomal marker. In bivalves, some data exist concerning sequence information but little knowledge is available concerning the physical mapping of histone genes. The histone H3 gene was sequenced in C. gigas and phylogenetic analysis revealed that C. gigas was more closely related to Ostrea edulis Linnaeus, 1758 and species of the genus Mytilus Linnaeus, 1758. In C. gigas, the histone H3 gene was mapped on two different pairs of chromosomes, one at an interstitial site on the long arm of chromosome pair 4, and the other on the telomeres of the smaller chromosome pair (pair 10. Polymorphism was detected on the telomeres of pair 10, once it was possible to observe single or double signals. Comparative chromosomal mapping should improve our understanding of bivalve genome organisation.

  9. Toxic effects of heavy metal Cu2+ on the pacific oyster Crassostrea gigas

    Science.gov (United States)

    Gao, Ceng; Zhang, Xinxin; Li, Xiumei; Tang, Xuexi

    2017-05-01

    The effects of different concentrations of heavy metal ions on the survival of the Pacific oyster Crassostrea gigas were studied by using experimental ecology method in 96 h. The results showed that the LC50 of copper ion was 21.748mg/L and the safe concentration was 2.1748mg/L mg/L. Under the condition of laboratory, under laboratory conditions, the research of Cu2+ Stress on the C. gigas gill and digestive gland and adductor muscle tissue SOD, GPx and the induction of CAT activity. The results showed that the activities of SOD, GPx and CAT in the C. gigas were significantly changed by copper ion + stress. The results showed that in the low concentration Cu2+ treatment could induce the three kinds of enzymes, in the high concentration Cu2+ treatment group, SOD and CAT and GPx on the inhibition of the effect. The sensitivity of the three antioxidant enzymes to copper ion showed a certain difference. The sensitivity of the three kinds of tissue enzymes to Cu2+ treatment was digestive gland> fascia> gill. The experimental results show that the single factor for copper in water pollutants, the C. gigas digestive gland tissue SOD, GPX and CAT activity has certain significance to it, but will it as index applied to the actual water need further study.

  10. A freak twin trilobite larva of the Indian horseshoe crab Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Mishra, J.K.; Chatterji, A; Parulekar, A

    Early embryonic stages of a horseshoe crab Tachypleus gigas were studied using micrographs of live embryo. A freak egg showing two trilobite larvae bridged with each other was noticed on 38th day after fertilization. Morphology of this egg has been...

  11. DNA methylation patterns provide insight into epigenetic regulation in the Pacific oyster (Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Gavery Mackenzie R

    2010-08-01

    Full Text Available Abstract Background DNA methylation is an epigenetic mechanism with important regulatory functions in animals. While the mechanism itself is evolutionarily ancient, the distribution and function of DNA methylation is diverse both within and among phylogenetic groups. Although DNA methylation has been well studied in mammals, there are limited data on invertebrates, particularly molluscs. Here we characterize the distribution and investigate potential functions of DNA methylation in the Pacific oyster (Crassostrea gigas. Results Methylation sensitive PCR and bisulfite sequencing PCR approaches were used to identify CpG methylation in C. gigas genes and demonstrated that this species possesses intragenic methylation. In silico analysis of CpGo/e ratios in publicly available sequence data suggests that DNA methylation is a common feature of the C. gigas genome, and that specific functional categories of genes have significantly different levels of methylation. Conclusions The Pacific oyster genome displays intragenic DNA methylation and contains genes necessary for DNA methylation in animals. Results of this investigation suggest that DNA methylation has regulatory functions in Crassostrea gigas, particularly in gene families that have inducible expression, including those involved in stress and environmental responses.

  12. Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hye-Young; Kim, Jun-Hyoung [Department of Food and Nutrition, Chosun University, Gwangju 501-759 (Korea, Republic of); Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo [Radiation Food Science and Biotechnology Team, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Kwon, Joog-Ho [Department of Food Science and Technology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Kyong-Su [Department of Food and Nutrition, Chosun University, Gwangju 501-759 (Korea, Republic of)], E-mail: kskim@chosun.ac.kr

    2007-11-15

    The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, {alpha}-pinene, camphene, {alpha}-limonene, {beta}-eudesmol, {alpha}-murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as {beta}-eudesmol, {alpha}-eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.

  13. The Global Invertebrate Genomics Alliance (GIGA). 2014. Developing Community Resources to Study Diverse Invertebrate Genomes

    NARCIS (Netherlands)

    Pomponi, S.A.

    2014-01-01

    Over 95% of all metazoan (animal) species comprise the “invertebrates,” but very few genomes from these organisms have been sequenced. We have, therefore, formed a “Global Invertebrate Genomics Alliance” (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major cha

  14. Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai

    Science.gov (United States)

    Seo, Hye-Young; Kim, Jun-Hyoung; Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo; Kwon, Joog-Ho; Kim, Kyong-Su

    2007-11-01

    The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, α-pinene, camphene, α-limonene, β-eudesmol, α-murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as β-eudesmol, α-eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.

  15. The Global Invertebrate Genomics Alliance (GIGA). 2014. Developing Community Resources to Study Diverse Invertebrate Genomes

    NARCIS (Netherlands)

    Pomponi, S.A.

    2014-01-01

    Over 95% of all metazoan (animal) species comprise the “invertebrates,” but very few genomes from these organisms have been sequenced. We have, therefore, formed a “Global Invertebrate Genomics Alliance” (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major

  16. Impact of an icy winter on the Pacific oyster (Crassostrea gigas Thunberg, 1793) populations in Scandinavia

    DEFF Research Database (Denmark)

    Strand, Åsa; Blanda, Elisa; Bodvin, Torjan;

    2012-01-01

    The Pacific oyster (Crassostrea gigas) is an invasive species that has dispersed into Scandinavia during the last few decades. The objective of this study was to evaluate the effects of extreme winter conditions on the mortality of the Pacific oyster in Scandinavia. The study was done by compilin...

  17. Malformaciones congénitas en una puesta de colúbridos (Hydrodynastes gigas)

    OpenAIRE

    1985-01-01

    En marzo de 1985, eclosionaron en la Sección Herpetología de la Fundación Miguel Lillo dirigida por el Dr. R. Laurent 19 viboreznos pertenecientes a la especie Hydrodynastes gigas, dos de los cuales con malformaciones congénitas.

  18. Induction of gynogenetic haploidy in oyster Crassostrea gigas, using ultra violet irradiated sperms

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.

    Eggs of Crassostrea gigas were fertilized with sperms exposed to different doses of UV irradiations by keeping a constant rate of 121.47 ergs. mm/2 sec/1 and changing the period of exposure from 4 to 90 sec. Samples of larvae were analysed...

  19. Unambiguous range-Doppler LADAR processing using 2 giga-sample-per-second noise waveforms

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Z. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States)]. E-mail: cole@s2corporation.com; Roos, P.A. [Spectrum Lab, Montana State University, P.O. Box 173510, Bozeman, MT 59717 (United States); Berg, T. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States); Kaylor, B. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States); Merkel, K.D. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States); Babbitt, W.R. [Spectrum Lab, Montana State University, P.O. Box 173510, Bozeman, MT 59717 (United States); Reibel, R.R. [S2 Corporation, 2310 University Way 4-1, Bozeman, MT 59715 (United States)

    2007-11-15

    We demonstrate sub-nanosecond range and unambiguous sub-50-Hz Doppler resolved laser radar (LADAR) measurements using spectral holographic processing in rare-earth ion doped crystals. The demonstration utilizes pseudo-random-noise 2 giga-sample-per-second baseband waveforms modulated onto an optical carrier.

  20. GIGA: a simple, efficient algorithm for gene tree inference in the genomic age

    Directory of Open Access Journals (Sweden)

    Thomas Paul D

    2010-06-01

    Full Text Available Abstract Background Phylogenetic relationships between genes are not only of theoretical interest: they enable us to learn about human genes through the experimental work on their relatives in numerous model organisms from bacteria to fruit flies and mice. Yet the most commonly used computational algorithms for reconstructing gene trees can be inaccurate for numerous reasons, both algorithmic and biological. Additional information beyond gene sequence data has been shown to improve the accuracy of reconstructions, though at great computational cost. Results We describe a simple, fast algorithm for inferring gene phylogenies, which makes use of information that was not available prior to the genomic age: namely, a reliable species tree spanning much of the tree of life, and knowledge of the complete complement of genes in a species' genome. The algorithm, called GIGA, constructs trees agglomeratively from a distance matrix representation of sequences, using simple rules to incorporate this genomic age information. GIGA makes use of a novel conceptualization of gene trees as being composed of orthologous subtrees (containing only speciation events, which are joined by other evolutionary events such as gene duplication or horizontal gene transfer. An important innovation in GIGA is that, at every step in the agglomeration process, the tree is interpreted/reinterpreted in terms of the evolutionary events that created it. Remarkably, GIGA performs well even when using a very simple distance metric (pairwise sequence differences and no distance averaging over clades during the tree construction process. Conclusions GIGA is efficient, allowing phylogenetic reconstruction of very large gene families and determination of orthologs on a large scale. It is exceptionally robust to adding more gene sequences, opening up the possibility of creating stable identifiers for referring to not only extant genes, but also their common ancestors. We compared trees

  1. Fishery Biology of Jumbo Flying Squid Dosidicus gigas off Costa Rica Dome

    Institute of Scientific and Technical Information of China (English)

    CHEN Xinjun; LI Jianghua; LIU Bilin; LI Gang; LU Huajie

    2014-01-01

    The jumbo flying squid (Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome (4˚-11˚N, 90˚-100˚W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6˚-9˚N and 91˚-94˚W and by 6˚30´-7˚30´N and 96˚-97˚W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29℃. The sex ratio of the total catch was 3.75:1 (female:male). The mantle length of the squid ranged from 211 to 355 mm (male) and from 204 to 429 mm (female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length (mm) and body weight (g) of the squid, there was no significant dif-ference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size (mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs (70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65%of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery re-sources.

  2. Fishery biology of jumbo flying squid Dosidicus gigas off Costa Rica Dome

    Science.gov (United States)

    Chen, Xinjun; Li, Jianghua; Liu, Bilin; Li, Gang; Lu, Huajie

    2014-06-01

    The jumbo flying squid ( Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome (4°-11°N, 90°-100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°-9°N and 91°-94°W and by 6°30'-7°30'N and 96°-97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29°C. The sex ratio of the total catch was 3.75:1 (female: male). The mantle length of the squid ranged from 211 to 355 mm (male) and from 204 to 429 mm (female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length (mm) and body weight (g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size (mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs (70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.

  3. Innovative uses of GigaPan Technology for Onsite and Distance Education

    Science.gov (United States)

    Bentley, C.; Schott, R. C.; Piatek, J. L.; Richards, B.

    2013-12-01

    GigaPans are gigapixel panoramic images that can be viewed at a wide range of magnifications, allowing users to explore them in various degrees of detail from the smallest scale to the full image extent. In addition to panoramic images captured with the GigaPan camera mount ('Dry Falls' - http://www.gigapan.com/gigapans/89093), users can also upload annotated images (For example, 'Massanutten sandstone slab with trace fossils (annotated)', http://www.gigapan.com/gigapans/124295) and satellite images (For example, 'Geology vs. Topography - State of Connecticut', http://www.gigapan.com/gigapans/111265). Panoramas with similar topics have been gathered together on the site in galleries, both user-generated and site-curated (For example, http://www.gigapan.com/galleries?categories=geology&page=1). Further innovations in display technology have also led to the development of improved viewers (for example, the annotations in the image linked above can be explored via paired viewers at http://coursecontent.nic.edu/bdrichards/gigapixelimages/callanview) GigaPan panoramas can be created through use of the GigaPan robotic camera mount and a digital camera (different models of the camera mount are available and work with a wide range of cameras). The camera mount can be used to create high-resolution pans ranging in scale from hand sample to outcrop up to landscape via the stitching software included with the robotic mount. The software can also be used to generate GigaPan images from other sources, such as thin section or satellite images, so these images can also be viewed with the online viewer. GigaPan images are typically viewed via a web-based interface that allows the user to interact with the image from the limits of the image detail up to the full panorama. After uploading, information can be added to panoramas with both text captions and geo-referencing (geo-located panoramas can then be viewed in Google Earth). Users can record specific locations and zoom levels in

  4. Parasitas em ostras de cultivo (Crassostrea rhizophorae e Crassostrea gigas da Ponta do Sambaqui, Florianópolis, SC Parasites in cultured oysters (Crassostrea rhizophorae and Crassostrea gigas from Ponta do Sambaqui, Florianópolis, SC

    Directory of Open Access Journals (Sweden)

    R.C. Sabry

    2005-09-01

    Full Text Available Estudou-se a presença de parasitas e realizaram-se exames macroscópicos e histológicos em ostras (Crassostrea rhizophorae e Crassostrea gigas cultivadas. Entre agosto de 2002 a maio de 2003, 30 indivíduos adultos de cada espécie foram coletados sazonalmente, totalizando 240 ostras. Os animais, provenientes de desova em laboratório, foram mantidos em lanternas de cultivo, em sistema suspenso tipo espinhel, com densidade de 40 ostras/andar. A cada coleta era registrada a mortalidade das ostras, a temperatura e a salinidade da água. A temperatura variou de 19 a 28,5°C e a salinidade, 31 a 35‰. A mortalidade foi de 48,3% para C. gigas e 70,8% para C. rhizophorae. A infestação pelo poliqueta Polydora websteri em C. gigas foi 100% durante todo o período e em C. rhizophorae, 100% em fevereiro e maio. O mal do pé foi observado em novembro (3,3% e maio (23,3% em C. gigas e maio (6,6% em C. rhizophorae. As maiores prevalências do protozoário Nematopsis sp. foram de 70 e 60% em C. gigas e C. rhizophorae, respectivamente. O protozoário Trichodina sp. ocorreu em 1,6% de C. rhizophorae, e larvas do cestóide Tylocephalum sp. foram observadas em 2,5% de C. gigas. Nenhum dos parasitas encontrados foi associado à mortalidade das ostras.Over a 10-month period, cultured oysters (Crassostrea rhizophorae and Crassostrea gigas from Ponta do Sambaqui, Florianopolis, Santa Catarina State were evaluated microscopically and histologically for parasite infection. Thirty mature individuals of each species were examined each season, for a total of 240 oysters. The animals, which originated from laboratory spawning, were kept in culture lanterns suspended in long-line systems at a density of 40 oysters per floor. Mortality, water temperature (19 to 28.5 ºC range and salinity (31 to 35‰ were recorded at each sampling. The total amount of dead oysters was 58 (48.3% to C. gigas and 85 (70.8% to C. rhizophorae. All C. gigas individuals were infected with

  5. Generation and analysis of a 29,745 unique Expressed Sequence Tags from the Pacific oyster (Crassostrea gigas assembled into a publicly accessible database: the GigasDatabase

    Directory of Open Access Journals (Sweden)

    Klopp Christophe

    2009-07-01

    Full Text Available Abstract Background Although bivalves are among the most-studied marine organisms because of their ecological role and economic importance, very little information is available on the genome sequences of oyster species. This report documents three large-scale cDNA sequencing projects for the Pacific oyster Crassostrea gigas initiated to provide a large number of expressed sequence tags that were subsequently compiled in a publicly accessible database. This resource allowed for the identification of a large number of transcripts and provides valuable information for ongoing investigations of tissue-specific and stimulus-dependant gene expression patterns. These data are crucial for constructing comprehensive DNA microarrays, identifying single nucleotide polymorphisms and microsatellites in coding regions, and for identifying genes when the entire genome sequence of C. gigas becomes available. Description In the present paper, we report the production of 40,845 high-quality ESTs that identify 29,745 unique transcribed sequences consisting of 7,940 contigs and 21,805 singletons. All of these new sequences, together with existing public sequence data, have been compiled into a publicly-available Website http://public-contigbrowser.sigenae.org:9090/Crassostrea_gigas/index.html. Approximately 43% of the unique ESTs had significant matches against the SwissProt database and 27% were annotated using Gene Ontology terms. In addition, we identified a total of 208 in silico microsatellites from the ESTs, with 173 having sufficient flanking sequence for primer design. We also identified a total of 7,530 putative in silico, single-nucleotide polymorphisms using existing and newly-generated EST resources for the Pacific oyster. Conclusion A publicly-available database has been populated with 29,745 unique sequences for the Pacific oyster Crassostrea gigas. The database provides many tools to search cleaned and assembled ESTs. The user may input and submit

  6. First record of Trichodina heterodentata (Ciliophora: Trichodinidae from Arapaima gigas cultivated in Peru Primeiro registro de Trichodina heterodentata (Ciliophora: Trichodinidae em Arapaima gigas cultivados no Peru

    Directory of Open Access Journals (Sweden)

    Luis Henostroza Miranda

    2012-09-01

    Full Text Available This study characterized morphologically Trichodina heterodentata Duncan, 1977 from cultivated fingerlings of "pirarucu" Arapaima gigas in Peru. Body and gill smears were air-dried at room temperature, impregnated with silver nitrate and/or stained with gomori trichromic. Prevalence was 100%. Trichodina heterodentata was considered a medium-sized trichodinid with mean body diameter of 56.0+ 5.25 (47.3-76.0 μm, denticulate ring 28.21± 2.71 (20-34.7 μm, adhesive disc 45.7±3.8 (37.1-57.3 μm diameter and number of denticles of 20.7± 2.6 (12-24. The present study reports not only the first occurrence of T. heterodentata in Peru but also the first record of this trichodinid infesting A. gigas. Camparative tables of all reports of T. heterodentata are also presented.Este estudo caracterizou morfologicamente Trichodina heterodentata Duncan, 1977 de alevinos de "pirarucu" Arapaima gigas cultivados no Peru. Esfregaços do corpo e brânquias foram secos à temperatura ambiente, impregnados com nitrato de prata e/ou corados com tricrômico de gômori. A prevalência foi de 100%. Trichodina heterodentata foi considerada um tricodinídeo de tamanho médio com diâmetro médio do corpo de 56,0+ 5,25 (47,3-76,0 μm, anel denticulado 28,21± 2,71 (20,0-34,7 μm, disco adesivo 45,7±3,8 (37,1-57,3 μm de diâmetro e número de dentículos de 20,7± 2,6 (12-24. O presente estudo registra não somente a primeira ocorrência de T. heterodentata no Peru mas também o primeiro registro do tricodinídeo parasitando A. gigas. Tabelas comparativas biométricas de todos os registros de T. heterodentata também são apresentados.

  7. Results and insights from the NCSU Insect Museum GigaPan project

    Directory of Open Access Journals (Sweden)

    Matthew Bertone

    2012-07-01

    Full Text Available Pinned insect specimens stored in museum collections are a fragile and valuable resource for entomological research. As such, they are usually kept away from viewing by the public and hard to access by experts. Here we present a method for mass imaging insect specimens, using GigaPan technology to achieve highly explorable, many-megapixel panoramas of insect museum drawers. We discuss the advantages and limitations of the system, and describe future avenues of collections research using this technology.

  8. Results and insights from the NCSU Insect Museum GigaPan project.

    Science.gov (United States)

    Bertone, Matthew A; Blinn, Robert L; Stanfield, Tanner M; Dew, Kelly J; Seltmann, Katja C; Deans, Andrew R

    2012-01-01

    Pinned insect specimens stored in museum collections are a fragile and valuable resource for entomological research. As such, they are usually kept away from viewing by the public and hard to access by experts. Here we present a method for mass imaging insect specimens, using GigaPan technology to achieve highly explorable, many-megapixel panoramas of insect museum drawers. We discuss the advantages and limitations of the system, and describe future avenues of collections research using this technology.

  9. Giga-Gauss scale quasistatic magnetic field generation in an 'escargot' target

    CERN Document Server

    Korneev, Ph; Tikhonchuk, V

    2014-01-01

    A simple setup for the generation of ultra-intense quasistatic magnetic fields, based on the generation of electron currents with a predefined geometry in a curved 'escargot' target, is proposed and analysed. Particle-In-Cell simulations and qualitative estimates show that giga-Gauss scale magnetic fields may be achieved with existent laser facilities. The described mechanism of the strong magnetic field generation may be useful in a wide range of applications, from laboratory astrophysics to magnetized ICF schemes.

  10. Size increment of jumbo flying squid Dosidicus gigas mature females in Peruvian waters, 1989-2004

    Science.gov (United States)

    Argüelles, Juan; Tafur, Ricardo; Taipe, Anatolio; Villegas, Piero; Keyl, Friedeman; Dominguez, Noel; Salazar, Martín

    2008-10-01

    Changes in population structure of the jumbo flying squid Dosidicus gigas in Peruvian waters were studied based on size-at-maturity from 1989 to 2004. From 1989 to 1999, mature squid belonging to the medium-sized group prevailed, but from 2001 on, mature squids were larger. This change is not related to the changes in sea surface temperature and we hypothesized that it was caused by the population increase of mesopelagic fishes as prey.

  11. ANALISIS KUALITAS RUMPUT LAUT Gracilaria gigas YANG DIBUDIDAYA PADA HABITAT LAUT DAN TAMBAK, NUSA TENGGARA BARAT

    Directory of Open Access Journals (Sweden)

    Farah Diana

    2014-03-01

    dengan kandungan N perairan dan indeks percabangan. Kualitas rumput laut berhubungan erat dengan suhu, DO, PO4-P, dan NH3-N terlarut dalam air. Tingginya rendemen agar dan kekuatan gel di tambak disebabkan oleh banyaknya kandungan nutrien dan unsur hara, sedangkan tingginya produktivitas hasil budidaya Gracilaria gigas di laut disebabkan oleh adanya respons struktural dan tekanan turgor pada rumput laut.

  12. Parasites in Arapaima gigas from the Peruvian Amazon by age group

    OpenAIRE

    Serrano-Martínez, Enrique; Grupo SALUVET-UPCH, Facultad de Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima; Tantaleán V., Manuel; Grupo SALUVET-UPCH, Facultad de Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima; Leguía P., Guillermo; Grupo SALUVET-UPCH, Facultad de Medicina Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima; Quispe H., Marco; Grupo SALUVET-UPCH, Facultad de Medicina Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima; Casas V., Gina C.; Grupo SALUVET-UPCH, Facultad de Medicina Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima

    2015-01-01

    This study was carried out in 120 paiches (Arapaima gigas) distributed in four age groups (10 to 30, 31 to 180, 181 to 365 days and >1 year of age) from fish farms in the Peruvian Amazon to determine the prevalence and the affected organs. Eight parasite species are reported: monogeneans (Dawestrema cycloancistrium and D. cycloancistrioides), digeneans (Caballerotrema brasiliense), protozoa (Piscinodinium pillulare, Ichthyophthirius multifiliis and Trichodina sp), cestodes (Schizochoerus l...

  13. Proximal composition and functional properties of lyophilizated surimi of Dosidicus gigas “jumbo squid”

    OpenAIRE

    Solari-Godiño, Armando; Córdova-Ramos, Javier S.; Pilco-Quesada, Silvia; Cerrón-Mallqui, Luz M.; Albrecht-Ruiz, Miguel; Sánchez Hernández, Jorge

    2017-01-01

    The purpose of the research was to determinate proximal composition and functional properties of the giant squid freeze-dried surimi (Dosidicus gigas). Surimi elaborated from giant squid and it lyophilized until obtaining surimi powder to evaluate its characteristics and functional properties. The protein content was 58.7% and carbohydrate 30.5%. Protein solubility in water and salt (3%) were 21.1% and 40.6% respectively, these values being higher than surimi powder of commercial species. The...

  14. Complete mitochondrial genome and phylogenic analysis of the mudskipper Scartelaos gigas (Perciformes, Gobiidae).

    Science.gov (United States)

    Li, Zhe; Zhang, Yuting; Chen, Shixi; Chen, Wei; Hong, Wanshu

    2016-09-01

    In this paper, the complete mitochondrial genome sequence of Scartelaos gigas was firstly determined. The circular genome (16 717 bp) comprises 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region. The overall base composition of S. gigas is 28.9% for C, 28.3% for A, 26.4% for T, 16.4% for G, with a slight A + T bias of 54.7%. In the control region, the termination-associated sequence and conserved sequence block domains were found, but the tandem repeat structure was not found. It has the typical vertebrate mitochondrial gene arrangement. The phylogenic analysis using the Neighbor-Joining method showed that the fishes belonging to Gobiidae, Odontoburidae, and Eleotridae formed three branches grouped with other fishes into one clade which separated from the mammals. We hope that the results from the present study will provide useful molecular information for the further studies on genetic structure and demographic history of S. gigas.

  15. Evidence of polygamy in the socially monogamous Amazonian fish Arapaima gigas (Schinz, 1822 (Osteoglossiformes, Arapaimidae

    Directory of Open Access Journals (Sweden)

    Izeni Pires Farias

    2015-03-01

    Full Text Available Arapaima gigas is one of the largest freshwater fishes of the world. It is socially monogamous, forming pairs, constructing a nest and providing parental care. We performed a paternity analysis under three scenarios in captive, semi-natural and natural areas using 10 microsatellite markers. As a positive control, we analyzed three pairs and their offspring isolated individually in artificial breeding ponds (a priori very high probability of monogamy. We then analyzed two samples of offspring from large artificial ponds with multiple adults but only one reproductive pair (a priori high probability of monogamy, two samples from semi-natural breeding station with multiple adults but only one reproductive pair (a priori high probability of monogamy, and a sample from a natural lake with multiple adults, some potentially breeding (a priori medium probability of monogamy. Analysis of patterns of Mendelian heredity suggested an extra-pair contribution for all broods except the positive controls. Similarly, results based on multilocus analysis estimated at least two sib-groups per nest. These results reject monogamy as a system of breeding in Arapaima gigas. From a management perspective, this behavior may be exploited to maintain genetic diversity in captive and as well in wild populations of Arapaima gigas.

  16. Effects of cadmium on aneuploidy and hemocyte parameters in the Pacific oyster, Crassostrea gigas

    Energy Technology Data Exchange (ETDEWEB)

    Bouilly, Karine [IFREMER, Laboratoire de Genetique et Pathologie, La Tremblade 17390 (France); Gagnaire, Beatrice [IFREMER, Laboratoire de Genetique et Pathologie, La Tremblade 17390 (France); Bonnard, Marc [IFREMER, Laboratoire de Genetique et Pathologie, La Tremblade 17390 (France); Thomas-Guyon, Helene [Laboratoire de Biologie et Environnement Marins, FRE-CNRS, 2727, Universite de La Rochelle, 22 Avenue Michel Crepeau, La Rochelle 17042 (France); Renault, Tristan [IFREMER, Laboratoire de Genetique et Pathologie, La Tremblade 17390 (France); Miramand, Pierre [Laboratoire de Biologie et Environnement Marins, FRE-CNRS, 2727, Universite de La Rochelle, 22 Avenue Michel Crepeau, La Rochelle 17042 (France); Lapegue, Sylvie [IFREMER, Laboratoire de Genetique et Pathologie, La Tremblade 17390 (France)]. E-mail: slapegue@ifremer.fr

    2006-06-15

    Pacific oysters, Crassostrea gigas, are commonly reared in estuaries where they are exposed to anthropogenic pollution. Much research has been made on the toxicity of cadmium to aquatic organisms because the compound recurrently contaminates their environment. Our study examined the influence of cadmium on aneuploidy level (lowered chromosome number in a percentage of somatic cells) and hemocyte parameters in C. gigas at different stages of life. Adults and juveniles were exposed to two different concentrations of cadmium. The first concentration applied was equivalent to a peak value found in Marennes-Oleron bay (Charente-Maritime, France; 50 ng L{sup -1}) and the second was 10 times higher (500 ng L{sup -1}). Exposure to 50 ng L{sup -1} cadmium caused a significant decrease in the survival time of C. gigas, but exposure to 500 ng L{sup -1} surprisingly affected the survival time positively. Significant differences in aneuploidy level were observed between the cadmium treatments and the control in adults but not in juveniles or the offspring of the adult groups. The effects of cadmium on hemocyte parameters were analyzed by flow cytometry. Several hemocyte parameters increased significantly after 21 days of cadmium exposure and subsequently decreased. Phenoloxidase-like activity, evaluated by spectrophotometry, varied over the time of the experiment and increased after 66 days of contact with 500 ng L{sup -1} cadmium. Taken together, cadmium at environmentally relevant concentrations seems to have only moderate effects on aneuploidy and hemocyte parameters.

  17. The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

    KAUST Repository

    Bracken-Grissom, Heather

    2013-12-12

    Over 95% of all metazoan (animal) species comprise the invertebrates, but very few genomes from these organisms have been sequenced. We have, therefore, formed a Global Invertebrate Genomics Alliance (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site () has been launched to facilitate this collaborative venture.

  18. Repertoire and evolution of TNF superfamily in Crassostrea gigas: implications for expansion and diversification of this superfamily in Mollusca.

    Science.gov (United States)

    Gao, Dahai; Qiu, Limei; Gao, Qiang; Hou, Zhanhui; Wang, Lingling; Song, Linsheng

    2015-08-01

    Tumor necrosis factor superfamily (TNFSF) members represent a group of cytokines participating in diverse immunological, pathological and developmental pathways. However, compared with deuterostomia and cnidaia, the composition and evolution of TNF homologous in protostomia are still not well understood. In the present study, a total of 81 TNF superfamily (TNFSF) genes from 15 mollusk species, including 23 TNFSF genes from Crassostrea gigas, were surveyed by genome-wide bioinformatics analysis. The phylogenetic analysis showed that 14 out of 23 C. gigas TNFSF genes in five clades exhibited orthologous relationships with Pinctada fucata TNFSF genes. Moreover, there were 15 C. gigas TNFSF genes located in oyster-specific clusters, which were contributed by small-scaled tandem and/or segmental duplication events in oyster. By comparing the sequences of duplicated TNFSF pairs, exon loss and variant in exon/intron length were revealed as the major modes of divergence in gene structure. Most of the duplicated C. gigas TNFSF pairs were evolved under purifying selection with consistent tissue expression patterns, implying functional constraint shaped diversification. This study demonstrated the expansion and early divergence of TNF superfamily in C. gigas, which provides potential insight into revealing the evolution and function of this superfamily in mollusk.

  19. The Kinome of Pacific Oyster Crassostrea gigas, Its Expression during Development and in Response to Environmental Factors.

    Directory of Open Access Journals (Sweden)

    Yanouk Epelboin

    Full Text Available Oysters play an important role in estuarine and coastal marine habitats, where the majority of humans live. In these ecosystems, environmental degradation is substantial, and oysters must cope with highly dynamic and stressful environmental constraints during their lives in the intertidal zone. The availability of the genome sequence of the Pacific oyster Crassostrea gigas represents a unique opportunity for a comprehensive assessment of the signal transduction pathways that the species has developed to deal with this unique habitat. We performed an in silico analysis to identify, annotate and classify protein kinases in C. gigas, according to their kinase domain taxonomy classification, and compared with kinome already described in other animal species. The C. gigas kinome consists of 371 protein kinases, making it closely related to the sea urchin kinome, which has 353 protein kinases. The absence of gene redundancy in some groups of the C. gigas kinome may simplify functional studies of protein kinases. Through data mining of transcriptomes in C. gigas, we identified part of the kinome which may be central during development and may play a role in response to various environmental factors. Overall, this work contributes to a better understanding of key sensing pathways that may be central for adaptation to a highly dynamic marine environment.

  20. Underwater towed video

    NARCIS (Netherlands)

    Boman, Erik; Graaf, de M.; Nagelkerke, L.A.J.; Rijn, van J.; Meijer Zu Schlochtern, Melanie; Smaal, A.C.

    2016-01-01

    Queen conch (Lobatus gigas) populations living deeper than 20 m are rarely studied, because of the limitations of conventional survey methods using divers [i.e., belt transect (BT), towed-diver].Acrucial management goal for conch populations is to maintain adult densities at adequate levels to ensur

  1. Relationship between single nucleotide polymorphism of glycogen synthase gene of Pacific oyster Crassostrea gigas and its glycogen content

    Science.gov (United States)

    Liu, Siwei; Li, Qi; Yu, Hong; Kong, Lingfeng

    2017-02-01

    Glycogen is important not only for the energy supplementary of oysters, but also for human consumption. High glycogen content can improve the stress survival of oyster. A key enzyme in glycogenesis is glycogen synthase that is encoded by glycogen synthase gene GYS. In this study, the relationship between single nucleotide polymorphisms (SNPs) in coding regions of Crassostrea gigas GYS (Cg-GYS) and individual glycogen content was investigated with 321 individuals from five full-sib families. Single-strand conformation polymorphism (SSCP) procedure was combined with sequencing to confirm individual SNP genotypes of Cg-GYS. Least-square analysis of variance was performed to assess the relationship of variation in glycogen content of C. gigas with single SNP genotype and SNP haplotype. As a consequence, six SNPs were found in coding regions to be significantly associated with glycogen content ( P polymorphism on the glycogen content and provided molecular biological information for the selective breeding of good quality traits of C. gigas.

  2. Comparison of the antioxidant defense system in Crassostrea rhizophorae and Crassostrea gigas exposed to domestic sewage discharges.

    Science.gov (United States)

    Zanette, Juliano; Nunes, Fabrício Flores; Medeiros, Igor Dias; Siebert, Marília Nardelli; Mattos, Jacó Joaquim; Lüchmann, Karim Hahn; Rodrigues de Melo, Cláudio Manoel; Bainy, Afonso Celso Dias

    2008-07-01

    Oysters Crassostrea rhizophorae and Crassostrea gigas were kept for fourteen days at four sites in São José, SC, Brazil, chosen according to a sewage discharge contamination gradient. Enzymatic activities of CAT, GST, G6PDH and GR were evaluated in gills and digestive glands. Higher CAT activity was observed in tissues of C. rhizophorae in response to sewage contamination possibly indicating peroxisome proliferation induction. C. gigas showed elevated G6PDH activity in digestive gland, and GR in gills, after domestic sewage exposure. In conclusion, C. rhizophorae and C. gigas showed different biochemical responses after in situ exposure to domestic sewage. However, C. rhizophorae showed more significant changes in CAT suggesting that this organism could be a better monitor to this kind of effluent.

  3. Study on Tenderization of Dosidicus gigas Skin%秘鲁鱿鱼皮嫩化工艺的研究

    Institute of Scientific and Technical Information of China (English)

    胡艺; 邓尚贵

    2016-01-01

    对秘鲁鱿鱼皮进行嫩化处理,改善鱿鱼皮口感,提升其嫩度,为后续加工生产提供技术支持。以经过脱酸处理的秘鲁鱿鱼皮为原料,以剪切力为指标,通过单因素和响应面试验优选木瓜蛋白酶嫩化秘鲁鱿鱼皮的工艺条件。研究表明:适宜的嫩化条件为木瓜蛋白酶浓度0.1%、处理时间40 min、温度35℃,在此条件下,鱿鱼皮得到嫩化,其剪切力为1.79 N,可溶性蛋白含量(CSP)为49 mg/g。%Tenderize Dosidicus gigas skin to improve the texture,enhance the tenderness,and provide the technical support for subsequent processing.Take the deacidified Dosidicus gigas skin as raw material,shearing force as indexes,Dosidicus gigas skin tenderized by papain is studied,the suitable tenderization conditions of Dosidicus gigas skin are optimized through single factor and orthogonal experiments.The result indicates that the suitable technological conditions for tenderization of Dosidicus gigas skin are as follows:papain concentration of 0.1%,soaking time of 40 min and temperature of 35 ℃.Under these conditions,the shearing force of Dosidicus gigas skin is up to 1.79 N and the concentration of soluble protein (CSP)is 49 mg/g.

  4. The Hadal Amphipod Hirondellea gigas possessing a unique cellulase for digesting wooden debris buried in the deepest seafloor.

    Directory of Open Access Journals (Sweden)

    Hideki Kobayashi

    Full Text Available The Challenger Deep in the Mariana Trench is the deepest point in the ocean (10,994 m. Certain deep-sea animals can withstand the extreme pressure at this great depth. The amphipod Hirondellea gigas is a resident of the Challenger Deep. Amphipods are common inhabitants at great depths and serve as scavengers. However, there is relatively little information available regarding the physiology of H. gigas or this organism's ecological interactions in the hadopelagic zone. To understand the feeding behavior of this scavenger in the deepest oligotrophic hadal zone, we analyzed the digestive enzymes in whole-body extracts. We describe the detection of amylase, cellulase, mannanase, xylanase, and α-glycosidase activities that are capable of digesting plant-derived polysaccharides. Our identification of glucose, maltose, and cellobiose in the H. gigas extracts indicated that these enzymes function under great pressure in situ. In fact, the glucose content of H. gigas averaged 0.4% (w/dry-w. The purified H. gigas cellulase (HGcel converted cellulose to glucose and cellobiose at an exceptional molar ratio of 2:1 and efficiently produced glucose from dried wood, a natural cellulosic biomass, at 35 °C. The enzyme activity increased under a high hydrostatic pressure of 100 MPa at 2 °C, conditions equivalent to those found in the Challenger Deep. An analysis of the amino acid sequence of HGcel supported its classification as a family 31 glycosyl hydrolase. However, none of the enzymes of this family had previously been shown to possess cellulase activity. These results strongly suggested that H. gigas adapted to its extreme oligotrophic hadal oceanic environment by evolving digestive enzymes capable of digesting sunken wooden debris.

  5. ENSO variability during MIS 11 (424-374 ka) from Tridacna gigas at Huon Peninsula, Papua New Guinea

    Science.gov (United States)

    Ayling, Bridget F.; Chappell, John; Gagan, Michael K.; McCulloch, Malcolm T.

    2015-12-01

    Marine Isotope Stage 11 (MIS 11) from ∼424,000 to 374,000 yrs ago included one of the longest and warmest interglacials of the last 800,000 yrs, and is a potential analogue for the Holocene due to the similarity of Earth's orbital configuration at this time. The question of how the El Niño-Southern Oscillation (ENSO) responds to warmer background climates remains unanswered and is critical to understand how the ENSO system will evolve under the influence of anthropogenic warming. In this study, we present a 35 yr-long, high-resolution record of MIS 11 climate variability in the Western Pacific Warm Pool (WPWP) based on coupled measurements of skeletal Mg/Ca and δ18O in giant Tridacna gigas clams from Huon Peninsula, Papua New Guinea. The δ18O of modern T. gigas from Huon Peninsula faithfully records sea surface temperature, salinity/rainfall and regional ENSO variability. The geochemical integrity of the MIS 11 T. gigas for recording paleo-ENSO events was established through trace element screening, detailed petrography and SEM analysis. The fossil T. gigas δ18O record indicates that ENSO was operating during a 35-yr window in MIS 11, but with fewer events of shorter duration compared to those experienced during the last 100 yrs. The suppressed ENSO variability in the MIS 11 T. gigas record corresponds with a reduction in the amplitude of the average annual cycle in δ18O values. Distinctive changes in local insolation seasonality, and T. gigas δ18O, brought about by changes in Earth's orbit, provide an additional geochronological constraint on the timing of reef growth at Huon Peninsula to around 402 ka during the MIS 11.3 sub-stage (∼424-395 ka).

  6. INFECCIÓN ELEVADA DE Nilonema senticosum EN ADULTOS DE Arapaima gigas CULTIVADOS EN LA AMAZONÍA PERUANA

    OpenAIRE

    Mathews D., Patrick; Universidade Estadual de Campinas, Programa de Biologia Animal, Instituto de Biologia; Ismiño O., Rosa; Instituto de Investigaciones de la Amazonía Peruana, Programa de Ecosistemas Acuáticos, Centro de Investigaciones de Quistococha; Malheiros, Antonio Francisco; Instituto de Biologia, Universidade Estadual de Mato Grosso

    2014-01-01

    Se colectaron 10 especímenes de paiche Arapaima gigas de un centro de cultivo piscícola semiintensivo de Maynas, Loreto, Perú, entre junio y octubre de 2011, para investigar la presencia de parásitos. Se identificó una alta infección de nematodos de la especie Nilomena senticosum. Se encontró una prevalencia de 100% y una intensidad media de 80 parásitos por pez. Ten specimens of paiche Arapaima gigas from a semi-intensive fish farm located in the province of Maynas, Loreto, Peru were exam...

  7. The nuclear receptor gene family in the Pacific oyster, Crassostrea gigas, contains a novel subfamily group.

    Science.gov (United States)

    Vogeler, Susanne; Galloway, Tamara S; Lyons, Brett P; Bean, Tim P

    2014-05-15

    Nuclear receptors are a superfamily of transcription factors important in key biological, developmental and reproductive processes. Several of these receptors are ligand- activated and through their ability to bind endogenous and exogenous ligands, are potentially vulnerable to xenobiotics. Molluscs are key ecological species in defining aquatic and terrestrial habitats and are sensitive to xenobiotic compounds in the environment. However, the understanding of nuclear receptor presence, function and xenobiotic disruption in the phylum Mollusca is limited. Here, forty-three nuclear receptor sequences were mined from the genome of the Pacific oyster, Crassostrea gigas. They include members of NR0-NR5 subfamilies, notably lacking any NR6 members. Phylogenetic analyses of the oyster nuclear receptors have been conducted showing the presence of a large novel subfamily group not previously reported, which is named NR1P. Homologues to all previous identified nuclear receptors in other mollusc species have also been determined including the putative heterodimer partner retinoid X receptor, estrogen receptor and estrogen related receptor. C. gigas contains a highly diverse set of nuclear receptors including a novel NR1 group, which provides important information on presence and evolution of this transcription factor superfamily in invertebrates. The Pacific oyster possesses two members of NR3, the sex steroid hormone receptor analogues, of which there are 9 in humans. This provides increasing evidence that steroid ligand specific expansion of this family is deuterostome specific. This new knowledge on divergence and emergence of nuclear receptors in C. gigas provides essential information for studying regulation of molluscan gene expression and the potential effects of xenobiotics.

  8. Comprehensive Model of Jumbo Squid Dosidicus gigas Trophic Ecology in the Northern Humboldt Current System

    Science.gov (United States)

    Alegre, Ana; Ménard, Frédéric; Tafur, Ricardo; Espinoza, Pepe; Argüelles, Juan; Maehara, Víctor; Flores, Oswaldo; Simier, Monique; Bertrand, Arnaud

    2014-01-01

    The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters. PMID:24465788

  9. Exploitable Lipids and Fatty Acids in the Invasive Oyster Crassostrea gigas on the French Atlantic Coast

    Directory of Open Access Journals (Sweden)

    Flore Dagorn

    2016-05-01

    Full Text Available Economic exploitation is one means to offset the cost of controlling invasive species, such as the introduced Pacific oyster (Crassostrea gigas Thunberg on the French Atlantic coast. Total lipid and phospholipid (PL fatty acids (FAs and sterols were examined in an invasive population of C. gigas in Bourgneuf Bay, France, over four successive seasons, with a view to identify possible sources of exploitable substances. The total lipid level (% dry weight varied from 7.1% (winter to 8.6% (spring. Of this, PLs accounted for 28.1% (spring to 50.4% (winter. Phosphatidylcholine was the dominant PL throughout the year (up to 74% of total PLs in winter. Plasmalogens were identified throughout the year as a series of eleven dimethylacetals (DMAs with chain lengths between C16 and C20 (up to 14.5% of PL FAs + DMAs in winter. Thirty-seven FAs were identified in the PL FAs. Eicosapentaenoic acid (20:5n-3 EPA/7.53% to 14.5% and docosahexaenoic acid (22:6n-3 DHA/5.51% to 9.5% were the dominant polyunsaturated FAs in all seasons. Two non-methylene-interrupted dienoic (NMID FAs were identified in all seasons: 7,13-docosadienoic and 7,15-docosadienoic acids, the latter being present at relatively high levels (up to 9.6% in winter. Twenty free sterols were identified, including cholesterol at 29.9% of the sterol mixture and about 33% of phytosterols. C. gigas tissues thus contained exploitable lipids for health benefits or as a potential source of high-quality commercial lecithin.

  10. Comprehensive model of Jumbo squid Dosidicus gigas trophic ecology in the Northern Humboldt current system.

    Directory of Open Access Journals (Sweden)

    Ana Alegre

    Full Text Available The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?. Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters.

  11. Comprehensive model of Jumbo squid Dosidicus gigas trophic ecology in the Northern Humboldt current system.

    Science.gov (United States)

    Alegre, Ana; Ménard, Frédéric; Tafur, Ricardo; Espinoza, Pepe; Argüelles, Juan; Maehara, Víctor; Flores, Oswaldo; Simier, Monique; Bertrand, Arnaud

    2014-01-01

    The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters.

  12. Dynamique et enzymologie de la digestion chez l'huitre Crassostrea gigas

    OpenAIRE

    Boucaud, C; Lebesnerais, C; Lubet, P.; Lihrmann, I

    1983-01-01

    Chez Crassostrea gigas (Thunberg) des expériences d'alimentation contrôlée ont permis d'établir les modalités et la chronologie du transit alimentaire. Différentes activités enzymatiques en relation avec la digestion (glycosidases, esterases et peptidases) ont été localisées dans l'appareil digestif et ont permis de préciser les sites de digestion des glucides et des protides et les sites d'absorption. Un schéma explicatif des différentes étapes de la digestion est proposé.

  13. Parasitas em ostras de cultivo (Crassostrea rhizophorae e Crassostrea gigas) da Ponta de Sambaqui, SC

    OpenAIRE

    Sabry, Rachel Costa

    2003-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Aqüicultura. Ostras (Crassostrea rhizophorae e Crassostrea gigas) foram estudadas quanto à presença de parasitas. Os animais foram obtidos do cultivo localizado na Praia da Ponta do Sambaqui - Florianópolis/SC. De agosto de 2002 a maio de 2003, 30 indivíduos adultos de cada espécie foram coletados sazonalmente, totalizando 240 ostras. Os animais, provenientes de desova...

  14. Massive settlements of the Pacific oyster, Crassostrea gigas, in Scandinavia : Original paper

    DEFF Research Database (Denmark)

    Wrange, Anna-Lisa; Valero, Johanna; Harkestad, Lisbeth S.;

    2010-01-01

    The Pacific oyster (Crassostrea gigas) is an important aquaculture species world-wide. Due to its wide environmental tolerance and high growth rate, it has also become a successful invader in many areas, leading to major ecosystem changes. Low water temperatures were previously believed to restrict...... the establishment of Pacific oysters in Scandinavia. However, recent surveys reveal that the Pacific oyster is now established in many areas in Scandinavia. The biomass of oysters in the Danish Wadden Sea has increased dramatically between 2005 and 2007, large numbers were observed along the Swedish west coast from...

  15. Massive settlements of the Pacific oyster, Crassostrea gigas, in Scandinavia : Invasion note

    DEFF Research Database (Denmark)

    Wrange, Anna-Lisa; Valero, Johanna; Harkestad, Lisbeth S.;

    2010-01-01

    The Pacific oyster (Crassostrea gigas) is an important aquaculture species world-wide. Due to its wide environmental tolerance and high growth rate, it has also become a successful invader in many areas, leading to major ecosystem changes. Low water temperatures were previously believed to restrict...... the establishment of Pacific oysters in Scandinavia. However, recent surveys reveal that the Pacific oyster is now established in many areas in Scandinavia. The biomass of oysters in the Danish Wadden Sea has increased dramatically between 2005 and 2007, large numbers were observed along the Swedish west coast from...

  16. Invasive range expansion by the Humboldt squid, Dosidicus gigas, in the eastern North Pacific.

    Science.gov (United States)

    Zeidberg, Louis D; Robison, Bruce H

    2007-07-31

    A unique 16-year time series of deep video surveys in Monterey Bay reveals that the Humboldt squid, Dosidicus gigas, has substantially expanded its perennial geographic range in the eastern North Pacific by invading the waters off central California. This sustained range expansion coincides with changes in climate-linked oceanographic conditions and a reduction in competing top predators. It is also coincident with a decline in the abundance of Pacific hake, the most important commercial groundfish species off western North America. Recognizing the interactive effects of multiple changes in the environment is an issue of growing concern in ocean conservation and sustainability research.

  17. VALORES HEMATOLÓGICOS DEL PAICHE Arapaima gigas DE LA AMAZONÍA PERUANA

    OpenAIRE

    Serrano M., Enrique; Grupo SALUVET-UPCH, Facultad de Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima; Leguía P., Guillermo; Grupo SALUVET-UPCH, Facultad de Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima; Quispe H., Marco; Grupo SALUVET-UPCH, Facultad de Medicina Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima; Casas V., Gina; Grupo SALUVET-UPCH, Facultad de Veterinaria y Zootecnia, Universidad Peruana Cayetano Heredia, Lima

    2013-01-01

    Se determinaron los valores hematológicos de paiche, Arapaima gigas, en 120 muestras de sangre colectadas entre mayo de 2009 y enero de 2011. Los peces procedían de dos centros de cultivo piscícola de la provincia de Maynas, Loreto, Perú. Las muestras fueron clasificadas de acuerdo al grupo etario: 10-30, 31-180, 181-365 y >365 días. Se obtuvieron valores de recuento de glóbulos rojos y blancos, hematocrito y hemoglobina, así como el recuento diferencial de leucocitos. Los valores de glóbu...

  18. Consumer Preference and Sensory Properties of the Pacific Cupped Oyster (Crassostrea gigas) and the European Flat Oyster (Ostrea edulis)

    NARCIS (Netherlands)

    Houcke, van Jasper; Altintzoglou, Themistoklis; Stieger, Markus; Linssen, Jozef; Luten, Joop

    2016-01-01

    Experts in the oyster supply chain (farmers, retailers, and gourmet chefs) in The Netherlands have suggested that the European flat oyster (Ostrea edulis) has superior sensory qualities compared to the Pacific cupped oyster (Crassostrea gigas). However, scientific evidence is lacking. The aim of

  19. Development and distribution of the non-indigenous Pacific oyster (Crassostrea gigas) in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Fey-Hofstede, F.E.; Dankers, N.M.J.A.; Steenbergen, J.; Goudswaard, P.C.

    2010-01-01

    Pacific oysters (Crassostrea gigas) were first observed in the Dutch Wadden Sea near Texel in 1983. The population increased slowly in the beginning but grew exponentially from the mid-1990s onwards, although now some stabilisation seems to be occurring. They occur on a variety of substrates such as

  20. Consumer Preference and Sensory Properties of the Pacific Cupped Oyster (Crassostrea gigas) and the European Flat Oyster (Ostrea edulis)

    NARCIS (Netherlands)

    Houcke, van Jasper; Altintzoglou, Themistoklis; Stieger, Markus; Linssen, Jozef; Luten, Joop

    2015-01-01

    Experts in the oyster supply chain (farmers, retailers, and gourmet chefs) in The Netherlands have suggested that the European flat oyster (Ostrea edulis) has superior sensory qualities compared to the Pacific cupped oyster (Crassostrea gigas). However, scientific evidence is lacking. The aim of

  1. Changes in molecular genetic variation at ALFP loci associated with naturalization and domestication of the Pacific oyster (Crassostrea gigas)

    Science.gov (United States)

    The Pacific oyster (Crassostrea gigas) is an important commercial species in the US Pacific Northwest with a history of propagation first using wild-caught seed imported directly from the Miyagi region of northern Japan (1920s – 1970s) followed by an extended period of seed collection from a few sel...

  2. Genomic analysis of the Pacific oyster (Crassostrea gigas) reveals possible conservation of vertebrate sex determination in a mollusc.

    Science.gov (United States)

    Zhang, Na; Xu, Fei; Guo, Ximing

    2014-09-11

    Despite the prevalence of sex in animal kingdom, we have only limited understanding of how sex is determined and evolved in many taxa. The mollusc Pacific oyster Crassostrea gigas exhibits complex modes of sexual reproduction that consists of protandric dioecy, sex change, and occasional hermaphroditism. This complex system is controlled by both environmental and genetic factors through unknown molecular mechanisms. In this study, we investigated genes related to sex-determining pathways in C. gigas through transcriptome sequencing and analysis of female and male gonads. Our analysis identified or confirmed novel homologs in the oyster of key sex-determining genes (SoxH or Sry-like and FoxL2) that were thought to be vertebrate-specific. Their expression profile in C. gigas is consistent with conserved roles in sex determination, under a proposed model where a novel testis-determining CgSoxH may serve as a primary regulator, directly or indirectly interacting with a testis-promoting CgDsx and an ovary-promoting CgFoxL2. Our findings plus previous results suggest that key vertebrate sex-determining genes such as Sry and FoxL2 may not be inventions of vertebrates. The presence of such genes in a mollusc with expression profiles consistent with expected roles in sex determination suggest that sex determination may be deeply conserved in animals, despite rapid evolution of the regulatory pathways that in C. gigas may involve both genetic and environmental factors.

  3. Spillover but no spillback of two invasive parasitic copepods from invasive Pacific oysters (Crassostrea gigas) to native bivalve hosts

    NARCIS (Netherlands)

    Goedknegt, M.A.; Schuster, Anne Karin; Buschbaum, Christian; Gergs, René; Jung, A.S.; Luttikhuizen, Pieternella C.; Meer, van der Jaap; Troost, Karin; Wegner, K.M.; Thieltges, David W.

    2016-01-01

    Invasive species can cause indirect effects on native biota by modifying parasite-host interactions and disease occurrence in native species. This study investigated the role of the invasive Pacific oyster (Crassostrea gigas) in potential spillover (co-introduced parasites infect native hosts) an

  4. Episodic human activities and seasonal impacts on the Tachypleus gigas (Muller, 1785) population at Tanjung Selangor in Peninsular Malaysia

    Digital Repository Service at National Institute of Oceanography (India)

    Nelson, B.R.; Satyanarayan, B.; Zhong, J.M.H.; Shaharome, F.; Sukumaran, M.; Chatterji, A.

    the spawning activity of Tachypleus gigas (Muller, 1785) in relation to local environmental conditions, was carried out from Tanjung Selangor (Sites 1-3) on the east coast of Peninsular Malaysia Southwest (SW) monsoon (May-September) was found to be more...

  5. PENYERAPAN KARBON PADA BUDIDAYA RUMPUT LAUT Kappaphycus alvarezii dan Gracilaria gigas DI PERAIRAN TELUK GERUPUK, LOMBOK TENGAH, NUSA TENGGARA BARAT

    Directory of Open Access Journals (Sweden)

    Erlania Erlania

    2013-08-01

    Full Text Available Pengikatan karbon oleh algae fotoautotrofik berpotensi untuk mengurangi pelepasan CO2 ke atmosfer dan dapat membantu mencegah percepatan terjadinya pemanasan global. Penelitian ini bertujuan untuk menganalisis tingkat penyerapan karbon pada budidaya rumput laut Kappaphycus alvarezii dan Gracilaria gigas berdasarkan aktivitas fotosintesis serta variabel-variabel yang mempengaruhinya. Budidaya rumput laut dilakukan dengan metode long-line di perairan Teluk Gerupuk, Lombok Tengah pada satu unit long-line dengan luas area 1.250 m2. Selama penelitian, dilakukan pengujian terhadap sampel rumput laut dan sampel air laut dari lokasi budidaya yang diambil pada hari ke-0, 10, 20, 30, dan 45 pemeliharaan. Laju penyerapan karbon total berdasarkan biomassa panen pada G. gigas hampir 300% lebih tinggi dibandingkan K. alvarezii. Selain itu, laju pertumbuhan dan produksi karbohidrat pada G. gigas juga lebih tinggi, yang mengindikasikan laju fotosintesis yang lebih tinggi, dan didukung oleh indeks percabangan yang juga lebih tinggi. Potensi penyerapan karbon di perairan Teluk Gerupuk mencapai 6.656,51 ton C/tahun untuk budidaya K. Alvarezii dan 19.339,02 ton C/tahun untuk budidaya G. gigas. Penyerapan karbon berhubungan dengan kandungan pigmen dan laju pertumbuhan rumput laut, serta konsentrasi CO2 dan kecerahan perairan.

  6. Toxicity assessment of peptaibols and contaminated sediments on Crassostrea gigas embryos.

    Science.gov (United States)

    Poirier, Laurence; Quiniou, Françoise; Ruiz, Nicolas; Montagu, Monique; Amiard, Jean-Claude; Pouchus, Yves François

    2007-08-01

    Peptaibols are known membrane-modifying peptides that were recently detected in marine sediments and mussels collected from a shellfish farming area (Fier d'Ars, Atlantic coast, France). In this investigation, embryotoxicity bioassays with oysters (Crassostrea gigas) were performed to assess acute toxicity of alamethicin and different groups of peptaibols produced by a Trichoderma longibrachiatum strain isolated from marine environment. C. gigas embryos appeared very sensitive to all the metabolites examined with higher toxic effects for long-sequence peptides (EC50 ranging from 10 to 64 nM). D-shaped larvae with mantle abnormality were particularly noticed when peptaibol concentrations increased. Disturbances of embryogenesis were also observed following exposure to organic and aqueous extract of sediments from Fier d'Ars (EC50=42.4 and 6.6 g L(-1) dry weight, respectively). Although peptaibol concentrations measured in these sediments could explain only a part of the toxic effects observed, this study suggests that these mycotoxins can induce larval abnormalities in a population of exposed animals at environmentally realistic concentrations. Their detection in coastal areas devoted to bivalve culture should be taken into account.

  7. Genetically Determined Variation in Developmental Physiology of Bivalve Larvae (Crassostrea gigas).

    Science.gov (United States)

    Francis Pan, T-C; Applebaum, Scott L; Manahan, Donal T

    2015-01-01

    Understanding the complex interactions that regulate growth and form is a central question in developmental physiology. We used experimental crosses of pedigreed lines of the Pacific oyster, Crassostrea gigas, to investigate genetically determined variations in larval growth and nutrient transport. We show that (i) transport rates at 10 and 100 μM glycine scale differentially with size; (ii) size-specific maximum transport capacity (Jmax) is genetically determined; and (iii) Jmax serves as an early predictive index of subsequent growth rate. This relationship between genetically determined Jmax and growth suggests the potential use of transporter genes as biomarkers of growth potential. Analysis of the genome of C. gigas revealed 23 putative amino acid transporter genes. The complexity of gene families that underpin physiological traits has additional precedents in this species and others and warrants caution in the use of gene expression as a biomarker for physiological state. Direct in vivo measurements of physiological processes using species with defined genotypes are required to understand genetically determined variance of nutrient flux and other processes that regulate development and growth.

  8. Histological survey of Pacific oysters Crassostrea gigas (Thunberg) in Galicia (NW Spain).

    Science.gov (United States)

    Iglesias, David; Rodríguez, Luis; Gómez, Luis; Azevedo, Carlos; Montes, Jaime

    2012-11-01

    In Galicia, there is an increasingly interest among representatives of the oyster industry in the development of Pacific oyster Crassostrea gigas culture. Nevertheless severe mortalities and emerging health problems in this species have been recently reported in European farming areas. A histological survey was performed from 2004 to 2009 to assess health status in both cultured and wild Galician oysters. Different symbiotic organisms and conditions were detected, including viral gametocytic hypertrophy (VGH) which is reported here for first time in Spanish coast. VGH, prokaryote-like colonies and ciliates were observed in oyster tissues without causing host damage. A haplosporidian infection, copepods inducing lesions and a cellular proliferative disorder were detected in some samples causing moderate host damage; their low prevalence suggests these parasites are not a threat for C. gigas in Galicia. None of the parasites detected is OIE (Office International des Epizooties: the World Organization for Animal Health) notifiable. Although the current study did not identify any pathogens or diseases of concern, it provides important prevalence baseline data for future health and epidemiological assessments needed to better understanding the existing and emerging health problems in this species.

  9. Genetics of the Steller's Sea Cow (Hydrodamalis gigas): A Study of Ancient Bone Material

    Science.gov (United States)

    Crerar, Lorelei D.

    Georg Wilhelm Steller was born 100 years before Darwin in 1709 and he was part of a vast exploration fifty years before Lewis and Clark explored America. Steller was important to the study of marine mammals because he was the only naturalist to see and describe the great northern sea cow ( Hydrodamalis gigas). Knowledge of an extinct population can be used to aid the conservation of a current population. Extraction of DNA from this extinct animal was performed in order to determine the population structure of the Steller's sea cow. A test was also developed that can definitively state whether or not a random bone sample came from H. gigas. This test could be used by the Fish and Wildlife Service (FWS) and the National Oceanic and Atmospheric Administration (NOAA) to examine material distributed in the North Pacific to determine whether samples are legally traded extinct Steller's sea cow or illegally traded extant marine mammal species protected under the Marine Mammal Protection Act (MMPA).

  10. The Rehbinder effect in iron during giga-cycle fatigue loading

    Science.gov (United States)

    Bannikov, M. V.; Naimark, O. B.

    2015-10-01

    The influence of the adsorptive strength reduction effect (the Rehbinder effect) on the fatigue life of pure iron under the giga-cycle loading regime was investigated. Specimens were loaded by an ultrasonic testing machine with a frequency of 20 kHz in air and in contact with eutectic alloy of gallium with tin and indium. A significant (by several orders of magnitude) worsening of the life-time of iron in contact with a molten metal as compared with tests in air was established. The liquid metal penetrates into the material to a depth of 200 μm to the center of a fatigue crack. The mechanism of the fatigue crack initiation in the giga-cycle regime of loading in contact with a surfactant is differing: the crack is formed on the surface of the specimen rather than within it as is the case for air. Based on the electron and optical microscopy data for the fracture surface, it can be concluded that exactly the change in the crack initiation mechanism reduces the fatigue life of iron in contact with a liquid metal because the initiated crack propagates regardless of the surfactant.

  11. The Rehbinder effect in iron during giga-cycle fatigue loading

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, M. V., E-mail: mbannikov@icmm.ru; Naimark, O. B. [Institute of Continuous Media Mechanics UrB RAS, Perm, 614013 (Russian Federation)

    2015-10-27

    The influence of the adsorptive strength reduction effect (the Rehbinder effect) on the fatigue life of pure iron under the giga-cycle loading regime was investigated. Specimens were loaded by an ultrasonic testing machine with a frequency of 20 kHz in air and in contact with eutectic alloy of gallium with tin and indium. A significant (by several orders of magnitude) worsening of the life-time of iron in contact with a molten metal as compared with tests in air was established. The liquid metal penetrates into the material to a depth of 200 μm to the center of a fatigue crack. The mechanism of the fatigue crack initiation in the giga-cycle regime of loading in contact with a surfactant is differing: the crack is formed on the surface of the specimen rather than within it as is the case for air. Based on the electron and optical microscopy data for the fracture surface, it can be concluded that exactly the change in the crack initiation mechanism reduces the fatigue life of iron in contact with a liquid metal because the initiated crack propagates regardless of the surfactant.

  12. DNA methylation is crucial for the early development in the Oyster C. gigas.

    Science.gov (United States)

    Riviere, Guillaume; Wu, Guan-Chung; Fellous, Alexandre; Goux, Didier; Sourdaine, Pascal; Favrel, Pascal

    2013-12-01

    In vertebrates, epigenetic modifications influence gene transcription, and an appropriate DNA methylation is critical in development. Indeed, a precise temporal and spatial pattern of early gene expression is mandatory for a normal embryogenesis. However, such a regulation and its underlying mechanisms remain poorly understood in more distant organisms such as Lophotrochozoa. Thus, despite DNA in the oyster genome being methylated, the role of DNA methylation in development is unknown. To clarify this point, oyster genomic DNA was examined during early embryogenesis and found differentially methylated. Reverse transcriptase quantitative polymerase chain reaction indicated stage-specific levels of transcripts encoding DNA-methyltransferase (DNMT) and methyl-binding domain proteins. In addition, as highlighted by electronic microscopy and immunohistochemistry, the DNMT inhibitor 5-aza-cytidine induced alterations in the quantity and the localisation of methylated DNA and severe dose-dependent development alterations and was lethal after zygotic genome reinitiation. Furthermore, methyl-DNA-immunoprecipitation-quantitative polymerase chain reaction revealed that the transcription level of most of the homeobox gene orthologues examined, but not of the other early genes investigated, was inversely correlated with their specific DNA methylation. Altogether, our results demonstrate that DNA methylation influences gene expression in Crassostrea gigas and is critical for oyster development, possibly by specifically controlling the transcription level of homeobox orthologues. These findings provide evidence for the importance of epigenetic regulation of development in Lophotrochozoans and bring new insights into the early life of C. gigas, one of the most important aquaculture resources worldwide.

  13. Reversible stress softening of collagen based networks from the jumbo squid mantle (Dosidicus gigas).

    Science.gov (United States)

    Torres, F G; Troncoso, O P; Rivas, E R; Gomez, C G; Lopez, D

    2014-04-01

    Dosidicus gigas is the largest and one of the most abundant jumbo squids in the eastern Pacific Ocean. In this paper we have studied the muscle of the mantle of D. gigas (DGM). Morphological, thermal and rheological properties were assessed by means of atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, thermogravimetry and oscillatory rheometry. This study allowed us to assess the morphological and rheological properties of a collagen based network occurring in nature. The results showed that the DGM network displays a nonlinear effect called reversible stress softening (RSS) that has been previously described for other types of biological structures such as naturally occurring cellulose networks and actin networks. We propose that the RSS could play a key role on the way jumbo squids withstand hydrostatic pressure. The results presented here confirm that this phenomenon occurs in a wider number of materials than previously thought, all of them exhibiting different size scales as well as physical conformation.

  14. Reversible stress softening of collagen based networks from the jumbo squid mantle (Dosidicus gigas)

    Energy Technology Data Exchange (ETDEWEB)

    Torres, F.G., E-mail: fgtorres@pucp.edu.pe [Department of Mechanical Engineering, Catholic University of Peru, Lima 32 (Peru); Troncoso, O.P.; Rivas, E.R. [Department of Mechanical Engineering, Catholic University of Peru, Lima 32 (Peru); Gomez, C.G. [Departament de Química Física and Institut de Ciencia dels Materials, Universitat de València, Dr. Moliner 50, Burjassot, E-46100 Valencia (Spain); Lopez, D. [Instituto de Ciencia y Tecnología de Polímeros, C.S.I.C., Calle Juan de la Cierva 3, 28006 Madrid (Spain)

    2014-04-01

    Dosidicus gigas is the largest and one of the most abundant jumbo squids in the eastern Pacific Ocean. In this paper we have studied the muscle of the mantle of D. gigas (DGM). Morphological, thermal and rheological properties were assessed by means of atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, thermogravimetry and oscillatory rheometry. This study allowed us to assess the morphological and rheological properties of a collagen based network occurring in nature. The results showed that the DGM network displays a nonlinear effect called reversible stress softening (RSS) that has been previously described for other types of biological structures such as naturally occurring cellulose networks and actin networks. We propose that the RSS could play a key role on the way jumbo squids withstand hydrostatic pressure. The results presented here confirm that this phenomenon occurs in a wider number of materials than previously thought, all of them exhibiting different size scales as well as physical conformation. - Highlights: • We studied the structure property relationships of the jumbo squid mantle. • Rheological tests showed that such a mantle exhibits reversible stress softening (RSS). • RSS could also play a role on the way jumbo squids withstand hydrostatic pressure.

  15. Behavioral ecology of jumbo squid (Dosidicus gigas) in relation to oxygen minimum zones

    Science.gov (United States)

    Stewart, Julia S.; Field, John C.; Markaida, Unai; Gilly, William F.

    2013-10-01

    Habitat utilization, behavior and food habits of the jumbo or Humboldt squid, Dosidicus gigas, were compared between an area recently inhabited in the northern California Current System (CCS) and a historically established area of residence in the Gulf of California (GOC). Low dissolved oxygen concentrations at midwater depths define the oxygen minimum zone (OMZ), an important environmental feature in both areas. We analyzed vertical diving behavior and diet of D. gigas and hydrographic properties of the water column to ascertain the extent to which squid utilized the OMZ in the two areas. The upper boundary of the OMZ has been shoaling in recent decades in the CCS, and this phenomenon has been proposed to vertically compress the pelagic environment inhabited by aerobic predators. A shoaling OMZ will also bring mesopelagic communities into a depth range with more illumination during daytime, making these organisms more vulnerable to predation by visual predators (i.e. jumbo squid). Because the OMZ in the GOC is considerably shallower than in the CCS, our study provides insight into the behavioral plasticity of jumbo squid and how they may respond to a shoaling OMZ in the CCS. We propose that shoaling OMZs are likely to be favorable to jumbo squid and could be a key indirect factor behind the recent range expansion of this highly migratory predator.

  16. Distinct immune responses of juvenile and adult oysters (Crassostrea gigas) to viral and bacterial infections.

    Science.gov (United States)

    Green, Timothy J; Vergnes, Agnes; Montagnani, Caroline; de Lorgeril, Julien

    2016-01-01

    Since 2008, massive mortality events of Pacific oysters (Crassostrea gigas) have been reported worldwide and these disease events are often associated with Ostreid herpesvirus type 1 (OsHV-1). Epidemiological field studies have also reported oyster age and other pathogens of the Vibrio genus are contributing factors to this syndrome. We undertook a controlled laboratory experiment to simultaneously investigate survival and immunological response of juvenile and adult C. gigas at different time-points post-infection with OsHV-1, Vibrio tasmaniensis LGP32 and V. aestuarianus. Our data corroborates epidemiological studies that juveniles are more susceptible to OsHV-1, whereas adults are more susceptible to Vibrio. We measured the expression of 102 immune-genes by high-throughput RT-qPCR, which revealed oysters have different transcriptional responses to OsHV-1 and Vibrio. The transcriptional response in the early stages of OsHV-1 infection involved genes related to apoptosis and the interferon-pathway. Transcriptional response to Vibrio infection involved antimicrobial peptides, heat shock proteins and galectins. Interestingly, oysters in the later stages of OsHV-1 infection had a transcriptional response that resembled an antibacterial response, which is suggestive of the oyster's microbiome causing secondary infections (dysbiosis-driven pathology). This study provides molecular evidence that oysters can mount distinct immune response to viral and bacterial pathogens and these responses differ depending on the age of the host.

  17. Invitro Antidiabetic Activities of Agar, Agarosa, and Agaropectin from Gracilaria gigas Seaweed

    Directory of Open Access Journals (Sweden)

    Hardoko

    2015-11-01

    Full Text Available Some types of seaweed are reported to have antidiabet activity in vivo or in vitro, but the activity antidiabet fractions of polysaccharides from seaweed has not been widely reported. Gracilaria gigas is one type of red seaweed that can produce agar and it has two factions, namely agarose and agaropectin. The aim of this study was to obtain an agar extract, agarose fraction, agaropektin fraction of Gracilaria gigas and to determine the α-glucosidase inhibitory activity of extracts and the fractions. Extraction of agar that used an ethanol solution, and to fractionate agarose and agaropektin used dimetilsulfoxide solution. The results showed that the fraction of the agarose having lower sulfate content (0.28% compared with agar (5.91% and agaropektin (6.07%. Types of samples (agar, agarose, and agaropektin and sample doses significantly in inhibiting α-glucosidase enzyme activity. Agarose fraction has IC50 value against α-glucosidase lowest (96.86 ± 4.61 ppm, followed by the extract agar (116.63 ± 5.61 ppm, then the fraction agaropektin (158.34 ± 1.77 ppm.

  18. The electro-mechanical integration of the NA62 GigaTracker time tagging pixel detector

    Energy Technology Data Exchange (ETDEWEB)

    Morel, M; Kluge, A; Rinella, G Aglieri; Ceccucci, A; Daguin, J; Fiorini, M; Kaplon, J; Noy, M; Perktold, L; Petagna, P; Riedler, P [CERN, CH-1211 Geneva 23 (Switzerland); Carassiti, V [INFN Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Jarron, P; Marchetto, F [INFN Torino, Via P. Giurial 1, 10125 Torino (Italy); Mapelli, A; Nuessle, G, E-mail: michel.morel@cern.ch [Universite Catholique de Louvain, 1348 Louvain-la-Neuve (Belgium)

    2010-12-15

    The NA62 GigaTracker is a low mass time tagging hybrid pixel detector operating in a beam with a particle rate of 750 MHz. It consists of three stations with a sensor size of 60 x 27mm{sup 2} containing 18000 pixels, each 300 x 300{mu}m{sup 2}. The active area is connected to a matrix of 2 x 5 pixel ASICs, which time tag the arrival of the particles with a binning of 100 ps. The detector operates in vacuum at -20 to 0{sup 0}C and the material budget per station must be below 0.5% X{sub 0}. Due to the high radiation environment of 2 x 10{sup 14} 1 MeV neutron equivalent cm{sup -2}/yr{sup -1} it is planned to exchange the detector modules regularly. The low material budget, cooling requirements and the request for easy module access has driven the electro-mechanical integration of the GigaTracker, which is presented in this paper.

  19. Parasitic infections in juveniles of Arapaima gigas (Schinz, 1822) cultivated in the Peruvian Amazon.

    Science.gov (United States)

    Delgado, Patrick Mathews; Delgado, John Paul Mathews; Orbe, Rosa Ismińo

    2013-01-01

    The paiche, Arapaima gigas represents a socio-economically important species in the Peruvian Amazon, and actually an intensive production for human consumption has emerged during the last years. Therefore, more studies are required in fish farming development, especially concerning populations of parasites that affect fish production yields. Eighty specimens of paiche collected between September and October of 2011 from semi-intensive fish farm in Loreto State, Peru, were examined for their helminthic parasites. Five species were recorded parasitizing A. gigas: Dawestrema cycloancistrium and Dawestrema cycloancistrioides (Monogenea) on gills, Trichodina sp. (Protozoa) on the skin, Caballerotrema arapaimense (Trematoda) in stomachs and Philometra senticosa (Nematoda) in the swim bladder. Highest prevalence was recorded for D. cycloancistrium (100.0%), D. cycloancistrioides (83.0%) and Trichodina sp. (50.0%) and highest values of mean intensity and mean abundance were recorded for D. cycloancistrium (260) parasites per individual. The results confirm the necessity of constant monitoring of fish, seeking the diagnosis and timely control of infestations with parasites, in order to eradicate the mortality of the host that leads unviable the fish farming intended for human consumption.

  20. Mo-Cu metal cluster formation and binding in an orange protein isolated from Desulfovibrio gigas.

    Science.gov (United States)

    Carepo, Marta S P; Pauleta, Sofia R; Wedd, Anthony G; Moura, José J G; Moura, Isabel

    2014-06-01

    The orange protein (ORP) isolated from the sulfate-reducing bacterium Desulfovibrio gigas (11.8 kDa) contains a mixed-metal sulfide cluster of the type [S2MoS2CuS2MoS2](3-) noncovalently bound to the polypeptide chain. The D. gigas ORP was heterologously produced in Escherichia coli in the apo form. Different strategies were used to reconstitute the metal cluster into apo-ORP and obtain insights into the metal cluster synthesis: (1) incorporation of a synthesized inorganic analogue of the native metal cluster and (2) the in situ synthesis of the metal cluster on the addition to apo-ORP of copper chloride and tetrathiomolybdate or tetrathiotungstate. This latter procedure was successful, and the visible spectrum of the Mo-Cu reconstituted ORP is identical to the one reported for the native protein with absorption maxima at 340 and 480 nm. The (1)H-(15)N heteronuclear single quantum coherence spectra of the reconstituted ORP obtained by strategy 2, in contrast to strategy 1, exhibited large changes, which required sequential assignment in order to identify, by chemical shift differences, the residues affected by the incorporation of the cluster, which is stabilized inside the protein by both electrostatic and hydrophobic interactions.

  1. GigaPan Technology to Enhance In-Class and In-Field Learning in Community College Settings

    Science.gov (United States)

    Villalobos, J. I.; Bentley, C.

    2014-12-01

    Community college students account for over 40% of all undergraduates in the United States as well as the majority of minority and non-traditional students attending undergraduate courses. Implementing innovative, cost effective, and formative pedagogies to the diverse backgrounds of students that typically enroll at a community is often a challenge. Interactive pedagogies in geology pose a unique challenge considering that students gain the most long-term knowledge when topics covered in a course are exposed to them in outdoor settings where they are allowed to explore and make connections. The ability to expose students to real world examples is challenging to many community college faculty considering that that many; lack funds or means for transportation of students, do not have administrative support on such endeavors, teach evening or night classes, or have a high percentage of students who are physically limited or have obligations to work and family. A joint collaborative between El Paso Community College (EPCC) and Northern Virginia Community College (NOVA) has explored the usage of GigaPan technology to create multi-layered online material to minimize these issues faced by many community college faculty and students. The primary layer of the online material is GigaPans of local geological sites that highlight large-scale structures in the El Paso, Texas region that are commonly used in local field trips and lab book material. The second layer is of Macro-GigaPans of hand samples of key outcrops from the primarily GigaPans which facilitate student learning, exploration, and ability to make connections by exploring smaller scale features of the primary layer. A third layer of online material, GigaPans of thin sections of hand samples (from secondary layers), and curriculum based on the GigaPans was then created to assist students in evaluating proposed hypotheses on the primary layers' geological origin. GigaPan cirriculum was utilized in introductory

  2. Analysis and Evaluation of the Northern Gulf Coast Four Kinds of Conch Nutrients%北部湾沿海4种海螺的营养成分分析与品质评价

    Institute of Scientific and Technical Information of China (English)

    甘雄; 庾艳霞; 钟秋平; 鲁栋梁; 庞庭才

    2014-01-01

    为准确、全面地了解广西沿海常见海螺营养成分,本研究以4种海螺为研究对象,采用常温干燥法、550℃干法、索氏提取法、微量凯氏定氮法依次对4种海螺贝肉一般营养成分进行测定,并利用高效液相色谱法、利用气相色谱/气质联用法对螺肉的氨基酸和脂溶性成分进行测定。结果显示:节蝾螺、粒花冠小月螺、朝鲜粒花冠螺、锈凹螺肉(鲜样)中的水分、灰分、粗脂肪、粗蛋白的质量分数平均值分别为77.93%、2.59%、1.46%、25.76%。4种螺肉均测出17种氨基酸,含量最多的是谷氨酸,最少的是天冬氨酸。用GC-MS测得最多的是N-棕榈酸含量为18.73,最少的是9-十六碳烯酸含量为0.602。%For accurate and comprehensive understanding of Guangxi coastal conch common nutrients, four trumpet shells as the research object were studied. Under normal temperature drying method, 550 ℃ dry process, soxhlet extraction method, micro kjeldahl determination of 4 kinds of conch shell meat general nutrients were determined. Using high performance liquid chromatography ( HPLC ) method, with gas chromatography and gas chromatography - mass spectrometry, the usage of snail meat amino acids, fat-soluble components were determined. Results showed that the section Rong screw, settled crowns of grain of miscarriage, north Korea crown bolt, hollow screw rust meat ( fresh sample) in the moisture, ash content, crude fat, crude protein, the average mass fraction were 77. 93%, 2. 59%, 1. 46% and 2. 59%, respectively. Four kinds of snail meat all were measured with 17 kinds of amino acids, glutamic acid content was the most, and the least amount of aspartic acid. Measured by GC -MS, the most N -hexadecanoic acid content was 18. 73 , the minimum was 9~16 , and carbon olefine acid content was 0. 602 .

  3. Larval and post-larval stages of Pacific oyster (Crassostrea gigas are resistant to elevated CO2.

    Directory of Open Access Journals (Sweden)

    Ko W K Ginger

    Full Text Available The average pH of surface oceans has decreased by 0.1 unit since industrialization and is expected to decrease by another 0.3-0.7 units before the year 2300 due to the absorption of anthropogenic CO2. This human-caused pH change is posing serious threats and challenges to the Pacific oyster (Crassostrea gigas, especially to their larval stages. Our knowledge of the effect of reduced pH on C. gigas larvae presently relies presumptively on four short-term (<4 days survival and growth studies. Using multiple physiological measurements and life stages, the effects of long-term (40 days exposure to pH 8.1, 7.7 and 7.4 on larval shell growth, metamorphosis, respiration and filtration rates at the time of metamorphosis, along with the juvenile shell growth and structure of the C. gigas, were examined in this study. The mean survival and growth rates were not affected by pH. The metabolic, feeding and metamorphosis rates of pediveliger larvae were similar, between pH 8.1 and 7.7. The pediveligers at pH 7.4 showed reduced weight-specific metabolic and filtration rates, yet were able to sustain a more rapid post-settlement growth rate. However, no evidence suggested that low pH treatments resulted in alterations to the shell ultrastructures (SEM images or elemental compositions (i.e., Mg/Ca and Sr/Ca ratios. Thus, larval and post-larval forms of the C. gigas in the Yellow Sea are probably resistant to elevated CO2 and decreased near-future pH scenarios. The pre-adapted ability to resist a wide range of decreased pH may provide C. gigas with the necessary tolerance to withstand rapid pH changes over the coming century.

  4. Biases in determining the diet of jumbo squid Dosidicus gigas (D' Orbigny 1835) (Cephalopoda: Ommastrephidae) off southern-central Chile (34°S-40°S)

    Science.gov (United States)

    Ibáñez, Christian M.; Arancibia, Hugo; Cubillos, Luis A.

    2008-12-01

    The diet of jumbo squid ( Dosidicus gigas) off southern-central Chile is described to examine potential biases in the determination of their main prey. Specimens were collected from catches using different fishing gear (jigging, trawl and purse-seine), from July 2003 to January 2004, and from December 2005 to October 2006. The stomach contents were analyzed in terms of frequency of occurrence, number, and weight of prey items and the diet composition was analyzed using Detrended Correspondence Analysis. In the industrial purse-seine fleet for jack mackerel ( Trachurus murphyi), the dominant prey of D. gigas was T. murphyi. In the industrial mid-trawl fishery for Patagonian grenadier ( Macruronus magellanicus), the dominant species in the diet of D. gigas was M. magellanicus. Similarly, Chilean hake ( Merluccius gayi) was the main prey in the diet of D. gigas obtained in the industrial trawl fishery for Chilean hake; and, in both artisanal fisheries (purse-seine for small pelagics and jigging), small pelagic fish and D. gigas were the main prey in the stomach contents of D. gigas. Cannibalism in D. gigas varied between different fleets and probably is related to stress behavior during fishing. The Detrended Correspondence Analysis ordination showed that the main prey in the diet of D. gigas is associated with the target species of the respective fishery. Consequently, biases are associated with fishing gear, leading to an overestimate in the occurrence of the target species in the diet. We recommend analyzing samples from jigging taken at the same time and place where the trawl and purse-seine fleets are operating to avoid this problem, and the application of new tools like stable isotope, heavy metal, and fatty acid signature analyses.

  5. Calcium mobilisation following shell damage in the Pacific oyster, Crassostrea gigas.

    Science.gov (United States)

    Sillanpää, J K; Ramesh, K; Melzner, F; Sundh, H; Sundell, K

    2016-06-01

    Shell growth of oysters requires calcium uptake from the environment and transport to the area of shell formation. A shell regeneration assay in combination with radiolabelled calcium was used to investigate uptake and distribution of calcium to different tissues and hemolymph fractions in Pacific oysters, Crassostrea gigas (Bivalvia, Ostreoida). Oysters were notched at the shell margin and subsequently sampled for hemolymph and grading of shell regeneration during a two week experimental period. Half of the oysters were additionally exposed to (45)Ca and sampled for hemolymph and tissues. Total plasma calcium concentrations increased in notched oysters compared to controls on 1, 2 and 7days after notching. A decrease in plasma calcium levels was apparent on day 4, for both total and ionic calcium. The shell regeneration assay in the notched oysters resulted in a visible deposition of CaCO3 onto the regenerate from day 7 onwards. This was coinciding with an increased uptake of total calcium on days 11 and 14 as well as free, i.e. ionic and ligand-bound calcium, on day 14. At day 1, notching also increased calcium uptake into the mantle tissues, in areas above the notch and near the hinge. During the experiment, both the total hemocyte count and the number of granulocytes increased in notched compared to control oysters. The present study suggests that induced shell damage results in a dynamic regulation of the calcium uptake from the environment and the distribution of calcium within the body, starting directly after notching. Increases in both total calcium concentrations and uptake rates coincided with the visible depositions of CaCO3 on the regenerate shell. C. gigas was found to transport calcium mainly in the ionic form in the hemolymph, with only minor parts being bound to proteins or smaller ligands. Hemolymph measurement also revealed that C. gigas is able to regulate the extracellular concentrations of calcium and potassium. The changes in plasma calcium

  6. A single bio-energetics growth and reproduction model for the oyster Crassostrea gigas in six Atlantic ecosystems

    Science.gov (United States)

    Alunno-Bruscia, Marianne; Bourlès, Yves; Maurer, Danièle; Robert, Stéphane; Mazurié, Joseph; Gangnery, Aline; Goulletquer, Philippe; Pouvreau, Stéphane

    2011-11-01

    Many studies based on bioenergetics growth models have investigated the effects of environmental factors on oyster ( Crassostrea gigas) growth and physiology. However, most of these models are site-specific and cannot be applied to other culture sites without the re-estimation of parameters or re-formulation of some processes. We aimed to develop a generic growth model suitable for application in contrasting environments, with a constant set of parameters. We tested the oyster-DEB model (Bourlès et al. 2009) for the stimulation of C. gigas growth in different cohorts (spats and adults) at major shellfish culture sites in France, in several years: Arcachon (1993-1994); Marennes-Oléron (2007); Quiberon (1999, 2000, 2001); Brest Harbour (2008); Mont-Saint-Michel Bay (2003); Baie-des-Veys (2002). These different ecosystems offer a wide range of values for the two forcing variables of the model: water temperature (range: 6-24 °C) and phytoplankton concentration (annual average: 110-700 × 10 3 cell L -1). The validation data (dry flesh mass of C. gigas) were obtained from various growth surveys carried out by IFREMER. The oyster-DEB model simulated the oyster growth dynamics of both spat and adult stages of C. gigas accurately over time at the various culture sites. The model captures: i) the active spring growth; ii) the timing and amplitude of spawning events; and iii) the lean periods ( i.e. loss of dry flesh mass) in autumn and winter. The half-saturation coefficient Xk is the only model parameter that varied between sites and years. This environment-specific coefficient reflects variability in the food of the oysters: quantitative and qualitative effects of the inorganic material and of the phytoplankton species on the feeding response of C. gigas. With a single set of parameters (other than for Xk), this is thus the first bio-energetic growth model for C. gigas robust enough and of a sufficiently generic nature for the accurate simulation of oyster growth in

  7. Production of Generation-2 Mekong giant catfish (Pangasinodon gigas cultured with Spirulina sp.

    Directory of Open Access Journals (Sweden)

    Kriangsak Meng-umphan

    2008-11-01

    Full Text Available The purpose of this study is to evaluate the treatment of Spirulina-supplemented pellet feed to 5-year-old F1 groups of Mekong giant catfish (Pangasinodon gigas from the brood stock and intended for use as breeders. The effects on their growth and maturation when cultured in an earthen pond were observed. Results revealed that, compared to control, there was more gain in weight while the feed conversion ratio was lower. The number of red blood cells was also higher while that of white blood cells was lower, compared to control. Out of 18 treated fish (9 males and 9 females, 6 males and 2 females gave sperms and eggs while none from control group did. It was concluded that Spirulina supplemented in pellet feed can improve growth and maturation performance to the brood stock of Mekong giant catfish.

  8. GigaDevice发布GD32F101系列入门级产品

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    半导体供应商GigaDevice(北京兆易创新)为进一步扩大GD32系列微控制器产品的选择范围,推出14款基于ARM7月刊新闻责任编辑黄友庚Codex—M3内核的GD32F101系列入门级32位通用MCU。其先进的片上资源配置,出色的实时控制能力及优化的功耗设计可以满足工业现场、消费电子及便携设备对性能和价格的双重需求,从而更适合成本敏感型嵌入式应用。

  9. Evaluation of Giga-bit Ethernet Instrumentation for SalSA Electronics Readout (GEISER)

    CERN Document Server

    Varner, G S; Ridley, D; Zhu, C; Gorham, P; Varner, Gary S.; Murakami, Laine; Ridley, David; Zhu, Chaopin; Gorham, Peter

    2005-01-01

    An instrumentation prototype for acquiring high-speed transient data from an array of high bandwidth antennas is presented. Multi-kilometer cable runs complicate acquisition of such large bandwidth radio signals from an extensive antenna array. Solutions using analog fiber optic links are being explored, though are very expensive. We propose an inexpensive solution that allows for individual operation of each antenna element, operating at potentially high local self-trigger rates. Digitized data packets are transmitted to the surface via commercially available Giga-bit Ethernet hardware. Events are then reconstructed on a computer farm by sorting the received packets using standard networking gear, eliminating the need for custom, very high-speed trigger hardware. Such a system is completely scalable and leverages the hugh capital investment made by the telecommunications industry. Test results from a demonstration prototype are presented.

  10. Characterization of the mantle transcriptome in bivalves: Pecten maximus, Mytilus edulis and Crassostrea gigas.

    Science.gov (United States)

    Yarra, Tejaswi; Gharbi, Karim; Blaxter, Mark; Peck, Lloyd S; Clark, Melody S

    2016-06-01

    The calcareous shells secreted by bivalve molluscs display diverse and species specific structural compositions, which indicates possible divergent biomineralization processes. Thus, studying multiple mollusc species will provide a more comprehensive understanding of shell formation. Here, the transcriptomes of the mantle tissues responsible for shell deposition were characterized in three commercially relevant bivalve species. Using high-throughput sequencing and bioinformatics tools, de novo transcriptome assemblies of mantle tissues were generated for the mussel Mytilus edulis, the oyster Crassostrea gigas and the scallop Pecten maximus. These transcriptomes were annotated, and contigs with similarity to proteins known to have shell formation roles in other species were identified. Comparison of the shell formation specific proteins in the three bivalves indicates the possibility of species specific shell proteins.

  11. Characterisation of the NA62 GigaTracker end of column readout ASIC

    CERN Document Server

    Noy, M; Perktold, L; Rinella, G A; Riedler, P; Morel, M; Kluge, A; Kaplon, J; Martin, E; Jarron, P

    2011-01-01

    The architecture and characterisation of the End Of Column demonstrator readout ASIC for the NA62 GigaTracker hybrid pixel detector is presented. This ASIC serves as a proof of principle for a pixel chip with 1800 pixels which must perform time stamping to better than 200 ps (RMS), provide 300 mu m pitch position information and operate with a dead-time of 1\\% or less for 800 MHz-1 GHz beam rate. The demonstrator ASIC comprises a full test column with 45 pixels alongside other test structures. The timewalk correction mechanism employed is measurement of the time-over-threshold, coupled with an off-detector look-up table. The time to digital converter is a delay locked loop with 32 contributing delay cells fed with a 320 MHz to yield a nominal bin size of 97 ps. Recently, P-in-N sensors have been bump-bonded to the ASIC and characterisation of these assemblies has begun.

  12. Impact of an icy winter on the Pacific oyster (Crassostrea gigas Thunberg, 1793) populations in Scandinavia

    DEFF Research Database (Denmark)

    Strand, Åsa; Blanda, Elisa; Bodvin, Torjan;

    2012-01-01

    The Pacific oyster (Crassostrea gigas) is an invasive species that has dispersed into Scandinavia during the last few decades. The objective of this study was to evaluate the effects of extreme winter conditions on the mortality of the Pacific oyster in Scandinavia. The study was done by compiling...... mortality data from independent surveys in Denmark, Sweden and Norway. Winter mortality of the oysters increased with latitude, which can be explained by the colder climate experienced at higher latitudes. Mortality was also found to be affected by site specific conditions such as water depth...... at the sampling sites of oyster populations. Despite the severe winter conditions of 2009/2010 causing high mortality, the Pacific oyster still exists in large numbers in Scandinavia. The present investigation indicates that extreme winter conditions may result in a temporary reduction of the density...

  13. [Determination of proximal chemical composition of squid (dosidicus gigas) and development of gel products].

    Science.gov (United States)

    Abugoch, L; Guarda, A; Pérez, L M; Paredes, M P

    1999-06-01

    The good nutritional properties of meat from big squid (Dosidicus gigas) living on the Chilean coast, was determined through its proximal composition 70 cal/100 g fresh meat; 82.23 +/- 0.98% moisture; 15.32 +/- 0.93% protein; 1.31 +/- 0.12% ashes; 0.87 +/- 0.18% fat and 0.27% NNE (non-nitrogen extract). The big squid meat was used to develop a gel product which contained NaCl and TPP. It was necessary to use additives for gel preparation, such as carragenin or alginate or egg albumin, due to the lack of gelation properties of squid meat. Formulations containing egg albumin showed the highest gel force measured by penetration as compared to those that contained carragenin or alginate.

  14. The jumbo squid, Dosidicus gigas (Ommastrephidae), living in oxygen minimum zones II: Blood-oxygen binding

    Science.gov (United States)

    Seibel, Brad A.

    2013-10-01

    Dosidicus gigas is a large, metabolically active squid that migrates across a strong oxygen and temperature gradient in the Eastern Pacific. Here we analyze the oxygen-binding properties of the squid's respiratory protein (hemocyanin, Hc) that facilitate such activity. A high Hc-oxygen affinity, strong temperature dependence, and pronounced pH sensitivity (P50=0.009T2.03, pH 7.4; Bohr coefficient=ΔlogP50/ΔpH=-1.55+0.034T) of oxygen binding facilitate night-time foraging in the upper water column, and support suppressed oxygen demand in hypoxic waters at greater depths. Expanding hypoxia may act to alter the species habitable depth range. This analysis supports the contention that ocean acidification could limit oxygen carrying capacity in squids at warmer temperature leading to reduced activity levels or altered distribution.

  15. The TDCPix ASIC: Tracking for the NA62 GigaTracker

    CERN Document Server

    Noy, Matthew; Bonacini, Sandro; Kaplon, Jan; Kluge, Alexander; Morel, Michel; Perktold, Lukas; Poltorak, Karolina

    2014-01-01

    The TDCPix is a hybrid pixel detector readout ASIC designed for the NA62 GigaTracker detec- tor. The asynchronously operating pixel array consists of 1800 pixels, each 300x300 m m 2 . The requirements are a single-hit timing resolution better than 200 ps RMS and a read-out efficiency of 99% or better in the presence of a beam rate between 800 MHz and 1 GHz . The discrimina- tor time walk effect is compensated by time-over-threshold discriminators connected to an array of 360 dual TDC channels. The TDCpix processes up to 210 Mhits = s and provides the hit data without the need of a trigger in a continuous data stream via four 3.2 Gb = s serialisers. Under test since January 2014, the TDCPix chip is fully functional and shows excellent performance.

  16. Evaluation of Giga-bit Ethernet instrumentation for SalSA electronics readout

    Energy Technology Data Exchange (ETDEWEB)

    Varner, Gary S. [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States)]. E-mail: varner@phys.hawaii.edu; Murakami, Laine [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States); Ridley, David [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States); Zhu Chaopin [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States); Gorham, Peter [Instrumentation Development Laboratory, Department of Physics and Astronomy, University of Hawaii at Manoa (United States)

    2005-12-01

    An instrumentation prototype for acquiring high-speed transient data from an array of high bandwidth antennas is presented. Multi-kilometer cable runs complicate acquisition of such large bandwidth radio signals from an extensive antenna array. Solutions using analog fiber optic links are being explored though are very expensive. We propose an inexpensive solution that allows for individual operation of each antenna element, operating at potentially high local self-trigger rates. Digitized data packets are transmitted to the surface via commercially available Giga-bit Ethernet hardware. Events are then reconstructed on a computer farm by sorting the received packets using standard networking gear, eliminating the need for custom, very high speed trigger hardware. Such a system is completely scalable and leverages the enormous capital investment made by the telecommunications industry. Test results from a demonstration prototype are presented.

  17. GigaGauss solenoidal magnetic field inside bubbles excited in under-dense plasma

    Science.gov (United States)

    Lécz, Zs.; Konoplev, I. V.; Seryi, A.; Andreev, A.

    2016-10-01

    This paper proposes a novel and effective method for generating GigaGauss level, solenoidal quasi-static magnetic fields in under-dense plasma using screw-shaped high intensity laser pulses. This method produces large solenoidal fields that move with the driving laser pulse and are collinear with the accelerated electrons. This is in contrast with already known techniques which rely on interactions with over-dense or solid targets and generates radial or toroidal magnetic field localized at the stationary target. The solenoidal field is quasi-stationary in the reference frame of the laser pulse and can be used for guiding electron beams. It can also provide synchrotron radiation beam emittance cooling for laser-plasma accelerated electron and positron beams, opening up novel opportunities for designs of the light sources, free electron lasers, and high energy colliders based on laser plasma acceleration.

  18. Giga-pixel lensfree holographic microscopy and tomography using color image sensors.

    Directory of Open Access Journals (Sweden)

    Serhan O Isikman

    Full Text Available We report Giga-pixel lensfree holographic microscopy and tomography using color sensor-arrays such as CMOS imagers that exhibit Bayer color filter patterns. Without physically removing these color filters coated on the sensor chip, we synthesize pixel super-resolved lensfree holograms, which are then reconstructed to achieve ~350 nm lateral resolution, corresponding to a numerical aperture of ~0.8, across a field-of-view of ~20.5 mm(2. This constitutes a digital image with ~0.7 Billion effective pixels in both amplitude and phase channels (i.e., ~1.4 Giga-pixels total. Furthermore, by changing the illumination angle (e.g., ± 50° and scanning a partially-coherent light source across two orthogonal axes, super-resolved images of the same specimen from different viewing angles are created, which are then digitally combined to synthesize tomographic images of the object. Using this dual-axis lensfree tomographic imager running on a color sensor-chip, we achieve a 3D spatial resolution of ~0.35 µm × 0.35 µm × ~2 µm, in x, y and z, respectively, creating an effective voxel size of ~0.03 µm(3 across a sample volume of ~5 mm(3, which is equivalent to >150 Billion voxels. We demonstrate the proof-of-concept of this lensfree optical tomographic microscopy platform on a color CMOS image sensor by creating tomograms of micro-particles as well as a wild-type C. elegans nematode.

  19. Evolution and functional analysis of the Pif97 gene of the Pacific oyster Crassostrea gigas

    Institute of Scientific and Technical Information of China (English)

    Xiaotong WANG; Xiaorui SONG; Tong WANG; Qihui ZHU; Guoying MIAO; Yuanxin CHEN; Xiaodong FANG

    2013-01-01

    Mollusc shell matrix proteins (SMPs) are important functional components embedded in the shell and play a role in shell formation.A SMP (Pif177) was identified previously from the nacreous layer of the Japanese pearl oyster Pinctada fucata,and its cleavage products (named pfPif97 and pfPif80 proteins) were found to bind to the chitin framework and induce aragonite crystal formation and orient the c axis.In this study,a homologue ofpfPifl77 was cloned from the mantle of the Pacific oyster Crassostrea gigas,containing the homologue of pfPif97 only and not pfPif80.This finding hints at the large divergence in gene structure between the two species.This homologue (cgPif97) shares characteristics with pfPif97,and suggests that the biological functions of these two proteins may be similar.The expression pattern of cgPif97 in different tissues and development stages indicates that it may play an important role in shell formation of the adult oyster.The morphology of the inner shell surface was affected by injected siRNA of cgPif97 and the calcite laths of the shell became thinner and narrower when the siRNA dose increased,suggesting that the cgPif97 gene plays an important role in calcite shell formation in C.gigas.In conclusion,we found evidence that the Pif177 gene evolved very fast but still retains a similar function among species [Current Zoology 59 (1):109-115,2013].

  20. Reactive oxygen species in unstimulated hemocytes of the pacific oyster Crassostrea gigas: a mitochondrial involvement.

    Directory of Open Access Journals (Sweden)

    Ludovic Donaghy

    Full Text Available The Pacific oyster Crassostrea gigas is a sessile bivalve mollusc whose homeostasis relies, at least partially, upon cells circulating in hemolymph and referred to as hemocytes. Oyster's hemocytes have been reported to produce reactive oxygen species (ROS, even in absence of stimulation. Although ROS production in bivalve molluscs is mostly studied for its defence involvement, ROS may also be involved in cellular and tissue homeostasis. ROS sources have not yet been described in oyster hemocytes. The objective of the present work was to characterize the ROS sources in unstimulated hemocytes. We studied the effects of chemical inhibitors on the ROS production and the mitochondrial membrane potential (Δψ(m of hemocytes. First, this work confirmed the specificity of JC-10 probe to measure Δψ(m in oyster hemocytes, without being affected by ΔpH, as reported in mammalian cells. Second, results show that ROS production in unstimulated hemocytes does not originate from cytoplasmic NADPH-oxidase, nitric oxide synthase or myeloperoxidase, but from mitochondria. In contrast to mammalian cells, incubation of hemocytes with rotenone (complex I inhibitor had no effect on ROS production. Incubation with antimycin A (complex III inhibitor resulted in a dose-dependent ROS production decrease while an over-production is usually reported in vertebrates. In hemocytes of C. gigas, the production of ROS seems similarly dependent on both Δψ(m and ΔpH. These findings point out differences between mammalian models and bivalve cells, which warrant further investigation about the fine characterization of the electron transfer chain and the respective involvement of mitochondrial complexes in ROS production in hemocytes of bivalve molluscs.

  1. A biomineralization study of the Indo-Pacific giant clam Tridacna gigas

    Science.gov (United States)

    Gannon, M. E.; Pérez-Huerta, A.; Aharon, P.; Street, S. C.

    2017-06-01

    The giant clam, Tridacna gigas, is an important faunal component of reef ecosystems of the Indo-Pacific region. In addition to its ecological role, shells of this bivalve species are useful bioarchives for past climate and environmental reconstructions. However, the biomineralization processes involved in shell aragonite deposition are insufficiently understood. Here, we present a study of the shell microstructure of modern specimens from Palm Island, Great Barrier Reef (GBR), Australia, and Huon Peninsula, Papua New Guinea (PNG), using a combination of petrography, scanning electron microscopy, electron backscatter diffraction, Raman spectroscopy and stable carbon isotope ratios. Daily growth increments were recognizable in all specimens through ontogeny, and counting these growth lines provides a robust specimen age estimate. For the internal layers, paired increments of organized aragonitic needles and compact, oblong crystals were recognized in a specimen from PNG, whereas specimens from GBR were composed of shield-like crystals that were not definable at the microscale. The combination of nutrient availability, rainfall and solar irradiance are likely to be the most significant factors controlling shell growth and may explain the observed differences in microstructure. The external layer, identical in all specimens, was composed of dendritic microstructure that is significantly enriched in 13C compared to the internal layer, suggesting different metabolic controls on layer deposition. We propose that the mineralization of the internal and external layers is independent from each other and associated with the activity of specific mantles. Future studies using T. gigas shells as bioarchives should consider the microstructure as it reflects the environment in which the individual lived and the differences in mineralization pathways of internal and external layers.

  2. Evolution and functional analysis of the Pif97 gene of the Pacific oyster Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Xiaotong WANG, Xiaorui SONG, Tong WANG, Qihui ZHU, Guoying MIAO, Yuanxin CHEN, Xiaodong FANG, Huayong QUE, Li LI, Guofan ZHANG

    2013-02-01

    Full Text Available Mollusc shell matrix proteins (SMPs are important functional components embedded in the shell and play a role in shell formation. A SMP (Pif177 was identified previously from the nacreous layer of the Japanese pearl oyster Pinctada fucata, and its cleavage products (named pfPif97 and pfPif80 proteins were found to bind to the chitin framework and induce aragonite crystal formation and orient the c axis. In this study, a homologue of pfPif177 was cloned from the mantle of the Pacific oyster Crassostrea gigas, containing the homologue of pfPif97 only and not pfPif80. This finding hints at the large divergence in gene structure between the two species. This homologue (cgPif97 shares characteristics with pfPif97, and suggests that the biological functions of these two proteins may be similar. The expression pattern of cgPif97 in different tissues and development stages indicates that it may play an important role in shell formation of the adult oyster. The morphology of the inner shell surface was affected by injected siRNA of cgPif97 and the calcite laths of the shell became thinner and narrower when the siRNA dose increased, suggesting that the cgPif97 gene plays an important role in calcite shell formation in C. gigas. In conclusion, we found evidence that the Pif177 gene evolved very fast but still retains a similar function among species [Current Zoology 59 (1: 109–115, 2013].

  3. Oxygen isotope fluctuations in a modern North Sea oyster (Crassostrea gigas) compared with annual variations in seawater temperature

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz; Wiechert, Uwe; Korte, Christoph

    2010-01-01

    A total of 181 oxygen isotope values from sequential samples of the left shell of a modern Pacific Oyster (Crassostrea gigas) that lived on a sub-tidal oyster bank in the List Basin (North Sea, Germany) shows periodically varying values between + 1.3‰ and -2.5‰. In order to test whether these d18O...... fluctuations reflect seawater temperature changes, the isotope values of the shell were compared to actual seawater temperature variations from the region. C. gigas serves as an excellent proxy for temperature of palaeoseawater and the results show that the examined oyster precipitated its shell in d18O...... equilibrium with the ambient seawater. A cessation of the oyster shell calcification starts at water temperatures below 6 °C, at lower temperatures than previously thought for Crassostrea. For palaeoclimate investigations the termination of shell production is important because the lowest temperatures might...

  4. Metabolic physiology of the Humboldt squid, Dosidicus gigas: Implications for vertical migration in a pronounced oxygen minimum zone

    Science.gov (United States)

    Rosa, Rui; Seibel, Brad A.

    2010-07-01

    The Humboldt (or jumbo) squid, Dosidicus gigas, is an active predator endemic to the Eastern Pacific that undergoes diel vertical migrations into a pronounced oxygen minimum layer (OML). Here, we investigate the physiological mechanisms that facilitate these migrations and assess the associated costs and benefits. Exposure to hypoxic conditions equivalent to those found in the OML (∼10 μM O 2 at 10 °C) led to a significant reduction in the squid’s routine metabolic rate (RMR), from 8.9 to 1.6 μmol O 2 g -1 h -1 ( p gigas may repay any oxygen debt accumulated during the daytime. The dive to deeper water may minimize exposure to stressful surface temperatures when most prey have migrated to depth during the daytime. The physiological and ecological strategies demonstrated here may have facilitated the recent range expansion of this species into northern waters where expanding hypoxic zones prohibit competing top predators.

  5. Boccardia sp. (Polychaete: Spionidae presence in Crassostrea gigas [Thunberg, 1873] oysters reared in the mid coast of the Mexican Pacific

    Directory of Open Access Journals (Sweden)

    M. C. Gallo-García

    2005-01-01

    Full Text Available Desde 1997 se han realizado varios estudios acerca del cultivo del ostión del Pacífico, Crassostrea gigas, en la Laguna de Barra de Navidad (Jalisco, México. La presencia de ampollas de lodo en las valvas internas del ostión causadas por gusanos barrenadores de la concha, ha representado uno de los principales problemas en el cultivo. Boccardia sp. (Polychaete: Spionidae fue identificado de una muestra de 60 ostiones estudiados. A pesar del efecto de este gusano en el cultivo de ostión, se carece de información sobre su impacto en la industria ostrícola mexicana. El presente trabajo representa un primer reporte sobre la ocurrencia de este poliqueto en los cultivos de C. gigas que se localizan en la costa media del Pacífico mexicano

  6. Transport of Pirarucu Arapaima gigas juveniles in plastic bag Transporte de juvenis de pirarucu Arapaima gigas em sacos plásticos

    Directory of Open Access Journals (Sweden)

    Levy de Carvalho Gomes

    2003-12-01

    Full Text Available This study examined the stress response of pirarucu juveniles in a closed system transport. Pirarucu (Arapaima gigas is a native Amazonian fish species from the Osteoglossidae family and an obligated air breather. A short duration transport trial (6h was undertaken comparing closed polyethylene bags filled with atmospheric air (Air group and bags filled with pure oxygen (Oxi group. Dissolved oxygen was the only water parameter that presented a difference between fish groups, and was saturated in the oxi group as expected. There was no mortality in either group after transport. Fish feeding was observed 36 h after transport for all fish, and normal feeding consumption was observed at 72 h. In both groups physiological responses were similar. Cortisol did not show any significant alteration during the sampled period. Unlike most fish species, cortisol values were unaltered in both groups during sampling, while glucose presented a significant change up to 12 h after transport. The results showed that pirarucu transport in plastic bags could be made with either atmospheric air or pure oxygen, since physiological response to stress, water quality and feeding behavior after 36 h were similar in both groups.Este estudo examinou as respostas de estresse de juvenis de pirarucu transportados em sistema fechado. Pirarucu (Arapaima gigas é um peixe nativo da bacia Amazônica, da família Osteoglossidae que possui respiração aérea obrigatória. Foi realizado um transporte de curta duração (6 h em sacos de polietileno inflados com ar atmosférico (grupo ar ou com oxigênio puro (grupo oxi. O oxigênio dissolvido foi o único parâmetro de qualidade da água que apresentou diferença estatística entre os grupos, e como esperado, o oxigênio estava supersaturado para o grupo oxi. Não houve mortalidade após o transporte em ambos os grupos. Os peixes se alimentaram 36 h após o transporte e apresentaram um consumo de ração habitual após 72 h. As

  7. Evidence for accumulation of Synechococcus elongatus (Cyanobacteria: Cyanophyceae) in the tissues of the oyster Crassostrea gigas (Mollusca: Bivalvia).

    Science.gov (United States)

    Avila-Poveda, Omar Hernando; Torres-Ariño, Alejandra; Girón-Cruz, Diego Ademir; Cuevas-Aguirre, Angel

    2014-10-01

    Cyanobacteria appear to have direct relations with mollusks in several aspects. This is the first time, distinguishing Gram-negative cyanoprokaryotic Synechococcus elongatus as bright yellow-gold autofluorescence by Lillie's and Hiss' staining methods on paraffin-embedded tissues of Crassostrea gigas. Three diets: cyanoprokaryotes, cyanoprokaryotes with microalgae, and only microalgae were evaluated. Cyanoprokaryotes were intact, densely bundled, and immersed in the cytosol of the digestive gland, connective tissue, mantle, and gonad of C. gigas, revealing an accumulation systemic without tissue damage observed by histology. Unexpectedly, cyanoprokaryotes were slightly most accumulated with microalgae diet by each of the tissues of the C. gigas than with any other diets. Cyanoprokaryotes tend to be in mean slightly higher in the digestive gland than in any other tissues respectively for each diet, although these values are closely similar to connective tissue. A possible order of exposure of the oyster tissues to accumulation of cyanoprokaryotes was digestive gland, connective tissue, mantle, and gonad. Thereby, the digestive gland could be the major target tissue for the accumulation. Our observations provide a valuable insight regarding the ability of cyanoprokaryotes to penetrate, spread, and remain inside the oyster tissues, suggesting for S. elongatus: (1) a pre-accumulation in oyster tissues from the natural environment, (2) a phagocytosis and/or endocytosis process rather than ingestion and extracellular digestion, (3) an apparent cellular division in the cytosol of oyster tissues, (4) an apparent inter-tissue movement, and (5) a possible endosymbiosis between C. gigas and S. elongatus. Hereby, it is possible that S. elongatus have a well-developed host-endobiont relationship with oysters, and thereby support future work toward a description of the escape and spreading mechanisms of S. elongatus inside the tissues of mollusks, and put forward questions as

  8. Fishery biology of the jumbo flying squid Dosidicus gigas off the Exclusive Economic Zone of Chilean waters

    Directory of Open Access Journals (Sweden)

    Bilin Liu

    2010-11-01

    Full Text Available The jumbo flying squid Dosidicus gigas is widely distributed in the eastern Pacific Ocean and supports an important fishery. Although many studies have been carried out on the biology of this species, limited biological information is available in the waters outside the Exclusive Economic Zone of Chile (EEZ (20°S-41°S and 74°30’W-84°W. Three surveys were conducted in this area by the Chinese squid jigging vessels during the period from April 2006 to May 2008. The majority of the catch in the survey was from the two areas defined by 37°30’-41°S and 78°30’-80°W and by 25°-30°S and 76°-77°30’W. The sex ratio (M: F of the catch was 1: 2.48. The mean mantle length (ML was 376 mm for males with a range of 257-721 mm and 388.7 mm for females with a range of 236-837 mm. Two distinguished size classes, medium- and large-sized groups, were identified in this study with the medium-sized group (350-450 mm ML consisting of 89% of the total catch. The sizes at first sexual maturity were 638 mm ML for females and 565 mm ML for males. This study suggests that all the individuals examined were hatched from March 2007 to February 2008, indicating that D. gigas might spawn all year around with a peak spawning time from November 2007 to January 2008. Most of the stomachs analyzed had food remains. The preys included three major groups: fish (mainly lanternfish, cephalopods and crustaceans, but D. gigas was the dominant species in the stomach contents, showing strong evidence of cannibalism. The information obtained from this study improves our understanding of the fishery biology of D. gigas off Chile.

  9. Association among growth, food consumption-related traits and amylase gene polymorphism in the Pacific oyster Crassostrea gigas

    OpenAIRE

    Huvet, Arnaud; Jeffroy, F; Fabioux, C.; Daniel, Jean-Yves; Quillien, Virgile; Van Wormhoudt, A; Moal, Jeanne; Samain, Jean-francois; Boudry, Pierre; Pouvreau, Stephane

    2008-01-01

    To examine further a previously reported association between amylase gene polymorphism and growth in the Pacific oyster Crassostrea gigas, ecophysiological parameters and biochemical and molecular expression levels of alpha-amylase were studied in Pacific oysters of different amylase genotypes. Genotypes that previously displayed significantly different growth were found to be significantly different for ingestion and absorption efficiency. These estimated parameters, used in a dynamic energy...

  10. Aceptabilidad de empanizados enriquecidos con harina de pota (Dosidicus gigas), huevo de codorniz (Coturnix coturnix) y pimiento amarillo (Capsicum annuum)

    OpenAIRE

    Guerrero Hurtado, Emma Del Rosario; Palomino Pezzutti, Ricardo Ramiro; Tamariz Grados, Nelly Norma; Cajaleón Asencios, Delia Haydee; Dextre Mendoza, Rodolfo Willian; Carreño Mundo, Humberto

    2015-01-01

    Objetivo: Evaluar la aceptabilidad de empanizados enriquecidos con harina de pota (Dosidicus gigas), huevo de codorniz (Coturnix coturnix) y pimiento amarillo (Capsicum annuum). Métodos: Optimizar una formulación de alimento listo para el consumo humano, conforme a requisitos: NTP NDECOPI: Harina de trigo, NTP 205. 027. 1996, NTP-CODEX STAN 166:2014 -Barritas, Porciones y Filetes de pescado empanizados o rebozados congelados. Resultados: El aroma, color y textura de los empanizados formula...

  11. Characterization of a defensin from the oyster Crassostrea gigas - Recombinant production, folding, solution structure, antimicrobial activities, and gene expression

    OpenAIRE

    Gueguen, Yannick; Herpin, Amaury; Aumelas, André; Garnier, Julien; Fievet, Julie; Escoubas, Jean-Michel; Bulet, Philippe; Gonzalez, Marcelo; Lelong, Christophe; Favrel, Pascal; Bachere, Evelyne

    2006-01-01

    In invertebrates, defensins were found in arthropods and in the mussels. Here, we report for the first time the identification and characterization of a defensin (Cg-Def) from an oyster. Cg-def mRNA was isolated from Crassostrea gigas mantle using an expressed sequence tag approach. To gain insight into potential roles of Cg-Def in oyster immunity, we produced the recombinant peptide in Escherichia coli, characterized its antimicrobial activities, determined its solution structure by NMR spec...

  12. Reproductive success and fry production of the paiche or pirarucu, Arapaima gigas (Schinz), in the region of Iquitos, Peru

    OpenAIRE

    Nunez Rodriguez, Jesus; Chu-Koo, F.; Berland, Magali; Arevalo, L.; Ribeyro, O.; Duponchelle, Fabrice; Renno, Jean-François

    2011-01-01

    Arapaima gigas (paiche) is the largest scaled fish species living in the Amazon basin. Its biology is both fascinating and misunderstood. In a context of overfishing, hence reduced natural populations, aquaculture of a fish with such interesting characteristics (large size, high growth rate, no intramuscular spines) is an important issue. The development of farming production would also reduce the fishing pressure on natural populations and allow re-stocking programmes in certain areas. To de...

  13. Genetic variation assessed with microsatellites in mass selection lines of the Pacific oyster ( Crassostrea gigas) in China

    Science.gov (United States)

    Wang, Xubo; Li, Qi; Yu, Hong; Kong, Lingfeng

    2016-12-01

    Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding programs in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a relatively large number of broodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided important information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.

  14. The jumbo squid, Dosidicus gigas (Ommastrephidae), living in oxygen minimum zones I: Oxygen consumption rates and critical oxygen partial pressures

    Science.gov (United States)

    Trueblood, Lloyd A.; Seibel, Brad A.

    2013-10-01

    Dosidicus gigas is a large, metabolically active, epipelagic squid known to undertake diel vertical migrations across a large temperature and oxygen gradient in the Eastern Pacific. Hypoxia is known to cause metabolic suppression in D. gigas. However, the precise oxygen level at which metabolic suppression sets in is unknown. Here we describe a novel ship-board swim tunnel respirometer that was used to measure metabolic rates and critical oxygen partial pressures (Pcrit) for adult squids (2-7kg). Metabolic rate measurements were validated by comparison to the activity of the Krebs cycle enzyme, citrate synthase, in mantle muscle tissue (2-17kg). We recorded a mean routine metabolic rate of 5.91μmolg-1h-1 at 10°C and 12.62μmolg-1h-1 at 20°C. A temperature coefficient, Q10, of 2.1 was calculated. D. gigas had Pcrits of 1.6 and 3.8kPa at 10 and 20°C, respectively. Oxygen consumption rate (MO2) varied with body mass (M) according to MO2=11.57M-0.12±0.03 at 10°C. Citrate synthase activity varied with body mass according to Y=9.32M-0.19±0.02.

  15. Roles of HynAB and Ech, the only two hydrogenases found in the model sulfate reducer Desulfovibrio gigas.

    Science.gov (United States)

    Morais-Silva, Fabio O; Santos, Catia I; Rodrigues, Rute; Pereira, Inês A C; Rodrigues-Pousada, Claudina

    2013-10-01

    Sulfate-reducing bacteria are characterized by a high number of hydrogenases, which have been proposed to contribute to the overall energy metabolism of the cell, but exactly in what role is not clear. Desulfovibrio spp. can produce or consume H2 when growing on organic or inorganic substrates in the presence or absence of sulfate. Because of the presence of only two hydrogenases encoded in its genome, the periplasmic HynAB and cytoplasmic Ech hydrogenases, Desulfovibrio gigas is an excellent model organism for investigation of the specific function of each of these enzymes during growth. In this study, we analyzed the physiological response to the deletion of the genes that encode the two hydrogenases in D. gigas, through the generation of ΔechBC and ΔhynAB single mutant strains. These strains were analyzed for the ability to grow on different substrates, such as lactate, pyruvate, and hydrogen, under respiratory and fermentative conditions. Furthermore, the expression of both hydrogenase genes in the three strains studied was assessed through quantitative reverse transcription-PCR. The results demonstrate that neither hydrogenase is essential for growth on lactate-sulfate, indicating that hydrogen cycling is not indispensable. In addition, the periplasmic HynAB enzyme has a bifunctional activity and is required for growth on H2 or by fermentation of pyruvate. Therefore, this enzyme seems to play a dominant role in D. gigas hydrogen metabolism.

  16. Hábitos alimentarios de Dosidicus gigas (D' Orbigny, 1835 (Cephalopoda: Teuthoidea frente a la costa centro-sur de Chile Feeding habits of Dosidicus gigas (D'Orbigny, 1835 (Cephalopoda: Teuthoidea in the central-south coast off Chile

    Directory of Open Access Journals (Sweden)

    PATRICIO ULLOA

    2006-12-01

    Full Text Available Se estudiaron los hábitos alimentarios del calamar rojo Dosidicus gigas (D'Orbigny, 1835 frente a la costa de Chile centro-sur, durante el invierno del año 2005. Se examinaron un total de 52 estómagos, en todos los cuales había contenido alimentario. Los ejemplares provenían de pescas efectuadas por la flota arrastrera industrial que opera entre 36°39' S y 38°55'S sobre la merluza común Merluccius gayi (Guichenot 1848 y a una profundidad media de 290 m sobre la plataforma continental. Para la descripción del espectro trófico, alimento principal y el establecimiento de las eventuales diferencias sexuales u ontogenéticas en la frecuencia de aparición de los ítemes presa, se utilizaron los métodos numérico, gravimétrico, de frecuencia de ocurrencia, índice de importancia relativa (IIR e índice de similitud porcentual (ISP. No se observaron diferencias sexuales ni ontogenéticas en la frecuencia de aparición de los ítemes presa. Los resultados muestran que D. gigas es un depredador oportunista, principalmente ictiófago, y secundariamente malacófago (incluye el canibalismo y carcinófago. Se discuten los eventuales motivos e implicancias de tal conductaA study on the feeding habits of the jumbo squid Dosidicus gigas (D'Orbigny, 1835 was carried out during the winter season 2005, in waters of the Chilean central and southern Pacific. A total of 52 jumbo squid stomachs from the fishing of the continental slope were collected and examined, in the Eighth and Ninth regions, between 36°40' S and 38°55'S, at an average depth of 290 m. To determine the trophic spectrum, the feeding preferences and the importance of the sex and ontogenetic condition in the diet, the numeric, gravimetric, frequency of occurrence methods, and the index of relative importance and dietary similarity were utilized. The frequency of the prey did not vary with relation to the sex and ontogenetic conditions, and was besides a hight trophic similarity in such

  17. Treatment of shrimp effluent by sedimentation and oyster filtration using Crassostrea gigas and C. rhizophorae

    Directory of Open Access Journals (Sweden)

    Roberto Ramos

    2009-06-01

    Full Text Available Efficiency in removing particulate matter from Litopenaeus vannamei shrimp culture effluent was assessed in laboratory scale employing sedimentation and oysters Crassostrea gigas and C. rhizophorae filtration processes. Cylindroconical tanks (100 L were used in duplicate for sedimentation and 50-L in triplicate for oyster filtration. Fifteen oysters of each species weighing 76-80 g were stocked in each of the filtration treatment experimental units (biomass of 1065 - 1174 g oyster per unit. The control treatment was a tank similar to those used in the filtration treatment but with empty oyster shells. Hydraulic retention time of the effluent was of 6 hours in each treatment. First, effluent went through sedimentation, and then the supernatant went through the filtration tanks. Temperature, pH, dissolved oxygen, salinity, turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5 were evaluated. During sedimentation and filtration, temperature, pH, salinity and dissolved oxygen concentration remained stable. Sedimentation removed 18, 5.6, 27.5, 45.40 and 23.2% of turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5, respectively. Chlorophyll a and BOD5 after sedimentation presented significant difference (PEm escala laboratorial, foi comparada a eficiência de remoção de material particulado presente no efluente do cultivo de camarão branco Litopenaeus vannamei, mediante o processo de sedimentação e filtração com ostra nativa Crassostrea rhizophorae e com ostra do pacifico Crassostrea gigas. No processo de sedimentação foram empregados tanques cilindro cônico, em duplicata, de cor preta com 100 L de capacidade total. Para o processo de filtração foram empregados tanques cilindro cônicos, em triplicata, de cor preta de 50 L de volume total. No tratamento de filtração cada unidade experimental foi estocada com 15 indivíduos de ostras de ambas as espécies, com peso médio entre 76

  18. Connected components labeling for giga-cell multi-categorical rasters

    Science.gov (United States)

    Netzel, Pawel; Stepinski, Tomasz F.

    2013-09-01

    Labeling of connected components in an image or a raster of non-imagery data is a fundamental operation in fields of pattern recognition and machine intelligence. The bulk of effort devoted to designing efficient connected components labeling (CCL) algorithms concentrated on the domain of binary images where labeling is required for a computer to recognize objects. In contrast, in the Geographical Information Science (GIS) a CCL algorithm is mostly applied to multi-categorical rasters in order to either convert a raster to a shapefile, or for statistical characterization of individual clumps. Recently, it has become necessary to label connected components in very large, giga-cell size, multi-categorical rasters but performance of existing CCL algorithms lacks sufficient speed to accomplish such task. In this paper we present a modification to the popular two-scan CCL algorithm that enables labeling of giga-cell size, multi-categorical rasters. Our approach is to apply a divide-and-conquer technique coupled with parallel processing to a standard two-scan algorithm. For specificity, we have developed a variant of a standard CCL algorithm implemented as r.clump in GRASS GIS. We have established optimal values of data blocks (stemming from the divide-and-conquer technique) and optimal number of computational threads (stemming from parallel processing) for a new algorithm called r.clump3p. The performance of the new algorithm was tested on a series of rasters up to 160 Mcells in size; for largest size test raster a speed up over the original algorithm is 74 times. Finally, we have applied the new algorithm to the National Land Cover Dataset 2006 raster with 1.6×1010 cells. Labeling this raster took 39 h using two-processors, 16 cores computer and resulted in 221,718,501 clumps. Estimated speed up over the original algorithm is 450 times. The r.clump3p works within the GRASS environment and is available in the public domain.

  19. Groundwater-ocean interaction and its effects on coastal ecological processes - are there groundwater-dependant ecosystems in the coastal zone?

    Science.gov (United States)

    Stieglitz, T. C.

    2013-05-01

    Hydrological land-ocean connectivity is an important driver of coastal ecosystems. Rivers are obvious and visible pathways for terrestrial runoff. The critical role of surface water discharge from rivers to coastal ecosystems has been well documented. Hidden from view, 'downstream' effects of coastal (supra-tidal, intertidal and submarine) groundwater discharge are far less well understood. Whilst hydrological and geochemical processes associated with coastal groundwater discharge have received an increasing amount of scientific attention over the past decade or so, the effects of groundwater flow on productivity, composition, diversity and functioning of coastal ecosystems along the world's shorelines have received little attention to date. Coastal groundwater discharge includes both terrestrial (fresh) groundwater fluxes and the recirculation of seawater through sediments, analogous to hyporheic flow in rivers. I will present an overview over relevant coastal hydrological processes, and will illustrate their ecological effects on examples from diverse tropical coastal ecosystems, e.g. (1) perennial fresh groundwater discharge from coastal sand dune systems permitting growth of freshwater-dependent vegetation in the intertidal zone of the Great Barrier Reef (Australia), (2) recirculation of seawater through mangrove forest floors directly affecting tree health and providing a pathway for carbon export from these ecosystems, (3) the local hydrology of groundwater-fed coastal inlets on Mexico's Yucatan peninsula affecting the movement behaviour of and habitat use by the queen conch Strombus gigas, an economically important species in the Caribbean region. These examples for hydrological-ecological coupling in the coastal zone invite the question if we should not consider these coastal ecosystems to be groundwater-dependent, in analogy to groundwater-dependency in freshwater aquatic systems.

  20. Preferential Bivalent Formation in Tetraploid Male of Pacific Oyster Crassostrea gigas Thunberg

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhengrui; WANG Xinglian; ZHANG Quanqi; Standish Allen Jr

    2014-01-01

    Artificially induced tetraploid Pacific oyster, Crassostrea gigas Thunberg, produces more aneuploid gametes than nor-mal diploid one, although they showed a comparable fecundity to diploidy. The meiotic chromosome configuration of 3 tetraploid and 1 tetraploid/triploid mosaic males were analyzed through direct chromosome observation. A majority of metaphase I spermato-cytes contained both bivalents and quadrivalents. The chromosome configuration of these males was characterized by preferential formation of bivalents to quadrivalents. Bivalents appeared in all spermatocytes and consisted of 86%of all chromosome aggregates. In comparison, quadrivalents occurred in 91%spermatocytes and consisted of only 12.6%of all chromosome aggregates. The mean bivalent frequency per spermatocyte varied between 14.4 and 17.2; while that of quadrivalents varied between 2.2 and 2.7. Most quadrivalents were tandemly chained (58%) or circled (39%). The total number of chromosome aggregates per spermatocyte ranged from 13 to 20 with an average of 17.6;while 18 (16 bivalents and 2 quadrivalents) was the most frequent. Univalents and trivalents appeared in very low frequency. Aneuploid (hypotetraploid) spermatocytes were observed in a low frequency. The chromosome con-figuration of in the mosaic individual was similar to that of tetraploid individuals. The percentage of triploid spermatocytes (2%) of the mosaic individual was significantly lower (χ2=30, P<0.01) than that of triploid cells (46%) in its somatic tissue.

  1. Digestion of Ceramide 2-Aminoethylphosphonate, a Sphingolipid from the Jumbo Flying Squid Dosidicus gigas, in Mice.

    Science.gov (United States)

    Tomonaga, Nami; Manabe, Yuki; Sugawara, Tatsuya

    2017-04-01

    Ceramide 2-aminoethylphosphonate (CAEP), a sphingophosphonolipid containing a carbon-phosphorus bond, is frequently found in marine organisms and has a unique triene type of sphingoid base in its structure. CAEP has not been evaluated as a food ingredient, although it is generally contained in Mollusca organisms such as squids and shellfish, which are consumed worldwide. In this study, we aimed to elucidate the effects of CAEP as a food component by evaluating the digestion of CAEP extracted from the skin of the jumbo flying squid Dosidicus gigas. Our results revealed that dietary CAEP was digested to free sphingoid bases via ceramides by the mouse small intestinal mucosa. At pH 7.2, CAEP was hydrolyzed more rapidly than the major mammalian sphingolipid sphingomyelin; however, the hydrolysis of CAEP was similar to that of sphingomyelin at pH 9.0. Thus, the digestion of CAEP may be catalyzed by alkaline spingomyelinase and other enzymes. Our findings provide important insights into the digestion of the dietary sphingophosphonolipid CAEP in marine foods.

  2. A comparative study of piscine defense: The scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula.

    Science.gov (United States)

    Sherman, Vincent R; Quan, Haocheng; Yang, Wen; Ritchie, Robert O; Meyers, Marc A

    2017-09-01

    We compare the characteristics of the armored scales of three large fish, namely the Arapaima gigas (arapaima), Latimeria chalumnae (coelacanth), and Atractosteus spatula (alligator gar), with specific focus on their unique structure-mechanical property relationships and their specialized ability to provide protection from predatory pressures, with the ultimate goal of providing bio-inspiration for manmade materials. The arapaima has flexible and overlapping cycloid scales which consist of a tough Bouligand-type arrangement of collagen layers in the base and a hard external mineralized surface, protecting it from piranha, a predator with extremely sharp teeth. The coelacanth has overlapping elasmoid scales that consist of adjacent Bouligand-type pairs, forming a double-twisted Bouligand-type structure. The collagenous layers are connected by collagen fibril struts which significantly contribute to the energy dissipation, so that the scales have the capability to defend from predators such as sharks. The alligator gar has inflexible articulating ganoid scales made of a hard and highly mineralized enamel-like outer surface and a tough dentine-like bony base, which resist powerful bite forces of self-predation and attack by alligators. The structural differences between the three scales correspond with the attack of their predators, and show refined mechanisms which may be imitated and incorporated into superior bioinspired and biomimetic designs that are specialized to resist specific modes of predation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Omega-3 fatty acids incorporated colloidal systems for the delivery of Angelica gigas Nakai extract.

    Science.gov (United States)

    Lee, Jeong-Jun; Park, Ju-Hwan; Lee, Jae-Young; Jeong, Jae Young; Lee, Song Yi; Yoon, In-Soo; Kang, Wie-Soo; Kim, Dae-Duk; Cho, Hyun-Jong

    2016-04-01

    Omega-3 (ω-3) fish oil-enriched colloidal systems were developed for the oral delivery of Angelica gigas Nakai (AGN) extract (ext). By constructing a pseudo-ternary phase diagram, the composition of oil-in-water (o/w) microemulsion (ME) systems based on ω-3 (oil), Labrasol (surfactant), and water was determined. AGN ext was dissolved into the ME system and d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) was added to the ME formulation in order to enhance the mucosal absorption of the pharmacologically active ingredients in the AGN ext. The droplet size of AGN-loaded MEs was 205-277 nm and their morphology was spherical. The release of major components of AGN, decursin (D) and decursinol angelate (DA), from ME formulations in pH 1.2 and 6.8 buffers was significantly greater (PAGN suspension group. The pharmacokinetic properties of AGN-loaded MEs in rats were evaluated by measuring decursinol (DOH) concentrations in plasma after oral administration. TPGS-included ME (F2) resulted in significantly greater (PAGN ext+TPGS, and AGN in suspension. Severe toxicity of F1 and F2 on the intestinal epithelium was not observed by histological staining. The colloidal carriers described herein are promising delivery systems for oral administration of AGN ext.

  4. Pathogenicity testing of shellfish hatchery bacterial isolates on Pacific oyster Crassostrea gigas larvae.

    Science.gov (United States)

    Estes, Robyn M; Friedman, Carolyn S; Elston, Ralph A; Herwig, Russell P

    2004-03-10

    Bacterial diseases are a major cause of larval mortality in shellfish hatcheries. Even with proper sanitation measures, bacterial pathogens cannot be eliminated in all cases. The pathogenicity of bacteria isolated from Pacific Northwest shellfish hatcheries to Pacific oyster Crassostrea gigas larvae was investigated. We found 3 highly pathogenic strains and 1 mildly pathogenic strain among 33 isolates tested. These strains appear to be members of the genus Vibrio. Although there have been many studies of bivalve bacterial pathogens, a standard method to assess bacterial pathogenicity in bivalve larvae is needed. Thus, we developed 2 methods using either 15 ml conical tubes or tissue culture plates that were employed for rapidly screening bacterial strains for pathogenicity to Pacific oyster larvae. The tissue culture plates worked well for screening both mildly pathogenic strains and LD50 (lethal dose) assays. This method allowed for non-intrusive and non-destructive observation of the oyster larvae with a dissecting microscope. The LD50 for the 3 highly pathogenic strains ranged between 1.6 and 3.6 x 10(4) colony forming units (CFU) ml(-1) after 24 h and between 3.2 x 102 and 1.9 x 10(3) CFU ml(-1) after 48 h.

  5. Effects of subchronic exposure to glyphosate in juvenile oysters (Crassostrea gigas): From molecular to individual levels.

    Science.gov (United States)

    Mottier, Antoine; Séguin, Alexis; Devos, Alexandre; Pabic, Charles Le; Voiseux, Claire; Lebel, Jean Marc; Serpentini, Antoine; Fievet, Bruno; Costil, Katherine

    2015-06-30

    Glyphosate-based herbicides are extensively used and can be measured in aquatic ecosystems, including coastal waters. The effect of glyphosate on non-target organisms is an issue of worldwide concern. The aim of this study was to investigate the effects of subchronic exposure to glyphosate in juvenile oysters, Crassostrea gigas. Yearling oysters were exposed to three concentrations of glyphosate (0.1, 1 and 100μgL(-1)) for 56days. Various endpoints were studied, from the individual level (e.g., gametogenesis and tissue alterations) to the molecular level (mRNA quantification), including biochemical endpoints such as glutathione-S-transferase (GST) and catalase activities and malondialdehyde content. No mortality and growth occurred during the experiment, and individual biomarkers revealed only slight effects. The levels of gene expression significantly increased in oysters exposed to the highest glyphosate concentration (GST and metallothioneins) or to all concentrations (multi-xenobiotic resistance). These results suggested an activation of defence mechanisms at the molecular level.

  6. Response to Selection for Fast Growth in the Second Generation of Pacific Oyster (Crassostrea gigas)

    Institute of Scientific and Technical Information of China (English)

    WANG Qingzhi; LI Qi; KONG Lingfeng; YU Ruihai

    2012-01-01

    Mass selection for fast growth was conducted in three Pacific oyster(Crassostrea gigas)stocks from China,Japan and Korea using previously established lines(CS1,JS 1,and KS 1).To determine whether continuous progress can be achieved by selection for growth,the progeny of three second-generation Pacific oyster lines was selected for shell height and evaluated via a 400-day farming experiment.When harvested at the end of the experiment,the selected crosses of CS2,JS2,and KS2 lines grew by 9.2%,10.2% and 9.6% larger than the control crosses,respectively.During grow-out stage,the genetic gain of three selected lines was (10.2 ± 1.4)%,(10.4 ± 0.3)%,and(8.4 ± 1.6)%,respectively;and the corresponding realized heritability was 0.457 ± 0.143,0.312 ±0.071 and 0.332 ± 0.009,respectively.These results indicated that the selection for fast growth achieved steady progress in the second generation of oyster.Our work provides supportive evidence for the continuity of the Pacific oyster selective breeding program.

  7. Epigenetic features in the oyster Crassostrea gigas suggestive of functionally relevant promoter DNA methylation in invertebrates.

    Directory of Open Access Journals (Sweden)

    Guillaume eRiviere

    2014-04-01

    Full Text Available DNA methylation is evolutionarily conserved. Vertebrates exhibit high, widespread DNA methylation whereas invertebrate genomes are less methylated, predominantly within gene bodies. DNA methylation in invertebrates is associated with transcription level, alternative splicing and genome evolution, but functional outcomes of DNA methylation remain poorly described in lophotrochozoans. Recent genome-wide approaches improve understanding in distant taxa such as molluscs, where the phylogenetic position and life traits of Crassostrea gigas make this bivalve an ideal model to study the physiological and evolutionary implications of DNA methylation. We review the literature about DNA methylation in invertebrates and focus on DNA methylation features in the oyster. Indeed, though our MeDIP-seq results confirm predominant intragenic methylation, the profiles depend on the oyster’s developmental and reproductive stage. We discuss the perspective that oyster DNA methylation could be biased toward the 5’-end of some genes, depending on physiological status, suggesting important functional outcomes of putative promoter methylation from cell differentiation during early development to sustained adaptation of the species to the environment.

  8. Effects of ocean acidification on immune responses of the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Wang, Qing; Cao, Ruiwen; Ning, Xuanxuan; You, Liping; Mu, Changkao; Wang, Chunlin; Wei, Lei; Cong, Ming; Wu, Huifeng; Zhao, Jianmin

    2016-02-01

    Ocean acidification (OA), caused by anthropogenic CO2emissions, has been proposed as one of the greatest threats in marine ecosystems. A growing body of evidence shows that ocean acidification can impact development, survival, growth and physiology of marine calcifiers. In this study, the immune responses of the Pacific oyster Crassostrea gigas were investigated after elevated pCO2 exposure for 28 days. The results demonstrated that OA caused an increase of apoptosis and reactive oxygen species (ROS) production in hemocytes. Moreover, elevated pCO2 had an inhibitory effect on some antioxidant enzyme activities and decreased the GSH level in digestive gland. However, the mRNA expression pattern of several immune related genes varied depending on the exposure time and tissues. After exposure to pCO2 at ∼2000 ppm for 28 days, the mRNA expressions of almost all tested genes were significantly suppressed in gills and stimulated in hemocytes. Above all, our study demonstrated that elevated pCO2 have a significant impact on the immune systems of the Pacific oyster, which may constitute as a potential threat to increased susceptibility of bivalves to diseases.

  9. Role of dissolved and particulate cadmium in the accumulation of cadmium in cultured oysters (Crassostrea gigas)

    Energy Technology Data Exchange (ETDEWEB)

    Lekhi, Priyanka [Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)], E-mail: anka.lekhi@ubc.ca; Cassis, D. [Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Pearce, C.M. [Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7 (Canada); Ebell, N. [Odyssey Shellfish Ltd., Nanoose Bay, BC V0R 9G0 (Canada); Maldonado, M.T. [Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Orians, K.J. [Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)

    2008-04-15

    Pacific oysters (Crassostrea gigas) collected on the coast of British Columbia, Canada have occasionally shown cadmium (Cd) concentrations at or above 2 {mu}g g{sup -1} (wet weight), which has resulted in the loss of some international markets. This study investigated the source and transfer of Cd to oysters by focusing on the role of dissolved and particulate Cd in seawater. Parameters monitored for 1 year at two oyster farm sites on Vancouver Island included: oyster tissue mass and shell length, Cd in oysters, dissolved Cd, particulate Cd, temperature and salinity. Results show that dissolved Cd was the main source of Cd to the oysters and that Cd was mainly concentrated in the gut tissues. A seasonal trend was observed in Cd in oysters, in which levels were lowest during periods of higher temperatures. Results also indicate that the local oceanographic inputs and sediment diagenesis directly affect dissolved Cd and thereby influence the Cd levels in oysters. Particulate matter was not found to be a source of Cd in oysters, and was actually negatively correlated. This was likely due to the uptake of dissolved Cd by phytoplankton and the effect of phytoplankton on oyster tissue mass.

  10. Characterisation of the NA62 GigaTracker end of column readout ASIC

    Science.gov (United States)

    Noy, M.; Aglieri Rinella, G.; Fiorini, M.; Jarron, P.; Kaplon, J.; Kluge, A.; Martin, E.; Morel, M.; Perktold, L.; Riedler, P.

    2011-01-01

    The architecture and characterisation of the End Of Column demonstrator readout ASIC for the NA62 GigaTracker hybrid pixel detector is presented. This ASIC serves as a proof of principle for a pixel chip with 1800 pixels which must perform time stamping to better than 200 ps (RMS), provide 300 μm pitch position information and operate with a dead-time of 1% or less for 800 MHz-1 GHz beam rate. The demonstrator ASIC comprises a full test column with 45 pixels alongside other test structures. The timewalk correction mechanism employed is measurement of the time-over-threshold, coupled with an off-detector look-up table. The time to digital converter is a delay locked loop with 32 contributing delay cells fed with a 320 MHz to yield a nominal bin size of 97 ps. Recently, P-in-N sensors have been bump-bonded to the ASIC and characterisation of these assemblies has begun.

  11. Identification and quantification of hepatotoxic pyrrolizidine alkaloids in the Ethiopian medicinal plant Solanecio gigas (Asteraceae).

    Science.gov (United States)

    Asres, K; Sporer, F; Wink, M

    2007-09-01

    The pyrrolizidine alkaloid content of Solanecio gigas (Vatke) C. Jeffrey (Asteraceae), an Ethiopian medicinal plant widely used for the treatment of colic, diarrhea, gout, otitis media, typhoid fever, and noted for its wound dressing and antiabortifacient activities was studied. The flower and leaf extracts contained 0.19% and 0.14% alkaloids (dry weight), respectively. GLC-MS analysis indicated that all the alkaloids in the flowers are pyrrolizidine alkaloids (PAs), whereas the leaves contain other type of alkaloids with PAs occurring in low concentrations. Roughly, 80% and 90% of the total PAs in the flowers and the leaves, respectively, were shown to occur as N-oxides. Eighteen alkaloids were detected in the flower extract with the retronecine type twelve-membered macrocyclic diesters integerrimine, senecionine and usaramine comprising 82% of the total PA content. Analysis of the PA profile of the leaves indicated that it has a simpler pattern than the one observed for the flowers. Only five PAs were detected in the leaves with integerrimine making up about 50% of the total PAs. Quantification of the PA content by GLC showed that the flowers and leaves contain 3321.21 and 84.84 microg per 10 g of dried plant material, respectively. These results indicate that users of this herb are at high risk of poisoning since the most toxic twelve membered macrocyclics of the retronecine type are the dominant PAs in the plant.

  12. The simple neuroendocrine-immune regulatory network in oyster Crassostrea gigas mediates complex functions

    Science.gov (United States)

    Liu, Zhaoqun; Wang, Lingling; Zhou, Zhi; Sun, Ying; Wang, Mengqiang; Wang, Hao; Hou, Zhanhui; Gao, Dahai; Gao, Qiang; Song, Linsheng

    2016-05-01

    The neuroendocrine-immune (NEI) regulatory network is a complex system, which plays an indispensable role in the immunity of the host. In the present study, the bioinformatical analysis of the transcriptomic data from oyster Crassostrea gigas and further biological validation revealed that oyster TNF (CgTNF-1 CGI_10018786) could activate the transcription factors NF-κB and HSF (heat shock transcription factor) through MAPK signaling pathway, and then regulate apoptosis, redox reaction, neuro-regulation and protein folding in oyster haemocytes. The activated immune cells then released neurotransmitters including acetylcholine, norepinephrine and [Met5]-enkephalin to regulate the immune response by arising the expression of three TNF (CGI_10005109, CGI_10005110 and CGI_10006440) and translocating two NF-κB (Cgp65, CGI_10018142 and CgRel, CGI_10021567) between the cytoplasm and nuclei of haemocytes. Neurotransmitters exhibited the immunomodulation effects by influencing apoptosis and phagocytosis of oyster haemocytes. Acetylcholine and norepinephrine could down-regulate the immune response, while [Met5]-enkephalin up-regulate the immune response. These results suggested that the simple neuroendocrine-immune regulatory network in oyster might be activated by oyster TNF and then regulate the immune response by virtue of neurotransmitters, cytokines and transcription factors.

  13. Linkage disequilibrium in wild and cultured populations of Pacific oyster ( Crassostrea gigas)

    Science.gov (United States)

    Guo, Xiang; Li, Qi; Kong, Lingfeng; Yu, Hong

    2016-04-01

    Linkage disequilibrium (LD) can be applied for mapping the actual genes responsible for variation of economically important traits through association mapping. The feasibility and efficacy of association studies are strongly dependent on the extent of LD which determines the number and density of markers in the studied population, as well as the experimental design for an association analysis. In this study, we first characterized the extent of LD in a wild population and a cultured mass-selected line of Pacific oyster ( Crassostrea gigas). A total of 88 wild and 96 cultured individuals were selected to assess the level of genome-wide LD with 53 microsatellites, respectively. For syntenic marker pairs, no significant association was observed in the wild population; however, three significant associations occurred in the cultured population, and the significant LD extended up to 12.7 cM, indicating that strong artificial selection is a key force for substantial increase of genome-wide LD in cultured population. The difference of LD between wild and cultured populations showed that association studies in Pacific oyster can be achieved with reasonable marker densities at a relatively low cost by choosing an association mapping population. Furthermore, the frequent occurrence of LD between non-syntenic loci and rare alleles encourages the joint application of linkage analysis and LD mapping when mapping genes in oyster. The information on the linkage disequilibrium in the cultured population is useful for future association mapping in oyster.

  14. A cytokine-like factor astakine accelerates the hemocyte production in Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Li, Yiqun; Jiang, Shuai; Li, Meijia; Xin, Lusheng; Wang, Lingling; Wang, Hao; Qiu, Limei; Song, Linsheng

    2016-02-01

    Astakine has been reported to be a hematopoietic growth factor of prokineticin homolog firstly found in arthropods freshwater crayfish Pacifastacus leniusculus. In the present study, an astakine homologous gene was identified from Pacific oyster Crassostrea gigas (designated CgAstakine). The full length cDNA of CgAstakine encoded a polypeptide of 103 amino acids containing a prokineticin (PK) domain homologous to that in astakine from freshwater crayfish P. leniusculus. The deduced amino acid sequence of CgAstakine shared higher similarity with those of other invertebrate astakines than prokineticins from vertebrates. The mRNA of CgAstakine was highly expressed in hepatopancreas and adductor muscle of oyster, while the CgAstakine protein was mainly distributed in hepatopancreas, gill and hemocytes. The mRNA expression of CgAstakine in hemocytes was significantly increased (p oyster hemocytes were incubated with 5 μg/mL recombinant CgAstakine protein (rCgAstakine) for 24 h in vitro, the proliferation of hemocytes was significantly increased to 1.89 fold of that in control group (p oyster hemocytes was significantly upregulated (2.45 fold of that in control group, p oysters were received an injection of rCgAstakine (0.5 μg/g). These results collectively indicated that CgAstakine could modulate the hemocytes proliferation both in vitro and in vivo, and probably involved in the hematopoietic process fighting against the invasion of foreign pathogens.

  15. Inheritance and Variation of Genomic DNA Methylation in Diploid and Triploid Pacific Oyster (Crassostrea gigas).

    Science.gov (United States)

    Jiang, Qun; Li, Qi; Yu, Hong; Kong, Lingfeng

    2016-02-01

    DNA methylation is an important epigenetic mechanism that could be responsive to environmental changes indicating a potential role in natural selection and adaption. In order to evaluate an evolutionary role of DNA methylation, it is essential to first gain a better insight into inheritability. To address this question, this study investigated DNA methylation variation from parents to offspring in the Pacific oyster Crassostrea gigas using fluorescent-labeled methylation-sensitive amplified polymorphism (F-MSAP) analysis. Most of parental methylated loci were stably transmitted to offspring segregating following Medelian expectation. However, methylated loci deviated more often than non-methylated loci and offspring showed a few de novo methylated loci indicating DNA methylation changes from parents to offspring. Interestingly, some male-specific methylated loci were found in this study which might help to explore sex determination in oyster. Despite environmental stimuli, genomic stresses such as polyploidization also can induce methylation changes. This study also compared global DNA methylation level and individual methylated loci between diploid and triploid oysters. Results showed no difference in global methylation state but a few ploidy-specific loci were detected. DNA methylation variation during polyploidization was less than autonomous methylation variation from parents to offspring.

  16. Investigation of jumbo squid (Dosidicus gigas) skin gelatin peptides for their in vitro antioxidant effects.

    Science.gov (United States)

    Mendis, Eresha; Rajapakse, Niranjan; Byun, Hee-Guk; Kim, Se-Kwon

    2005-09-09

    Peptides derived from tryptic hydrolysate of jumbo squid (Dosidicus gigas) skin gelatin were assessed for their antioxidant properties in different in vitro assay systems. The hydrolysate itself exhibited a strong lipid peroxidation inhibition and it was much higher than that of natural antioxidant, alpha-tocopherol. In addition, it could scavenge highly active free radicals in oxidative systems, in the order of hydroxyl and carbon-centered radicals. Two representative peptides with comparatively higher antioxidant potency were purified and characterized as Phe-Asp-Ser-Gly-Pro-Ala-Gly-Val-Leu (880.18 Da) and Asn-Gly-Pro-Leu-Gln-Ala-Gly-Gln-Pro-Gly-Glu-Arg (1241.59 Da). Furthermore, viability of radical-mediated oxidation-induced human lung fibroblasts was enhanced following the treatment of two peptides. However it did not exhibit substantial ion chelation, and we presumed that the observed radical scavenging potency of these peptides play a vital role for their strong antioxidant activity. Based on our results we suggest that hydrophobic amino acids present in peptide sequences contributed greatly for observed antioxidant activities.

  17. Purification and characterization of trimethylamine-N-oxide demethylase from jumbo squid (Dosidicus gigas).

    Science.gov (United States)

    Fu, Xue-Yan; Xue, Chang-Hu; Miao, Ben-Chun; Liang, Jun-Ni; Li, Zhao-Jie; Cui, Feng-Xia

    2006-02-08

    Trimethylamine-N-oxide demethylase (TMAOase) was purified from Jumbo squid (Dosidicus gigas) and characterized in detail herein. The TMAOase was extracted from squid with 20 mM Tris-acetate buffer (pH 7.0) containing 1.0 M NaCl, followed by acid treatment and heat treatment. Then it was purified by deithylaminoethyl-cellulose and Sephacryl S-300 chromatography, subsequently resulting in an 839-fold purification. The molecular mass of the TMAOase was defined to be 17.5 kDa. The optimum pH of the purified TMAOase was 7.0, and its optimum temperature was confirmed to be 55 degrees C. The TMAOase was stable to heat treatment up to 50 degrees C and stable at pH 7.0-9.0. Reducing agents such as DTT, Na2SO3, and NADH were effective at activating TMAOase, and ethylenediaminetetraacetic acid, as well as Mg2+ and Ca2+, could also enhance the activity of TMAOase remarkably, whereas the TMAOase could be significantly inhibited by tea polyphenol, phytic acid and acetic acid. In addition, the TMAOase converted TMAO to dimethylamine and formaldehyde stoichiometrically with a K(m) of 26.2 mM.

  18. Onshore-offshore movement of jumbo squid (Dosidicus gigas) on the continental shelf

    Science.gov (United States)

    Stewart, Julia S.; Gilly, William F.; Field, John C.; Payne, John C.

    2013-10-01

    Jumbo squid (Dosidicus gigas) have greatly extended their range in the California Current System, where they forage on a variety of ecologically and economically important species that inhabit both coastal and offshore mesopelagic regions. Swimming abilities and behavior are important factors in assessing the impacts of this range expansion, particularly in regard to foraging in conjunction with onshore-offshore movement over the continental shelf. Here we describe a study of horizontal movements by jumbo squid along and across the continental shelf off Washington, USA, using acoustic tags in association with the Census of Marine Life's Pacific Ocean Shelf Tracking Program (POST) receiver arrays. We detected frequent movements along the shelf break, movement onto the shelf at night, and no evidence of movement as a cohesive school. Our results demonstrate feasibility of using acoustic tags and arrays to document horizontal movements of jumbo squid along and across the continental shelf. This is important in order to determine how those movements overlap with those of other ecologically and commercially important fish species.

  19. Partial characterization of an effluent produced by cooking of Jumbo squid (Dosidicus gigas) mantle muscle.

    Science.gov (United States)

    Rosas-Romero, Zaidy G; Ramirez-Suarez, Juan C; Pacheco-Aguilar, Ramón; Lugo-Sánchez, Maria E; Carvallo-Ruiz, Gisela; García-Sánchez, Guillermina

    2010-01-01

    Jumbo squid (Dosidicus gigas) mantle muscle was cooked simulating industrial procedures (95 degrees C x 25 min, 1.2:5 muscle:water ratio). The effluent produced was analyzed for chemical and biochemical oxygen demands (COD and BOD(5), respectively), proximate analysis, flavor-related compounds (free amino acids, nucleotides and carbohydrates) and SDS-PAGE. The COD and BOD(5) exhibited variation among samplings (N=3) (27.4-118.5 g O(2)/L for COD and 11.3-26.7 g O(2)/L for BOD(5)). The effluent consisted of 1% total solids, 75% of which represented crude protein. Sixty percent of the total free amino acid content, which imparts flavor in squid species, corresponded to glutamic acid, serine, glycine, arginine, alanine, leucine and lysine. The nucleotide concentration followed this order, Hx>ADP>AMP>ATP>IMP>HxR. The variation observed in the present work was probably due to physiological maturity differences among the squid specimens (i.e., juvenile versus mature). Solids present in squid cooking effluent could be recovered and potentially used as flavor ingredients in squid-analog production by the food industry.

  20. Characteristics of deacetylation and depolymerization of β-chitin from jumbo squid (Dosidicus gigas) pens.

    Science.gov (United States)

    Jung, Jooyeoun; Zhao, Yanyun

    2011-09-27

    This study evaluated the deacetylation characteristics of β-chitin from jumbo squid (Dosidicus gigas) pens by using strongly alkaline solutions of NaOH or KOH. Taguchi design was employed to investigate the effect of reagent concentration, temperature, time, and treatment step on molecular mass (MM) and degree of deacetylation (DDA) of the chitosan obtained. The optimal treatment conditions for achieving high MM and DDA of chitosan were identified as: 40% NaOH at 90°C for 6h with three separate steps (2h+2h+2h) or 50% NaOH at 90°C for 6h with one step, or 50% KOH at 90°C for 4h with three steps (1h+1h+2h) or 6h with one step. The most important factor affecting DDA and MM was temperature and time, respectively. The chitosan obtained was then further depolymerized by cellulase or lysozyme with cellulase giving a higher degradation ratio, lower relative viscosity, and a larger amount of reducing-end formations than that of lysozyme due to its higher susceptibility. This study demonstrated that jumbo squid pens are a good source of materials to produce β-chitosan with high DDA and a wide range of MM for various potential applications.

  1. Trace element concentrations in the top predator jumbo squid (Dosidicus gigas) from the Gulf of California.

    Science.gov (United States)

    Raimundo, Joana; Vale, Carlos; Rosa, Rui

    2014-04-01

    Jumbo (or Humboldt) squid, Dosidicus gigas, is a large jet-propelled top oceanic predator off the Eastern Pacific. The present study reports, for the first time, concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd and Pb in gills, mantle and digestive gland of this powerful pelagic squid in the Gulf of California. Zinc and Cu were the most abundant elements. All elements, with the exception of As, were largely stored in digestive gland; particularly Cd that reached concentrations between 57 and 509 µg g(-1). Significant relationships between tissues were found for Co (digestive gland-gills), As (gills-mantle) and Cd (digestive gland-mantle). Proportionality of Cd concentrations between mantle and digestive gland suggested that detoxification capacity by digestive gland was insufficient to avoid the transfer of this element to mantle and other tissues. Nonetheless, Cd concentrations in the mantle were always below the regulatory limit and, therefore lack of constraints for human consumption. On the basis of the fishery landings, one may estimate that up to 1t of Cd can be annually removed by jumbo squid fisheries.

  2. Salting-in effect on muscle protein extracted from giant squid (Dosidicus gigas).

    Science.gov (United States)

    Zhang, Rui; Zhou, Ru; Pan, Weichun; Lin, Weiwei; Zhang, Xiuzhen; Li, Mengya; Li, Jianrong; Niu, Fuge; Li, Ang

    2017-01-15

    The salting-in effect on muscle protein is well-known in food science but hard to explain using conventional theories. Myofibrillar protein extracted from the giant squid (Dosidicus gigas) was selected as a model muscle protein to study this mechanism in KCl solutions. Changes in the secondary structures of myofibrillar protein molecules caused by concentrated salts, particularly in the paramyosin molecule conformation, have been reported. Zeta-potential determinations showed that these secondary structures have modified protein molecule surfaces. The zeta-potential of the myofibrillar protein molecules fell from -7.24±0.82 to -9.99±1.65mV with increasing salt concentration from 0.1 to 0.5M. The corresponding second virial coefficient increased from -85.43±3.8×10(-7) to -3.45±1.3×10(-7) molmLg(-2). The extended law of corresponding states suggests that reduced attractive interactions increase the protein solubility. Solubility measurements in alternating KCl concentrations showed that the conformational change was reversible.

  3. Zooming to the centre of the Milky Way - GigaGalaxy Zoom phase 2

    Science.gov (United States)

    2009-09-01

    The second of three images of ESO's GigaGalaxy Zoom project has just been released online. It is a new and wonderful 340-million-pixel vista of the central parts of our home galaxy as seen from ESO's Paranal Observatory with an amateur telescope. This 34 by 20-degree wide image provides us with a view as experienced by amateur astronomers around the world. However, its incredible beauty and appeal owe much to the quality of the observing site and the skills of Stéphane Guisard, the world-renowned astrophotographer, who is also an ESO engineer. This second image directly benefits from the quality of Paranal's sky, one of the best on the planet, where ESO's Very Large Telescope is located. In addition, Guisard has drawn on his professional expertise as an optical engineer specialising in telescopes, a rare combination in the world of astrophotographers. Guisard, as head of the optical engineering team at Paranal, is responsible for ensuring that the Very Large Telescope has the best optical performance possible. To create this stunning, true-colour mosaic of the Galactic Centre region, Guisard assembled about 1200 individual images, totalling more than 200 hours of exposure time, collected over 29 nights, during Guisard's free time, while working during the day at Paranal [1]. The image shows the region spanning the sky from the constellation of Sagittarius (the Archer) to Scorpius (the Scorpion). The very colourful Rho Ophiuchi and Antares region is a prominent feature to the right, although much darker areas, such as the Pipe and Snake nebulae also stand out. The dusty lane of our Milky Way runs obliquely through the image, dotted with remarkable bright, reddish nebulae, such as the Lagoon and the Trifid Nebulae, as well as NGC 6357 and NGC 6334. This dark lane also hosts the very centre of our Galaxy, where a supermassive black hole is lurking. "The area I have depicted in this image is an incredibly rich region of the sky, and the one I find most beautiful

  4. Trojan Horse Strategy for Non-invasive Interference of Clock Gene in the Oyster Crassostrea gigas.

    Science.gov (United States)

    Payton, Laura; Perrigault, Mickael; Bourdineaud, Jean-Paul; Marcel, Anjara; Massabuau, Jean-Charles; Tran, Damien

    2017-08-01

    RNA interference is a powerful method to inhibit specific gene expression. Recently, silencing target genes by feeding has been successfully carried out in nematodes, insects, and small aquatic organisms. A non-invasive feeding-based RNA interference is reported here for the first time in a mollusk bivalve, the pacific oyster Crassostrea gigas. In this Trojan horse strategy, the unicellular alga Heterocapsa triquetra is the food supply used as a vector to feed oysters with Escherichia coli strain HT115 engineered to express the double-stranded RNA targeting gene. To test the efficacy of the method, the Clock gene, a central gene of the circadian clock, was targeted for knockout. Results demonstrated specific and systemic efficiency of the Trojan horse strategy in reducing Clock mRNA abundance. Consequences of Clock disruption were observed in Clock-related genes (Bmal, Tim1, Per, Cry1, Cry2, Rev.-erb, and Ror) and triploid oysters were more sensitive than diploid to the interference. This non-invasive approach shows an involvement of the circadian clock in oyster bioaccumulation of toxins produced by the harmful alga Alexandrium minutum.

  5. On-Chip Multi-Giga Bit Cycle-to-Cycle Jitter Measurement Circuit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jingkai; Chung Len Lee; TIAN Chao; YU Fei

    2007-01-01

    This paper presents an on-chip measurement circuit to measure multi-giga bit cycle-to-cycle jitter based on the vernier occillator (VO), which is inherited from the famous vernier delay line. The calibration method is also given. The circuit adopts a differential digital controlled delay element, which makes the circuit flexible in adjusting the measurement resolution, and a highly sensitive phase capturer, which makes the circuit able to measure jitters in pico-second range. The parallel structure makes it possible to measure consecutive cycle-to-cycle jitters. The performance of the circuit was verified via simulation with SMIC 0.18 urn process. During simulation under the clock with the period of 750 ps, the error between the measured RMS jitter and the theoretical RMS jitter was just 2.79 ps. Monte Carlo analysis was also conducted. With more advanced technology, the circuit can work better. This new structure can be implemented in chips as a built-in self-test IP core for testing jitter of PLL or other clocks.

  6. Extraction and Identification of the Pigment in the Adductor Muscle Scar of Pacific Oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Shixin Hao

    Full Text Available In this study, UV (ultraviolet and IR (infrared radiation spectral analysis were integrated to identify the pigment in the adductor muscle scar of the Pacific oyster Crassostrea gigas. The pigment was extracted from the adductor muscle scars of cleaned oyster shells that were pulverized, hydrolyzed in hot hydrochloric acid, purified with diethyl ether, and dissolved in 0.01 mL/L NaOH. The maximum absorption of the pigment in the UV absorption spectrum within the range of 190-500 nm was observed between 210-220 nm. The UV absorbance decreased with increasing wavelength which was consistent with the UV spectral absorption characteristics of melanin. In addition, Fourier transform infrared spectroscopy scanning revealed characteristic absorption peaks that emerged near 3440 cm-1 and 1630 cm-1, which was consistent with infrared scanning features of eumelanin (a type of melanin. This study has demonstrated for the first time that the pigment in the adductor muscle scar of the Pacific oyster is melanin, hinting that the adductor muscle could be another organ pigmenting the mollusc shell with melanin other than mantle.

  7. The inhibitory role of γ-aminobutyric acid (GABA) on immunomodulation of Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Li, Meijia; Qiu, Limei; Wang, Lingling; Wang, Weilin; Xin, Lusheng; Li, Yiqun; Liu, Zhaoqun; Song, Linsheng

    2016-05-01

    γ-aminobutyric acid (GABA) is an inhibitory neurotransmitter to suppress the immune-mediated pro-inflammatory reactions, and it has been used in the treatment of many inflammation-related diseases in vertebrates, while its immunomodulatory role in invertebrates has never been reported. In the present study, GABA was found to exist in the hemolymph of Pacific oyster Crassostrea gigas, and its concentration decreased slightly from 8.00 ± 0.37 μmol L(-1) at normal condition to 7.73 ± 0.15 μmol L(-1) at 6 h after LPS stimulation, and then increased to 9.34 ± 0.15 μmol L(-1), 8.86 ± 0.68 μmol L(-1) at 12 h and 48 h, respectively. After LPS stimulation, the mRNA expressions of pro-inflammatory cytokines (CgIL-17 and CgTNF) and immune effectors (CgSOD and CgBPI), and the protein expression of NOS increased significantly, and these increased trends were remarkably inhibited by GABA stimulation. At the same time, the phagocytosis rate and apoptosis rate of immunocytes also increased obviously after LPS stimulation, whereas the increase was repressed with the addition of GABA. The results collectively demonstrated that GABA was an indispensable inhibitory agent for both humoral and cellular immune response, which mainly functioned at the late phase of immune response to avoid the excess immune reactions and maintain the immune homeostasis.

  8. Trace metal contents of the pacific oyster ( Crassostrea gigas) purchased from markets in Hong Kong

    Science.gov (United States)

    Cheung, Y. H.; Wong, M. H.

    1992-11-01

    Arsenic, cadmium, chromium, and copper concentrations of the Pacific oyster, Crassostrea gigas, purchased from four different markets were determined in this project. In general, gill tissue had the highest proportion of metal contents (34%-67%) when compared with other tissue parts (mantle, viscera, and adductor muscle), except for arsenic, which showed the highest level in adductor muscle (44%). Smaller oysters (longitudinal length of soft body part less than 6 cm) had higher metal levels than larger ones (longitudinal length of soft body part more than 6 cm), except copper. None of the four metals examined showed an obvious seasonal trend, although cadmium levels seemed to be higher in autumn and winter months. Arsenic, cadmium, and copper levels in oysters purchased from different markets and different months obtained in the present study were higher when compared with past reports. Cadmium levels, as high as 10.98 mg/kg (dry weight basis) have been obtained. This approaches the safety limit that may be hazardous to human health. Continual monitoring of cadmium and other trace metals of toxicological significance to man in Hong Kong seafood is recommended.

  9. Metals concentrations in sediments and oyster Crassostrea gigas from La Pitahaya lagoon, Sinaloa, NW Mexico

    Science.gov (United States)

    Luna Varela, R.; Muñoz Sevilla, N.; Campos Villegas, L.; Rodriguez Espinosa, P.; Gongora Gomez, A.; MP, J.

    2013-05-01

    This present study was performed in a culture of Crassostrea gigas in La Pitahaya, Sinaloa, México. The main objective is to identify the enrichment pattern of trace elements (Cu, Cd, Cr, Ni, Pb, Zn, Hg, As, V) also was determine concentrations thereof in oyster. Four sampling sites were selected, two smaller channels which connect the lagoon directly , the region of culture and connection with the sea ; and each sampling consisted of 4 sample sediments and 50 oysters of commercial size per mounth . Concentrations of trace metals were determined using atomic absorption spectrophotometry (AAS). The higher concentration of elements in certain samples clearly suggests that they are directly fed by the smaller channels which connect the lagoon directly. These small channels often carry the contaminants which are absorbed and deposited in the sediments. The results were also compared with the Effect Range Low (ERL) and Effect Range Medium (ERM) of NOAA and it indicates that Ni is above the ERL values. Cadmium, lead, chrome and copper concentrations exceeded the limits permissible of bivalbe mollusks established by the sanitary regulations

  10. Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in pacific oyster (Crassostrea gigas).

    Science.gov (United States)

    Su, Yi-Cheng; Yang, Qianru; Häse, Claudia

    2010-06-01

    The efficacy of refrigerated-seawater depuration for reducing Vibrio parahaemolyticus levels in Pacific oyster (Crassostrea gigas) was investigated. Raw Pacific oysters were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (10(5) to 10(6) most probable number [MPN] per g) and depurated with refrigerated seawater (5 degrees C) in a laboratory-scale recirculation system equipped with a 15-W gamma UV sterilizer. Depuration with refrigerated seawater for 96 h reduced V. parahaemolyticus populations by >3.0 log MPN/g in oysters harvested in the winter. However, 144 h of depuration at 5 degrees C was required to achieve a 3-log reduction in oysters harvested in the summer. Depuration with refrigerated seawater at 5 degrees C for up to 144 h caused no significant fatality in the Pacific oyster and could be applied as a postharvest treatment to reduce V. parahaemolyticus contamination in Pacific oysters. Further studies are needed to validate the efficacy of the depuration process for reducing naturally accumulated V. parahaemolyticus in oysters.

  11. Arsenic and arsenic species in cultured oyster (Crassostrea gigas and C. corteziensis) from coastal lagoons of the SE Gulf of California, Mexico.

    Science.gov (United States)

    Bergés-Tiznado, Magdalena E; Páez-Osuna, Federico; Notti, Alessandra; Regoli, Francesco

    2013-01-01

    The aim of this study was to evaluate the bioavailability of arsenic (As) through cultured oyster Crassostrea gigas and Crassostrea corteziensis from four coastal lagoons (SE Gulf of California). Organisms were collected in two seasons (rainy and dry season), and they were analyzed for total arsenic and chemical speciation of this element. The concentrations of As in oyster soft tissue fluctuated between 5.44 and 9.56 μg/g for rainy season and 6.46 and 8.33 μg/g for dry season (dry weight) in C. gigas. In C. corteziensis, the As concentrations were Mexico and indicate that C. gigas and C. corteziensis farmed in this area are safe for human consumption in terms of arseno-compounds.

  12. Comparative Transcriptome Analysis of the Pacific Oyster Crassostrea gigas Characterized by Shell Colors: Identification of Genetic Bases Potentially Involved in Pigmentation.

    Directory of Open Access Journals (Sweden)

    Dandan Feng

    Full Text Available Shell color polymorphisms of Mollusca have contributed to development of evolutionary biology and population genetics, while the genetic bases and molecular mechanisms underlying shell pigmentation are poorly understood. The Pacific oyster (Crassostrea gigas is one of the most important farmed oysters worldwide. Through successive family selection, four shell color variants (white, golden, black and partially pigmented of C. gigas have been developed. To elucidate the genetic mechanisms of shell coloration in C. gigas and facilitate the selection of elite oyster lines with desired coloration patterns, differentially expressed genes (DEGs were identified among the four shell color variants by RNA-seq.Digital gene expression generated over fifteen million reads per sample, producing expression data for 28,027 genes. A total number of 2,645 DEGs were identified from pair-wise comparisons, of which 432, 91, 43 and 39 genes specially were up-regulated in white, black, golden and partially pigmented shell of C. gigas, respectively. Three genes of Abca1, Abca3 and Abcb1 which belong to the ATP-binding cassette (ABC transporters super-families were significantly associated with white shell formation. A tyrosinase transcript (CGI_10008737 represented consistent up-regulated pattern with golden coloration. We proposed that white shell variant of C. gigas could employ "endocytosis" to down-regulate notch level and to prevent shell pigmentation.This study discovered some potential shell coloration genes and related molecular mechanisms by the RNA-seq, which would provide foundational information to further study on shell coloration and assist in selective breeding in C. gigas.

  13. Field clearance of an intertidal bivalve bed: relative significance of the co-occurring blue mussel Mytilus edulis and Pacific oyster Crassostrea gigas

    DEFF Research Database (Denmark)

    Vismann, Bent; Holm, Mark Wejlemann; Davids, Jens

    2016-01-01

    At an approximately 12 000 m2 sheltered intertidal bivalve bed in the western part of the Limfjord, Denmark, the Pacific oyster Crassostrea gigas co-occurs with the blue mussel Mytilus edulis. The relative significance of the impact of the 2 species on phytoplankton density during a tidal cycle...... was estimated by combining field measurements of clearance rates and modelling of the bivalve bed (topography, biomass distribution, temporal and spatial water coverage and depth). The average density of C. gigas and M. edulis was 35 ± 36 and 1001 ± 685 ind. m−2, respectively. The water volume cleared during...

  14. Mercury in cultured oysters (Crassostrea gigas Thunberg, 1793 and C. corteziensis Hertlein, 1951) from four coastal lagoons of the SE Gulf of California, Mexico.

    Science.gov (United States)

    Osuna-Martínez, C C; Páez-Osuna, F; Alonso-Rodríguez, R

    2010-09-01

    In order to determine the mercury concentrations in cultured oysters from coastal lagoons (SE Gulf of California), several individuals of Crassostrea gigas and C. corteziensis were collected and their mercury levels were measured with a cold vapor analyzer. The mean concentrations during the rainy and dry seasons, respectively, were 0.70 and 0.15 microg g(-1) in C. gigas and 0.56 and 0.18 microg g(-1) in C. corteziensis. During the rainy season, elevated mercury contents are apparently related to terrigen transport from the watershed, while during the dry season, the moderate levels are related to upwellings.

  15. Locomotion and behavior of Humboldt squid, Dosidicus gigas, in relation to natural hypoxia in the Gulf of California, Mexico.

    Science.gov (United States)

    Gilly, William F; Zeidberg, Louis D; Booth, J Ashley T; Stewart, Julia S; Marshall, Greg; Abernathy, Kyler; Bell, Lauren E

    2012-09-15

    We studied the locomotion and behavior of Dosidicus gigas using pop-up archival transmitting (PAT) tags to record environmental parameters (depth, temperature and light) and an animal-borne video package (AVP) to log these parameters plus acceleration along three axes and record forward-directed video under natural lighting. A basic cycle of locomotor behavior in D. gigas involves an active climb of a few meters followed by a passive (with respect to jetting) downward glide carried out in a fins-first direction. Temporal summation of such climb-and-glide events underlies a rich assortment of vertical movements that can reach vertical velocities of 3 m s(-1). In contrast to such rapid movements, D. gigas spends more than 80% of total time gliding at a vertical velocity of essentially zero (53% at 0±0.05 m s(-1)) or sinking very slowly (28% at -0.05 to -0.15 m s(-1)). The vertical distribution of squid was compared with physical features of the local water column (temperature, oxygen and light). Oxygen concentrations of ≤20 μmol kg(-1), characteristic of the midwater oxygen minimum zone (OMZ), can influence the daytime depth of squid, but this depends on location and season, and squid can 'decouple' from this environmental feature. Light is also an important factor in determining daytime depth, and temperature can limit nighttime depth. Vertical velocities were compared over specific depth ranges characterized by large differences in dissolved oxygen. Velocities were generally reduced under OMZ conditions, with faster jetting being most strongly affected. These data are discussed in terms of increased efficiency of climb-and-glide swimming and the potential for foraging at hypoxic depths.

  16. Gender determination in the Paiche or Pirarucu (Arapaima gigas) using plasma vitellogenin, 17beta-estradiol, and 11-ketotestosterone levels.

    Science.gov (United States)

    Chu-Koo, F; Dugué, R; Alván Aguilar, M; Casanova Daza, A; Alcántara Bocanegra, F; Chávez Veintemilla, C; Duponchelle, F; Renno, J-F; Tello, Salvador; Nuñez, J

    2009-03-01

    Arapaima gigas is an air-breathing giant fish of Amazonian rivers. Given its great economic and cultural importance, the aquaculture development of this species represents an evident solution to face the decline of wild populations. In captivity, reproduction occurs generally in large earthen ponds where stocks of a few tens of brooders are maintained together at the beginning of the rainy season (December-March in the Peruvian Amazon). Fry production relies on the spontaneous formation of male and female pairs, which build a nest, delimit a territory and guard the offspring for at least 20 days from other congeners and predators. However, as sex determination of A. gigas is not possible by morphological criteria, it is very difficult to optimize reproduction conditions and fry production in each pond, which seriously hampers the culture of this species. This situation prompted us to develop sexing methodologies based on (1) the detection of female specific plasma Vitellogenin (Vtg) using an enzyme immuno assay (EIA), and (2) the determination of plasma 17beta-estradiol and 11-ketotestosterone levels for immature specimens. The Vtg purification was performed by electro-elution after polyacrilamide gel electrophoresis (PAGE) from plasma of 17beta-estradiol treated A. gigas juveniles. Two different Vtg molecules were isolated, (Vtg(1) and Vtg(2)) with 184 and 112 kDa apparent molecular masses, respectively, and two antibodies were raised in rabbits for each Vtg molecule. Adult fish were 100% accurately sexed by Vtg EIA, while 100% of immature fish and 95% of adults were accurately sexed by 17beta-Estradiol and 11-Ketestosterone ratios. We also observed different color pattern development in male and female adult fish (6-year-olds) around the reproductive period.

  17. Bioaccumulation of trace metals in farmed pacific oysters Crassostrea gigas from SW Gulf of California coast, Mexico.

    Science.gov (United States)

    Jonathan, M P; Muñoz-Sevilla, N P; Góngora-Gómez, Andrés Martin; Luna Varela, Raquel Gabriela; Sujitha, S B; Escobedo-Urías, D C; Rodríguez-Espinosa, P F; Campos Villegas, Lorena Elizabeth

    2017-11-01

    The aim of the study was to evaluate the bioavailability of trace metals (Chromium, Copper, Nickel, Lead, Zinc, Cadmium, Arsenic, and Mercury) in the commercially consumed Crassostrea gigas oysters collected over a 12-month growth period (2011-12) from an experimental cultivation farm in La Pitahaya, Sinaloa State, Mexico. Sediment and water samples were also collected from four different zones adjacent to the cultivation area to identify the concentration patterns of metals. The results revealed that sewage disposals, fertilizers used for agricultural practices and shrimp culture are the major sources for the enrichment of certain toxic metals. The metal concentrations in oysters presented a decreasing order of abundance (all values in mg Kg(-1)): Zn (278.91 ± 93.03) > Cu (63.13 ± 31.72) > Cr (22.29 ± 30.23) > Cd (14.54 ± 4.28) > Ni (9.41 ± 11.33) > Pb (2.22 ± 1.33) > As (0.58 ± 0.91) > Hg (0.04 ± 0.06). Bioconcentration Factor (BCF) and Biota Sediment Accumulation Factor (BSAF) exhibited that C. gigas in the region are strong accumulators for Zn and Cd respectively. Thus, the present study proves to fulfill the gap in understanding the rate of bioaccumulation of metals in C. gigas which is regarded as the most sought after oyster species globally. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Status of the Pacific Oyster Crassostrea gigas (Thunberg, 1793) in the western Limfjord, Denmark – Five years of population development

    DEFF Research Database (Denmark)

    Groslier, Tilde; Christensen, Helle Torp; Davids, Jens

    2014-01-01

    The Pacific oyster, Crassostrea gigas, was introduced into the Netherlands in 1964 for aquaculture purposes and has since spread extensively in Northern European waters. Eight locations in the western part of the Limfjord, Denmark, first sampled in 2006 were revisited in 2011, to determine how...... not expanded in terms of geographic distribution. While reproduction does occur, conditions for population growth appear to be suboptimal. The species has become established in western Limfjord but abundance is low and densities are much lower than those considered harmful to the ecosystem. At present, the C...

  19. Parasitas em ostras de cultivo (Crassostrea rhizophorae e Crassostrea gigas) da Ponta do Sambaqui, Florianópolis, SC

    OpenAIRE

    Sabry,R.C.; Magalhães,A R.M.

    2005-01-01

    Estudou-se a presença de parasitas e realizaram-se exames macroscópicos e histológicos em ostras (Crassostrea rhizophorae e Crassostrea gigas) cultivadas. Entre agosto de 2002 a maio de 2003, 30 indivíduos adultos de cada espécie foram coletados sazonalmente, totalizando 240 ostras. Os animais, provenientes de desova em laboratório, foram mantidos em lanternas de cultivo, em sistema suspenso tipo espinhel, com densidade de 40 ostras/andar. A cada coleta era registrada a mortalidade das ostras...

  20. Inheritance of 15 microsatellites in the Pacific oyster Crassostrea gigas: segregation and null allele identification for linkage analysis

    Institute of Scientific and Technical Information of China (English)

    LI Li; GUO Ximing; ZHANG Guofan

    2009-01-01

    Microsatellites were screened in a backcross family of the Pacific oyster, Crassostrea gigas. Fifteen microsatellite loci were distinguishable and polymorphic with 6 types of allele-combinations. Null alleles were detected in 46.7% of loci, accounting for 11.7% of the total alleles. Four loci did not segregate in Mendelian Ratios. Three linkage groups were identified among 7 of the 15 segregating loci. Fluorescence-based automated capillary electrophoresis (ABI 310 Genetic Analyzer) that used to detect the microsatellite loci, has been proved a fast, precise, and reliable method in microsatellite genotyping.

  1. VALOR AGREGADO DE LAS ESPECIES Brycon erythropterum (SÁBALO), Colossoma macropomum (GAMITANA), Arapaima gigas (PAICHE) y Agouti paca (MAJAS)

    OpenAIRE

    Doylith Vásquez Jurafo; Cinthya Córdova Ríos; Wendy Olórtegui Morey; Nirsa Cachique Oliveira; Luis Silva Ramos; Ricardo García Pinchi

    2012-01-01

    El presente trabajo tiene como objetivo  la obtención de  productos mínimamente procesados (PMP) de Brycon erythropterum (SÁBALO), Colossoma macropomum (GAMITANA), Arapaima gigas (PAICHE), y Agouti paca (MAJAS) congelado y empacado al vacio. Para las especies piscícolas, se ha aplicado un diseño factorial de 32 con dos factores de estudios: concentración de NaCl en la solución osmótica con tres niveles (15, 20 y 25 %) y temperatura de proceso  con tres niveles de estudio (5, 10 y 15 °C). Para...

  2. New Insight for the Genetic Evaluation of Resistance to Ostreid Herpesvirus Infection, a Worldwide Disease, in Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Lionel Dégremont

    Full Text Available The Pacific oyster, Crassostrea gigas, is the most important commercial oyster species cultivated in the world. Meanwhile, the ostreid herpesvirus 1 (OsHV-1 is one of the major pathogens affecting the Pacific oyster, and numerous mortality outbreaks related to this pathogen are now reported worldwide. To assess the genetic basis of resistance to OsHV-1 infection in spat C. gigas and to facilitate breeding programs for such a trait, if any exist, we compared the mortality of half- and full-sib families using three field methods and a controlled challenge by OsHV-1 in the laboratory. In the field, three methods were tested: (A one family per bag; (B one family per small soft mesh bag and all families inside one bag; (C same as the previous methods but the oysters were individually labelled and then mixed. The mean mortality ranged from 80 to 82% and was related to OsHV-1 based on viral DNA detection. The narrow-sense heritability for mortality, and thus OsHV-1 resistance, ranged from 0.49 to 0.60. The high positive genetic correlations across the field methods suggested no genotype by environment interaction. Ideally, selective breeding could use method B, which is less time- and space-consuming. The narrow sense heritability for mortality under OsHV-1 challenge was 0.61, and genetic correlation between the field and the laboratory was ranged from 0.68 to 0.75, suggesting a weak genotype by environment interaction. Thus, most of families showing the highest survival performed well in field and laboratory conditions, and a similar trend was also observed for families with the lowest survival. In conclusion, this is the first study demonstrating a large additive genetic variation for resistance to OsHV-1 infection in C. gigas, regardless of the methods used, which should help in selective breeding to improve resistance to viral infection in C. gigas.

  3. Pengaruh chitosan belangkas (Tachypleus gigas nanopartikel terhadap celah antara berbagai jenis semen ionomer kaca dengan dentin

    Directory of Open Access Journals (Sweden)

    Henny Sutrisman

    2014-09-01

    Full Text Available Background: The development of dental material restoration is regarded to be relevant to obtain a better bonding between dental structure and restorative materials. Glass ionomer cement (GIC is a bioactive material. Resin-modified GIC (RMGIC is an alternative to the conventional glass ionomer. Nowadays with nano technology, this material is available in nano particle glass ionomer form in order to enhance the bond strength between tooth structure and restoration. The use of the natural product in dentistry such as chitosan has increased widely. Chitosan is one of the natural materials that used to improve the bioactivity of the glass ionomer. studies showed that addition of chitosan high molecule to GIC can increase mechanical performance and capability and also as a catalyst to release fluoride ions. Purpose: This study was aimed to examine the effect of the addition of high molecular nanoparticle chitosan derived from horseshoe crab (Tachypleus gigas on interface of RMGIC, nano RMGIC and the dentin surface. Methods: Nano particle chitosan was added to the restorative materials and then applied to the class I cavity of premolar and then the tooth was sectioned with diamond disc. specimens were prepared for sEM examination. Results: The result showed that the addition of chitosan increases adhesion between restoration and dentin structure. Conclusion: The addition of nanoparticle chitosan with a high molecular weight of 0.015% into RMGIC and nanoparticle RMGIC can improve the adhesion of restorative material to dentin structure.Latar belakang: Perkembangan restorasi bahan gigi untuk mendapatkan ikatan yang lebih baik antara struktur gigi dan bahan restoratif. semen ionomer kaca (sIK adalah bahan bioaktif. semen ionomer kaca modifikasi resin (sIKMR adalah sebuah alternatif untuk ionomer kaca konvensional. saat ini dengan teknologi nano, bahan ini tersedia dalam bentuk partikel nano ionomer kaca untuk meningkatkan kekuatan ikatan antara struktur

  4. PROPAGASI BIBIT RUMPUT LAUT Gracilaria gigas PADA TAHAP KULTUR JARINGAN, AKLIMATISASI, DAN PEMBESARAN

    Directory of Open Access Journals (Sweden)

    Siti Fadilah

    2017-01-01

    Full Text Available Ketersediaan bibit rumput laut secara berkesinambungan diperlukan untuk meningkatkan produktivitas budidayanya. Kultur jaringan adalah salah satu metode yang digunakan untuk memenuhi kebutuhan bibit tersebut. Penelitian ini bertujuan untuk mengevaluasi performansi pertumbuhan dan sintasan bibit rumput laut Gracilaria gigas pada tiga tahap propagasi bibit rumput laut. Propagasi bibit rumput laut dilakukan melalui tahap kultur jaringan, kemudian dilanjutkan dengan aklimatisasi dan pembesaran bibit. Pada tahap kultur, eksplan dengan panjang awal ± 2 cm dikultur dalam 2 L media air laut yang diperkaya pupuk PES 20 mL/L. Kepadatan eksplan adalah 500, 750, 1.000, dan 1.250 per L. Eksplan dipelihara selama delapan minggu dengan pembaruan media setiap minggu. Pada tahap aklimatisasi bibit, perlakuan yang dicobakan adalah penambahan pupuk organik dengan dosis 0,025; 0,05; dan 0,1 mL/L. Aklimatisasi dilakukan dengan menggunakan kontainer plastik dengan 20 L media air laut selama delapan minggu. Pembesaran bibit dilakukan di kotak hapa berukuran 50 cm x 50 cm x 50 cm di laut selama tujuh minggu. Hasil menunjukkan bahwa tidak ada beda nyata (P>0,05 sintasan antar kepadatan eksplan. Sintasan eksplan pada tahap kultur di atas 95%. Pada tahap aklimatisasi, dosis pupuk organik 0,05 mL/L cenderung memberikan pertumbuhan bibit yang lebih baik daripada dosis lainnya. Pertumbuhan bibit rumput laut pada pembesaran di laut setelah tujuh minggu mengikuti persamaan y= 17,09x + 27,8 dengan rata-rata LPH sebesar 3,57%/hari. Sustainability supply of seaweed seedlings is needed to improve its productivity. Tissue culture is one of the methods applied to fulfill the seedlings demands. This study aims to evaluate the growth performance and survival rate of seaweed seedlings Gracilaria gigas at three stages of seedling propagation. Seedling propagation was carried out by three stages namely, tissue culture acclimatization and seedlings rearing. For the stage of tissue

  5. Shotgun proteomics reveals physiological response to ocean acidification in Crassostrea gigas.

    Science.gov (United States)

    Timmins-Schiffman, Emma; Coffey, William D; Hua, Wilber; Nunn, Brook L; Dickinson, Gary H; Roberts, Steven B

    2014-11-03

    Ocean acidification as a result of increased anthropogenic CO2 emissions is occurring in marine and estuarine environments worldwide. The coastal ocean experiences additional daily and seasonal fluctuations in pH that can be lower than projected end-of-century open ocean pH reductions. In order to assess the impact of ocean acidification on marine invertebrates, Pacific oysters (Crassostrea gigas) were exposed to one of four different p CO2 levels for four weeks: 400 μatm (pH 8.0), 800 μatm (pH 7.7), 1000 μatm (pH 7.6), or 2800 μatm (pH 7.3). At the end of the four week exposure period, oysters in all four p CO2 environments deposited new shell, but growth rate was not different among the treatments. However, micromechanical properties of the new shell were compromised by elevated p CO2. Elevated p CO2 affected neither whole body fatty acid composition, nor glycogen content, nor mortality rate associated with acute heat shock. Shotgun proteomics revealed that several physiological pathways were significantly affected by ocean acidification, including antioxidant response, carbohydrate metabolism, and transcription and translation. Additionally, the proteomic response to a second stress differed with p CO2, with numerous processes significantly affected by mechanical stimulation at high versus low p CO2 (all proteomics data are available in the ProteomeXchange under the identifier PXD000835). Oyster physiology is significantly altered by exposure to elevated p CO2, indicating changes in energy resource use. This is especially apparent in the assessment of the effects of p CO2 on the proteomic response to a second stress. The altered stress response illustrates that ocean acidification may impact how oysters respond to other changes in their environment. These data contribute to an integrative view of the effects of ocean acidification on oysters as well as physiological trade-offs during environmental stress.

  6. Effect of carbonate chemistry alteration on the early embryonic development of the Pacific oyster (Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Frédéric Gazeau

    Full Text Available Ocean acidification, due to anthropogenic CO₂ absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportions of abnormal development under low pH conditions, they did not allow attribution to pH induced changes in physiology or changes due to a decrease in aragonite saturation state. This study aims to assess the impact of several carbonate-system perturbations on the growth of Pacific oyster (Crassostrea gigas larvae during the first 3 days of development (until shelled D-veliger larvae. Seawater with five different chemistries was obtained by separately manipulating pH, total alkalinity and aragonite saturation state (calcium addition. Results showed that the developmental success and growth rates were not directly affected by changes in pH or aragonite saturation state but were highly correlated with the availability of carbonate ions. In contrast to previous studies, both developmental success into viable D-shaped larvae and growth rates were not significantly altered as long as carbonate ion concentrations were above aragonite saturation levels, but they strongly decreased below saturation levels. These results suggest that the mechanisms used by these organisms to regulate calcification rates are not efficient enough to compensate for the low availability of carbonate ions under corrosive conditions.

  7. Gene expression profiling of genetically determined growth variation in bivalve larvae (Crassostrea gigas).

    Science.gov (United States)

    Meyer, E; Manahan, D T

    2010-03-01

    Growth rates in animals are governed by a wide range of biological factors, many of which remain poorly understood. To identify the genes that establish growth differences in bivalve larvae, we compared expression patterns in contrasting phenotypes (slow- and fast-growth) that were experimentally produced by genetic crosses of the Pacific oyster Crassostrea gigas. Based on transcriptomic profiling of 4.5 million cDNA sequence tags, we sequenced and annotated 181 cDNA clones identified by statistical analysis as candidates for differential growth. Significant matches were found in GenBank for 43% of clones (N=78), including 34 known genes. These sequences included genes involved in protein metabolism, energy metabolism and regulation of feeding activity. Ribosomal protein genes were predominant, comprising half of the 34 genes identified. Expression of ribosomal protein genes showed non-additive inheritance - i.e. expression in fast-growing hybrid larvae was different from average levels in inbred larvae from these parental families. The expression profiles of four ribosomal protein genes (RPL18, RPL31, RPL352 and RPS3) were validated by RNA blots using additional, independent crosses from the same families. Expression of RPL35 was monitored throughout early larval development, revealing that these expression patterns were established early in development (in 2-day-old larvae). Our findings (i) provide new insights into the mechanistic bases of growth and highlight genes not previously considered in growth regulation, (ii) support the general conclusion that genes involved in protein metabolism and feeding regulation are key regulators of growth, and (iii) provide a set of candidate biomarkers for predicting differential growth rates during animal development.

  8. Antioxidant deficit in gills of Pacific oyster (Crassostrea gigas) exposed to chlorodinitrobenzene increases menadione toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Trevisan, Rafael; Arl, Miriam [Departamento de Bioquimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Sacchet, Cassia Lopes [Universidade do Oeste do Estado de Santa Catarina, 89600-000 Joacaba, SC (Brazil); Engel, Cristiano Severino; Danielli, Naissa Maria; Mello, Danielle Ferraz [Departamento de Bioquimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Brocardo, Caroline [Universidade do Oeste do Estado de Santa Catarina, 89600-000 Joacaba, SC (Brazil); Maris, Angelica Francesca [Departamento de Biologia Celular, Embriologia e Genetica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Dafre, Alcir Luiz, E-mail: alcir@ccb.ufsc.br [Departamento de Bioquimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil)

    2012-02-15

    Disturbances in antioxidant defenses decrease cellular protection against oxidative stress and jeopardize cellular homeostasis. To knock down the antioxidant defenses of Pacific oyster Crassostrea gigas, animals were pre-treated with 1-chloro-2,4-dinitrobenzene (CDNB) and further challenged with pro-oxidant menadione (MEN). CDNB pre-treatment (10 {mu}M for 18 h) was able to consume cellular thiols in gills, decreasing GSH (53%) and decrease protein thiols (25%). CDNB pre-treatment also disrupted glutathione reductase and thioredoxin reductase activity in the gills, but likewise strongly induced glutathione S-transferase activity (270% increase). Surprisingly, hemocyte viability was greatly affected 24 h after CDNB removal, indicating a possible vulnerability of the oyster immune system to electrophilic attack. New in vivo approaches were established, allowing the identification of higher rates of GSH-CDNB conjugate export to the seawater and enabling the measurement of the organic peroxide consumption rate. CDNB-induced impairment in antioxidant defenses decreased the peroxide removal rate from seawater. After showing that CDNB decreased gill antioxidant defenses and increased DNA damage in hemocytes, oysters were further challenged with 1 mM MEN over 24 h. MEN treatment did not affect thiol homeostasis in gills, while CDNB pre-treated animals recovered GSH and PSH to the control level after 24 h of depuration. Interestingly, MEN intensified GSH and PSH loss and mortality in CDNB-pre-treated animals, showing a clear synergistic effect. The superoxide-generating one-electron reduction of MEN was predominant in gills and may have contributed to MEN toxicity. These results support the idea that antioxidant-depleted animals are more susceptible to oxidative attack, which can compromise survival. Data also corroborate the idea that gills are an important detoxifying organ, able to dispose of organic peroxides, induce phase II enzymes, and efficiently export GSH

  9. Metals and trace elements in giant garter snakes (Thamnophis gigas) from the Sacramento Valley, California, USA

    Science.gov (United States)

    Wylie, G.D.; Hothem, R.L.; Bergen, D.R.; Martin, L.L.; Taylor, R.J.; Brussee, B.E.

    2009-01-01

    The giant garter snake (GGS; Thamnophis gigas) is a federally listed threatened species endemic to wetlands of the Central Valley of California. Habitat destruction has been the main factor in the decline of GGS populations, but the effects of contaminants on this species are unknown. To contribute to the recovery of these snakes, the U.S. Geological Survey (USGS) began studies of the life history and habitat use of GGSs in 1995. During a series of investigations conducted from 1995 to the present, specimens of dead GGSs were opportunistically collected from the Colusa National Wildlife Refuge (CNWR), the Natomas Basin, and other sites in northern California. Whole snakes were stored frozen for potential future analysis. As funding became available, we analyzed tissues of 23 GGSs to determine the concentrations of total mercury (Hg) and other trace elements in livers and concentrations of Hg in brains and tail clips. Mercury concentrations (??g/g, wet weight) ranged from 0.08 to 1.64 in livers, 0.01 to 0.18 in brains, and 0.02 to 0.32 in tail clips. In livers, geometric mean concentrations (??g/g, dry weight) of arsenic (25.7) and chromium (1.02) were higher than most values from studies of other snakes. Mercury concentrations in tail clips were positively correlated with concentrations in livers and brains, with the most significant correlations occurring at the Natomas Basin and when Natomas and CNWR were combined. Results indicate the value of using tail clips as a nonlethal bioindicator of contaminant concentrations. ?? 2008 US Government.

  10. Foraging ecology and movement patterns of jumbo squid (Dosidicus gigas) in the California Current System

    Science.gov (United States)

    Field, John C.; Elliger, Carl; Baltz, Ken; Gillespie, Graham E.; Gilly, William F.; Ruiz-Cooley, R. I.; Pearse, Devon; Stewart, Julia S.; Matsubu, William; Walker, William A.

    2013-10-01

    From 2002 to 2010, the jumbo squid (Dosidicus gigas) has been regularly encountered in large numbers throughout the California Current System (CCS). This species, usually found in subtropical waters, could affect coastal pelagic ecosystems and fisheries as both predator and prey. Neither the abundance of jumbo squid nor the optimal ocean conditions in which they flourish are well known. To understand better the potential impacts of this species on both commercial fisheries and on food-web structure we collected nearly 900 specimens from waters of the CCS, covering over 20° of latitude, over a range of depths and seasons. We used demographic information (size, sex, and maturity state) and analyzed stomach contents using morphological and molecular methods to best understand the foraging ecology of this species in different habitats of the CCS. Squid were found to consume a broad array of prey. Prey in offshore waters generally reflected the forage base reported in previous studies (mainly mesopelagic fishes and squids), whereas in more coastal waters (shelf, shelf break and slope habitats) squid foraged on a much broader mix that included substantial numbers of coastal pelagic fishes (Pacific herring and northern anchovy, as well as osmerids and salmonids in northern waters) and groundfish (Pacific hake, several species of rockfish and flatfish). We propose a seasonal movement pattern, based on size and maturity distributions along with qualitative patterns of presence or absence, and discuss the relevance of both the movement and distribution of jumbo squid over space and time. We find that jumbo squid are a generalist predator, which feeds primarily on small, pelagic or mesopelagic micronekton but also on larger fishes when they are available. We also conclude that interactions with and potential impacts on ecosystems likely vary over space and time, in response to both seasonal movement patterns and highly variable year-to-year abundance of the squid themselves.

  11. Sequential isotopic signature along gladius highlights contrasted individual foraging strategies of jumbo squid (Dosidicus gigas.

    Directory of Open Access Journals (Sweden)

    Anne Lorrain

    Full Text Available BACKGROUND: Cephalopods play a major role in marine ecosystems, but knowledge of their feeding ecology is limited. In particular, intra- and inter-individual variations in their use of resources has not been adequatly explored, although there is growing evidence that individual organisms can vary considerably in the way they use their habitats and resources. METHODOLOGY/PRINCIPAL FINDINGS: Using δ(13C and δ(15N values of serially sampled gladius (an archival tissue, we examined high resolution variations in the trophic niche of five large (>60 cm mantle length jumbo squids (Dosidicus gigas that were collected off the coast of Peru. We report the first evidence of large inter-individual differences in jumbo squid foraging strategies with no systematic increase of trophic level with size. Overall, gladius δ(13C values indicated one or several migrations through the squid's lifetime (∼8-9 months, during which δ(15N values also fluctuated (range: 1 to 5‰. One individual showed an unexpected terminal 4.6‰ δ(15N decrease (more than one trophic level, thus indicating a shift from higher- to lower-trophic level prey at that time. The data illustrate the high diversity of prey types and foraging histories of this species at the individual level. CONCLUSIONS/SIGNIFICANCE: The isotopic signature of gladii proved to be a powerful tool to depict high resolution and ontogenic variations in individual foraging strategies of squids, thus complementing traditional information offered by stomach content analysis and stable isotopes on metabolically active tissues. The observed differences in life history strategies highlight the high degree of plasticity of the jumbo squid and its high potential to adapt to environmental changes.

  12. Dispersal capacity and genetic structure of Arapaima gigas on different geographic scales using microsatellite markers.

    Directory of Open Access Journals (Sweden)

    Juliana Araripe

    Full Text Available Despite the ecological and economic importance of the Arapaima gigas (Cuvier 1817, few data about its dispersal capacity are available. The present study was based on the analysis of microsatellite markers in order to estimate the dispersal capacity of the species on fine, meso, and large geographic scales. For this, 561 specimens obtained from stocks separated by distances of up to 25 km (fine scale, 100 km (meso scale, and 1300-2300 km (large scale were analyzed. The fine scale analysis indicated a marked genetic similarity between lakes, with low genetic differentiation, and significant differences between only a few pairs of sites. Low to moderate genetic differentiation was observed between pairs of sites on a meso scale (100 km, which could be explained by the distances between sites. By contrast, major genetic differentiation was recorded in the large scale analysis, that is, between stocks separated by distances of over 1300 km, with the analysis indicating that differentiation was not related solely to distance. The genetic structuring analysis indicated the presence of two stocks, one represented by the arapaimas of the Mamirauá Reserve, and the other by those of Santarém and Tucuruí. The dispersal of arapaimas over short distances indicates a process of lateral migration within the várzea floodplains, which may be the principal factor determining the considerable homogeneity observed among the várzea lakes. The populations separated by distances of approximately 100 km were characterized by reduced genetic differentiation, which was associated with the geographic distances between sites. Populations separated by distances of over 1300 km were characterized by a high degree of genetic differentiation, which may be related primarily to historical bottlenecks in population size and the sedentary behavior of the species. Evidence was found of asymmetric gene flow, resulting in increasing genetic variability in the population of the

  13. Trails of river monsters: Detecting critically endangered Mekong giant catfish Pangasianodon gigas using environmental DNA

    Directory of Open Access Journals (Sweden)

    Bellemain Eva

    2016-07-01

    Full Text Available Pressures on freshwater biodiversity in Southeast Asia are accelerating, yet the status and conservation needs of many of the region’s iconic fish species are poorly known. The Mekong is highly species diverse and supports four of the six largest freshwater fish globally, three of which, including Mekong giant catfish (Pangasianodon gigas, are Critically Endangered. Emerging environmental DNA (eDNA techniques have potential for monitoring threatened freshwater biodiversity, yet have not been applied in complex and biodiverse tropical ecosystems such as the Mekong. We developed species-specific primers for amplifying Mekong giant catfish DNA. In situ validation demonstrated that the DNA amplification was successful for all samples taken in reservoirs with known presence of Mekong giant catfish independent of fish density. We collected water samples from six deep pools on the Mekong, identified through Local Ecological Knowledge, in Cambodia, Lao PDR, and Thailand. DNA was extracted and amplified from these samples using the designed primers and probes. Mekong giant catfish DNA was detected from one sample from the species’ presumed spawning grounds on the Mekong mainstream, near the border between northern Thailand and Lao PDR. eDNA sampling using species-specific primers has potential for surveying and monitoring poorly known species from complex tropical aquatic environments. However accounting for false absences is likely to be required for the method to function with precision when applied to extremely rare species that are highly dispersed within a large river system. We recommend that such approach be utilised more widely by freshwater conservation practitioners for specific applications. The method is best suited for baseline biodiversity assessments or to identify and prioritise locations for more rigorous sampling. Our methods are particularly relevant for systems or species with limited baseline data or with physical characteristics

  14. Bacterial survival following shock compression in the GigaPascal range

    Science.gov (United States)

    Hazael, Rachael; Fitzmaurice, Brianna C.; Foglia, Fabrizia; Appleby-Thomas, Gareth J.; McMillan, Paul F.

    2017-09-01

    The possibility that life can exist within previously unconsidered habitats is causing us to expand our understanding of potential planetary biospheres. Significant populations of living organisms have been identified at depths extending up to several km below the Earth's surface; whereas laboratory experiments have shown that microbial species can survive following exposure to GigaPascal (GPa) pressures. Understanding the degree to which simple organisms such as microbes survive such extreme pressurization under static compression conditions is being actively investigated. The survival of bacteria under dynamic shock compression is also of interest. Such studies are being partly driven to test the hypothesis of potential transport of biological organisms between planetary systems. Shock compression is also of interest for the potential modification and sterilization of foodstuffs and agricultural products. Here we report the survival of Shewanella oneidensis bacteria exposed to dynamic (shock) compression. The samples examined included: (a) a ;wild type; (WT) strain and (b) a ;pressure adapted; (PA) population obtained by culturing survivors from static compression experiments to 750 MPa. Following exposure to peak shock pressures of 1.5 and 2.5 GPa the proportion of survivors was established as the number of colony forming units (CFU) present after recovery to ambient conditions. The data were compared with previous results in which the same bacterial samples were exposed to static pressurization to the same pressures, for 15 minutes each. The results indicate that shock compression leads to survival of a significantly greater proportion of both WT and PA organisms. The significantly shorter duration of the pressure pulse during the shock experiments (2-3 μs) likely contributes to the increased survival of the microbial species. One reason for this can involve the crossover from deformable to rigid solid-like mechanical relaxational behavior that occurs for

  15. Helmintos parasitos do pirarucu, Arapaima gigas (Schinz, 1822 (Osteoglossiformes: Arapaimidae, no rio Araguaia, estado de Mato Grosso, Brasil Helminth parasites of pirarucu, Arapaima gigas (Schinz, 1822 (Osteoglossiformes: Arapaimidae from Araguaia River, State of Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Sonia M. C. dos Santos

    2008-09-01

    Full Text Available Foram examinados 65 exemplares de pirarucu em agosto de 2004, provenientes do rio Araguaia, Estado de Mato Grosso, Brasil para o estudo dos seus helmintos parasitos. Cinco espécies foram registradas parasitando Arapaima gigas: Dawestrema cycloancistrium (Monogenea nas brânquias, Nilonema senticosum e Goezia spinulosa (Nematoda na vesícula gasosa e no estômago respectivamente; Caballerotrema brasiliense (Digenea e Polyacanthorhynchus rhopalorhynchus (Acanthocephala no intestino. Os valores mais altos de prevalência foram observados para D. cycloancistrium (100% and P. rhopalorhynchus (96,9%. Os maiores valores de intensidade e abundância média foram calculados para C. brasiliense e N. senticosum (61 e 46,9, respectivamente. Todas estas espécies são registradas pela primeira vez na Bacia do Rio Araguaia.Sixty-five specimens of pirarucu collected in August 2004 from Araguaia River, State of Mato Grosso, Brazil, were examined to study their helminth parasites. Five species were recorded parasitic Arapaima gigas: Dawestrema cycloancistrium (Monogenea in gills, Nilonema senticosum and Goezia spinulosa (Nematoda in the swimbladder and stomach, respectively; Caballerotrema brasiliense (Digenea and Polyacanthorhynchus rhopalorhynchus (Acanthocephala in the intestine. Highest prevalence values were detected for D. cycloancistrium (100% and P. rhopalorhynchus (96.9%. Highest values of mean intensity and mean abundance were detected for C. brasiliense and N. senticosum (61 and 46.9, respectively. All these species are recorded by the first time in the Araguaia River basin.

  16. Biochemical and volatile organic compound profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea gigas) cultivated in the Eastern Scheldt and Lake Grevelingen, the Netherlands

    NARCIS (Netherlands)

    Houcke, van Jasper; Medina, Isabel; Linssen, Jozef; Luten, Joop

    2016-01-01

    The aim of this study was to evaluate the effect of two important different geographical cultivation areas in the Netherlands (Eastern Scheldt and Lake Grevelingen) on the volatile organic compound (VOC) profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea gigas)

  17. EFFECTS OF TUNGSTATE ON THE GROWTH OF DESULFOVIBRIO-GIGAS NCIMB-9332 AND OTHER SULFATE-REDUCING BACTERIA WITH ETHANOL AS A SUBSTRATE

    NARCIS (Netherlands)

    HENSGENS, CMH; NIENHUISKUIPER, ME; HANSEN, TA

    1994-01-01

    Growth of Desulfovibrio gigas NCIMB 9332 in mineral, vitamin-supplemented media with ethanol as substrate was strongly stimulated by the addition of tungstate (optimal level approximately 10(-7) M). At suboptimal tungstate concentrations, up to 1.0 mM acetaldehyde was detected in the culture superna

  18. Metabolic Cost of Protein Synthesis in Larvae of the Pacific Oyster (Crassostrea gigas) Is Fixed Across Genotype, Phenotype, and Environmental Temperature.

    Science.gov (United States)

    Lee, Jimmy W; Applebaum, Scott L; Manahan, Donal T

    2016-06-01

    The energy made available through catabolism of specific biochemical reserves is constant using standard thermodynamic conversion equivalents (e.g., 24.0 J mg protein(-1)). In contrast, measurements reported for the energy cost of synthesis of specific biochemical constituents are highly variable. In this study, we measured the metabolic cost of protein synthesis and determined whether this cost was influenced by genotype, phenotype, or environment. We focused on larval stages of the Pacific oyster Crassostrea gigas, a species that offers several experimental advantages: availability of genetically pedigreed lines, manipulation of ploidy, and tractability of larval forms for in vivo studies of physiological processes. The cost of protein synthesis was measured in larvae of C. gigas for 1) multiple genotypes, 2) phenotypes with different growth rates, and 3) different environmental temperatures. For all treatments, the cost of protein synthesis was within a narrow range--near the theoretical minimum--with a fixed cost (mean ± one standard error, n = 21) of 2.1 ± 0.2 J (mg protein synthesized)(-1) We conclude that there is no genetic variation in the metabolic cost of protein synthesis, thereby simplifying bioenergetic models. Protein synthesis is a major component of larval metabolism in C. gigas, accounting for more than half the metabolic rate in diploid (59%) and triploid larvae (54%). These results provide measurements of metabolic cost of protein synthesis in larvae of C. gigas, an indicator species for impacts of ocean change, and provide a quantitative basis for evaluating the cost of resilience.

  19. DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas

    Science.gov (United States)

    Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

    2016-09-01

    The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change.

  20. Field clearance of an intertidal bivalve bed: relative significance of the co-occurring blue mussel Mytilus edulis and Pacific oyster Crassostrea gigas

    DEFF Research Database (Denmark)

    Vismann, Bent; Holm, Mark Wejlemann; Davids, Jens;

    2016-01-01

    At an approximately 12 000 m2 sheltered intertidal bivalve bed in the western part of the Limfjord, Denmark, the Pacific oyster Crassostrea gigas co-occurs with the blue mussel Mytilus edulis. The relative significance of the impact of the 2 species on phytoplankton density during a tidal cycle...

  1. Coexistence of Pacific oyster Crassostrea gigas (Thunberg, 1793) and blue mussels Mytilus edulis Linnaeus, 1758 on a sheltered intertidal bivalve bed?

    DEFF Research Database (Denmark)

    Holm, M.W.; Davids, J.K.; Dolmer, Per;

    2016-01-01

    The invasive Pacific oyster, Crassostrea gigas Thunberg, 1793 was introduced in Denmark for aquaculture in the 1970s. Presently, feral populations are found in many parts of the country, with the largest populations established on existing beds of blue mussel, Mytilus edulis Linnaeus, 1758...

  2. Causes and effects of a highly successful marine invasion: Case-study of the introduced Pacific oyster Crassostrea gigas in continental NW European estuaries

    NARCIS (Netherlands)

    Troost, K.

    2010-01-01

    Since the 1960's, the Pacific oyster Crassostrea gigas has been introduced for mariculture at several locations within NW Europe. The oyster established itself everywhere and expanded rapidly throughout the receiving ecosystems, forming extensive and dense reef structures. It became clear that the P

  3. 杨圆蚧天敌昆虫的初步研究%On Natural Enemy of Quadraspidiotus gigas Thiem et Gerneck

    Institute of Scientific and Technical Information of China (English)

    孙岩; 李峰; 刘仲仁; 连月英; 刘婷婷

    2001-01-01

    本文记述了杨圆蚧(Quadraspidiotus gigas Thiem et Gerneck)的天敌昆虫种类,并对其生活习性进行了初步观察,对其利用价值进行了分析,对天敌的利用途径进行了探索.

  4. Feeding current characteristics of three morphologically different bivalve suspension feeders, Crassostrea gigas Mytilus edulis and Cerastoderma edule , in relation to food competition

    NARCIS (Netherlands)

    Troost, K.; Stamhuis, E.J.; Duren, L.A.; Wolff, W.

    2009-01-01

    Introduced Pacific oysters (Crassostrea gigas) have shown rapid expansion in the Oosterschelde estuary, while stocks of native bivalves declined slightly or remained stable. This indicates that they might have an advantage over native bivalve filter feeders. Hence, at the scale of individual bivalve

  5. Feeding current characteristics of three morphologically different bivalve suspension feeders, Crassostrea gigas, Mytilus edulis and Cerastoderma edule, in relation to food competition

    NARCIS (Netherlands)

    Troost, K.; Stamhuis, E.J.; van Duren, L.A; Wolff, W.J.

    2009-01-01

    Introduced Pacific oysters (Crassostrea gigas) have shown rapid expansion in the Oosterschelde estuary, while stocks of native bivalves declined slightly or remained stable. This indicates that they might have an advantage over native bivalve filter feeders. Hence, at the scale of individual bivalve

  6. DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas

    Science.gov (United States)

    Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

    2016-01-01

    The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change. PMID:27666088

  7. The enkephalinergic nervous system and its immunomodulation on the developing immune system during the ontogenesis of oyster Crassostrea gigas.

    Science.gov (United States)

    Liu, Zhaoqun; Zhou, Zhi; Wang, Lingling; Song, Xiaorui; Chen, Hao; Wang, Weilin; Liu, Rui; Wang, Mengqiang; Wang, Hao; Song, Linsheng

    2015-08-01

    Enkephalinergic neuroendocrine-immune regulatory system is one of the most important neuroendocrine-immune systems in both vertebrates and invertebrates for its significant role in the immune regulation. In the present study, the early onset of enkephalinergic nervous system and its immunomodulation on the developing immune system during the ontogenesis of oyster Crassostrea gigas were investigated to illustrate the function of neural regulation on the innate immune system in oyster larvae. [Met(5)]-enkephalin (Met-ENK) was firstly observed on the marginal of the dorsal half of D-hinged larvae. Six immune-related molecules, including four PRRs (CgCTL-1, CgCTL-2, CgCTL-4, CgNatterin-3) and two immune effectors (CgTNF-1 and CgEcSOD) were detected in the early developmental stages of trochophore, D-hinged and umbo larvae of oyster. After incubated with [Met(5)]-enkephalin, the mRNA expression level of all the PRRs changed significantly (p nervous system of oyster was firstly appeared in D-hinged larvae, while the primitive immune defense system existed in the region of prototroch in trochophore larvae and developed maturely after D-hinged larvae. The developing immune system could be regulated by the neurotransmitter [Met(5)]-enkephalin released by the neuroendocrine system in oyster C. gigas.

  8. Casting Activity of Scherotheca gigas in No-Till Mediterranean Soils: Role in Organic Matter Incorporation and Influence of Aridity

    Directory of Open Access Journals (Sweden)

    Paloma Bescansa

    2010-01-01

    Full Text Available The behaviour of earthworms, their role in organic matter incorporation into the soil, and the influence of aridity in such processes in arid and semiarid regions have scarcely been studied. In this study, physico-chemical analyses of the casts and the surrounding no-till agricultural soils of three experimental sites representing an aridity gradient in Navarre (NW Spain were done. The casts were formed by the activity of the only anecic species, Scherotheca gigas (Dugès, 1828, ubiquitous in no-till soils in this region. We observed a significant depletion of clay and higher concentration of total organic C and labile C in the form of particulate organic matter (POM in the casts as compared to the surrounding soil, suggesting selective ingestion of soil by S. gigas. This, together with the observation of increased concentration in POM with increasing aridity, suggests a major role of this species in the observed progressive gains of organic C stocks in no-till soils in the region.

  9. Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package.

    Science.gov (United States)

    Rosen, Hannah; Gilly, William; Bell, Lauren; Abernathy, Kyler; Marshall, Greg

    2015-01-15

    Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behaviors in free-swimming D. gigas in the Gulf of California with a focus on color-generating (chromogenic) behaviors. We documented two dynamic displays without artificial lighting at depths of up to 70 m. One dynamic pattern, termed 'flashing' is characterized by a global oscillation (2-4 Hz) of body color between white and red. Flashing was almost always observed when other squid were visible in the video frame, and this behavior presumably represents intraspecific signaling. Amplitude and frequency of flashing can be modulated, and the phase relationship with another squid can also be rapidly altered. Another dynamic display termed 'flickering' was observed whenever flashing was not occurring. This behavior is characterized by irregular wave-like activity in neighboring patches of chromatophores, and the resulting patterns mimic reflections of down-welled light in the water column, suggesting that this behavior may provide a dynamic type of camouflage. Rapid and global pauses in flickering, often before a flashing episode, indicate that flickering is under inhibitory neural control. Although flashing and flickering have not been described in other squid, functional similarities are evident with other species.

  10. EMBRYONIC DEVELOPMENTAL ANOMALY IDENTIFICATION OF GIANT MIMI-MINTUNO (Tachupleus gigas DURING ARTIFICIAL INCUBATION PERIOD IN THE VIAL BOTTLES

    Directory of Open Access Journals (Sweden)

    Ciptono Ciptono

    2016-04-01

    Full Text Available This study aims to reveal the phenomenon of presence / absence of anomalies in the early development of Mimi-giant mintuno (Tachypleus gigas during artificial incubation in the vial bottles. Samples 5 eggs are fertilized incorporated into transparent 50 bottles and vials each filled with clear sea water medium. Embryonic stages (instars hatch, bottles marked, then dumped seawater medium was replaced with 4% formalin solution and glycerin amount of 5% by volume, up to ¾ of the total volume of the vial bottles. Standard stages of giant Mimi-mintuno embryonic normal development Mimi-mintuno according to Itow (1988. The description type of anomalies contained in the post-hatching embryo development. The observations are documented in the form of stereo-microphotograph. The results showed that there are forms anomalies: (a. Delayed development, the structure of the body is not perfect; (b. In observation of the embryo hatches, open shell and egg perivitelline membrane has been opened but delayed development, the structure of the body is not perfect; (c. Embryos after hatched perfectly, abnormalities of morphologic structure such as abnormal protrusion on the dorsal carapace part found.   Keywords: Tachypleus gigas, artificially, incubation

  11. A Label-Free Proteomic Analysis on Competent Larvae and Juveniles of the Pacific Oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Pin Huan

    Full Text Available Current understandings on the molecular mechanisms underlying bivalve metamorphosis are still fragmentary, and a comprehensive description is required. In this study, using a large-scale label-free proteomic approach, we described and compared the proteomes of competent larvae (CL and juveniles (JU of the Pacific oyster, Crassostrea gigas. A total of 788 proteins were identified: 392 in the CL proteome and 636 in the JU proteome. Gene Ontology analysis of the proteome from each sample revealed active metabolic processes in both stages. Further quantitative analyses revealed 117 proteins that were differentially expressed between the two samples. These proteins were divided into eight groups: cytoskeleton and cell adhesion, protein synthesis and degradation, immunity and stress response, development of particular tissues, signal regulation, metabolism and energy supply, transport, and other proteins. A certification experiment using real-time PCR assay confirmed 20 of 30 examined genes exhibited the same trends at the mRNA and protein levels. The differentially expressed proteins may play roles in tissue remodeling, signal transduction, and organ development during and after metamorphosis. Novel roles were proposed for some differentially expressed proteins, such as chymotrypsin. The results of this work provide an overview of metamorphosis and post-metamorphosis development of C. gigas at the protein level. Future studies on the functions of the differentially expressed proteins will help to obtain a more in-depth understanding of bivalve metamorphosis.

  12. Variations in the pallial organ sizes of the invasive oyster, Crassostrea gigas, along an extreme turbidity gradient

    Science.gov (United States)

    Dutertre, Mickaël; Barillé, Laurent; Beninger, Peter G.; Rosa, Philippe; Gruet, Yves

    2009-11-01

    Spatial size variations of labial palps, gills and the adductor muscle of the invasive feral oyster, Crassostrea gigas, were studied along two gradients of suspended particulate matter (SPM) concentrations in the temperate macrotidal Bourgneuf Bay, (annual mean SPM concentration gradient of 21.0-154.0 mg l -1) and the adjacent Loire Estuary (annual mean SPM concentration gradient of 24.1-630.4 mg l -1) on the French Atlantic Coast. The gill-to-palp (G:P) ratios decreased with increasing turbidity, both in the bay and the estuary. Changes in G:P ratios were chiefly related to palp area variations, increasing gradually from low turbidity to very high-turbidity sites, while gill area showed no clear relationship with turbidity conditions. The G:P ratio, showing a significant relationship ( r2 = 0.97) with SPM concentrations, is proposed as a pallial organ index of oyster acclimation to turbidity conditions. The area of the striated part of the adductor muscle was always greater than that of the smooth one, and adductor muscle area tended to decrease when SPM concentration increased. These observations show the morphological capacity of the oyster C. gigas to tolerate SPM concentrations above the feeding cessation thresholds previously determined experimentally. They also suggest that pallial organ size variations could help explain the success of recent feral oyster invasions in temperate turbid ecosystems.

  13. Cellular and Transcriptional Responses of Crassostrea gigas Hemocytes Exposed in Vitro to Brevetoxin (PbTx-2

    Directory of Open Access Journals (Sweden)

    Alcir Luiz Dafre

    2012-03-01

    Full Text Available Hemocytes mediate a series of immune reactions essential for bivalve survival in the environment, however, the impact of harmful algal species and their associated phycotoxins upon bivalve immune system is under debate. To better understand the possible toxic effects of these toxins, Crassostrea gigas hemocytes were exposed to brevetoxin (PbTx-2. Hemocyte viability, monitored through the neutral red retention and MTT reduction assays, and apoptosis (Hoechst staining remained unchanged during 12 h of exposure to PbTx-2 in concentrations up to 1000 µg/L. Despite cell viability and apoptosis remained stable, hemocytes incubated for 4 h with 1000 µg/L of PbTx-2 revealed higher expression levels of Hsp70 (p < 0.01 and CYP356A1 ( p < 0.05 transcripts and a tendency to increase FABP expression, as evaluated by Real-Time quantitative PCR. The expression of other studied genes (BPI, IL-17, GSTO, EcSOD, Prx6, SOD and GPx remained unchanged. The results suggest that the absence of cytotoxic effects of PbTx-2 in Crassostrea gigas hemocytes, even at high concentrations, allow early defense responses to be produced by activating protective mechanisms associated to detoxification (CYP356A1 and possibly FABP and stress (Hsp70, but not to immune or to antioxidant (BPI, IL-17, EcSOD, Prx6, GPx and SOD related genes.

  14. Hybridization Between Natural Extract of Angelica gigas Nakai and Inorganic Nanomaterial of Layered Double Hydroxide via Reconstruction Reaction.

    Science.gov (United States)

    Kim, Tae-Hyun; Kim, Hyoung-Jun; Choi, Ae-Jin; Choi, Hyun-Jin; Oh, Jae-Min

    2016-01-01

    We have hybridized layered double hydroxide (LDH) with Angelica gigas Nakai root extract (AGNR) through reversible dehydration-rehydration reaction which is known as reconstruction. LDHs having well-ordered hydrotalcite-like crystal structure and average size 250 ± 20 nm were prepared by hydrothermal method. The root of Angelica gigas Nakai, which has been utilized in the treatment of female disorders as herbal medicine, was treated with methanol to obtain extract. Pristine LDHs were calcined at 400 °C for 8 hours to obtain layered double oxide (LDO), which was further dispersed into extract solution with various AGNR/LDO weight ratios, 0.11, 0.21 and 0.43. The extract content in each hybrid increased in proportion to initial AGNR/LDO ratio, showing the highest content of ~12%. The zeta potential of LDH shifted from +44 mV to +20 mV upon hybridization with extract, which was attributed to the adsorption of negatively charged organic moieties in AGNR on LDH surface. The scanning electron microscopic (SEM) results exhibited that the random stacking of LDH nanolayers resulted in LDH-AGNR hybrid with house-of-cards structure, of which inter-particle cavity serves nano-reservoir for natural extract. According to quantitative analyses, it was revealed that the content of active components in AGNR increased when they were hybridized with LDHs compared with those in AGNR alone.

  15. Molecular Characterization and Functional Analysis of a Putative Octopamine/Tyramine Receptor during the Developmental Stages of the Pacific Oyster, Crassostrea gigas

    Science.gov (United States)

    Ji, Peng; Xu, Fei; Huang, Baoyu; Li, Yingxiang; Li, Li; Zhang, Guofan

    2016-01-01

    Octopamine (OA) and its precursor, tyramine (TA), participate in invertebrate development such as growth, maturation, and reproduction by activating their corresponding G protein-coupled receptors (GPCRs). Although OA was first discovered in mollusks (octopus), subsequent studies on OA, TA and related receptors have primarily been conducted in Ecdysozoa, especially in insects. Accordingly, only limited reports on OA/TA receptors in mollusks are available and their physiological roles remain unclear. Here, a full-length cDNA encoding a putative 524 amino acid OA/TA receptor (CgGPR1) was isolated from the Pacific oyster Crassostrea gigas. CgGPR1 was most closely related to the Lymnaea stagnalis OA receptor OAR2 in sequence. Phylogenetic analysis showed that CgGPR1 belongs to a poorly studied subfamily of invertebrate OA/TA receptors. The spatio-temporal expression of CgGPR1 in C. gigas larvae was examined by quantitative real-time PCR and Western blot analysis. CgGPR1 was expressed during all developmental stages of C. gigas with higher levels at mid-developmental stages, indicating its potential role in embryogenesis and tissue differentiation. Immunoreactive fluorescence of CgGPR1 was mainly observed in the velum, foot, gill and mantle of C. gigas larvae. CgGPR1 transcripts were detected in all the tested organs of adult C. gigas, with highest level in the mantle. Pharmacological analysis showed that cAMP and Ca2+ concentrations remained unchanged in HEK293 cells expressing CgGPR1 upon addition of OA, TA or related amines, suggesting that CgGPR1 modulates other unknown molecules rather than cAMP and Ca2+. Our study sheds light on CgGPR1 function in oysters. PMID:27992549

  16. The immunological capacity in the larvae of Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Song, Xiaorui; Wang, Hao; Xin, Lusheng; Xu, Jiachao; Jia, Zhihao; Wang, Lingling; Song, Linsheng

    2016-02-01

    As the immune system has not fully developed during early developmental stages, bivalve larvae are more susceptible for pathogens, which frequently leads to the significant mortality in hatcheries. In the present study, the development of immune system and its response against bacteria challenge were investigated in order to characterize the repertoire of immunological capacity of Pacific oyster Crassostrea gigas during the ontogenesis. The phagocytosis was firstly observed in the early D-veliger larvae (17 hpf), especially in their velum site, which indicated the appearance of functional hemocytes during early D-veliger larvae stage. The whole-mount immunofluorescence assay of three pattern recognition receptors (integrin β-1, caspase-3 and C-type lectin 3) and one immune effector gene (IL17-5) was performed in blastula, early D-veliger and umbo larvae, suggested that velum and digestive gland were the potential sites of immune system in the larvae. The lowest activities of antioxidant enzymes (superoxide dismutase and catalase) and hydrolytic enzyme (lysozyme), as well as descended expression levels of 12 immune genes at the transition between embryogenesis and planktonic, indicated that the larvae at hatching (9 hpf) were in hypo-immunity. While the ascending activities of enzymes and expression levels of seven immune genes during the trochophore stage (15 hpf) suggested the initiation of immune system. The steadily increasing trend of all the 12 candidate genes at the early umbo larvae (120 h) hinted that the immune system was well developed at this stage. After bacterial challenge, some immune recognition (TLR4) and immune effector (IL17-5 and defh2) genes were activated in blastula stage (4 hpf), and other immune genes were up regulated in D-veliger larvae, indicating that the zygotic immune system could respond earlier against the bacterial challenge during its development. These results indicated that the cellular and humoral immune components

  17. Cultivo de la ostra Crassostrea gigas (Thunberg, 1795 en un vivero artesanal, La arena, Casma

    Directory of Open Access Journals (Sweden)

    Paul Baltazar

    2014-06-01

    Full Text Available El presente trabajo describe la metodología empleada para el cultivo de la ostra del Pacífico Crassostrea gigas en un vivero artesanal, en el Centro Acuícola La Arena, Casma. Se utilizó reproductores en fase intermedia de madurez gonádica procedentes de líneas de cultivo del Centro Acuícola. El acondicionamiento se realizó en tanques de fibra de vidrio de 1000 L, con agua de mar sin filtrar a una temperatura de 27 ± 0,9 oC; adicionalmente se les alimentó con fécula de maíz y microalgas obtenidas en el lugar y cultivadas al aire libre. El desove se indujo para un grupo sólo por estimulación térmica (30 a 31 oC y para el otro se añadió además peróxido de hidrógeno, a lo cual se presentaron respuestas diferentes. A los 20 minutos después de la fertilización se observó, en el 100% de huevos fecundados, el cuerpo polar definido y a las 24 horas las larvas veliger. Las larvas alcanzaron el estado de pediveliger luego de 20 días de cultivo, con tallas promedios de 237 ± 10 µm. Para la fijación de las larvas se utilizó conchuela molida (300 µm, plástico negro lijado y valvas de ostras. A los 33 días se obtuvieron semillas con tallas medias de 1262 ± 204 µm las que fueron colocadas en pearl net para su desarrollo en el mar. A los 30 días de la siembra en el mar, la talla promedio de las postlarvas alcanzó los 13,4 ± 3,4 mm. El trabajo muestra las ventajas de la metodología descrita en la producción masiva de semillas en un vivero artesanal.

  18. Transcriptional changes in Crassostrea gigas oyster spat following a parental exposure to the herbicide diuron

    Energy Technology Data Exchange (ETDEWEB)

    Rondon, R. [Ifremer, IHPE UMR 5244, Univ. Perpignan Via Domitia, CNRS, Univ. Montpellier, F-34095 Montpellier (France); Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan (France); Akcha, F. [Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France); Alonso, P. [CNRS, IHPE UMR 5244, Univ. Perpignan Via Domitia, IFREMER, Univ. Montpellier, F-34095 Montpellier (France); Menard, D.; Rouxel, J. [Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France); Montagnani, C., E-mail: cmontagn@ifremer.fr [Ifremer, IHPE UMR 5244, Univ. Perpignan Via Domitia, CNRS, Univ. Montpellier, F-34095 Montpellier (France); Mitta, G.; Cosseau, C.; Grunau, C. [Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan (France)

    2016-06-15

    Highlights: • Remodeling of the transcriptome of the offspring of oysters exposed to diuron (838 gene which expression is modulated). • Functions related to cytoskeleton organization, translation, ATP synthesis were activated. • Functions linked to transcription and protein degradation were altered. • Up-regulation of genes involved in energy production, protein synthesis and mitosis. • Catch-up growth phenomenon could allow the spats to compensate for slower growth. - Abstract: The Pacific oyster Crassostrea gigas is the main oyster species produced in the world, and a key coastal economic resource in France. High mortalities affect Pacific oysters since 2008 in France and Europe. Their origins have been attributed to a combination of biotic and abiotic factors, underlining the importance of environment quality. The impact of water pollution has been pointed out and one of the pollutants, the genotoxic herbicide diuron, occurs at high concentrations all along the French coasts. Previous work has revealed that a parental exposure to diuron had a strong impact on hatching rates and offspring development even if spats were not exposed to diuron themselves. In this study, we explored for the first time the transcriptional changes occurring in oyster spats (non exposed) originating from genitors exposed to an environmentally relevant concentration of diuron during gametogenesis using the RNAseq methodology. We identified a transcriptomic remodeling revealing an effect of the herbicide. Different molecular pathways involved in energy production, translation and cell proliferation are particularly disturbed. This analysis revealed modulated candidate genes putatively involved in response to oxidative stress and mitochondrial damage in offspring of genitors exposed to diuron. Complementary measures of the activity of enzymes involved in these latter processes corroborate the results obtained at the transcriptomic level. In addition, our results suggested an

  19. Effets apoptotiques du dinoflagellé Alexandrium catenella et de ses toxines sur les cellules immunitaires de l'huître creuse Crassostrea gigas. Implications dans la susceptibilité de l'huître aux vibrioses

    OpenAIRE

    Abi-Khalil, Célina

    2016-01-01

    In France, oyster sites in the Mediterranean Sea are regularly confronted to high mortalities of Crassostrea gigas juveniles and to recurrent blooms of the dinoflagellate producer of Paralytic Shellfish Toxins (PSTs), Alexandrium catenella. Among the pathogens associated to these mortalities, we found Vibrio strains belonging to Splendidus clade. We here focus on theinteractions between A. catenella and the oyster C. gigas challenged with pathogenic vibrios. In the first part of this work, we...

  20. Crecimiento del ostión Crassostrea gigas (Thunberg, 1795 cultivado en el estero La Piedra, Sinaloa, México

    Directory of Open Access Journals (Sweden)

    A. M. Góngora-Gómez

    2012-01-01

    Full Text Available Se realizó un ciclo de engorda (noviembre 2004- mayo 2005 con el ostión Crassostrea gigas en el estero La Piedra, Guasave (Sinaloa, México, usando canastas suspendidas en una línea madre para evaluar su crecimiento y supervivencia. Se utilizaron 10,000 semillas (3.5 ± 0.5 mm de altura inicial. Los valores promedios de los parámetros del agua fueron: temperatura, 22.2 ± 3.2°C; oxígeno disuelto, 6.8 ± 2.3 mg/l; y salinidad, 32.8 ± 3.14 ups; mientras que el promedio de la concentración de clorofila a fue de 3.2 ± 0.8 mg/m3. Los animales mostraron un crecimiento de 0.26 mm/día para la altura de su concha y 0.42 g/día de peso corporal. El índice de condición mostró un ligero descenso en el último mes de cultivo de 9.54 a 8.68. La fórmula: Peso = -15.4352 + 0.7968 Altura (r2 = 88.29; = 12.88; F = 37,71; P = 0.0017 describe la relación entre el peso y la altura de C. gigas en el cultivo. Se obtuvieron diferencias significativas entre el peso e índice de condición (P = 0.0023. Se registró una mortalidad total de 12%. Los resultados obtenidos indican que la temporada otoño-pri-mavera es favorable para el cultivo del ostión del Pacífico C. gigas en el estero La Piedra, Guasave, Sinaloa, ya que alcanzó la talla comercial (109.8 mm y 88.7 g en siete meses de cultivo.

  1. The raised coral reef complex of the Kenyan coast: Tridacna gigas U-series dates and geological implications

    Science.gov (United States)

    Accordi, Giovanni; Brilli, Mauro; Carbone, Federico; Voltaggio, Mario

    2010-08-01

    The Kenyan coast is characterized by a raised fossil reef complex cut by a series of morphological terraces. Shallow subtidal coralgal facies containing Tridacna gigas shells are found at different heights along the coast. Alpha-spectrometric U-series methods were applied to 18 T. gigas samples from different locations along this reef complex with an elevation range from 0 to 15 m above present sea level to obtain chronological information. Apparent U-Th ages, based on the assumption of closed system behaviour, correspond to early marine isotope stage (MIS) 5 ( n = 17) and MIS 7 ( n = 1). However, initial 234U/ 238U activity ratios exhibit a wide range, in many cases much greater than present seawater, which is likely to be associated with diagenetic alteration and migration of U-series isotopes. For this reason, we attempted a form of open system isochron dating after separating the Tridacna samples into three different groups on the basis of current elevation and distribution along the coast. An 'isochron' age of 120 ± 4 ka (1 σ) was obtained for the higher elevation group, placed in the terraced central coastal area; another age, statistically undistinguishable from the previous one, of 118 ± 7 ka (1 σ) was obtained for the group confined along the northern coast. These two groups correspond to a transgressive-regressive cycle connected to the maximum sea level highstand during the MIS 5e. A third 'isochron' age of 100 ± 4 ka (1 σ) was obtained for the group confined along the southern coast, encompassing part of the isotopic substages MIS 5c and d. Based on these data, and on the ecology of T. gigas whose optimal present-day depth range can be considered of 3-10 m below sea level, a maximum tectonic coastal uplift rate of between, respectively, 0.12 and 0.18 mm a -1 was calculated for the period since formation of these shells, and then the paleobathymetry of Tridacna facies has been inferred.

  2. Comparison of haemocytic parameters among flat oyster Ostrea edulis stocks with different susceptibility to bonamiosis and the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Comesaña, Pilar; Casas, Sandra M; Cao, Asunción; Abollo, Elvira; Arzul, Isabelle; Morga, Benjamin; Villalba, Antonio

    2012-03-01

    Farming of the flat oyster Ostrea edulis in Europe is severely constrained by the protozoan Bonamia ostreae. The introduction of the resistant species Crassostrea gigas has been a relief for the farmers, while the pilot programmes to select O. edulis strains resistant to bonamiosis performed in various countries can be seen as a promising strategy to minimise the effects of bonamiosis. However, the physiological bases of this differential susceptibility remain unknown. A search for an explanation of the intra and interspecific differences in oyster susceptibility to bonamiosis was accomplished by comparing some immune parameters among various O. edulis stocks and C. gigas. On December 2003, naïve and Bonamia-relatively resistant flat oysters from Ireland, Galician flat oysters and Pacific oysters C. gigas were deployed in a Galician area affected by bonamiosis; haemolymph samples were taken in February and May 2004. A new oyster deployment at the same place was carried out on June 2004 and haemolymph sampling was performed on April 2005. On November 2004, new sets of Irish flat oysters and C. gigas were deployed in Ireland and haemolymph sampling was performed in June 2005. Various haemocytic parameters were measured: total and differential haemocyte count, phagocytic ability, respiratory burst (superoxide anion [O(2)(-)] and hydrogen peroxide [H(2)O(2)]) and nitric oxide [NO] production. The comparison of the parameters was carried out at 3 levels: (1) between O. edulis and C. gigas, (2) among O. edulis stocks with different susceptibility to bonamiosis, and (3) between Bonamia-infected and non infected O. edulis. In addition, haemocyte-B. ostreaein vitro encounters were performed to analyse interspecific differences in the haemocytic respiratory burst, using flow cytometry. Significant differences associated with total and differential haemocyte count, and respiratory burst between O. edulis and C. gigas were detected, which could be linked to differences in

  3. Proteolytic activity of the Gymnorhynchus gigas plerocercoid: purification and properties of a collagenase from the crude extract.

    Science.gov (United States)

    Vázquez-López, C; de Armas-Serra, C; Giménez-Pardo, C; Rodríguez-Caabeiro, F

    1999-01-01

    The present report demonstrates that the Gymnorhynchus gigas plerocercoid possesses various types of endo- and exoproteases with activity against general (azocoll, azocasein, and azoalbumin) and specific substrates (elastin, keratin, collagen, hemoglobin, fibrinogen, plasma, and immunoglobulin G). The activity against collagen is principally due to a 24-kDa collagenase with an isoelectric point of 7.5 and without isoforms or sugar residues. Moreover, its high degree of proteolytic activity against collagen under conditions similars to those encountered by the parasite in its hosts (pH and temperature) and its similarity to metallo- and cysteine proteases (the principal protease types implicated in degradation of tissues) suggests the importance of this molecule as a lytic enzyme principally implicated in penetration processes across the teleost muscle or/and into the gastrointestinal system of elasmobranch fishes as well as in molting processes.

  4. The Giant Pacific Oyster (Crassostrea gigas) as a modern analogue for fossil ostreoids

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz; Böhm, Florian; Rickaby, Rosalind E.M.;

    2013-01-01

    variability is possible. Here, two shell structures of modern Giant Pacific Oysters (Crassostrea gigas), the chalky substance and foliate layers, have been sampled for trace element distributions (Mg, Sr, Mn) and stable isotope variability (C, O, Ca). Oxygen isotopes exhibit a clear seasonal signature. Mean...... carbon isotope values of different oysters agree within 0.1 ‰, but ontogenic variability is complicated by shell growth patterns and potential small vital effects. The calcium isotope ratios are found to be constant throughout ontogeny within analytical precision at a value of δ44/40Ca = 0.68 ± 0.16 ‰ (2...... sd) SRM 915a which is consistent with other bivalve species. Calcium isotope ratios in oyster shell material might thus be a possible proxy for palaeo seawater calcium isotope ratios. Element/Ca ratios are significantly higher in the chalky substance than in the foliate layers and especially high Sr...

  5. Molecular evidence of the protozoan parasite Marteilia refringens in Crassostrea gigas and Crassostrea corteziensis from the Gulf of California

    Directory of Open Access Journals (Sweden)

    José Manuel Grijalva-Chon

    2015-09-01

    Full Text Available The search for exotic pathogens related to the outbreaks and in surveillance samplings of the Mexican oyster farms, is a recent activity achieved by academic institutions and state committees for Aquatic Animal Health, with remarkable results. In samples of Crassostrea gigas collected through December 2009, January 2010 and November 2010, and of C. corteziensis in September 2011, the protozoan Marteilia refringens was detected for the first time in the Gulf of California. The carrier oysters were from cultures without abnormal mortality rates, whereby, the use of histology, in situ hybridization and transmission electron microscopy studies are necessary to determine if M. refringens has become established in the Gulf of California oyster cultures. Detection of M. refringens is of great concern to the global oyster farming industry.

  6. Characteristics of the Aragonitic Layer in Adult Oyster Shells, Crassostrea gigas: Structural Study of Myostracum including the Adductor Muscle Scar

    Directory of Open Access Journals (Sweden)

    Seung-Woo Lee

    2011-01-01

    Full Text Available Myostracum, which is connected from the umbo to the edge of a scar, is not a single layer composed of prismatic layers, but a hierarchically complex multilayered shape composed of minerals and an organic matrix. Through the analysis of the secondary structure, the results revealed that a β-antiparallel structure was predominant in the mineral phase interface between the myostracum (aragonite and bottom folia (calcite. After the complete decalcification and deproteinization, the membrane obtained from the interface between the myostracum buried in upper folia, and the bottom folia was identified as chitin. The transitional zone in the interface between the adductor muscle scar and folia are verified. The myostracum disappeared at the edge of the scar of the posterior side. From this study, the entire structure of the myostracum from the adult oyster shell of Crassostrea gigas could be proposed.

  7. The specifically enhanced cellular immune responses in Pacific oyster (Crassostrea gigas) against secondary challenge with Vibrio splendidus.

    Science.gov (United States)

    Zhang, Tao; Qiu, Limei; Sun, Zhibin; Wang, Lingling; Zhou, Zhi; Liu, Rui; Yue, Feng; Sun, Rui; Song, Linsheng

    2014-07-01

    The increasing experimental evidences suggest that there are some forms of specific acquired immunity in invertebrates, but the underlying mechanism is not fully understood. In the present study, Pacific oyster (Crassostrea gigas) stimulated primarily by heat-killed Vibrio splendidus displayed stronger immune responses at cellular and molecular levels when they encountered the secondary challenge of live V. splendidus. The total hemocyte counts (THC) increased significantly after the primary stimulation of heat-killed V. splendidus, and it increased even higher (p oysters received the secondary stimulation with live V. splendidus, and the phagocytic rate was also enhanced significantly (p oysters after the secondary stimulation of V. splendidus were higher (p oyster with specifically enhanced phagocytosis and rapidly promoted regeneration of circulating hemocytes when the primed oysters encountered the secondary challenge with V. splendidus.

  8. Conformational changes in proteins recovered from jumbo squid (Dosidicus gigas) muscle through pH shift washing treatments.

    Science.gov (United States)

    Cortés-Ruiz, Juan A; Pacheco-Aguilar, Ramón; Ramírez-Suárez, Juan C; Lugo-Sánchez, Maria E; García-Orozco, Karina D; Sotelo-Mundo, Rogerio R; Peña-Ramos, Aida

    2016-04-01

    Conformational and thermal-rheological properties of acidic (APC) and neutral (NPC) protein concentrates were evaluated and compared to those of squid (Dosidicus gigas) muscle proteins (SM). Surface hydrophobicity, sulfhydryl status, secondary structure profile, differential scanning calorimetry and oscillatory dynamic rheology were used to evaluate the effect of treatments on protein properties. Acidic condition during the washing process (APC) promoted structural and conformational changes in the protein present in the concentrate produced. These changes were enhanced during the heat setting of the corresponding sol. Results demonstrate that washing squid muscle under the proposed acidic conditions is a feasible technological alternative for squid-based surimi production improving its yield and gel-forming ability.

  9. Production and functional evaluation of a protein concentrate from giant squid (Dosidicus gigas) by acid dissolution and isoelectric precipitation.

    Science.gov (United States)

    Cortés-Ruiz, Juan A; Pacheco-Aguilar, Ramón; Elena Lugo-Sánchez, M; Gisela Carvallo-Ruiz, M; García-Sánchez, Guillermina

    2008-09-15

    A protein concentrate from giant squid (Dosidicus gigas) was produced under acidic conditions and its functional-technological capability evaluated in terms of its gel-forming ability, water holding capacity and colour attributes. Technological functionality of the concentrate was compared with that of squid muscle and a neutral concentrate. Protein-protein aggregates insoluble at high ionic strength (I=0.5M), were detected in the acidic concentrate as result of processing with no preclusion of its gel-forming ability during the sol-to-gel thermal transition. Even though washing under acidic condition promoted autolysis of the myosin heavy chain, the acidic concentrate displayed an outstanding ability to gel giving samples with a gel strength of 455 and 1160gcm at 75% and 90% compression respectively, and an AA folding test grade indicative of high gel strength, elasticity, and cohesiveness. The process proved to be a good alternative for obtaining a functional protein concentrate from giant squid muscle.

  10. Analysis of the tenderisation of jumbo squid (Dosidicus gigas) meat by ultrasonic treatment using response surface methodology.

    Science.gov (United States)

    Hu, Yaqin; Yu, Hiaxia; Dong, Kaicheng; Yang, Shuibing; Ye, Xingqian; Chen, Shiguo

    2014-10-01

    Due to its unique structure, jumbo squid (Dosidicus gigas) meat is sensitive to heat treatment, which makes the traditional squid products taste tough and hard. This study aimed to tenderise jumbo squid meat through ultrasonic treatment. Response surface methodology (RSM) was used to predict the tenderising effect of various treatment conditions. According to the results of RSM, the optimal conditions appeared to be a power of 186.9 W, a frequency of 25.6 kHz, and a time of 30.8 min, and the predicted values of flexibility and firmness under these optimal conditions were 2.40 mm and 435.1 g, respectively. Protein degradation and a broken muscle fibre structure were observed through histological assay and SDS-PAGE, which suggests a satisfactory tenderisation effect.

  11. Description of plastic remains found in the stomach contents of the jumbo squid Dosidicus gigas landed in Ecuador during 2014.

    Science.gov (United States)

    Rosas-Luis, Rigoberto

    2016-12-15

    Squids are active and opportunistic predators that feed on a wide range of prey. Their active movements in the water column and their voracity promote a high consumption of food. In the pelagic environment off Ecuador, marine pollution is characterized by plastic debris with a mainland origin, including plastics trash of fishing gears. The objective of this work was to describe the presence of plastic remains in the stomach contents of Dosidicus gigas caught off the coast of Ecuador. Results demonstrated that 12% of the stomachs contained plastic remains. These plastics were identified as multifilament of polyethylene lines and polyvinyl chloride remains. Findings of this work could be related to an increase in the discharge of solid materials in the water column, increasing the probability to be ingested by the jumbo squid.

  12. Effect of Bovine Plasma Protein on Autolysis and Gelation of Protein Extracted from Giant Squid (Dosidicus gigas Mantle

    Directory of Open Access Journals (Sweden)

    Laura Raquel Marquez-Alvarez

    2015-01-01

    Full Text Available The effect of bovine plasma protein (BPP on the inhibition of autolytic activity and its effect on the gelling properties of a protein concentrate (PC obtained from jumbo squid (Dosidicus gigas mantle were investigated. Sols and gels were prepared from the PC by adding different amounts of BPP (0, 1, and 2%. Dynamic oscillatory measurements indicated that systems with 1% BPP had a higher elastic modulus (G′, in which hydrophobic interactions were favored. Concerning the technological and textural quality of the gels, BPP caused a greater water holding capacity (WHC, force, cohesiveness, and elasticity, probably due to improvement of the electrostatic and hydrophobic interactions during gel formation. Scanning electron microscopy (SEM allowed visualization of the formation of more rigid and ordered gels with less porosity when BPP was added. Therefore, the addition of BPP improved the gelling capacity of proteins extracted from giant squid.

  13. High cone-angle x-ray computed micro-tomography with 186 GigaVoxel datasets

    Science.gov (United States)

    Myers, Glenn R.; Latham, Shane J.; Kingston, Andrew M.; Kolomazník, Jan; Krajíček, Václav; Krupka, TomáÅ.¡; Varslot, Trond K.; Sheppard, Adrian P.

    2016-10-01

    X-ray computed micro-tomography systems are able to collect data with sub-micron resolution. This high- resolution imaging has many applications but is particularly important in the study of porous materials, where the sub-micron structure can dictate large-scale physical properties (e.g. carbonates, shales, or human bone). Sample preparation and mounting become diffiult for these materials below 2mm diameter: consequently, a typical ultra-micro-CT reconstruction volume (with sub-micron resolution) will be around 3k x 3k x 10k voxels, with some reconstructions becoming much larger. In this paper, we discuss the hardware (MPI-parallel CPU/GPU) and software (python/C++/CUDA) tools used at the ANU CTlab to reconstruct 186 GigaVoxel datasets.

  14. Cellular and biochemical responses of the oyster Crassostrea gigas to controlled exposures to metals and Alexandrium minutum

    Energy Technology Data Exchange (ETDEWEB)

    Haberkorn, Hansy; Lambert, Christophe; Le Goïc, Nelly [Laboratoire des Sciences de l‘Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané (France); Quéré, Claudie [IFREMER Centre de Brest, Laboratoire de Physiologie des Invertébrés, Unité Physiologie Fonctionnelle des Organismes Marins, BP 70, 29280 Plouzané (France); Bruneau, Audrey; Riso, Ricardo; Auffret, Michel [Laboratoire des Sciences de l‘Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané (France); Soudant, Philippe, E-mail: Philippe.Soudant@univ-brest.fr [Laboratoire des Sciences de l‘Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané (France)

    2014-02-15

    Highlights: •Oysters, C. gigas, were exposed to both metals and PST-producer A. minutum. •Oysters exposed to metals accumulated about thirty-six times less PSTs. •Exposure to both metals and A. minutum induced antagonistic or synergetic effects. -- Abstract: Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd–Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd–Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd–Cu induced significant changes in neutral lipids (increase in diacylglycerol – DAG – and decrease in sterols) and phospholipids (decreases in phosphatidylcholine, phosphatidylethanolamine, cardiolipin and ceramide aminoethylphosphonate) of digestive gland suggesting that lipid metabolism disruptions and/or lipid peroxidation have occurred. Simultaneously, concentrations, percentages of dead cells and phenoloxidase activity of hemocytes increased in oysters exposed to metals while reactive oxygen species production of hemocytes decreased. Feeding on the harmful dinoflagellate A. minutum resulted in significant decreases in monoacylglycerol (MAG) and DAG and ether glycerides (EG), as well as significant increases in hemocyte concentration and phagocytic activity as compared to oysters fed T. lutea. Finally, the present study revealed that short-term, simultaneous exposure to Cd–Cu and A. minutum may induce antagonistic (i.e. hemocyte concentration and phagocytosis) or synergic (i.e. DAG content in

  15. Jumbo squid (Dosidicus gigas) mantle collagen: extraction, characterization, and potential application in the preparation of chitosan-collagen biofilms.

    Science.gov (United States)

    Uriarte-Montoya, Mario Hiram; Arias-Moscoso, Joe Luis; Plascencia-Jatomea, Maribel; Santacruz-Ortega, Hisila; Rouzaud-Sández, Ofelia; Cardenas-Lopez, Jose Luis; Marquez-Rios, Enrique; Ezquerra-Brauer, Josafat Marina

    2010-06-01

    Collagen-based biomaterials have been widely used due to its binding capabilities. However the properties and potential use of new collagen sources are still under investigation. Fish by-products are an excellent source of collagen. Thus, acid-soluble collagen (ASC) was extracted, and biochemical and physicochemically characterized from one under-utilized specie, jumbo squid (Dosidicus gigas). In addition, commercial chitosan (95-50%)-ASC (5-50%) blend films were successfully prepared by casting, and characterized by infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The molecular masses of the ASC subunits were about 190kDa, 110kDa, and 97kDa, the content of proline and hydroxyproline was 10.9% and 2.8%, respectively. The FT-IR and nuclear magnetic resonance spectra ((1)H NMR) confirmed collagen peptidic crosslinks, and one endothermic peak was found at 119 degrees C. The FT-IR spectrum showed that chitosan and ASC remain linked into the films mainly due to hydrogen bonding. The 85:15 (chitosan:ASC) ratio was selected for its thermal and mechanical analyses. The thermograms of this film indicated the presence of two peaks, one at 87-98 degrees C and the other at 142-182 degrees C. The chitosan:ASC blend produced a transparent and brittle film, with high percentage of elongation at break, and low tensile strength in comparison to chitosan films. D. gigas mantle might be useful as a new source of plasticizer agent in the preparation of biofilms in composites with chitosan.

  16. Gametogenesis in the Pacific Oyster Crassostrea gigas: A Microarrays-Based Analysis Identifies Sex and Stage Specific Genes

    Science.gov (United States)

    Dheilly, Nolwenn M.; Lelong, Christophe; Huvet, Arnaud; Kellner, Kristell; Dubos, Marie-Pierre; Riviere, Guillaume; Boudry, Pierre; Favrel, Pascal

    2012-01-01

    Background The Pacific oyster Crassostrea gigas (Mollusca, Lophotrochozoa) is an alternative and irregular protandrous hermaphrodite: most individuals mature first as males and then change sex several times. Little is known about genetic and phenotypic basis of sex differentiation in oysters, and little more about the molecular pathways regulating reproduction. We have recently developed and validated a microarray containing 31,918 oligomers (Dheilly et al., 2011) representing the oyster transcriptome. The application of this microarray to the study of mollusk gametogenesis should provide a better understanding of the key factors involved in sex differentiation and the regulation of oyster reproduction. Methodology/Principal Findings Gene expression was studied in gonads of oysters cultured over a yearly reproductive cycle. Principal component analysis and hierarchical clustering showed a significant divergence in gene expression patterns of males and females coinciding with the start of gonial mitosis. ANOVA analysis of the data revealed 2,482 genes differentially expressed during the course of males and/or females gametogenesis. The expression of 434 genes could be localized in either germ cells or somatic cells of the gonad by comparing the transcriptome of female gonads to the transcriptome of stripped oocytes and somatic tissues. Analysis of the annotated genes revealed conserved molecular mechanisms between mollusks and mammals: genes involved in chromatin condensation, DNA replication and repair, mitosis and meiosis regulation, transcription, translation and apoptosis were expressed in both male and female gonads. Most interestingly, early expressed male-specific genes included bindin and a dpy-30 homolog and female-specific genes included foxL2, nanos homolog 3, a pancreatic lipase related protein, cd63 and vitellogenin. Further functional analyses are now required in order to investigate their role in sex differentiation in oysters. Conclusions

  17. Effects of chronic exposure to ionising radiation in the Pacific oyster Crassostrea gigas

    Energy Technology Data Exchange (ETDEWEB)

    Fievet, B.; Devos, A.; Voiseux, C.; Leconte-Pradines, C. [Institut de Radioprotection et de Surete' Nucleaire (France); Dallas, L.; Jha, A. [University of Plymouth (United Kingdom)

    2014-07-01

    The Cotentin peninsula (Normandy, France) hosts nuclear industry facilities which operate with controlled discharges of radionuclides in the marine environment. Compared to natural radioactivity, the increase by artificial radionuclides is small but constant. As a consequence, marine species are chronically exposed to low additional doses of ionizing radiation (IR). The effects of chronic exposure to radionuclides were investigated in early stages of development of the Japanese oyster Crassostrea gigas. On the basis of literature, mollusks are expected to be particularly resistant to acute IR (UNSCEAR, 1996. Sources and effects of ionizing radiation. Report to the General Assembly, with Scientific Annex. 86 p). Two different chronic exposure conditions consisted in external ({sup 137}Cs) and internal ({sup 241}Am) irradiation for two weeks. Biological endpoints were analyzed in parallel at both the integrated (growth) and molecular (target stress gene expression) levels. To identify potential biological targets of IR, oysters were first exposed to very high dose rates and radionuclide activities with the perspective to reduce the levels and to derive dose-response curves. Although the initial exposure levels ({sup 137}Cs 30 000 μGy.h{sup -1}; {sup 241}Am 57 000 Bq.L{sup -1}) were many orders of magnitude higher than those encountered in the natural environment, no significant change in the measured parameters was observed. This result was surprising because data from the literature showed that exposure of mussel Mytilus edulis to {sup 3}H at lower doses rates (10-100 μGy.h{sup -1}) induced DNA damage in hemocytes (Jha et al., 2005. Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 586, 47-57). To understand this apparent discrepancy between those two filtering bivalves, a new experiment was performed to compare the response

  18. Organochlorine compounds in blue mussels, Mytilus edulis, and Pacific oysters, Crassostrea gigas, from seven sites in the Lower Saxonian Wadden Sea, Southern North Sea.

    Science.gov (United States)

    Dörr, Barbara; Liebezeit, Gerd

    2009-12-01

    Blue mussels (Mytilus edulis) and Pacific oysters (Crassostrea gigas) collected at seven locations in the Lower Saxonian Wadden Sea in January and February 2007 were analysed for organochlorine compounds. Contaminants were present in all samples, albeit with variable amounts and composition. The highest values were found in the Jade Bay. Congener PCB 153 was the contaminant which had the highest content of all organochlorines tested (475.75-937.39 ng/g lipid). DDT was detected in one sample only while DDD and DDE were found in all samples, the latter with contents up to 351.34 ng/g lipid. No clear differentiation could be made in terms of accumulation of organochlorines for M. edulis and C. gigas. Comparison with data from 2001 to 2006 showed an increase in 2007, which may be due to the different season the samples were taken.

  19. Suppression substractive hybridisation (SSH) and real time PCR reveal differential gene expression in the Pacific cupped oyster, Crassostrea gigas, challenged with Ostreid herpesvirus 1

    OpenAIRE

    2011-01-01

    Virus-induced genes were identified using suppression subtractive hybridisation (SSH) from Pacific cupped oyster, Crassostrea gigas, haemocytes challenged by OsHV-1. A total of 304 clones from SSH forward library were sequenced. Among these sequences, some homologues corresponded to (i) immune related genes (macrophage express protein, IK cytokine, interferon-induced protein 44 or multicopper oxidase), (ii) apoptosis related genes (Bcl-2) and (iii) cell signalling and virus receptor genes (gl...

  20. Expression patterns indicate that BMP2/4 and Chordin, not BMP5-8 and Gremlin, mediate dorsal-ventral patterning in the mollusk Crassostrea gigas.

    Science.gov (United States)

    Tan, Sujian; Huan, Pin; Liu, Baozhong

    2016-12-16

    Though several bilaterian animals use a conserved BMP2/4-Chordin antagonism to pattern the dorsal-ventral (DV) axis, the only lophotrochozoan species in which early DV patterning has been studied to date, the leech Helobdella robusta, appears to employ BMP5-8 and Gremlin. These findings call into question the conservation of a common DV patterning mechanism among bilaterian animals. To explore whether the unusual DV patterning mechanism in H. robusta is also used in other lophotrochozoan species, we investigated the expression of orthologous genes in the early embryo of a bivalve mollusk, Crassostrea gigas. Searching of the genome and phylogenetic analysis revealed that C. gigas possesses single orthologs of BMP2/4, Chordin, and BMP5-8 and no Gremlin homolog. Whole mount in situ hybridization revealed mRNA localization of BMP2/4 and Chordin on the opposite sides of embryos, suggesting the potential involvement of a BMP2/4-Chordin antagonism in DV patterning in this species. Furthermore, universal BMP5-8 expression and the absence of a Gremlin homolog in the C. gigas genome called into question any major contribution by BMP5-8 and Gremlin to early DV patterning in this species. Additionally, we identified seven genes showing asymmetric expression along the DV axis, providing further insight into DV patterning in C. gigas. We present the first report of a Chordin gene in a lophotrochozoan species and of the opposite expression of BMP2/4 (dorsal) and Chordin (ventral) along the D/V axis of a lophotrochozoan embryo. The findings of this study further the knowledge of axis formation in lophotrochozoan species and provide insight into the evolution of the animal DV patterning mechanism.

  1. Development of genomic microsatellite multiplex PCR using dye-labeled universal primer and its validation in pedigree analysis of Pacific oyster ( Crassostrea gigas)

    Science.gov (United States)

    Liu, Ting; Li, Qi; Song, Junlin; Yu, Hong

    2017-02-01

    There is an increasing requirement for traceability of aquaculture products, both for consumer protection and for food safety. There are high error rates in the conventional traceability systems depending on physical labels. Genetic traceability technique depending on DNA-based tracking system can overcome this problem. Genealogy information is essential for genetic traceability, and microsatellite DNA marker is a good choice for pedigree analysis. As increasing genotyping throughput of microsatellites, microsatellite multiplex PCR has become a fast and cost-effective technique. As a commercially important cultured aquatic species, Pacific oyster Crassostrea gigas has the highest global production. The objective of this study was to develop microsatellite multiplex PCR panels with dye-labeled universal primer for pedigree analysis in C. gigas, and these multiplex PCRs were validated using 12 full-sib families with known pedigrees. Here we developed six informative multiplex PCRs using 18 genomic microsatellites in C. gigas. Each multiplex panel contained a single universal primer M13(-21) used as a tail on each locus-specific forward primer and a single universal primer M13(-21) labeled with fluorophores. The polymorphisms of the markers were moderate, with an average of 10.3 alleles per locus and average polymorphic information content of 0.740. The observed heterozygosity per locus ranged from 0.492 to 0.822. Cervus simulations revealed that the six panels would still be of great value when massive families were analysed. Pedigree analysis of real offspring demonstrated that 100% of the offspring were unambiguously allocated to their parents when two multiplex PCRs were used. The six sets of multiplex PCRs can be an important tool for tracing cultured individuals, population genetic analysis, and selective breeding program in C. gigas.

  2. Effects of exposure to oxamyl, carbofuran, dichlorvos, and lindane on acetylcholinesterase activity in the gills of the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Anguiano, Gerardo A; Amador, Alejandro; Moreno-Legorreta, Manuel; Arcos-Ortega, Fabiola; Vazquez-Boucard, Celia

    2010-08-01

    Acetylcholinesterase (AChE) activity has been used to test the exposure of mollusk bivalves to pesticides and other pollutants. The Pacific oyster Crassostrea gigas is a species with a worldwide distribution, and it has a high commercial value. The use of this species as a bioindicator in the marine environment, and the use of measurements of AChE activity in tissues of C. gigas require prior evaluation of organisms exposed to several toxic compounds in the laboratory. In our study, the effects of pesticides on AChE activity in the gills and mantle tissues of C. gigas were analyzed by exposing animals to organophosphate (dichlorvos), carbamate (carbofuran and oxamyl), and organochlorine (lindane) pesticides. Adult Pacific oysters were exposed to several concentrations (0.1-200 microM) of dichlorvos, carbofuran, and oxamyl for 96 h, and lindane (1.0 and 2.5 microM) was applied for 12 days. In gill tissues, all pesticides analyzed caused a decrease in AChE activity when compared to the control unexposed group. The mean inhibition concentration (IC(50)) values were determined for dichlorvos, carbofuran, and oxamyl pesticides. Dichlorvos had the highest toxic effect, with an IC(50) of 1.08 microM; lesser effects were caused by oxamyl and carbofuran, with IC(50)s of 1.67 and 3.03 microM, respectively. This study reports the effects of pesticides with several chemical structures and validates measurement of AChE activity in the gill tissues of C. gigas for use in environmental evaluations or food quality tests.

  3. A comparison of fishery biology of jumbo flying squid, Dosidicus gigas outside three Exclusive Economic Zones in the Eastern Pacific Ocean

    Science.gov (United States)

    Liu, Bilin; Chen, Xinjun; Yi, Qian

    2013-05-01

    Although many studies on the fishery biology of jumbo flying squid, Dosidicus gigas, have been conducted in the coastal areas within Exclusive Economic Zones (EEZs) of various countries due to its commercial and ecological importance, limited biological information is available from waters outside these EEZs. In this paper, we examined D. gigas fishery biology from waters outside Chilean, Peruvian and Costa Rican EEZs, based on the fishery data collected by Chinese jigging vessels during 2006 to 2010. The dominant mantle lengths of D. gigas were 350-450 mm, 250-400 mm and 250-350 mm outside Chilean, Peruvian and Costa Rican EEZs, respectively. Size structure analysis show that a medium-sized group existed mostly in the waters outside the Chilean and Peruvian EEZs, whereas a small-sized group occurred mainly in the waters outside the Costa Rican EEZ. The longevity of the squid outside the Costa Rican EEZ was less than 10 months, while most of those outside Chilean and Peruvian EEZs were about 1-1.5 years and very few large individuals were 1.5-2 years old. A higher percentage of mature individuals existed outside Costa Rican EEZ implying the region as a potential spawning ground, while lower proportions of mature squid outside the Peruvian and Chilean EEZs indicated that spawning may be occurring outside our study area. Spatial differences in sizes at maturity of the squid are thought to be result from different environmental factors especially different temperature and nutrition among the three areas. Stomach-content analysis showed that cannibalism was important in the diet of D. gigas. Stress generated by jigging may increase the incidence of cannibalism.

  4. A comparison of fishery biology of jumbo flying squid,Dosidicus gigas outside three Exclusive Economic Zones in the Eastern Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    LIU Bilin; CHEN Xinjun; YI Qian

    2013-01-01

    Although many studies on the fishery biology of jumbo flying squid,Dosidicus gigas,have been conducted in the coastal areas within Exclusive Economic Zones (EEZs) of various countries due to its commercial and ecological importance,limited biological information is available from waters outside these EEZs.In this paper,we examined D.gigas fishery biology from waters outside Chilean,Peruvian and Costa Rican EEZs,based on the fishery data collected by Chinese jigging vessels during 2006 to 2010.The dominant mantle lengths of D.gigas were 350-450 mm,250-400 mm and 250-350 mm outside Chilean,Peruvian and Costa Rican EEZs,respectively.Size structure analysis show that a medium-sized group existed mostly in the waters outside the Chilean and Peruvian EEZs,whereas a small-sized group occurred mainly in the waters outside the Costa Rican EEZ.The longevity of the squid outside the Costa Rican EEZ was less than 10 months,while most of those outside Chilean and Peruvian EEZs were about 1-1.5 years and very few large individuals were 1.5-2 years old.A higher percentage of mature individuals existed outside Costa Rican EEZ implying the region as a potential spawning ground,while lower proportions of mature squid outside the Peruvian and Chilean EEZs indicated that spawning may be occurring outside our study area.Spatial differences in sizes at maturity of the squid are thought to be result from different environmental factors especially different temperature and nutrition among the three areas.Stomach-content analysis showed that cannibalism was important in the diet of D.gigas.Stress generated by jigging may increase the incidence of cannibalism.

  5. Effects of in vitro exposure to diarrheic toxin producer Prorocentrum lima on gene expressions related to cell cycle regulation and immune response in Crassostrea gigas.

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    Reyna de Jesús Romero-Geraldo

    Full Text Available BACKGROUND: Crassostrea gigas accumulates diarrheic shellfish toxins (DSP associated to Prorocentrum lima of which Okadaic acid (OA causes specific inhibitions of serine and threonine phosphatases 1 and 2A. Its toxic effects have been extensively reported in bivalve mollusks at cellular and physiological levels, but genomic approaches have been scarcely studied. METHODOLOGY/PRINCIPAL FINDINGS: Acute and sub-chronic exposure effects of P. lima were investigated on farmed juvenile C. gigas (3-5 mm. The Pacific oysters were fed with three dinoflagellate concentrations: 0.3, 3, and 30 ×10(3 cells mL-1 along with a nontoxic control diet of Isochrysis galbana. The effects of P. lima on C. gigas were followed by analyzing expression levels of a total of four genes, three involved in cell cycle regulation and one in immune response by polymerase chain reaction and real time quantitative PCR, where changes in time and cell concentration were found. The highest expression levels were found in oysters fed 3 × 10(3 cells mL-1 at 168 h for the cycle regulator p21 protein (9 fold, chromatin assembly factor 1 p55 subunit (8 fold, elongation factor 2 (2 fold, and lipopolysaccharide/β-1, 3 glucan binding protein (13 fold above base line. Additionally, the transcript level of all the genes decreased in oysters fed wich the mixed diet 30 × 10(3 cells mL-1 of dinoflagellate after 72 h and was lowest in the chromatin assembly factor 1 p55 subunit (0.9 fold below baseline. CONCLUSIONS: On C. gigas the whole cell ingestion of P lima caused a clear mRNA modulation expression of the genes involved in cell cycle regulation and immune system. Over-expression could be related to DNA damage, disturbances in cell cycle continuity, probably a genotoxic effect, as well as an activation of its innate immune system as first line of defense.

  6. Horizontal movements, vertical-habitat utilization and diet of the jumbo squid ( Dosidicus gigas) in the Pacific Ocean off Baja California Sur, Mexico

    Science.gov (United States)

    Bazzino, Gastón; Gilly, William F.; Markaida, Unai; Salinas-Zavala, César A.; Ramos-Castillejos, Jorge

    2010-07-01

    We deployed four pop-up archival-transmitting (PAT) tags on jumbo squid ( Dosidicus gigas) collected in the Pacific Ocean off the main entrance to Magdalena Bay on the Baja California peninsula in June 2005. This is the first successful deployment of PAT tags on jumbo squid in an area outside the Gulf of California. Summary data were obtained through the ARGOS satellite system for three of the tags; the fourth tag was physically recovered. All of the tagged squid tended to remain on the shallow continental shelf for several days after tagging and then moved offshore into deeper water. Three of the four squid appeared to migrate in a general southerly direction while the fourth remained offshore of Magdalena Bay. All of the squid spent most daylight hours at depths that were associated with the hypoxic oxygen minimum layer, and at night they spent a majority of time in the upper 50 m of the water column. Stomach content analysis and tag temperature-depth data during the first days after tagging revealed that the squid were feeding on pelagic red crabs ( Pleuroncodes planipes) and several larger, neritic fishes over the continental shelf off Magdalena Bay during a seasonal nearshore upwelling. Comparison of our results with those previously collected in the Gulf of California reveal that Dosidicus gigas can vary its behavior and diet to suit local environmental conditions. This adaptability is likely to be an important factor in the ability of D. gigas to invade and colonize new areas.

  7. Foraging behavior of parasitoid chalcid to the essential oil from bark of Populus pseudo-simonii×P. Nigra and Quadraspidiotus gigas

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Four-armed airflow olfactometer was used to determining the foraging behavior of Pteroptrix longgiclava (Girault) (Hymenoptera: Aphelinidae) and Encar siagigas (Tshumakova) (Hymenoptera: Aphelinidae) to the essential oils which em itted from the healthy bark of Populus pseudo-simonii ×P. Nigra, the infested b ark injured by Quadraspidiotus gigas (Thiem & Gerneck), the body and scale of fi xed 1st-instar-nymph of Q. Gigas. The results from these experiments showed that the volatile oils produced from the injured bark and from the scale of fixed 1s t-instar-nymph had a higher attractive ability to female adults of the two species of wasps. The essential oil produced from the scale of the pest at dosages of 3-7μL and the essential oil emitted by injured bark at dosages of 5-9 Μl had a stronger alluring effect on the host searching behavior of Pteroptrix longgiclava. The essential oil from the body of fixed 1st-instar-nymph of Q. Gigas also had certain effect on the host locating effort of Pteroptrix longgiclava and Encar siagigas. Those two wasps did not shown any reaction to the essential oil produced by the healthy bark of poplar.

  8. The final spawning ground of Tachypleus gigas (Müller, 1785) on the east Peninsular Malaysia is at risk: a call for action.

    Science.gov (United States)

    Nelson, Bryan Raveen; Satyanarayana, Behara; Moh, Julia Hwei Zhong; Ikhwanuddin, Mhd; Chatterji, Anil; Shaharom, Faizah

    2016-01-01

    Tanjung Selongor and Pantai Balok (State Pahang) are the only two places known for spawning activity of the Malaysian horseshoe crab - Tachypleus gigas (Müller, 1785) on the east coast of Peninsular Malaysia. While the former beach has been disturbed by several anthropogenic activities that ultimately brought an end to the spawning activity of T. gigas, the status of the latter remains uncertain. In the present study, the spawning behavior of T. gigas at Pantai Balok (Sites I-III) was observed over a period of thirty six months, in three phases, between 2009 and 2013. Every year, the crab's nesting activity was found to be high during Southwest monsoon (May-September) followed by Northeast (November-March) and Inter monsoon (April and October) periods. In the meantime, the number of female T. gigas in 2009-2010 (Phase-1) was higher (38 crabs) than in 2010-2011 (Phase-2: 7 crabs) and 2012-2013 (Phase-3: 9 crabs) for which both increased overexploitation (for edible and fishmeal preparations) as well as anthropogenic disturbances in the vicinity (sand mining since 2009, land reclamation for wave breaker/parking lot constructions in 2011 and fishing jetty construction in 2013) are responsible. In this context, the physical infrastructure developments have altered the sediment close to nesting sites to be dominated by fine sand (2.5Xφ ) with moderately-well sorted (0.6-0.7σφ), very-coarse skewed (-2.4SKφ), and extremely leptokurtic (12.6Kφ) properties. Also, increased concentrations of Cadmium (from 4.2 to 13.6 mg kg(-1)) and Selenium (from 11.5 to 23.3 mg kg(-1)) in the sediment, and Sulphide (from 21 to 28 µg l(-1)) in the water were observed. In relation to the monsoonal changes affecting sheltered beach topography and sediment flux, the spawning crabs have shown a seasonal nest shifting behaviour in-between Sites I-III during 2009-2011. However, in 2012-2013, the crabs were mostly restricted to the areas (i.e., Sites I and II) with high oxygen (5.5-8.0 mg l

  9. Gametogenesis in the Pacific oyster Crassostrea gigas: a microarrays-based analysis identifies sex and stage specific genes.

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    Nolwenn M Dheilly

    Full Text Available BACKGROUND: The Pacific oyster Crassostrea gigas (Mollusca, Lophotrochozoa is an alternative and irregular protandrous hermaphrodite: most individuals mature first as males and then change sex several times. Little is known about genetic and phenotypic basis of sex differentiation in oysters, and little more about the molecular pathways regulating reproduction. We have recently developed and validated a microarray containing 31,918 oligomers (Dheilly et al., 2011 representing the oyster transcriptome. The application of this microarray to the study of mollusk gametogenesis should provide a better understanding of the key factors involved in sex differentiation and the regulation of oyster reproduction. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression was studied in gonads of oysters cultured over a yearly reproductive cycle. Principal component analysis and hierarchical clustering showed a significant divergence in gene expression patterns of males and females coinciding with the start of gonial mitosis. ANOVA analysis of the data revealed 2,482 genes differentially expressed during the course of males and/or females gametogenesis. The expression of 434 genes could be localized in either germ cells or somatic cells of the gonad by comparing the transcriptome of female gonads to the transcriptome of stripped oocytes and somatic tissues. Analysis of the annotated genes revealed conserved molecular mechanisms between mollusks and mammals: genes involved in chromatin condensation, DNA replication and repair, mitosis and meiosis regulation, transcription, translation and apoptosis were expressed in both male and female gonads. Most interestingly, early expressed male-specific genes included bindin and a dpy-30 homolog and female-specific genes included foxL2, nanos homolog 3, a pancreatic lipase related protein, cd63 and vitellogenin. Further functional analyses are now required in order to investigate their role in sex differentiation in oysters

  10. [A study on feeding ecology and migration patterns of Dosidicus gigas off Peru using stable isotope analysis].

    Science.gov (United States)

    Gong, Yi; Chen, Xin-jun; Li, Yun-kai; Han, Meng-jie

    2015-09-01

    As a pelagic cephalopod and one of the main target species of Chinese distant water fishery, jumbo squids (Dosidicus gigas) play a major role in the marine ecosystems of the eastern Pacific. Understanding the feeding ecology and migration patterns of jumbo squids is of importance for better utilizing the resources. The isotopic signatures of gladius, have been proved to be a powerful tool to reveal high resolution and ontogenic variations in individual foraging strategies of squids; which is an archival tissue with no elemental turnover after formation. In this study, the growth equation of gladius proostracum was established based on the age information determined by statolith. Gladius was cut successionally by the growth curve of gladius proostracum, the stable isotopic values of the gladius profiles were determined, and the feeding ecology and migration patterns of jumbo squids during its growth process were investigated. Results showed that the jumbo squids began to migrate after 180 days of postnatal, and their trophic levels tended to decrease throughout the life span. These results demonstrated the feasibility of using continuous sampling hard tissue to study the feeding ecology and habitat transfer of jumbo squids.

  11. Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster (Crassostrea gigas) and culture broth under different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Pil-Mun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Park, Jae Seok [Korea Food and Drug Administration, Seoul 122-704 (Korea, Republic of); Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Baek, Min [Atomic Energy Policy Division, Ministry of Education, Science and Technology, Gwacheon 427-715 (Korea, Republic of); Chung, Young-Jin [Department of Food and Nutrition, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster (Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D{sub 10} value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

  12. Microbiological quality of oysters (Crassostrea gigas produced and commercialized in the coastal region of Florianópolis - Brazil

    Directory of Open Access Journals (Sweden)

    Pereira Murilo Anderson

    2006-01-01

    Full Text Available Oysters are filter feeders able to ingest particles in suspension that may carry pathogenic microorganisms. In this respect, the consumption of raw oysters can cause foodborne diseases in humans. The aim of the present study was to evaluate the microbiological quality of Crassostrea gigas oysters cultivated and commercialized in the coastal region of Florianópolis, SC, Brazil. The study comprised counts of coliforms at 35ºC and at 45ºC, Escherichia coli and coagulase-positive staphylococci, and detection of Salmonella sp, Vibrio cholerae and Vibrio parahaemolyticus. Ninety samples were analyzed, 45 of them collected at seafood commercial establishments and the other 45 were collected in the cultivation area. All analyses were performed according to methods of the American Public Health Association. Vibrio cholerae, V. parahaemolyticus and Salmonella sp. were not detected in any of the samples. Coagulase-positive staphylococci were observed in only one sample (80 CFU/g. The counts of coliforms at 35 and 45ºC indicated that samples obtained from both the cultivation area and place of sale were contaminated. E. coli was detected in 4 (9% samples collected in the cultivation area and in 16 (35.5% samples obtained from commercial establishments. These results indicate the need for monitoring the quality of raw oysters, including the implantation of programs for good mollusk manipulation and management practices.

  13. Unequal and genotype-dependent expression of mitochondrial genes in larvae of the pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Curole, Jason P; Meyer, Eli; Manahan, Donal T; Hedgecock, Dennis

    2010-04-01

    Mitochondria are essential for regulation of energy metabolism, but little is known about patterns of mitochondrial genome expression in invertebrates. To explore the association of mitochondrial expression with differential growth of Crassostrea gigas, the Pacific oyster, we crossed two inbred lines to produce inbred and hybrid larvae, which grew at different rates under the same environmental conditions. Using high-throughput cloning and sequencing methods, we identified 1.1 million expressed sequence tags from the mitochondrial genome, 96.7% of which were perfect matches to genes targeted by the method. Expression varied significantly among genes, ranging over nearly four orders of magnitude, from mt:lRNA, which constituted 21% of all transcripts, to mt:CoII, which constituted less than 0.02% of all transcripts. Variable expression of genes coding for subunits of macromolecular complexes (e.g., mt:CoI and mt:CoII) implies that stoichiometry in these complexes must be regulated post-transcriptionally. Surprisingly, the mitochondrial transcriptome contained non-coding transcripts, which may play a role in the regulation of mitochondrial function. Finally, mitochondrial expression depended strongly on maternal factors and nuclear-cytoplasmic interactions, which may explain previously observed growth differences between reciprocal hybrids. Differences in mitochondrial gene expression could provide a biochemical index for the metabolic basis of genetically determined differences in larval growth.

  14. Exposure to the Neurotoxic Dinoflagellate, Alexandrium catenella, Induces Apoptosis of the Hemocytes of the Oyster, Crassostrea gigas

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    Walid Medhioub

    2013-12-01

    Full Text Available This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7 at 29 h, suggesting that the intrinsic pathway was activated. No modulation of the expression of genes implicated in the cell signaling Fas-Associated protein with Death Domain (FADD and initiation-phase (caspase-2 was observed, suggesting that only the extrinsic pathway was not activated. Moreover, the clear time-dependent upregulation of five (Bcl2, BI-1, IAP1, IAP7B and Hsp70 inhibitors of apoptosis-related genes associated with the return to the initial number of hemocytes in apoptosis at 48 h of exposure suggests the involvement of strong regulatory mechanisms of apoptosis occurring in the hemocytes of the Pacific oyster.

  15. Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster ( Crassostrea gigas) and culture broth under different conditions

    Science.gov (United States)

    Jung, Pil-Mun; Park, Jae Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Baek, Min; Chung, Young-Jin; Lee, Ju-Woon

    2009-07-01

    Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster ( Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D10 value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

  16. Abundance and sexual size dimorphism of the giant gartersnake (Thamnophis gigas) in the Sacramento valley of California

    Science.gov (United States)

    Wylie, G.D.; Casazza, M.L.; Gregory, C.J.; Halstead, B.J.

    2010-01-01

    The Giant Gartersnake (Thamnophis gigas) is restricted to wetlands of the Central Valley of California. Because of wetland loss in this region, the Giant Gartersnake is both federally and state listed as threatened. We conducted markrecapture studies of four populations of the Giant Gartersnake in the Sacramento Valley (northern Central Valley), California, to obtain baseline data on abundance and density to assist in recovery planning for this species. We sampled habitats that ranged from natural, unmanaged marsh to constructed managed marshes and habitats associated with rice agriculture. Giant Gartersnake density in a natural wetland (1.90 individuals/ha) was an order of magnitude greater than in a managed wetland subject to active season drying (0.17 individuals/ha). Sex ratios at all sites were not different from 1 1, and females were longer and heavier than males. Females had greater body condition than males, and individuals at the least disturbed sites had significantly greater body condition than individuals at the managed wetland. The few remaining natural wetlands in the Central Valley are important, productive habitat for the Giant Gartersnake, and should be conserved and protected. Wetlands constructed and restored for the Giant Gartersnake should be modeled after the permanent, shallow wetlands representative of historic Giant Gartersnake habitat. ?? 2010 Society for the Study of Amphibians and Reptiles.

  17. Oyster (Crassostrea gigas Hydrolysates Produced on a Plant Scale Have Antitumor Activity and Immunostimulating Effects in BALB/c Mice

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    Yu-Zhong Zhang

    2010-02-01

    Full Text Available Oyster extracts have been reported to have many bioactive peptides. But the function of oyster peptides produced by proteolysis is still unknown. In this study, the oligopeptide-enriched hydrolysates from oyster (Crassostrea gigas were produced using the protease from Bacillus sp. SM98011 at laboratory level, and scaled up to pilot (100 L and plant (1,000 L levels with the same conditions. And the antitumor activity and immunostimulating effects of the oyster hydrolysates in BALB/c mice were investigated. The growth of transplantable sarcoma-S180 was obviously inhibited in a dose-dependent manner in BALB/c mice given the oyster hydrolysates. Mice receiving 0.25, 0.5 and 1 mg/g of body weight by oral gavage had 6.8%, 30.6% and 48% less tumor growth, respectively. Concurrently, the weight coefficients of the thymus and the spleen, the activity of natural killer (NK cells, the spleen proliferation of lymphocytes and the phagocytic rate of macrophages in S180-bearing mice significantly increased after administration of the oyster hydrolysates. These results demonstrated that oyster hydrolysates produced strong immunostimulating effects in mice, which might result in its antitumor activity. The antitumor and immunostimulating effects of oyster hydrolysates prepared in this study reveal its potential for tumor therapy and as a dietary supplement with immunostimulatory activity.

  18. Inheritance mode of microsatellite loci and their use for kinship analysis in the Pacific oyster (Crassostrea gigas)

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Five full-sib families of the Pacific oyster (Crassostrea gigas) larvae were used to study the mode of inheritance at eight microsatellite loci, and the feasibility of these markers for kinship estimate was also examined. All eight microsatellite loci were compatible with Mendelian inheritance. Neither evidence of sex-linked barriers to transmission nor evidence of major barriers to fertilization between gametes from the parents was shown. Three of the eight loci showed the presence of null alleles in four families, demonstrating the need to conduct comprehensive species-specific inheritance studies for microsatellite loci used in population genetic studies. Although the null allele heterozygotes were considered as homozygotes in the calculation of genetic distance, offspring from five full-sib families were unambiguously discriminated in the neighbor-joining dendrogram. This result indicates that the microsatellite markers may be capable of discriminating between related and unrelated oyster larvae in the absence of pedigree information, and is applicable to the investigation of the effective number of parents contributing to the hatchery population of the Pacific oyster.

  19. Probing for heavy element impurities in the shell of the Pacific oyster, Crassostrea gigas, with nuclear microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Markwitz, A. E-mail: a.markwitz@gns.cri.nz; Barry, B.; Gauldie, R.W.; Roberts, R.D

    2003-09-01

    Nuclear microscopy was performed on shells of the Pacific oyster, Crassostrea gigas, to probe for heavy element impurities. For the studies 14 shells from the Auckland and the Marlborough Sounds region were chosen. In sections, the shells appear as opaque with white and grey zones, which are related to alternating layers of calcite and aragonite. Raster scans with 2.5 MeV protons over the sections (scan area 5 x 5 mm) were used in the experiment to measure trace elements in the ppm region using proton induced X-ray spectroscopy. Two dimensional maps and line scans revealed the presence of bromine in all shells investigated. Bromine was found to be related with the pattern of calcium. Hot spots of iron proved to be a common feature in the shells as well. In some shells, copper and zinc were also measured in hot spots of a few micrometers in diameter. Spatially resolved results on the micrometer level indicate the usefulness of nuclear microscopy for the detection of heavy elements in shells of the Pacific oyster.

  20. Molecular Cloning and Characterization of Full-Length cDNA of Calmodulin Gene from Pacific Oyster Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Xing-Xia Li

    2016-01-01

    Full Text Available The shell of the pearl oyster (Pinctada fucata mainly comprises aragonite whereas that of the Pacific oyster (Crassostrea gigas is mainly calcite, thereby suggesting the different mechanisms of shell formation between above two mollusks. Calmodulin (CaM is an important gene for regulating the uptake, transport, and secretion of calcium during the process of shell formation in pearl oyster. It is interesting to characterize the CaM in oysters, which could facilitate the understanding of the different shell formation mechanisms among mollusks. We cloned the full-length cDNA of Pacific oyster CaM (cgCaM and found that the cgCaM ORF encoded a peptide of 113 amino acids containing three EF-hand calcium-binding domains, its expression level was highest in the mantle, hinting that the cgCaM gene is probably involved in shell formation of Pacific oyster, and the common ancestor of Gastropoda and Bivalvia may possess at least three CaM genes. We also found that the numbers of some EF hand family members in highly calcified species were higher than those in lowly calcified species and the numbers of these motifs in oyster genome were the highest among the mollusk species with whole genome sequence, further hinting the correlation between CaM and biomineralization.

  1. Biophysical studies of interaction between hydrolysable tannins isolated from Oenothera gigas and Geranium sanguineum with human serum albumin.

    Science.gov (United States)

    Sekowski, Szymon; Ionov, Maksim; Kaszuba, Mateusz; Mavlyanov, Saidmukhtar; Bryszewska, Maria; Zamaraeva, Maria

    2014-11-01

    Tannins, secondary plant metabolites, possess diverse biological activities and can interact with biopolymers such as lipids or proteins. Interactions between tannins and proteins depend on the structures of both and can result in changes in protein structure and activity. Because human serum albumin is the most abundant protein in plasma and responsible for interactions with important biological compounds (e.g. bilirubin) and proper blood pressure, therefore, it is very important to investigate reactions between HSA and tannins. This paper describes the interaction between human serum albumin (HSA) and two tannins: bihexahydroxydiphenoyl-trigalloylglucose (BDTG) and 1-O-galloyl-4,6-hexahydroxydiphenoyl-β-d-glucose (OGβDG), isolated from Geranium sanguineum and Oenothera gigas leafs, respectively. Optical (spectrofluorimetric) and chiral optical (circular dichroism) methods were used in this study. Fluorescence analysis demonstrated that OGβDG quenched HSA fluorescence more strongly than BDTG. Both OGβDG and BDTG formed complexes with albumin and caused a red shift of the fluorescence spectra but did not significantly change the protein secondary structure. Our studies clearly demonstrate that the tested tannins interact very strongly with human serum albumin (quenching constant K=88,277.26±407.04 M(-1) and K=55,552.67±583.07 M(-1) respectively for OGβDG and BDTG) in a manner depending on their chemical structure.

  2. Oyster (Crassostrea gigas) hydrolysates produced on a plant scale have antitumor activity and immunostimulating effects in BALB/c mice.

    Science.gov (United States)

    Wang, Yu-Kai; He, Hai-Lun; Wang, Guo-Fan; Wu, Hao; Zhou, Bai-Cheng; Chen, Xiu-Lan; Zhang, Yu-Zhong

    2010-02-02

    Oyster extracts have been reported to have many bioactive peptides. But the function of oyster peptides produced by proteolysis is still unknown. In this study, the oligopeptide-enriched hydrolysates from oyster (Crassostrea gigas) were produced using the protease from Bacillus sp. SM98011 at laboratory level, and scaled up to pilot (100 L) and plant (1,000 L) levels with the same conditions. And the antitumor activity and immunostimulating effects of the oyster hydrolysates in BALB/c mice were investigated. The growth of transplantable sarcoma-S180 was obviously inhibited in a dose-dependent manner in BALB/c mice given the oyster hydrolysates. Mice receiving 0.25, 0.5 and 1 mg/g of body weight by oral gavage had 6.8%, 30.6% and 48% less tumor growth, respectively. Concurrently, the weight coefficients of the thymus and the spleen, the activity of natural killer (NK) cells, the spleen proliferation of lymphocytes and the phagocytic rate of macrophages in S180-bearing mice significantly increased after administration of the oyster hydrolysates. These results demonstrated that oyster hydrolysates produced strong immunostimulating effects in mice, which might result in its antitumor activity. The antitumor and immunostimulating effects of oyster hydrolysates prepared in this study reveal its potential for tumor therapy and as a dietary supplement with immunostimulatory activity.

  3. Age, maturation, and population structure of the Humboldt squid Dosidicus gigas off the Peruvian Exclusive Economic Zones

    Institute of Scientific and Technical Information of China (English)

    LIU Bilin; CHEN Xinjun; CHEN Yong; TIAN Siquan; LI Jianhua; FANG Zhou; YANG Mingxia

    2013-01-01

    Age,maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones (EEZ) during 2008-2010.Estimated ages ranged from 144 to 633 days,confirming that the squid is a short-lived species with longevity no longer than 2 years.Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round.Back-calculated hatching dates for the samples were from January 22nd,2008 to April 22nd,2010 with a peak between January and March.Two size-based and two hatching date-based populations could be defined from mantle length (ML) at maturity and back-calculated hatching dates,respectively.Females matured at a larger size than males,and there was a significant difference in ML at maturity between the two hatching groups (P<0.05).The waters adjacent to 11°S off the Peruvian EEZ may be a potential spawning ground.This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ,which should be considered in the assessment and management of this important resource.

  4. Age, maturation, and population structure of the Humboldt squid Dosidicus gigas off the Peruvian Exclusive Economic Zones

    Science.gov (United States)

    Liu, Bilin; Chen, Xinjun; Chen, Yong; Tian, Siquan; Li, Jianhua; Fang, Zhou; Yang, Mingxia

    2013-01-01

    Age, maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones (EEZ) during 2008-2010. Estimated ages ranged from 144 to 633 days, confirming that the squid is a short-lived species with longevity no longer than 2 years. Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round. Back-calculated hatching dates for the samples were from January 22nd, 2008 to April 22nd, 2010 with a peak between January and March. Two size-based and two hatching date-based populations could be defined from mantle length (ML) at maturity and back-calculated hatching dates, respectively. Females matured at a larger size than males, and there was a significant difference in ML at maturity between the two hatching groups ( P <0.05). The waters adjacent to 11°S off the Peruvian EEZ may be a potential spawning ground. This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ, which should be considered in the assessment and management of this important resource.

  5. ESR studies on the thermal decomposition of trimethylamine oxide to formaldehyde and dimethylamine in jumbo squid (Dosidicus gigas) extract.

    Science.gov (United States)

    Zhu, Junli; Jia, Jia; Li, Xuepeng; Dong, Liangliang; Li, Jianrong

    2013-12-15

    The effects of ferrous iron, heating temperature and different additives on the decomposition of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA) and generation of free radicals in jumbo squid (Dosidicus gigas) extract during heating were evaluated by electron spin resonance (ESR). The thermal decomposition of TMAO to TMA, DMA and FA and free radical signals was observed in squid extract, whereas no DMA, FA and free radical signals were detected in cod extract or in aqueous TMAO solution in vitro at high temperatures. Significant increase in levels of DMA, FA and radicals intensity were observed in squid extract and TMAO solution in the presence of ferrous iron with increasing temperature. Hydrogen peroxide stimulated the production of DMA, FA and ESR signals in squid extract, while citric acid, trisodium citrate, calcium chloride, tea polyphenols and resveratrol had the opposite effect. Similar ESR spectra of six peaks regarded as amminium radical were detected in the squid extract and TMAO-iron(II) solution, suggesting that the amminium radical was involved in the decomposition of TMAO. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Evaluation of Estrogenic Activity of Extract from the Herbal Mixture Cynanchum wilfordii Hemsley, Phlomis umbrosa Turczaninow, and Angelica gigas Nakai

    Science.gov (United States)

    Kim, Se Jong; Jin, Sun Woo; Lee, Gi-Ho; Kim, Yong An; Jeong, Hye Gwang

    2017-01-01

    Hormone replacement therapy (HRT) consists of highly effective prescription medications for treating menopausal symptoms; however, these agents have exhibited side effects including the risk of estrogen-induced carcinogenesis. Therefore, interest in phytotherapy-based materials as a natural source of alternatives to estrogen therapy has increased. However, some of these herbal medicines have been reported to increase the risk of estrogen-induced cancer. Herbal formulations composed of a combination of Cynanchum wilfordii Hemsley (CW), Phlomis umbrosa Turczaninow (PU), and Angelica gigas Nakai (AG) extracts (CPAE) have been used for treating menopausal symptoms. Therefore, in this study, we aimed to examine the safety of CPAE by determining its potential adverse estrogenic activity using the Organization for Economic Cooperation and Development (OECD) test guideline 455 (TG455) in a stably transfected transcriptionally activated human estrogen receptor α (hERα)-HeLa9903 cell model. We found that CPAE did not how any estrogenic activity or stimulate promoters containing estrogen response elements in MCF-7 cells. In addition, CPAE showed no significant selective activity against hERα and hERβ, non-selective activity against the ER, or effects on ER target gene expression. Furthermore, CPAE did not significantly induce MCF-7 cell proliferation and uterine weight increase in ovariectomized rats. These results demonstrate that CPAE can be used as beneficial herbal drug for prevention and therapeutic intervention of estrogen carcinogenesis in menopausal women. PMID:28133516

  7. A simple proof of the characterization of functions of low Aviles Giga energy on a ball via regularly

    CERN Document Server

    Lorent, Andrew

    2010-01-01

    The Aviles Giga functional is a well known second order functional that forms a model for blistering and in a certain regime liquid crystals, a related functional models thin magnetized films. Given Lipschitz domain $\\Omega\\subset R^2$ the functional is $I_{\\epsilon}(u)=1/2\\int_{\\Omega} \\epsilon^{-1}|1-|Du|^2|^2+\\epsilon|D^2 u|^2$ where $u$ belongs to the subset of functions in $W^{2,2}_{0}(\\Omega)$ whose gradient (in the sense of trace) satisfies $Du(x)\\cdot \\eta_x=1$ where $\\eta_x$ is the inward pointing unit normal to $\\partial \\Omega$ at $x$. In Jabin, Otto, Perthame characterized a class of functions which includes all limits of sequences $u_n\\in W^{2,2}_0(\\Omega)$ with $I_{\\epsilon_n}(u_n)\\to 0$ as $\\epsilon_n\\to 0$. A corollary to their work is that if there exists such a sequence $(u_n)$ for a bounded domain $\\Omega$, then $\\Omega$ must be a ball and (up to change of sign) $u:=\\lim_{n\\to \\infty} u_n =\\mathrm{dist}(\\cdot,\\partial\\Omega)$. Recently we provided a quantitative generalization of this corol...

  8. Association among growth, food consumption-related traits and amylase gene polymorphism in the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Huvet, A; Jeffroy, F; Fabioux, C; Daniel, J Y; Quillien, V; Van Wormhoudt, A; Moal, J; Samain, J F; Boudry, P; Pouvreau, S

    2008-12-01

    To examine further a previously reported association between amylase gene polymorphism and growth in the Pacific oyster Crassostrea gigas, ecophysiological parameters and biochemical and molecular expression levels of alpha-amylase were studied in Pacific oysters of different amylase genotypes. Genotypes that previously displayed significantly different growth were found to be significantly different for ingestion and absorption efficiency. These estimated parameters, used in a dynamic energy budget model, showed that observed ingestion rates (unlike absorption efficiencies) allowed an accurate prediction of growth potential in these genotypes. The observed association between growth and amylase gene polymorphism is therefore more likely to be related to ingestion than to absorption efficiency. Additionally, relative mRNA levels of the two amylase cDNAs were also strongly associated with amylase gene polymorphism, possibly reflecting variation in an undefined regulatory region, although no corresponding variation was observed in specific amylase activity. Amylase gene sequences were determined for each genotype, showing the existence of only synonymous or functionally equivalent non-synonymous polymorphisms. The observed associations among growth, food consumption-related traits and amylase gene polymorphism are therefore more likely to be related to variation in the level of amylase gene expression than to functional enzymatic variants.

  9. Species identification of Ommastrephes bartramii, Dosidicus gigas, Sthenoteuthis oualaniensis and Illex argentinus (Ommastrephidae using beak morphological variables

    Directory of Open Access Journals (Sweden)

    Xinjun Chen

    2012-07-01

    Full Text Available Four oceanic squid species, Ommastrephes bartramii, Dosidicus gigas, Sthenoteuthis oualaniensis and Illex argentinus, not only support important commercial fisheries, but also play a vital role in their marine ecosystems. It is therefore important to identify them in the analyses of their predators’ stomach contents as this can yield critical information on the trophic dynamics of ecosystems. Hard beaks of the four species frequently found in their predators’ stomachs can be used to identify them. In this study, to remove the effect of size differences among individuals, measurements of upper and lower beaks were standardized with an allometric model. A discriminant analysis was carried out to compare morphological differences among the four species and between the sexes for each species. The upper rostral width and upper rostral length showed the greatest interspecific variation in the beak morphological variables of the four Ommastrephidae. The linear discriminant functions of beak morphological variables were developed for the four Ommastraphidae, which resulted in a rate of correct species classification of over 97%. Sexual dimorphism was also found in the beak morphology of O. bartramii and I. argentinus. This study suggests that morphological variables can be used to reliably classify Ommastrephidae at genus level, which can help identify the specie in the stomachs of cephalopod predators. This helps to improve the understanding of the role cephalopods play in their marine ecosystems.

  10. Molecular Cloning and Characterization of Full-Length cDNA of Calmodulin Gene from Pacific Oyster Crassostrea gigas

    Science.gov (United States)

    Li, Xing-Xia; Yu, Wen-Chao; Cai, Zhong-Qiang; He, Cheng; Wei, Na

    2016-01-01

    The shell of the pearl oyster (Pinctada fucata) mainly comprises aragonite whereas that of the Pacific oyster (Crassostrea gigas) is mainly calcite, thereby suggesting the different mechanisms of shell formation between above two mollusks. Calmodulin (CaM) is an important gene for regulating the uptake, transport, and secretion of calcium during the process of shell formation in pearl oyster. It is interesting to characterize the CaM in oysters, which could facilitate the understanding of the different shell formation mechanisms among mollusks. We cloned the full-length cDNA of Pacific oyster CaM (cgCaM) and found that the cgCaM ORF encoded a peptide of 113 amino acids containing three EF-hand calcium-binding domains, its expression level was highest in the mantle, hinting that the cgCaM gene is probably involved in shell formation of Pacific oyster, and the common ancestor of Gastropoda and Bivalvia may possess at least three CaM genes. We also found that the numbers of some EF hand family members in highly calcified species were higher than those in lowly calcified species and the numbers of these motifs in oyster genome were the highest among the mollusk species with whole genome sequence, further hinting the correlation between CaM and biomineralization. PMID:27703977

  11. An evaluation of the efficacy of using environmental DNA (eDNA) to detect giant gartersnakes (Thamnophis gigas)

    Science.gov (United States)

    Halstead, Brian J.; Wood, Dustin A.; Bowen, Lizabeth; Waters, Shannon C.; Vandergast, Amy G.; Ersan, Julia S.; Skalos, Shannon M.; Casazza, Michael L.

    2017-09-28

    Detecting populations of rare or cryptic species is essential for their conservation. For species like giant gartersnakes (Thamnophis gigas), conventional survey methods can be expensive and inefficient. These sampling difficulties might be overcome by modern techniques that detect deoxyribonucleic acid (DNA) shed by organisms into the environment (eDNA). We evaluated the efficacy of detecting giant gartersnake eDNA in water samples from the laboratory and at locations with known giant gartersnake populations in the Sacramento Valley of California, and failed to detect giant gartersnake DNA in most laboratory and all field samples. Aspects of giant gartersnake biology—such as highly keratinized skin and spending extensive time in the terrestrial environment, as well as hot, sunny, and turbid conditions in wetlands and canals of the Sacramento Valley—likely contributed to low detection probabilities. Although detection of eDNA shows promise under many conditions, further development is needed before sampling for eDNA is a viable option for detecting giant gartersnake populations.

  12. Composición proximal y propiedades funcionales del surimi liofilizado de Dosidicus gigas “ calamar gigante”

    Directory of Open Access Journals (Sweden)

    Armando Solari - Godiño

    2017-01-01

    Full Text Available El propósito de la investigación fue determinar la composición proximal y propiedades funcionales del surimi liofilizado de calamar gigante ( Dosidicus gigas . Se elaboró surimi a partir de calamar gigante y fue liofilizado hasta obtener surimi en polvo para evaluar sus características y prop iedades funcionales. El contenido de proteínas fue 58,7% y carbohidratos 30,5%. La solubilidad proteica en agua y sal (3% fueron 21,1% y 40,6% respectivamente, siendo estos valores superiores a surimi en polvo de especies comerciales. La capacidad de geli ficación fue 2,4% y la capacidad emulsificante fue 79,9% a una concentración del 1,0%. El color en la escala de Hunter fue L*: 91,5; a*: 0,5; b*:7,0. El surimi en polvo de calamar gigante fue considerado como un polvo proteico funcional debido a su conteni do porcentual proteico, y tuvieron buenas características tecnológicas y de gran potencial en la industria alimentaria .

  13. Genomics study of the exposure effect of Gymnodinium catenatum, a paralyzing toxin producer, on Crassostrea gigas' defense system and detoxification genes.

    Directory of Open Access Journals (Sweden)

    Norma García-Lagunas

    Full Text Available BACKGROUND: Crassostrea gigas accumulates paralytic shellfish toxins (PST associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response. PRINCIPAL FINDINGS: We found that 24 h feeding on toxic dinoflagellate cells (acute exposure induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense (copper/zinc superoxide dismutase, Cu/Zn-SOD, cell detoxification (glutathione S-transferase, GST and cytochrome P450, CPY450, intermediate immune response activation (lipopolysaccharide and beta glucan binding protein, LGBP, and stress responses (glutamine synthetase, GS in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days (30×10³ cells mL⁻¹ showed higher gene expression levels. A significant increase was observed in Cu/Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum (3×10³ cells mL⁻¹ produced a significant increase on the transcription level than in a mixed diet (3×10³ cells mL⁻¹ of G. catenatum+0.75×10⁶ cells mL⁻¹ I. galbana in all the analyzed genes. CONCLUSIONS: Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to

  14. Prevalencia del protozoario Perkinsus sp. en un cultivo de ostión japonés Crassostrea gigas en Sinaloa, México

    Directory of Open Access Journals (Sweden)

    Lizeth Carolina Villanueva-Fonseca

    2013-11-01

    Full Text Available Crassostrea gigas es un molusco bivalvo de gran importancia comercial. En el noroeste de México su producción es afectada por mortalidades cuyo origen infeccioso no ha sido determinado claramente. En este trabajo se determinó la prevalencia e intensidad de la infección por Perkinsus sp. en un cultivo de C. gigas en el ciclo 2011-2012. El cultivo se hizo en un sistema de línea suspendida con densidades de 28 y 42 ostiones/canasta y se determinó un tamaño de muestra de 30 ostiones por mes. La detección de Perkinsus sp. se hizo de acuerdo a los protocolos de la Organización Mundial de Sanidad Animal (OIE para Medio Fluido de Tioglicolato y PCR. Con ambos métodos se determinó la prevalencia de Perkinsus sp., que varió entre 3,3 y 40%. La intensidad de la infección estuvo en niveles 1 y 2, de acuerdo a la escala de Mackin. La mortalidad acumulativa en las densidades de 28 y 42 ostiones por canasta fue del 4 y 6%, respectivamente. Las mayores mortalidades del ostión y las mayores prevalencias de Perkinsus sp. ocurrieron en septiembre (2,7 y 16,6% y octubre (1,5 y 23,3%, respectivamente, cuando la temperatura fue alta. En conclusión, Perkinsus sp. fue detectado en un cultivo de C. gigas en el estero La Pitahaya con prevalencia moderada, baja intensidad de infección y mayor presencia en los meses más calurosos del ciclo de cultivo.

  15. Aspectos reprodutivos e perfil hormonal dos esteróides sexuais do pirarucu, Arapaima gigas (SCHINZ,1822, em condições de cativeiro Reproductive aspects and sexual steroids hormonal profiles of pirarucu, Arapaima gigas (SCHINZ,1822, in captivity conditions

    Directory of Open Access Journals (Sweden)

    Leonardo Bruno Barbosa Monteiro

    2010-09-01

    Full Text Available Esta pesquisa teve como objetivo caracterizar a reprodução e o perfil hormonal dos esteróides sexuais do pirarucu, Arapaima gigas, além de validar um aspecto do dimorfismo sexual secundário. O experimento foi realizado na Fazenda Santo Antônio II, em Presidente Figueredo-AM, no período de fevereiro de 2004 a fevereiro de 2005. Foram selecionados 24 exemplares e divididos em três grupos de oito peixes (grupo "A", "B" e "C" com pirarucus de mais de quatro anos de idade, com três anos e dois anos, respectivamente. Os pirarucus foram estocados em três tanques de 400m², um para cada grupo. Aspectos comportamentais, como o interesse por alimento, brigas, formação de casais e presença de ninhos, foram observados ao longo de todo o experimento. Amostras de sangue foram coletadas mensalmente, de todos os peixes, observou-se a presença de uma mancha alaranjada no macho como uma característica sexual secundária. Foram mensurados os níveis de testosterona (T, 17beta-estradiol (E2 e 17alfa-hidroxi-progesterona (17aOHP através de radioimunoensaio (RIA de fase sólida. Todos os machos dos grupos "A" e "B" puderam ser identificados pela mancha alaranjada na região inferior da cabeça, corroborada pela concentração de testosterona, comprovando o conhecimento empírico dos ribeirinhos. Os níveis de T e E2 nos peixes do grupo "A" e "B" tiveram maiores picos no início do período de chuva, enquanto que o 17aOHP teve oscilações constantes e pequenos picos no final do período chuvoso, os peixes do grupo "C" acompanharam essa tendência em concentrações menores.The purpose of this study was to characterize the growth, reproduction and hormonal profile of pirarucu, Arapaima gigas, and validate one sexual dimorphism characteristic. The experiment was carried in the fish farm Santo Antonio II, Presidente Figueredo city in the state of Amazonas Brazil, from February 2004 to February 2005. In the experiment, 24 fishes were selected and divided

  16. Biodisponibilidade de zinco de ostras (Crassostrea gigas cultivadas em fl orianópolis / SC
    bioavailability of oysters (crassostrea gigas cultivated in Florianopólis / SC

    Directory of Open Access Journals (Sweden)

    R. CAETANO

    2010-05-01

    Full Text Available

    O objetivo deste trabalho foi avaliar a biodisponibilidade do zinco presente nas ostras Crassostrea gigas cultivadas na região de Florianópolis, SC em ratas adultas (Rattus norvegicus, pois nessa região as ostras são fontes de zinco biodisponível. Foi realizado ensaio biológico durante 49 dias, sendo que os 24 animais foram distribuídos em três grupos: G1: dieta controle (AIN-93M, G2: dieta isenta de zinco (AIN-93M modifi cada; G3: dieta isenta de zinco e acrescida de ostras. Ao fi nal do experimento foram coletados os fêmures dos animais para análise do teor de zinco, por espectrofotometria de absorção atômica. As ostras in natura apresentaram 4,38mg% de zinco. Quanto ao teor de zinco no fêmur, os grupos G1 (246,62 ± 9,97μg Zn/g osso e G3 (221,41 ± 15,80 μg apresentaram elevadas concentrações (p < 0,05 quando comparados ao grupo G0 (155,0 ± 32,80 μg e G2 (110,12 ± 32,88 μg.

  17. Morfologia e crescimento do músculo estriado esquelético no pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae = Morphology and skeletal muscle growth in pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae

    Directory of Open Access Journals (Sweden)

    Fernanda Regina Carani

    2008-04-01

    Full Text Available O objetivo deste trabalho foi avaliar as características morfológicas e de crescimento do músculo estriado esquelético no pirarucu (Arapaima gigas. Foram utilizados animais em duas fases de crescimento: alevinos, com 50 dias de idade, e juvenis, com umano de idade. Após eutanásia dos animais, fragmentos musculares das regiões dorsal, lateral cranial e lateral caudal foram coletados e congelados em nitrogênio líquido. Cortes histológicos (10 mm foram submetidos às colorações HE e Tricrômico de Gomori, para a análise morfológica, e NADH-TR, para a análise do metabolismo oxidativo das fibras musculares. Foi calculado o menor diâmetro das fibras musculares brancas nas regiões dorsal e lateral cranial. A musculatura dorsal branca mostrou-se mais desenvolvida e, namusculatura lateral, observaram-se compartimentos distintos: superficial vermelho e profundo branco. Nos alevinos, o crescimento muscular ocorreu predominantemente por hiperplasia das fibras e, nos juvenis, predominou o crescimento muscular por hipertrofia.The aim of this work was to evaluate the morphological and growth characteristics of skeletal muscle tissue in pirarucu (Arapaimagigas using alevins (50 days old and juveniles (1 year old. Muscle samples were collected from dorsal, lateral cranial and lateral caudal regions, and then frozen in liquid nitrogen. Histological frozen sections (10μm were stained with HE and Gomori Trichrome formorphological analysis, and NADH-TR to evaluate muscle fiber oxidative metabolism. Morphometric analysis samples were obtained from dorsal and lateral cranial regions, and the smallest-diameter white fibers were measured. White dorsal muscle was thicker, andtwo muscle fiber compartments were identified in the lateral cranial region: red (superficial and white (deep muscle. Hyperplasia muscle growth predominated in alevins and hypertrophy in juveniles.

  18. Characterisation and genetic polymorphism of metallothionein gene CgMT4 in experimental families of Pacific oyster Crassostrea gigas displaying summer mortality.

    Science.gov (United States)

    David, Elise; Tanguy, Arnaud; Moraga, Dario

    2012-02-01

    Summer mortality events have been observed in Pacific oyster Crassostrea gigas for several decades. This paper examines the selective pressure exerted by summer mortality on the polymorphism of a newly identified oyster metallothionein gene. CgMT4 cDNA and genomic sequences were obtained. CgMT4 was studied in two generations of oysters reared in three sites on the French Atlantic coast, using single strand conformation polymorphism analysis. Four alleles were detected. Individuals carrying genotype MT4-CD seem to have higher susceptibility to summer risk conditions. The MT4 gene could be a potential new genetic marker for susceptibility; further validation studies are recommended.

  19. The final spawning ground of Tachypleus gigas (Muller, 1785) on the east Peninsular Malaysia is at risk: A call for action.

    Digital Repository Service at National Institute of Oceanography (India)

    Nelson, B.R.; Satyanarayan, B.; Moh, J.H.Z.; Ikhwanuddin, M.; Chatterji, A.; Shaharom, F.

    ). In this context, the Spearman’s rank correlation coefficients (ρ values) were considered for denoting positive and negative impact of the environmental variables on T. gigas nesting sites. RESULTS Spawning population and nesting Out of thirty-six months... changes caused by physical infrastructure developments locally (during 2011–2013). The loss of horseshoe crabs can vary between genders. The male and female ratio of 31:38 in Phase-1 decreased to 13:7 in Phase-2 and 19:9 in Phase...

  20. Coexistence of Pacific oyster Crassostrea gigas (Thunberg, 1793) and blue mussels Mytilus edulis Linnaeus, 1758 on a sheltered intertidal bivalve bed?

    DEFF Research Database (Denmark)

    Holm, M.W.; Davids, J.K.; Dolmer, Per;

    2016-01-01

    The invasive Pacific oyster, Crassostrea gigas Thunberg, 1793 was introduced in Denmark for aquaculture in the 1970s. Presently, feral populations are found in many parts of the country, with the largest populations established on existing beds of blue mussel, Mytilus edulis Linnaeus, 1758...... and M. edulis were collected from the bivalve bed, shell lengths were converted into biomass, which were interpolated to create biomass contours and combined with modelled topography of the bivalve bed to study niche separation. The bivalve bed slowly extended northwards over a period of 11 years, where...

  1. Field clearance of an intertidal bivalve bed: relative significance of the co-occurring blue mussel Mytilus edulis and Pacific oyster Crassostrea gigas

    DEFF Research Database (Denmark)

    Vismann, Bent; Holm, Mark Wejlemann; Davids, Jens;

    2016-01-01

    At an approximately 12 000 m2 sheltered intertidal bivalve bed in the western part of the Limfjord, Denmark, the Pacific oyster Crassostrea gigas co-occurs with the blue mussel Mytilus edulis. The relative significance of the impact of the 2 species on phytoplankton density during a tidal cycle....... However, the estimated water column cleared during low tide is overestimated due to phytoplankton depletion. Hence, it is concluded that the bivalve bed clears the water close to 1 time each tidal cycle. This, together with a low dry weight of soft parts, indicates that the bivalve bed, in general...

  2. Gills are an initial target of zinc oxide nanoparticles in oysters Crassostrea gigas, leading to mitochondrial disruption and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Trevisan, Rafael; Delapedra, Gabriel; Mello, Danielle F.; Arl, Miriam [Department of Biochemistry, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Schmidt, Éder C. [Department of Cell Biology, Embryology and Genetic, Federal University of Santa Catarina, 88049-900 Florianópolis, SC (Brazil); Meder, Fabian; Monopoli, Marco [Centre for Bionano Interactions, University College Dublin, Dublin (Ireland); Cargnin-Ferreira, Eduardo [Federal Institute of Santa Catarina, Campus Garopaba, Laboratory of Histological Markers, 88495-000 Garopaba, SC (Brazil); Bouzon, Zenilda L. [Department of Cell Biology, Embryology and Genetic, Federal University of Santa Catarina, 88049-900 Florianópolis, SC (Brazil); Fisher, Andrew S. [School of Geography, Earth and Environmental Sciences, University of Plymouth, PL4 8AA Plymouth (United Kingdom); Sheehan, David [Department of Biochemistry, University College Cork, Cork (Ireland); Dafre, Alcir L., E-mail: alcir.dafre@ufsc.br [Department of Biochemistry, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil)

    2014-08-15

    Graphical abstract: - Highlights: • ZnONP exposure causes an initial accumulation of zinc in gills and later in digestive gland. • Zinc burden occurs by ZnONP endocytosis or uptake of ionic zinc after dissociation. • ZnONP exposure disrupts mitochondrial ultrastructure in both tissues. • Mitochondrial damage and oxidative stress are major features of ZnONP acute toxicity. - Abstract: The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnONP) was investigated in Pacific oysters Crassostrea gigas. The nanoscale of ZnONP, in vehicle or ultrapure water, was confirmed, presenting an average size ranging from 28 to 88 nm. In seawater, aggregation was detected by TEM and DLS analysis, with an increased average size ranging from 1 to 2 μm. Soluble or nanoparticulated zinc presented similar toxicity, displaying a LC{sub 50} (96 h) around 30 mg/L. High zinc dissociation from ZnONP, releasing ionic zinc in seawater, is a potential route for zinc assimilation and ZnONP toxicity. To investigate mechanisms of toxicity, oysters were treated with 4 mg/L ZnONP for 6, 24 or 48 h. ZnONP accumulated in gills (24 and 48 h) and digestive glands (48 h). Ultrastructural analysis of gills revealed electron-dense vesicles near the cell membrane and loss of mitochondrial cristae (6 h). Swollen mitochondria and a more conspicuous loss of mitochondrial cristae were observed after 24 h. Mitochondria with disrupted membranes and an increased number of cytosolic vesicles displaying electron-dense material were observed 48 h post exposure. Digestive gland showed similar changes, but these were delayed relative to gills. ZnONP exposure did not greatly affect thiol homeostasis (reduced and oxidized glutathione) or immunological parameters (phagocytosis, hemocyte viability and activation and total

  3. Anti-cancer and other bioactivities of Korean Angelica gigas Nakai (AGN) and its major pyranocoumarin compounds.

    Science.gov (United States)

    Zhang, Jinhui; Li, Li; Jiang, Cheng; Xing, Chengguo; Kim, Sung-Hoon; Lü, Junxuan

    2012-12-01

    Korean Angelica gigas Nakai (AGN) is a major medicinal herb used in Asian countries such as Korea and China. Traditionally, its dried root has been used to treat anemia, pain, infection and articular rheumatism in Korea, most often through boiling in water to prepare the dosage forms. The pyranocoumarin compound decursin and its isomer decursinol angelate (DA) are the major chemical components in the alcoholic extracts of the root of AGN. The in vitro anti-tumor activities of decursin and/or DA against prostate cancer, lung cancer, breast cancer, colon cancer, bladder cancer, sarcoma, myeloma and leukemia have been increasingly reported in the past decade whereas the in vivo efficacy in mouse models was established only for a few organ sites. Preliminary pharmacokinetic studies by us and others in rodent models indicated that decursinol (DOH), which has much less in vitro direct anticancer activities by itself, is the major and rapid in vivo hydrolysis metabolite of both decursin and DA. Besides decursin, DA and DOH, other chemical components in AGN such as polysaccharides and polyacetylenes have been reported to exert anti-cancer and anti-inflammation activities as well. We systematically reviewed the published literature on the anti-cancer and other bio-activities effects of AGN extract and decursin, DA and DOH, as well as other chemicals identified from AGN. Although a number of areas are identified that merit further investigation, one critical need is first-in-human studies of the pharmacokinetics of decursin/DA to determine whether humans differ from rodents in absorption and metabolism of these compounds.

  4. Pesticide residues, heavy metals, and DNA damage in sentinel oysters Crassostrea gigas from Sinaloa and Sonora, Mexico.

    Science.gov (United States)

    Vázquez-Boucard, Celia; Anguiano-Vega, Gerardo; Mercier, Laurence; Rojas del Castillo, Emilio

    2014-01-01

    Pesticides and heavy metals were analyzed in sentinel Crassostrea gigas oysters placed in six aquaculture sites close to a contaminated agricultural region. Each site was sampled twice. Tests revealed the presence of organochlorine (OC) pesticides in the oysters at concentrations varying from 31.8 to 72.5 μg/kg for gamma-hexachlorocyclohexane (γ-HCH); from 1.2 to 3.1 μg/kg for dichlorodiphenyldichloroethylene (4,4-DDE); from 1.6 to 2.3 μg/kg for endosulfan I; and from 1.4 to 41.2 μg/kg for endosulfan II, as well as heavy metals in concentrations that exceeded Mexican tolerance levels (405.5 to 987.8 μg/g for zinc; 4.2 to 7.3 μg/g for cadmium; and 7.2 to 9.9 μg/g for lead). Significant levels of DNA damage in oyster hemocytes were also detected. There was a significant, positive correlation between genotoxic damage and concentration of nickel or the presence of endosulfan II. Cellular viability evaluated by cytotoxic analyses was found to be high at 80%. Marked inhibition in activity of acetylcholinesterase (AChE ) and induction of glutathione S-transferase (GST) activity was noted. Data demonstrated a significant relation between AChE activity inhibition and presence of endosulfan II, γ-HCH, copper, lead, and 4,4-DDE, as well as between AChE and GST activity at different sites.

  5. Expression Characterization of Stress Genes Under High and Low Temperature Stresses in the Pacific Oyster, Crassostrea gigas.

    Science.gov (United States)

    Zhu, Qihui; Zhang, Linlin; Li, Li; Que, Huayong; Zhang, Guofan

    2016-04-01

    As a characteristic sessile inhabitant of the intertidal zone, the Pacific oyster Crassostrea gigas occupies one of the most physically stressful environments on earth. With high exposure to terrestrial conditions, oysters must tolerate broad fluctuations in temperature range. However, oysters' cellular and molecular responses to temperature stresses have not been fully characterized. Here, we analyzed oyster transcriptome data under high and low temperatures. We also identified over 30 key temperature stress-responsive candidate genes, which encoded stress proteins such as heat shock proteins and apoptosis-associated proteins. The expression characterization of these genes under short-term cold and hot environments (5 and 35 °C) and long-term cold environments (5 °C) was detected by quantitative real-time PCR. Most of these genes reached expression peaks during the recovery stage after 24 h of heat stress, and these genes were greatly induced around day 3 in long-term cold stress while responded little to short-term cold stress. In addition, in the second heat stress after 2 days of recovery, oysters showed milder expression in these genes and a lower mortality rate, which indicated the existence of plasticity in the oyster's response to heat stress. We confirmed that homeostatic flexibility and anti-apoptosis might be crucial centers of temperature stress responses in oysters. Furthermore, we analyzed stress gene families in 11 different species and found that the linage-specific expansion of stress genes might be implicated in adaptive evolution. These results indicated that both plasticity and evolution played an important role in the stress response adaptation of oysters.

  6. 杨圆蚧、柳蛎蚧研究进展%Research Advances on Quadraspididiotus gigas And Lepidosaphes salicina

    Institute of Scientific and Technical Information of China (English)

    刘军侠; 刘宽余; 林同; 甄志先; 曲宝雪

    2001-01-01

    @@ 杨圆蚧Quadraspididiotus gigas (Thiem et Gerneck)、柳蛎蚧Lepidosaphes salicina Borchsenius.隶属于同翅目Homoptera 盾蚧科Diaspididae,是杨树的重要害虫.两蚧在东北三省、内蒙古、山西、宁夏等省大量成灾,严重威胁杨树人工林速生丰产.20世纪60~90年代,北方各省份及大专院校相继立题研究,现将两蚧研究进展综述如下. 1 分布、寄主及危害 1.1 分布 国外:杨圆蚧广泛分布于前苏联、意大利、西班牙、南斯拉夫、荷兰、瑞士、东德、匈牙利、捷克、保加利亚、土尔其、阿尔及利亚等地.柳蛎蚧主要分布在前苏联、日本和朝鲜.国内:两蚧在黑龙江、吉林、辽宁、内蒙古、山西、陕西、甘肃、青海、宁夏、新疆、河北均有分布,柳蛎蚧在山东、云南亦有分布[1~7].

  7. VALOR AGREGADO DE LAS ESPECIES Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE y Agouti paca (MAJAS

    Directory of Open Access Journals (Sweden)

    Doylith Vásquez Jurafo

    2012-12-01

    Full Text Available El presente trabajo tiene como objetivo  la obtención de  productos mínimamente procesados (PMP de Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE, y Agouti paca (MAJAS congelado y empacado al vacio. Para las especies piscícolas, se ha aplicado un diseño factorial de 32 con dos factores de estudios: concentración de NaCl en la solución osmótica con tres niveles (15, 20 y 25 % y temperatura de proceso  con tres niveles de estudio (5, 10 y 15 °C. Para el Agouti paca (majas se aplico un diseño factorial completamente aleatorizado con tres factores de estudio: tiempo de proceso (30, 60 y 90 minutos, método de ahumado (ahumado líquido y ahumado en caliente y tipo de corte del músculo (partes y filetes. Para trabajar se ha diseñado y montado un deshidratador Osmótico teniendo en cuenta, diámetro de tubería, deshidratador propiamente dicho con doble chaqueta, capacidad del deshidratador en función del volumen de la Salmuera.  Todos los productos se obtuvieron  en procesos con 10 °C y tiempos entre 30 min y  90 min. El tiempo de vida en almacenamiento en las evaluaciones de aroma y color en majas tienen una vida útil de 4 meses de almacenados a -18 °C. Los análisis microbiológicos realizados a los PMP no pasan los límites de la NTS Nº 071 MINSA/DIGESA V01.

  8. Postmortem biochemical behavior of giant squid (Dosidicus gigas) mantle muscle stored in ice and its relation with quality parameters.

    Science.gov (United States)

    Márquez-Ríos, E; Morán-Palacio, E F; Lugo-Sánchez, M E; Ocano-Higuera, V M; Pacheco-Aguilar, R

    2007-09-01

    Several freshness and spoilage indicators were monitored to characterize the postmortem biochemistry of giant squid (Dosidicus gigas) mantle muscle. Squid samples were obtained directly from the sea and kept at 0 degrees C during a 15-d storage period. Data at zero time were obtained from cryogenically frozen samples at time of capture. The adenosine 5'-triphosphate (ATP) degradation followed a different pattern as compared with that from fish species. ATP was almost completely depleted at 24-h postcatch from 6.54 to <1 micromol/g, while at the same time Hx was the predominant catabolite with a concentration of 4 mumol/g, reaching 6.85 micromol/g at day 15. K-value data followed a logarithmic pattern with time instead of a linear one, with no change after day 3, thus reducing its suitability as a freshness index. The coefficient Hx/AMP seems to be an adequate alternative for this purpose due to its constant increment with time. The high NH4Cl content in mantle muscle (461.3 +/- 24.5 mg of NH4(+)/100 g) derived from its physiological importance for the species compromises the use of the distillation step of the TVB-N analysis commonly used as a spoilage index. This fact explains why the initially high value of TVB-N detected in mantle muscle (243.7 mg N/100 g) did not correlate with the initial low TMA-N content (1.5 +/- 0.1 mg/100 g of muscle). The results suggested that under the experimental conditions the shelf life of squid exceeds 15 d.

  9. Effect of pulsed ultrasound on the physicochemical characteristics and emulsifying properties of squid (Dosidicus gigas) mantle proteins.

    Science.gov (United States)

    Higuera-Barraza, O A; Torres-Arreola, W; Ezquerra-Brauer, J M; Cinco-Moroyoqui, F J; Rodríguez Figueroa, J C; Marquez-Ríos, E

    2017-01-12

    Food technologists are always looking to improve the functional properties of proteins. In this sense, in last years ultrasound has been used to improve some functional properties. For this reason, and considering that jumbo squid is an important fishery in northwest Mexico, the purpose of this research was to determine the effect of pulsed ultrasound on the physicochemical characteristics and emulsifying properties of squid (Dosidicus gigas) mantle proteins. Pulsed ultrasound (20kHz, 20, and 40% amplitude) was applied for 30, 60, and 90s to a protein extract prepared from giant squid mantle causing an increase (p<0.05) in surface hydrophobicity (So) from 108.4±1.4 to 239.1±2.4 after application of pulsed ultrasound at 40% of amplitude for 90s. The electrophoretic profile and the total and reactive sulfhydryl contents were not affected (p⩾0.05) by the ultrasound treatment. The emulsifying ability of the protein solution was improved (p<0.05), whereas the Emulsifier Activity Index (EAI) varied from123.67±5.52m(2)/g for the control and increased up to 217.7±3.8m(2)/g after application of the ultrasound. The Stability Emulsifier Index (EEI) was improved at 40% of amplitude by 60 and 90s. The results suggested that pulsed ultrasound used as pretreatment induced conformational changes in giant squid proteins, which improved the interfacial association between protein-oil phases, thus contributing to the improvement of their emulsifient properties.

  10. Metabolic suppression during protracted exposure to hypoxia in the jumbo squid, Dosidicus gigas, living in an oxygen minimum zone.

    Science.gov (United States)

    Seibel, Brad A; Häfker, N Sören; Trübenbach, Katja; Zhang, Jing; Tessier, Shannon N; Pörtner, Hans-Otto; Rosa, Rui; Storey, Kenneth B

    2014-07-15

    The jumbo squid, Dosidicus gigas, can survive extended forays into the oxygen minimum zone (OMZ) of the Eastern Pacific Ocean. Previous studies have demonstrated reduced oxygen consumption and a limited anaerobic contribution to ATP production, suggesting the capacity for substantial metabolic suppression during hypoxic exposure. Here, we provide a more complete description of energy metabolism and explore the expression of proteins indicative of transcriptional and translational arrest that may contribute to metabolic suppression. We demonstrate a suppression of total ATP demand under hypoxic conditions (1% oxygen, PO2 =0.8 kPa) in both juveniles (52%) and adults (35%) of the jumbo squid. Oxygen consumption rates are reduced to 20% under hypoxia relative to air-saturated controls. Concentrations of arginine phosphate (Arg-P) and ATP declined initially, reaching a new steady state (~30% of controls) after the first hour of hypoxic exposure. Octopine began accumulating after the first hour of hypoxic exposure, once Arg-P breakdown resulted in sufficient free arginine for substrate. Octopine reached levels near 30 mmol g(-1) after 3.4 h of hypoxic exposure. Succinate did increase through hypoxia but contributed minimally to total ATP production. Glycogenolysis in mantle muscle presumably serves to maintain muscle functionality and balance energetics during hypoxia. We provide evidence that post-translational modifications on histone proteins and translation factors serve as a primary means of energy conservation and that select components of the stress response are altered in hypoxic squids. Reduced ATP consumption under hypoxia serves to maintain ATP levels, prolong fuel store use and minimize the accumulation of acidic intermediates of anaerobic ATP-generating pathways during prolonged diel forays into the OMZ. Metabolic suppression likely limits active, daytime foraging at depth in the core of the OMZ, but confers an energetic advantage over competitors that must

  11. Transcriptomic profiling of gametogenesis in triploid Pacific Oysters Crassostrea gigas: towards an understanding of partial sterility associated with triploidy.

    Directory of Open Access Journals (Sweden)

    Nolwenn M Dheilly

    Full Text Available BACKGROUND: Triploidy can occur in many animal species but is often lethal. Among invertebrates, amphibians and fishes, triploids are viable although often sterile or infertile. Most triploids of the Pacific oyster Crassostrea gigas are almost sterile (named "3nβ" yet a low but significant proportion show an advanced gametogenesis (named "3nα". These oysters thus constitute an interesting model to study the effect of triploidy on germ cell development. We used microarrays to compare the gonad transcriptomes of diploid 2n and the abovementioned triploid 3nβ and 3nα male and female oysters throughout gametogenesis. RESULTS: All triploids displayed an upregulation of genes related to DNA repair and apoptosis and a downregulation of genes associated with cell division. The comparison of 3nα and 3nβ transcriptomes with 2n revealed the likely involvement of a cell cycle checkpoint during mitosis in the successful but delayed development of gonads in 3nα individuals. In contrast, a disruption of sex differentiation mechanisms may explain the sterility of 3nβ individuals with 3nβ females expressing male-specific genes and 3nβ males expressing female-specific genes. CONCLUSIONS: The disruption of sex differentiation and mitosis may be responsible for the impaired gametogenesis of triploid Pacific oysters. The function of the numerous candidate genes identified in our study should now be studied in detail in order to elucidate their role in sex determination, mitosis/meiosis control, pachytene cell cycle checkpoint, and the control of DNA repair/apoptosis.

  12. Significance of physicochemical forms of storage in microalgae in predicting copper transfer to filter-feeding oysters (Crassostrea gigas).

    Science.gov (United States)

    Amiard-Triquet, Claude; Berthet, Brigitte; Joux, Lamia; Perrein-Ettajani, Hanane

    2006-02-01

    Copper distribution has been examined in two microalgae (Haslea ostrearia, Diatom; Tetraselmis suecica, Prasinophyceae) exposed to Cu at 30 microg/L(-1). Exchangeable copper linked at the cell surface was desorbed using 8-hydroxyquinoline-5-sulfonate as complexing agent. Then, incorporated copper was separated between soluble and insoluble fractions. In addition, algae were resuspended in acid solutions, the pHs of which covered the range existing in the digestive tract of bivalves. Considering that the soluble fraction is the most easily transferred in the food chain and that exchangeable Cu is easily desorbed, the percentages of Cu potentially available in microalgae have been assessed. These percentages have been compared with those retained in oysters Crassostrea gigas fed with contaminated microalgae in previous studies. In H. ostrearia, the potentially available fraction of Cu (90%) was very similar to the percentage retained by oysters (93%) when the bivalves were acclimated to this food for 3 weeks. Only half (21%) of the potentially available Cu of T. suecica (42%) was readily assimilated in oysters after 3 weeks. This is in agreement with the results of the desorption tests at physiological pHs which showed that only 15-25% of Cu was lost, despite solubilization of other constituents of T. suecica as demonstrated by the decrease in their dry weight. Bioavailability determined from metal speciation in food allows a relevant prediction of the trophic transfer in the case of H. ostrearia, but caution is recommended in generalizing this mode of assessment as shown in the case of T. suecica.

  13. Characterization of a defensin from the oyster Crassostrea gigas. Recombinant production, folding, solution structure, antimicrobial activities, and gene expression.

    Science.gov (United States)

    Gueguen, Yannick; Herpin, Amaury; Aumelas, André; Garnier, Julien; Fievet, Julie; Escoubas, Jean-Michel; Bulet, Philippe; Gonzalez, Marcelo; Lelong, Christophe; Favrel, Pascal; Bachère, Evelyne

    2006-01-06

    In invertebrates, defensins were found in arthropods and in the mussels. Here, we report for the first time the identification and characterization of a defensin (Cg-Def) from an oyster. Cg-def mRNA was isolated from Crassostrea gigas mantle using an expressed sequence tag approach. To gain insight into potential roles of Cg-Def in oyster immunity, we produced the recombinant peptide in Escherichia coli, characterized its antimicrobial activities, determined its solution structure by NMR spectroscopy, and quantified its gene expression in vivo following bacterial challenge of oysters. Recombinant Cg-Def was active in vitro against Gram-positive bacteria but showed no or limited activities against Gram-negative bacteria and fungi. The activity of Cg-Def was retained in vitro at a salt concentration similar to that of seawater. The Cg-Def structure shares the so-called cystine-stabilized alpha-beta motif (CS-alphabeta) with arthropod defensins but is characterized by the presence of an additional disulfide bond, as previously observed in the mussel defensin (MGD-1). Nevertheless, despite a similar global fold, the Cg-Def and MGD-1 structures mainly differ by the size of their loops and by the presence of two aspartic residues in Cg-Def. Distribution of Cg-def mRNA in various oyster tissues revealed that Cg-def is mainly expressed in mantle edge where it was detected by mass spectrometry analyses. Furthermore, we observed that the Cg-def messenger concentration was unchanged after bacterial challenge. Our results suggest that Cg-def gene is continuously expressed in the mantle and would play a key role in oyster by providing a first line of defense against pathogen colonization.

  14. Exposure to the toxic dinoflagellate Alexandrium catenella modulates juvenile oyster Crassostrea gigas hemocyte variables subjected to different biotic conditions.

    Science.gov (United States)

    Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-Louis; Miner, Philippe; Le Grand, Jacqueline; Lambert, Christophe; Le Goïc, Nelly; Hégaret, Hélène; Fabioux, Caroline

    2016-04-01

    The Pacific oyster Crassostrea gigas is an important commercial species cultured throughout the world. Oyster production practices often include transfers of animals into new environments that can be stressful, especially at young ages. This study was undertaken to determine if a toxic Alexandrium bloom, occurring repeatedly in French oyster beds, could modulate juvenile oyster cellular immune responses (i.e. hemocyte variables). We simulated planting on commercial beds by conducting a cohabitation exposure of juvenile, "specific pathogen-free" (SPF) oysters (naïve from the environment) with previously field-exposed oysters to induce interactions with new microorganisms. Indeed, toxic Alexandrium spp. exposures have been reported to modulate bivalve interaction with specific pathogens, as well as physiological and immunological variables in bivalves. In summary, SPF oysters were subjected to an artificial bloom of Alexandrium catenella, simultaneously with a cohabitation challenge. Exposure to A. catenella, and thus to the paralytic shellfish toxins (PSTs) and extracellular bioactive compounds produced by this alga, induced higher concentration, size, complexity and reactive oxygen species (ROS) production of circulating hemocytes. Challenge by cohabitation with field-exposed oysters also activated these hemocyte responses, suggesting a defense response to new microorganism exposure. These hemocyte responses to cohabitation challenge, however, were partially inhibited by A. catenella exposure, which enhanced hemocyte mortality, suggesting either detrimental effects of the interaction of both stressors on immune capacity, or the implementation of an alternative immune strategy through apoptosis. Indeed, no infection with specific pathogens (herpesvirus OsHV-1 or Vibrio aesturianus) was detected. Additionally, lower PST accumulation in challenged oysters suggests a physiological impairment through alteration of feeding-related processes. Overall, results of this

  15. VALOR AGREGADO DE LAS ESPECIES Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE y Agouti paca (MAJAS

    Directory of Open Access Journals (Sweden)

    Doylith Vásquez Jurafo

    2012-12-01

    Full Text Available El presente trabajo tiene como objetivo la obtención de productos mínimamente procesados (PMP de Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE, y Agouti paca (MAJAS congelado y empacado al vacio. Para las especies piscícolas, se ha aplicado un diseño factorial de 32 con dos factores de estudios: concentración de NaCl en la solución osmótica con tres niveles (15, 20 y 25 % y temperatura de proceso con tres niveles de estudio (5, 10 y 15 °C. Para el Agouti paca (majas se aplicó un diseño factorial completamente aleatorizado con tres factores de estudio: tiempo de proceso (30, 60 y 90 minutos, método de ahumado (ahumado líquido y ahumado en caliente y tipo de corte del músculo (partes y filetes. Para trabajar se ha diseñado y montado un deshidratador Osmótico teniendo en cuenta, diámetro de tubería, deshidratador propiamente dicho con doble chaqueta, capacidad del deshidratador en función del volumen de la Salmuera.  Todos los productos se obtuvieron en procesos con 10 °C y tiempos entre 30 min y 90 min. El tiempo de vida en almacenamiento en las evaluaciones de aroma y color en majas tienen una vida útil de 4 meses de almacenados a -18 °C. Los análisis microbiológicos realizados a los PMP no pasan los límites de la NTS Nº 071 MINSA/DIGESA V01.

  16. Densidad, estructura de tallas y actividad reproductiva del caracol rosado Eustrombus gigas (Mesogastropoda: Strombidae en Banco Chinchorro, México

    Directory of Open Access Journals (Sweden)

    Yuself R Cala

    2013-12-01

    Full Text Available Eustrombus gigas es uno de los recursos pesqueros costeros más valiosos en la región del Caribe y constituye un molusco con un elevado valor estético y ecológico. En esta investigación se evalúa su densidad total, densidad de adultos, la estructura de tallas y frecuencia de evidencias reproductivas en Banco Chinchorro, México, periodo 2009-2010; durante tres períodos (de lluvias, seca y de frentes fríos en tres zonas: Norte, Centro y Sur. La densidad total para el área de estudio varió de 127ind./ha en lluvias a 384ind./ha en seca, la menor densidad se presentó en la zona Norte del Banco (198ind./ha y la mayor en la zona Sur (385ind./ha. La densidad de caracoles adultos fue baja (6.11ind./ha en seca y 8.33ind./ha en lluvias y 5.55, 7.05 y 8.33ind./ha para las zonas Centro, Sur y Norte, respectivamente. Las densidades de adultos estuvieron por debajo del umbral mínimo necesario para mantener la reproducción. El 42% de la población es vulnerable a la pesca (Lsi≥200mm; sin embargo, solo 2.2% de la población alcanza un Gl>15mm. Solo se observaron seis evidencias de reproducción durante el período de estudio, lo que señala la presencia del efecto Allee en la población y la urgente necesidad del cierre de su pesquería. Se proponen tres puntos importantes para el manejo de la especie: cierre de la pesca, monitoreo de la población y la implementación refugios pesqueros

  17. 木瓜蛋白酶嫩化秘鲁鱿鱼肉工艺条件的研究%Study on optimization for tenderization conditions of Dosidicus gigas meat by papain

    Institute of Scientific and Technical Information of China (English)

    郑贤孟; 杨文鸽; 徐大伦

    2013-01-01

    Using the shearing force and concentration of soluble protein(CSP) as indexes,the tenderization of Dosidicus gigas meat by papain was studied,and the suitable tenderization conditions of Dosidicus gigas meat were optimizated through single factor and orthogonal experiment.The results indicated that the suitable technological conditions for tenderization of Dosidicus gigas meat were as follows:papain concentration 1%,soaking time 40min,temperature 50℃ and pH7.0.Under these conditions,the shearing force of Dosidicus gigas meat was up to 2060.141g.%以鱿鱼肉的剪切力和可溶性蛋白含量(CSP)为指标,通过单因素和正交实验优化木瓜蛋白酶嫩化秘鲁鱿鱼肉的工艺条件.结果显示秘鲁鱿鱼肉适宜的嫩化条件为:木瓜蛋白酶浓度1%、处理时间40min、温度50℃、pH7.0,在此条件下鱿鱼肉得到嫩化,其剪切力为2060.141g.

  18. Molecular Characterization of Voltage-Gated Sodium Channels and Their Relations with Paralytic Shellfish Toxin Bioaccumulation in the Pacific Oyster Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Floriane Boullot

    2017-01-01

    Full Text Available Paralytic shellfish toxins (PST bind to voltage-gated sodium channels (Nav and block conduction of action potential in excitable cells. This study aimed to (i characterize Nav sequences in Crassostrea gigas and (ii investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav in C. gigas: a Nav1 (CgNav1 and a Nav2 (CgNav2 with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts of CgNav1 named A, B and C, were characterized. The expression of CgNav1, analyzed by in situ hybridization, is specific to nervous cells and to structures corresponding to neuromuscular junctions. Real-time PCR analyses showed a strong expression of CgNav1A in the striated muscle while CgNav1B is mainly expressed in visceral ganglia. CgNav1C expression is ubiquitous. The PST binding site (domain II of CgNav1 variants possess an amino acid Q that could potentially confer a partial saxitoxin (STX-resistance to the channel. The CgNav1 genotype or alternative splicing would not be the key point determining PST bioaccumulation level in oysters.

  19. Concomitant herpes-like virus infections in hatchery-reared larvae and nursery-cultured spat Crassostrea gigas and Ostrea edulis.

    Science.gov (United States)

    Renault, T; Le Deuff, R M; Chollet, B; Cochennec, N; Gérard, A

    2000-09-28

    Concomitant sporadic high mortalities were reported in France in May 1994 among batches of hatchery-reared larval Pacific oysters Crassostrea gigas and European flat oysters Ostrea edulis in 2 hatcheries, and in June and July 1994 among batches of cultured spat of both species in a shellfish nursery. Histological observation showed the presence of cellular abnormalities in moribund animals. Transmission electron microscopy revealed the presence of herpes-like virus particles in infected larvae and spat of both oyster species. This is the first description of a herpes-like virus infection in larval O. edulis. Viruses observed in diseased larvae and spat of both species are similar with respect to ultrastructure and morphogenesis. They were detected simultaneously in C. gigas and O. edulis larvae and spat, indicating possible interspecific transmission. Moreover, these viruses are associated with high mortality rates in both oyster species. An electron microscopic examination revealed hemocytes with condensed chromatin and extensive perinuclear fragmentation of chromatin. These data suggest that herpes-like viruses infecting oysters may induce apoptosis in oyster hemocytes.

  20. Paralytic Toxins Accumulation and Tissue Expression of α-Amylase and Lipase Genes in the Pacific Oyster Crassostrea gigas Fed with the Neurotoxic Dinoflagellate Alexandrium catenella

    Directory of Open Access Journals (Sweden)

    Mohamed Laabir

    2012-11-01

    Full Text Available The pacific oyster Crassostrea gigas was experimentally exposed to the neurotoxic Alexandrium catenella and a non-producer of PSTs, Alexandrium tamarense (control algae, at concentrations corresponding to those observed during the blooming period. At fixed time intervals, from 0 to 48 h, we determined the clearance rate, the total filtered cells, the composition of the fecal ribbons, the profile of the PSP toxins and the variation of the expression of two α-amylase and triacylglecerol lipase precursor (TLP genes through semi-quantitative RT-PCR. The results showed a significant decrease of the clearance rate of C. gigas fed with both Alexandrium species. However, from 29 to 48 h, the clearance rate and cell filtration activity increased only in oysters fed with A. tamarense. The toxin concentrations in the digestive gland rose above the sanitary threshold in less than 48 h of exposure and GTX6, a compound absent in A. catenella cells, accumulated. The α-amylase B gene expression level increased significantly in the time interval from 6 to 48 h in the digestive gland of oysters fed with A. tamarense, whereas the TLP gene transcript was significantly up-regulated in the digestive gland of oysters fed with the neurotoxic A. catenella. All together, these results suggest that the digestion capacity could be affected by PSP toxins.

  1. Molecular and histological identification of Marteilioides infection in Suminoe Oyster Crassostrea ariakensis, Manila Clam Ruditapes philippinarum and Pacific Oyster Crassostrea gigas on the south coast of Korea.

    Science.gov (United States)

    Limpanont, Yanin; Yanin, Limpanont; Kang, Hyun-Sil; Hong, Hyun-Ki; Jeung, Hee-Do; Kim, Bong-Kyu; Le, Thanh Cuong; Kim, Young-Ok; Choi, Kwang-Sik

    2013-11-01

    The oyster ovarian parasite Marteilioides chungmuensis has been reported from Korea and Japan, damaging the oyster industries. Recently, Marteilioides-like organisms have been identified in other commercially important marine bivalves. In this study, we surveyed Marteilioides infection in the Manila clam Ruditapes philippinarum, Suminoe oyster Crassostrea ariakensis, and Pacific oyster Crassostrea gigas, using histology and Marteilioides-specific small subunit (SSU) rDNA PCR. The SSU rDNA sequence of M. chungmuensis (1716 bp) isolated from C. gigas in Tongyoung bay was 99.9% similar to that of M. chungmuensis reported in Japan. Inclusions of multi-nucleated bodies in the oocytes, typical of Marteilioides infection, were identified for the first time in Suminoe oysters. The SSU rDNA sequence of a Marteilioides-like organism isolated from Suminoe oysters was 99.9% similar to that of M. chungmuensis. Marteilioides sp. was also observed from 7 Manila clams of 1840 individuals examined, and the DNA sequences of which were 98.2% similar to the known sequence of M. chungmuensis. Unlike Marteilioides infection of Pacific oysters, no remarkable pathological symptoms, such as large multiple lumps on the mantle, were observed in infected Suminoe oysters or Manila clams. Distribution of the infected Manila clams, Suminoe oysters and Pacific oysters was limited to small bays on the south coast, suggesting that the southern coast is the enzootic area of Marteilioides infection.

  2. The Properties of Chondroitin Sulfate from Dosidicus gigas Cartilage%秘鲁巨鱿软骨硫酸软骨素理化性质研究

    Institute of Scientific and Technical Information of China (English)

    李燕妮; 郭琳; 许维娜

    2016-01-01

    探索一种新的硫酸软骨素来源。以秘鲁巨鱿软骨为原料,经过酶解、超滤浓缩和乙醇沉淀的方法获得硫酸软骨素。秘鲁巨鱿硫酸软骨素得率为3.2%,比旋度为-25.2°,黏均分子量为157000,硫酸软骨素E型二糖占总二糖比例的17%。秘鲁巨鱿软骨可以作为一种硫酸软骨素新原料。%The arm of this research was to explore a new sources of chondroitin sulfate. With the purification process of enzymolysis,filtration and ethanol precipitation,chondroitin sulfate(CS) was purified from the carti-lage of Dosidicus gigas and characterized in an effort to find alternative source. The yield of CS was about 3.2%, the specific rotation was-25.2°,viscosity-average molecular was 157 000,the E-type disulfated disaccharides was 17%in all CS extracts. The Dosidicus gigas cartilage can be used as a new source of CS.

  3. A preliminary analysis of trace-elemental signatures in statoliths of different spawning cohorts for Dosidicus gigas off EEZ waters of Chile

    Science.gov (United States)

    Liu, Bilin; Chen, Xinjun; Fang, Zhou; Hu, Song; Song, Qian

    2015-12-01

    We applied solution-based ICP-MS method to quantify the trace-elemental signatures in statoliths of jumbo flying squid, Dosidius gigas, which were collected from the waters off northern and central Chile during the scientific surveys carried out by Chinese squid jigging vessels in 2007 and 2008. The age and spawning date of the squid were back-calculated based on daily increments in statoliths. Eight elemental ratios (Sr/Ca, Ba/Ca, Mg/Ca, Mn/Ca, Na/Ca, Fe/Ca, Cu/Ca and Zn/Ca) were analyzed. It was found that Sr is the second most abundant element next to Ca, followed by Na, Fe, Mg, Zn, Cu, Ba and Mn. There was no significant relationship between element/Ca and sea surface temperature (SST) and sea surface salinity (SSS), although weak negative or positive tendency was found. MANOVA analysis showed that multivariate elemental signatures did not differ among the cohorts spawned in spring, autumn and winter, and no significant difference was found between the northern and central sampling locations. Classification results showed that all individuals of each spawned cohorts were correctly classified. This study demonstrates that the elemental signatures in D. gigas statoliths are potentially a useful tool to improve our understanding of its population structure and habitat environment.

  4. Molecular Characterization of Voltage-Gated Sodium Channels and Their Relations with Paralytic Shellfish Toxin Bioaccumulation in the Pacific Oyster Crassostrea gigas

    Science.gov (United States)

    Boullot, Floriane; Castrec, Justine; Bidault, Adeline; Dantas, Natanael; Payton, Laura; Perrigault, Mickael; Tran, Damien; Amzil, Zouher; Boudry, Pierre; Soudant, Philippe; Hégaret, Hélène; Fabioux, Caroline

    2017-01-01

    Paralytic shellfish toxins (PST) bind to voltage-gated sodium channels (Nav) and block conduction of action potential in excitable cells. This study aimed to (i) characterize Nav sequences in Crassostrea gigas and (ii) investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav in C. gigas: a Nav1 (CgNav1) and a Nav2 (CgNav2) with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts of CgNav1 named A, B and C, were characterized. The expression of CgNav1, analyzed by in situ hybridization, is specific to nervous cells and to structures corresponding to neuromuscular junctions. Real-time PCR analyses showed a strong expression of CgNav1A in the striated muscle while CgNav1B is mainly expressed in visceral ganglia. CgNav1C expression is ubiquitous. The PST binding site (domain II) of CgNav1 variants possess an amino acid Q that could potentially confer a partial saxitoxin (STX)-resistance to the channel. The CgNav1 genotype or alternative splicing would not be the key point determining PST bioaccumulation level in oysters. PMID:28106838

  5. Starch supplementation modulates amylase enzymatic properties and amylase B mRNA level in the digestive gland of the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Huvet, A; Jeffroy, F; Daniel, J Y; Quéré, C; Le Souchu, P; Van Wormhoudt, A; Boudry, P; Moal, J; Samain, J F

    2012-09-01

    In the oyster Crassostrea gigas consumption-related traits, amylase properties and growth were found to be linked through genotypes that differed for polymorphism in the two amylase genes AMYA and AMYB. Modulation of AMYA mRNA level had already been observed in response to food availability, whereas the functional role of AMYB was still unknown. To improve knowledge about the regulation of amylase expression in C. gigas and the respective roles of the two genes, we made an assay of amylase expression at mRNA and enzymatic levels in the digestive gland of oysters that had received dietary supplements of starch. After 18 days, a significant increase of translatable mRNA for AMYB was observed, with a correlated increase in Michaelis-Menten constant Km values and a decrease in total amylase activity. This modulation is the first evidence of observable functioning of AMYB in digestive processes. Amylase B is suggested to display a higher Km than amylase A, offering a means of adapting to high substrate concentrations. The highest starch supplement level (10 mgL(-1)) induced alteration in oyster physiology. The 1 mgL(-1) treatment should be tested as a practical food supplement that could lead to growth benefits for oysters.

  6. The hematopoiesis in gill and its role in the immune response of Pacific oyster Crassostrea gigas against secondary challenge with Vibrio splendidus.

    Science.gov (United States)

    Li, Yiqun; Song, Xiaorui; Wang, Weilin; Wang, Lingling; Yi, Qilin; Jiang, Shuai; Jia, Zhihao; Du, Xinyu; Qiu, Limei; Song, Linsheng

    2017-06-01

    Increasing evidences have demonstrated that the invertebrate gill is a predominant tissue participating in the immune response during pathogen challenge. In the present study, the hematopoiesis and immune activities in gill of Pacific oyster Crassostrea gigas were investigated. Stem-like cells with big nuclei and thin cytoplasm were found in the tubules of gill filaments, where DNA synthesis is active and hemocytes production are exuberant. The oysters primarily stimulated by formaldehyde-killed Vibrio splendidus exhibited stronger immune responses and enhanced cell regeneration in gill when they encountered the secondary challenge of live V. splendidus. After the secondary stimulation with V. splendidus, the expression levels of CgClec-4 and CgIFN in the gill of oysters pre-stimulated with formaldehyde-killed V. splendidus were significantly higher (p challenge with V. splendidus. ROS production was also enhanced (p challenge. The phagocytic rate in gill of oysters pre-stimulated with formaldehyde-killed V. splendidus was significantly increased (p challenge with live V. splendidus, showing faster response than that pre-stimulated with filter-sterilized sea water. These results collectively showed that the immune parameters in gill were apparently enhanced after secondary challenge with live V. splendidus, indicating that hematopoiesis might participate in immune priming in Pacific oyster C. gigas.

  7. Study of the difference in rectal and ear canal temperature according to the conformation of the acoustic conch in dogsEstudo da diferença das temperaturas retal e do canal auditivo de acordo com a conformação da concha acústica em cães

    Directory of Open Access Journals (Sweden)

    Eduardo Negri Mueller

    2012-10-01

    Full Text Available The auditory thermometry has being used for measurement of temperature of dogs. However there is different acoustic conch conformation in this species, being that the pendulous ears can alter the auditory microclimate. This research aimed to study the difference of rectal and auditory canal temperatures according to acoustic conch conformation in dogs. One hundred and eleven dogs were used with erect ears (group I, semi-pendulous (group II and pendulous (group II with 37 animals each group. The measurement of rectal temperature (TR was realized with traditional thermometer mercury column and measurement of both external ears temperature with infrared ear thermometer. The average hearing temperature (TAM was obtained and realized difference between TR and TAM, being the results classify in scores, A=TAMA termometria auditiva vem sendo utilizada para mensuração da temperatura em cães. Porém, existem diferentes conformações da concha acústica nesta espécie, sendo que orelhas pendulares podem alterar o microclima auditivo. Portanto, objetivou-se estudar a diferença das temperaturas retal e do canal auditivo de acordo com a conformação da concha acústica em cães. Foram utilizados 111 cães hígidos com orelhas ereta (grupo I, semipendular (grupo II e pendular (grupo III com 37 animais cada. A aferição da temperatura retal (TR foi realizada com termômetro tradicional coluna de mercúrio e aferição da temperatura de ambas as orelhas externas com termômetro auricular infravermelho. Foi obtida temperatura auditiva média (TAM e realizada diferença entre TR e TAM, sendo os resultados classificados em escores, A=TAM

  8. 长牡蛎肉小肽营养液的研制%The Preparation of Small Peptides Nutrient Solution by Enzymatic Method from Ostrea Gigas Thunberg Meat

    Institute of Scientific and Technical Information of China (English)

    方富永; 芦志刚; 苗艳丽; 胡世伟; 黄勇; 宋文东

    2012-01-01

    To study the technological conditions of small peptides nutrient solution preparation from Ostrea gigas Thunberg meat, first .Taking the hydrolyzing degree as the target to determine the optimum conditions of Ostrea gigas Thunberg meat hydrolyzed respectively by neutral protease, papain and bromelain. Based on orthogonal test, the best technological conditions hydrolyzed respectively by single protease were confirmed; and then three enzymes composite enzyme hydrolysis tests were proceeded.on the basis of hydrolyzing degree,the perfect match and the best technological conditions of enzyme hydrolysis were confirmed. On these grounds, the enzyme hydrolysate of Ostrea gigas Thunberg meat was prepared. Finally, small peptides nutrient solution was made from the enzyme hydrolysate under the condition of optimum formula confirmed by the orthogonal test.the composite hydrolyzing degree of Ostrea gigas Thunberg meat hydrolyzed by three protease can reach 52.97% under the optimum technological conditions, The peak value of relative molecular mass of these small peptide varied from 300 to 1 000 determined by polyacrylamide gradient gel vertical flatbed electrophoresis. The content of 17 free amino acids was 500.16 mg/100 mL. The optimum formula of small peptides nutrient solution.: hydrolysate (mL) : sucrose (g) :citric acid (g):sodium chloride (g)in proper sequence were as follow 100∶10∶ 0.2∶0.2. The total amount of free amino acids ≥5 000 mg/L. The nutritious liquid with eutrophy and simple preparation technology can be be applied to the high-priced exploitation of Ostrea gigas Thunberg meat.%研究长牡蛎肉小肽营养液制备的工艺条件.先以水解度为指标,确定长牡蛎肉中性蛋白酶、木瓜蛋白酶、菠萝蛋白酶单酶的最适水解条件,通过正交试验确定各单酶水解的最佳工艺条件;然后以此为基础进行三酶复合试验,根据水解度确定最佳工艺条件,制备长牡蛎肉水解液;最后以该水解液

  9. Stanols as a tool to track the origin of microbial contamination of oysters, Crassostrea gigas, in shellfish areas.

    Science.gov (United States)

    Harrault, Loïc; Jardé, Emilie; Jeanneau, Laurent; Petitjean, Patrice

    2013-04-01

    Runoff of cattle manures (cows, pigs, sheeps) or discharge of effluent from wastewater treatment plants (WWTP) into aquatic ecosystems can lead to microbiological contamination of waters and living organisms. In coastal ecosystems and particularly in shellfish harvesting areas, the presence of pathogen microorganisms in waters induces fecal contamination of filter feeding bivalves (oysters, mussels, scallops…), therefore leading to human health risks associated to the consumption of these contaminated organisms. Watershed management plans that aim at limiting these risks require the development of tools able to identify fecal contamination sources. The fecal indicator bacteria used in the regulations to determine fecal contamination are not source specific since they are found in the feces of most warm-blooded animals. Thus, microbiological biomarkers have been developed in association with chemical biomarkers as Microbial Source Tracking (MST) methods. Fecal stanols, by-products of sterols obtained by human and animal microbial gut flora, are found in considerable amounts in feces with different relative proportions depending on their animal or human source. Recently, in association with microbiological biomarkers, the stanol fingerprint of contaminated waters has been successfully used to determine the main source of fecal contamination (cow, pig or human sources) in rural watersheds (Brittany, France). Up to now, the use of the stanol fingerprint to track the fecal contamination in shellfish tissues, especially bivalves, has been limited to the analysis of coprostanol, a stanol commonly associated to human contamination. Therefore, whether the stanol fingerprint can be used as a MST method in bivalves or not is still unknown. The first aim of this study was to compare several organic extraction procedures of stanols in the oyster Crassostrea gigas to determine a reliable method for stanol fingerprint analysis in bivalves. Solvent extraction and purification

  10. Non-additive effects of ocean acidification in combination with warming on the larval proteome of the Pacific oyster, Crassostrea gigas.

    Science.gov (United States)

    Harney, Ewan; Artigaud, Sébastien; Le Souchu, Pierrick; Miner, Philippe; Corporeau, Charlotte; Essid, Hafida; Pichereau, Vianney; Nunes, Flavia L D

    2016-03-01

    Increasing atmospheric carbon dioxide results in ocean acidification and warming, significantly impacting marine invertebrate larvae development. We investigated how ocean acidification in combination with warming affected D-veliger larvae of the Pacific oyster Crassostrea gigas. Larvae were reared for 40h under either control (pH8.1, 20 °C), acidified (pH7.9, 20 °C), warm (pH8.1, 22 °C) or warm acidified (pH7.9, 22 °C) conditions. Larvae in acidified conditions were significantly smaller than in the control, but warm acidified conditions mitigated negative effects on size, and increased calcification. A proteomic approach employing two-dimensional electrophoresis (2-DE) was used to quantify proteins and relate their abundance to phenotypic traits. In total 12 differentially abundant spots were identified by nano-liquid chromatography-tandem mass spectrometry. These proteins had roles in metabolism, intra- and extra-cellular matrix formations, stress response, and as molecular chaperones. Seven spots responded to reduced pH, four to increased temperature, and six to acidification and warming. Reduced abundance of proteins such as ATP synthase and GAPDH, and increased abundance of superoxide dismutase, occurred when both pH and temperature changes were imposed, suggesting altered metabolism and enhanced oxidative stress. These results identify key proteins that may be involved in the acclimation of C. gigas larvae to ocean acidification and warming. Increasing atmospheric CO2 raises sea surface temperatures and results in ocean acidification, two climatic variables known to impact marine organisms. Larvae of calcifying species may be particularly at risk to such changing environmental conditions. The Pacific oyster Crassostrea gigas is ecologically and commercially important, and understanding its ability to acclimate to climate change will help to predict how aquaculture of this species is likely to be impacted. Modest, yet realistic changes in pH and

  11. Spatial patterns in the condition index of the wild Pacific oyster Crassostrea gigas in a macrotidal coastal ecosystem: Influence of tidal processes and beyond

    Science.gov (United States)

    Gasmi, Sonia; Bernard, Ismaël; Pouvreau, Stéphane; Maurer, Danièle; Schaal, Gauthier; Ganthy, Florian; Cominassi, Louise; Allain, Gwenhael; Sautour, Benoit; David, Valérie

    2017-01-01

    In macrotidal coastal ecosystems, spatial heterogeneity of the water column properties is induced by both oceanic and continental influences. Hydrodynamic processes generate a land-sea gradient of environmental conditions, affecting the biological performances of sedentary organisms. The aim of the present study is to establish an extensive spatial assessment in the reproductive investment of the wild Pacific oyster Crassostrea gigas in Arcachon Bay. This is done by looking for a relationship between the Lawrence and Scott condition index (LSCI) and two tidal processes: the immersion level (IL) and the local oceanic flushing time (LoFt). The LSCI of C. gigas was assessed, just before gamete release, at 68 sampling stations in Arcachon Bay. Oyster performance was overall low and spatially variable. Significant differences in the LSCI were detected between the outer and inner bay. Oyster reefs located toward the mouth of the bay exhibited high LSCI (between 9 and 11), while oyster reefs located in inner bay, especially in south-eastern part around the Eyre River, had low LSCI (below 6). Linear modelling allowed to highlight significant effects of both tidal processes IL and LoFt on the obtained LSCI gradient. IL, LoFt explained 33% of the spatial variability observed on LSCI (IL = 3%; LoFt = 17%; LoFt + IL: 13%), 6% were attributed to the intra-station variation (ISv). Thus, high IL and rapid LoFt favor a better development of somatic-gonadal volume, probably because of longer feeding time and higher supply of food from the ocean by tide flows. Disentangling the effects of IL and LoFt on LSCI allowed to describe the spatial pattern in 61% of variability not explained by both tidal factors. A residual gradient directed southeast-northwest highlighted that others factors, independent from IL and LoFt seems to hamper inner bay oyster reproductive performance. Consequently, investigating on the ecological functioning (Eyre influences), trophic potential and anthropogenic

  12. Analysis of Giga-size Earth Observation Data in Open Source GRASS GIS 7 - from Desktop to On-line Solutions.

    Science.gov (United States)

    Stepinski, T. F.; Mitasova, H.; Jasiewicz, J.; Neteler, M.; Gebbert, S.

    2014-12-01

    GRASS GIS is a leading open source GIS for geospatial analysis and modeling. In addition to being utilized as a desktop GIS it also serves as a processing engine for high performance geospatial computing for applications in diverse disciplines. The newly released GRASS GIS 7 supports big data analysis including temporal framework, image segmentation, watershed analysis, synchronized 2D/3D animations and many others. This presentation will focus on new GRASS GIS 7-powered tools for geoprocessing giga-size earth observation (EO) data using spatial pattern analysis. Pattern-based analysis connects to human visual perception of space as well as makes geoprocessing of giga-size EO data possible in an efficient and robust manner. GeoPAT is a collection of GRASS GIS 7 modules that fully integrates procedures for pattern representation of EO data and patterns similarity calculations with standard GIS tasks of mapping, maps overlay, segmentation, classification(Fig 1a), change detections etc. GeoPAT works very well on a desktop but it also underpins several GeoWeb applications (http://sil.uc.edu/ ) which allow users to do analysis on selected EO datasets without the need to download them. The GRASS GIS 7 temporal framework and high resolution visualizations will be illustrated using time series of giga-size, lidar-based digital elevation models representing the dynamics of North Carolina barrier islands over the past 15 years. The temporal framework supports efficient raster and vector data series analysis and simplifies data input for visual analysis of dynamic landscapes (Fig. 1b) allowing users to rapidly identify vulnerable locations, changes in built environment and eroding coastlines. Numerous improvements in GRASS GIS 7 were implemented to support terabyte size data processing for reconstruction of MODIS land surface temperature (LST) at 250m resolution using multiple regressions and PCA (Fig. 1c) . The new MODIS LST series (http://gis.cri.fmach.it/eurolst/) includes

  13. Type-like of HBGAs inCrassostrea gigas and its binding properties with norovirus P particles%长牡蛎中类HBGAs的分型及与诺如病毒P粒子结合特性研究

    Institute of Scientific and Technical Information of China (English)

    马丽萍; 苏来金; 赵峰; 周德庆

    2015-01-01

    Objective To know the features of type-like HBGAs in digestive tissue ofCrassostrea gigas, and analyze its binding properties of GII.4 genotypenorovirus variants, and to research the mechanism of enrichment.MethodsEight types HBGAs-specific monoclonal antibodies (MAbs) from human were used to establish the ELISA method for type-like HBGAs inCrassostrea gigas. Binding profile between type-like HBGAs inCrassostrea gigas and 5 GII.4 genotypenorovirus variants were also analyzed.ResultsA-like, H1-like, Lea-like and Ley-like were the main types HBGAs existed in digestive tissue ofCrassostrea gigas. 2006b variant and 95/96US variant binding with A-like, H1-like and ley-like HBGAs inCrassostrea gigas. However, Camberwell_91 variant and Hunter_2004 variant only bind with ley-like HBGA, and sakai variant bind no type HBGA inCrassostrea gigas.Conclusion There are A-like, H1-like, Lea-like and Ley-like type HBGAs in digestive tissue ofCrassostrea gigas. GII.4 genotypenorovirus variants mainly bind with A-like , H1-like and Ley-like HBGA inCrassostrea gigas.%目的:了解长牡蛎(Crassostrea gigas)消化道组织中类组织血型抗原(histo-blood group antigens, HBGAs)的类型特点,分析其与诺如病毒的结合特性,以探讨长牡蛎富集诺如病毒的机制。方法利用8种HBGAs单克隆抗体,建立长牡蛎中类HBGAs检测的ELISA方法,并分析其主要型别。同时,利用5种体外表达的 GII.4型诺如病毒 P 粒子分析其与长牡蛎中类 HBGA 的结合特性。结果长牡蛎消化道组织中存在类A, H1, Lea和Ley型HBGA;55019株(2006b变异株)和97-1l株(95/96US变异株) GII.4型诺如病毒P粒子可通过类A、H1和Ley型HBGA与长牡蛎消化道组织相结合,91(Camberwell_91株)和42(Hunter_2004)株可通过类Ley型HBGA与长牡蛎消化道组织相结合,156株(sakai株)不与任何类型类HBGA结合。结论长牡蛎消化道组织中存在类A、H1、Lea和Ley型HBGA, GII.4型诺如病毒主要通过类A、H1和Ley型HBGA

  14. Identification of Proteins with Potential Osteogenic Activity Present in the Water-Soluble Matrix Proteins from Crassostrea gigas Nacre Using a Proteomic Approach

    Directory of Open Access Journals (Sweden)

    Daniel V. Oliveira

    2012-01-01

    Full Text Available Nacre, when implanted in vivo in bones of dogs, sheep, mice, and humans, induces a biological response that includes integration and osteogenic activity on the host tissue that seems to be activated by a set of proteins present in the nacre water-soluble matrix (WSM. We describe here an experimental approach that can accurately identify the proteins present in the WSM of shell mollusk nacre. Four proteins (three gigasin-2 isoforms and a cystatin A2 were for the first time identified in WSM of Crassostrea gigas nacre using 2DE and LC-MS/MS for protein identification. These proteins are thought to be involved in bone remodeling processes and could be responsible for the biocompatibility shown between bone and nacre grafts. These results represent a contribution to the study of shell biomineralization process and opens new perspectives for the development of new nacre biomaterials for orthopedic applications.

  15. Combined climate- and prey-mediated range expansion of Humboldt squid (Dosidicus gigas), a large marine predator in the California Current System.

    Science.gov (United States)

    Stewart, Julia S; Hazen, Elliott L; Bograd, Steven J; Byrnes, Jarrett E K; Foley, David G; Gilly, William F; Robison, Bruce H; Field, John C

    2014-06-01

    Climate-driven range shifts are ongoing in pelagic marine environments, and ecosystems must respond to combined effects of altered species distributions and environmental drivers. Hypoxic oxygen minimum zones (OMZs) in midwater environments are shoaling globally; this can affect distributions of species both geographically and vertically along with predator-prey dynamics. Humboldt (jumbo) squid (Dosidicus gigas) are highly migratory predators adapted to hypoxic conditions that may be deleterious to their competitors and predators. Consequently, OMZ shoaling may preferentially facilitate foraging opportunities for Humboldt squid. With two separate modeling approaches using unique, long-term data based on in situ observations of predator, prey, and environmental variables, our analyses suggest that Humboldt squid are indirectly affected by OMZ shoaling through effects on a primary food source, myctophid fishes. Our results suggest that this indirect linkage between hypoxia and foraging is an important driver of the ongoing range expansion of Humboldt squid in the northeastern Pacific Ocean.

  16. ESP-102, a combined extract of Angelica gigas, Saururus chinensis and Schizandra chinensis, protects against glutamate-induced toxicity in primary cultures of rat cortical cells.

    Science.gov (United States)

    Ma, Choong Je; Kim, Seung Hyun; Lee, Ki Yong; Oh, Taehwan; Kim, Sun Yeou; Sung, Sang Hyun; Kim, Young Choong

    2009-11-01

    It was reported previously that ESP-102, a combined extract of Angelica gigas, Saururus chinensis and Schizandra chinensis, significantly improved scopolamine-induced memory impairment in mice and protected primary cultured rat cortical cells against glutamate-induced toxicity. To corroborate this effect, the action patterns of ESP-102 were elucidated using the same in vitro system. ESP-102 decreased the cellular calcium concentration increased by glutamate, and inhibited the subsequent overproduction of cellular nitric oxide and reactive oxygen species to the level of control cells. It also preserved cellular activities of antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and glutathione reductase reduced in the glutamate-injured neuronal cells. While a loss of mitochondrial membrane potential was observed in glutamate treated cells, the mitochondrial membrane potential was maintained by ESP-102. These results support that the actual mechanism of neuroprotective activity of ESP-102 against glutamate-induced oxidative stress might be its antioxidative activity.

  17. Growth, fatness and gross biochemical composition of the japanese oyster Crassostrea gigas in stanway cylinders in the bay of Arcachon, France

    OpenAIRE

    Robert, Rene; Trut, Gilles; Borel, Michel; Maurer, Daniele

    1992-01-01

    Le cylindre Stanway a été testé à partir de septembre 1989 jusqu'en août 1991 dans la baie d'Arcachon. Les essais ont été effectués principalement sur l'huître japonaise Crassostrea gigas dans une région exposée au vent. Le développement de la semence, le naissain, les huîtres âgées de 18 mois et l'engraissage des huîtres âgées de 2 ans ont été étudiés. Par comparaison aux sacs en plastique, le cylindre Stanway a des effets très positifs sur la survie et la croissance de la semence de Crasso...

  18. Ostreid herpesvirus 1 infection among Pacific oyster (Crassostrea gigas) Spat: relevance of water temperature to virus replication and circulation prior to the onset of mortality.

    Science.gov (United States)

    Renault, Tristan; Bouquet, Anne Lise; Maurice, Julien-Thomas; Lupo, Coralie; Blachier, Philippe

    2014-09-01

    A number of bivalve species worldwide, including the Pacific oyster, Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified as Ostreid herpesvirus 1 (OsHV-1) within the family Malacoherpesviridae. Since 2008, mass mortality outbreaks among C. gigas in Europe have been related to the detection of a variant of OsHV-1 called μVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed in 4 different locations in the Marennes-Oleron area (France): an oyster pond ("claire"), a shellfish nursery, and two locations in the field. Mortality rates were recorded based on regular observation, and samples were collected to search for and quantify OsHV-1 DNA by real-time PCR. Although similar massive mortality rates were reported at the 4 sites, mortality was detected earlier in the pond and in the nursery than at both field sites. This difference may be related to earlier increases in water temperature. Mass mortality was observed among oysters a few days after increases in the number of PCR-positive oysters and viral-DNA amounts were recorded. An initial increment in the number of PCR-positive oysters was reported at both field sites during the survey in the absence of significant mortality. During this period, the water temperature was below 16°C.

  19. Ostreid Herpesvirus 1 Infection among Pacific Oyster (Crassostrea gigas) Spat: Relevance of Water Temperature to Virus Replication and Circulation Prior to the Onset of Mortality

    Science.gov (United States)

    Bouquet, Anne Lise; Maurice, Julien-Thomas; Lupo, Coralie; Blachier, Philippe

    2014-01-01

    A number of bivalve species worldwide, including the Pacific oyster, Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified as Ostreid herpesvirus 1 (OsHV-1) within the family Malacoherpesviridae. Since 2008, mass mortality outbreaks among C. gigas in Europe have been related to the detection of a variant of OsHV-1 called μVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed in 4 different locations in the Marennes-Oleron area (France): an oyster pond (“claire”), a shellfish nursery, and two locations in the field. Mortality rates were recorded based on regular observation, and samples were collected to search for and quantify OsHV-1 DNA by real-time PCR. Although similar massive mortality rates were reported at the 4 sites, mortality was detected earlier in the pond and in the nursery than at both field sites. This difference may be related to earlier increases in water temperature. Mass mortality was observed among oysters a few days after increases in the number of PCR-positive oysters and viral-DNA amounts were recorded. An initial increment in the number of PCR-positive oysters was reported at both field sites during the survey in the absence of significant mortality. During this period, the water temperature was below 16°C. PMID:24973071

  20. Genome-wide and single-base resolution DNA methylomes of the Pacific oyster Crassostrea gigas provide insight into the evolution of invertebrate CpG methylation.

    Science.gov (United States)

    Wang, Xiaotong; Li, Qiye; Lian, Jinmin; Li, Li; Jin, Lijun; Cai, Huimin; Xu, Fei; Qi, Haigang; Zhang, Linlin; Wu, Fucun; Meng, Jie; Que, Huayong; Fang, Xiaodong; Guo, Ximing; Zhang, Guofan

    2014-12-16

    Studies of DNA methylomes in a wide range of eukaryotes have revealed both conserved and divergent characteristics of DNA methylation among phylogenetic groups. However, data on invertebrates particularly molluscs are limited, which hinders our understanding of the evolution of DNA methylation in metazoa. The sequencing of the Pacific oyster Crassostrea gigas genome provides an opportunity for genome-wide profiling of DNA methylation in this model mollusc. Homologous searches against the C. gigas genome identified functional orthologs for key genes involved in DNA methylation: DNMT1, DNMT2, DNMT3, MBD2/3 and UHRF1. Whole-genome bisulfite sequencing (BS-seq) of the oyster's mantle tissues revealed that more than 99% methylation modification was restricted to cytosines in CpG context and methylated CpGs accumulated in the bodies of genes that were moderately expressed. Young repeat elements were another major targets of CpG methylation in oysters. Comparison with other invertebrate methylomes suggested that the 5'-end bias of gene body methylation and the negative correlation between gene body methylation and gene length were the derived features probably limited to the insect lineage. Interestingly, phylostratigraphic analysis showed that CpG methylation preferentially targeted genes originating in the common ancestor of eukaryotes rather than the oldest genes originating in the common ancestor of cellular organisms. Comparative analysis of the oyster DNA methylomes and that of other animal species revealed that the characteristics of DNA methylation were generally conserved during invertebrate evolution, while some unique features were derived in the insect lineage. The preference of methylation modification on genes originating in the eukaryotic ancestor rather than the oldest genes is unexpected, probably implying that the emergence of methylation regulation in these 'relatively young' genes was critical for the origin and radiation of eukaryotes.

  1. Development of a Pacific oyster (Crassostrea gigas) 31,918-feature microarray: identification of reference genes and tissue-enriched expression patterns

    Science.gov (United States)

    2011-01-01

    Background Research using the Pacific oyster Crassostrea gigas as a model organism has experienced rapid growth in recent years due to the development of high-throughput molecular technologies. As many as 56,268 EST sequences have been sequenced to date, representing a genome-wide resource that can be used for transcriptomic investigations. Results In this paper, we developed a Pacific oyster microarray containing oligonucleotides representing 31,918 transcribed sequences selected from the publicly accessible GigasDatabase. This newly designed microarray was used to study the transcriptome of male and female gonads, mantle, gills, posterior adductor muscle, visceral ganglia, hemocytes, labial palps and digestive gland. Statistical analyses identified genes differentially expressed among tissues and clusters of tissue-enriched genes. These genes reflect major tissue-specific functions at the molecular level, such as tissue formation in the mantle, filtering in the gills and labial palps, and reproduction in the gonads. Hierarchical clustering predicted the involvement of unannotated genes in specific functional pathways such as the insulin/NPY pathway, an important pathway under study in our model species. Microarray data also accurately identified reference genes whose mRNA level appeared stable across all the analyzed tissues. Adp-ribosylation factor 1 (arf1) appeared to be the most robust reference for normalizing gene expression data across different tissues and is therefore proposed as a relevant reference gene for further gene expression analysis in the Pacific oyster. Conclusions This study provides a new transcriptomic tool for studies of oyster biology, which will help in the annotation of its genome and which identifies candidate reference genes for gene expression analysis. PMID:21951653

  2. A C1q domain containing protein from Crassostrea gigas serves as pattern recognition receptor and opsonin with high binding affinity to LPS.

    Science.gov (United States)

    Jiang, Shuai; Li, Hui; Zhang, Daoxiang; Zhang, Huan; Wang, Lingling; Sun, Jinsheng; Song, Linsheng

    2015-08-01

    C1q proteins serve as pattern recognition receptors and involve in the pathogen recognition and complement pathway activation. In the present study, a novel C1q domain containing protein from Crassostrea gigas (designated CgC1qDC-1) was isolated by liposaccharide-Sepharose 6B affinity chromatography. The coding sequence of CgC1qDC-1 gene was determined by performing a homologous search of eight tryptic peptides identified by MALDI-TOF/TOF-MS against the genome of C. gigas. The coding sequence of CgC1qDC-1 was of 387 bp encoding a polypeptide of 128 amino acids containing a typical globular C1q domain. The globular C1q domain possessed eight β strands with a jelly-roll topology structure, which was similar to the structure of human gC1q domain. The mRNA transcripts of CgC1qDC-1 were dominantly expressed in mantle and hemocytes, while low expressed in hepatopancreas, gonad, gill and muscle. The expression level of CgC1qDC-1 increased drastically at 6 h after Vibrio splendidus stimulation, and then gradually fell to the normal level at about 24 h. ELISA assay quantified that CgC1qDC-1 bound to LPS with high binding affinity (Kd = 0.09 × 10(-6) M). Moreover, CgC1qDC-1 significantly enhanced the phagocytosis of oyster hemocytes towards Gram-negative bacteria Escherichia coli and V. splendidus. These results collectively indicated that CgC1qDC-1 could serve as pattern recognition receptor and opsonin in the innate immune response against invading Gram-negative bacteria.

  3. Effect of acclimatization on hemocyte functional characteristics of the Pacific oyster (Crassostrea gigas) and carpet shell clam (Ruditapes decussatus).

    Science.gov (United States)

    Hurtado, Miguel Ángel; da Silva, Patricia Mirella; Le Goïc, Nelly; Palacios, Elena; Soudant, Philippe

    2011-12-01

    Most experimental procedures on molluscs are done after acclimatization of wild animals to lab conditions. Similarly, short-term acclimation is often unavoidable in a field survey when biological analysis cannot be done within the day of sample collection. However, acclimatization can affect the general physiological condition and particularly the immune cell responses of molluscs. Our aim was to study the changes in the hemocyte characteristics of the Pacific oyster Crassostrea gigas and the carpet shell clam Ruditapes decussatus acclimated 1 or 2 days under emersed conditions at 14 ± 1 °C and for 1, 2, 7, or 10 days to flowing seawater conditions (submerged) at 9 ± 1 °C, when compared to hemolymph withdrawn from organisms sampled in the field and immediately analyzed in the laboratory (unacclimated). The hemocyte characteristics assessed by flow cytometry were the total (THC) and differential hemocyte count, percentage of dead cells, phagocytosis, and reactive oxygen species (ROS) production. Dead hemocytes were lower in oysters acclimated both in emersed and submerged conditions (1%-5%) compared to those sampled in the field (7%). Compared to oysters, the percentage of dead hemocytes was lower in clams (0.4% vs. 1.1%) and showed a tendency to decrease during acclimatization in both emersed and submerged conditions. In comparison to organisms not acclimated, the phagocytosis of hemocytes decreased in both oysters and clams acclimated under submerged conditions, but was similar in those acclimated in emersed conditions. The ROS production remained stable in both oysters and clams acclimated in emersed conditions, whereas in submerged conditions ROS production did not change in both the hyalinocytes and granulocytes of oysters, but increased in clams. In oysters, the THC decreased when they were acclimated 1 and 2 days in submerged conditions and was mainly caused by a decrease in granulocytes, but the decrease in THC in oysters acclimated 2 days in emersed

  4. Maternal inheritance of mitochondrial DNA (mtDNA) in the Pacific oyster (Crassostrea gigas): a preliminary study using mtDNA sequence analysis with evidence of random distribution of MitoTracker-stained sperm mitochondria in fertilized eggs.

    Science.gov (United States)

    Obata, Mayu; Shimizu, Michiyo; Sano, Natsumi; Komaru, Akira

    2008-03-01

    In many bivalve species, paternal and maternal mitochondrial DNA (mtDNA) from sperm and eggs is transmitted to the offspring. This phenomenon is known as doubly uniparental inheritance (DUI). In these species, sperm mtDNA (M type) is inherited by the male gonad of the offspring. Egg mtDNA (F type) is inherited by both male and female somatic cells and female gonadal cells. In Mytilidae, sperm mitochondria are distributed in the cytoplasm of differentiating male germ cells because they are transmitted to the male gonad. In the present study, we investigated maternal inheritance of mtDNA in the Pacific oyster, Crassostrea gigas. Sequence analysis of two mitochondrial non-coding regions revealed an identical sequence pattern in the gametes and adductor muscle samples taken from six males and five females. To observe whether sperm mitochondria were specifically located in the cytoplasm of differentiating germ cells, their distribution was recorded in C. gigas fertilized eggs by vital staining with MitoTracker Green. Although the 1D blastomere was identified in the cytoplasm of differentiating germ cells, sperm mitochondria were located at the 1D blastomere in only 32% of eggs during the 8-cell stage. Thus, in C. gigas, sperm mitochondria do not specifically locate in the germ cell region at the 1D blastomere. We suggest that the distribution of sperm mitochondria is not associated with germ cell formation in C. gigas. Furthermore, as evidenced by the mtDNA sequences of two non-coding regions, we conclude that mitochondrial DNA is maternally inherited in this species.

  5. A Production Calendar Based on Water Temperature, Spat Size, and Husbandry Practices Reduce OsHV-1 μvar Impact on Cultured Pacific Oyster Crassostrea gigas in the Ebro Delta (Catalonia), Mediterranean Coast of Spain

    Science.gov (United States)

    Carrasco, Noèlia; Gairin, Ignasi; Pérez, Josu; Andree, Karl B.; Roque, Ana; Fernández-Tejedor, Margarita; Rodgers, Chris J.; Aguilera, Cristobal; Furones, M. Dolors

    2017-01-01

    Since 2006, the production of Pacific oyster Crassostrea gigas in the Ebro Delta area has dramatically declined from around 800 metric tons (MT) per year to 138 MT in 2011. This decline in production has had a significant socio-economic impact in a region where the shellfish sector is a traditional economic activity for many families. The identified agent responsible for this reduction in C. gigas production was Ostreid Herpesvirus microvar (OsHV-1 μvar), which has been associated with C. gigas spat mortalities in France, and in many other countries. In Spain the episodes of mortality became critical for the regional shellfish production between 2008 until 2014, with mortality percentage up to 100%. In this study, local hatchery C. gigas spat was used as sentinel animals for epidemiological studies and management tests carried out with the aim of reducing oyster mortality in the Ebro Delta area. A production calendar mainly based on water temperature dynamics was designed around an optimal schedule for spat immersion. The immersion calendar included two optimal periods for spat immersion, in summer when temperatures are ≥25°C and at the end of autumn and beginning of winter when they are ≤13°C. Such production planning has reduced mortalities from 80% (in 2014 and previous years) to 2–7.5% in 2015 in cemented oysters. Furthermore, other recommendations related to spat immersion size, culture density and methodology, and cementing calendar, which helped to achieve the results presented, were also recorded and transferred to local producers. This work presents a successfully tested management strategy reducing OsHV-1 μvar impact by designing new field management practices mainly focused on the handling and timing of spat immersion. This approach could be used as a management model in areas presenting similar production practices and environmental characteristics.

  6. Utilisation des protozoaires ciliés (Paramecium africanum, Colpidium uncinatum, Neobursaridium gigas pour l'épuration bactériologique des eaux polluées en microcosme

    Directory of Open Access Journals (Sweden)

    Nguedji, JBT.

    2003-01-01

    Full Text Available An Microcosm Use of Ciliate Protozoa (Paramecium africanum, Colpidium uncinatum, Neobursaridium gigas for Bacterial Purification of Polluted Water. Tests on the grazing of ciliated protozoa Paramecium africanum, Colpidium uncinatum and Neobursaridium gigas on the bacteria Escherichia coli and Staphylococcus sp. were carried out in an microcosm aquatic environment. These tests aimed at assessment of the role of these predators protozoa in the bacterial purification of polluted water. The evolution of the feeding kinetics of these protozoa shows a phase of adaptation of the predator to the prey, with a slow feeding rate and a phase of accelerate of feeding. The two phases are separated by a short period of recognition. The polynomial functions of the kinetics of predation show that C. uncinatum and P. africanum graze faster on E. coli than on Staphylococcus sp., meanwhile N. gigas feeds slowly on E. coli than on Staphylococcus sp. The time of contact between the ciliated protozoa and the bacteria, the predatory protozoa specie and the specie of the bacteria, should be considered simultaneously when evaluating the variation of bacterial concentrations in aquatic environment being purified.

  7. Selection of anti-browning agents for Dosidicus gigas slice%秘鲁鱿鱼丝褐变抑制剂的筛选

    Institute of Scientific and Technical Information of China (English)

    林丹; 薛勇; 崔宏博; 王超; 薛长湖

    2012-01-01

    In order to select effective and safe anti-browning agents for Dosidicus gigas slice,glucose-Lys system and squid slice extraction-celite system were used as simulation systems to investigate those agents'anti-browning effects on Dosidicus gigas slice,including sodium sulfite,glutathione,cinnamic acid,citric acid,calcium lactate,ferulic,pentasodium tripolyphosphate,compound of ferulic and citric acid,and compound of cinnamic acid and citric acid.And the most effective agents were added in the Dosidicus gigas slice to test its anti-browning capacity.The result indicated that the compound of citric acid and ferulic was the most effective anti-browning agent compared with the others.The compound,in which citric acid at the concentration of 50mmol/L,was the most efficient anti-browning agent during storage at the temperature of 60℃ and the inhibiting browning rate could reach 23% after 4 days.However,its anti-browning capacity did not increase at the presence of ferulic.%建立了糖-赖氨酸与鱿鱼丝浸提液-硅藻土体系两种秘鲁鱿鱼丝褐变的模拟体系,对亚硫酸钠、谷胱甘肽、肉桂酸、柠檬酸、乳酸钙、阿魏酸和多聚磷酸钠这7种褐变抑制剂,以及阿魏酸、肉桂酸与柠檬酸的协同抗褐变作用进行探讨,并将选出的褐变抑制剂应用于秘鲁鱿鱼丝中进行验证。结果表明:在模拟体系中,柠檬酸和阿魏酸的混合物抗褐变作用较为突出。在阿魏酸与柠檬酸的混合褐变抑制剂中,50mmol/L的柠檬酸的添加量在60℃时有效抑制秘鲁鱿鱼丝中的褐变反应,其抗褐变率随反应时间的延长而增大,在反应的第4d可达到23%。此混合物中柠檬酸在抗褐变过程中起主导作用,且在本实验范围内,随着其添加量的增加抗褐变效果增强,而阿魏酸的添加量对总抗褐变效果无明显影响。

  8. Structural studies on labial palps of Chlamys farreri and Crassostrea gigas%栉孔扇贝和太平洋牡蛎的唇瓣结构

    Institute of Scientific and Technical Information of China (English)

    绳秀珍; 王德秀; 任素莲; 范瑞青; 高澜

    2001-01-01

    运用石蜡切片和扫描电镜技术研究了栉孔扇贝和太平洋牡蛎的唇瓣结构。结果表明,2种贝的唇瓣结构都是中间一层结缔组织,两侧被覆纤毛柱状上皮,结缔组织中富含血腔隙。栉孔扇贝唇瓣的粘膜上皮由柱状细胞和杯状细胞组成;而太平洋牡蛎由柱状细胞、杯状细胞和嗜酸性粒分泌细胞组成。扫描电镜下,2种贝唇瓣的褶皱面呈现沟和嵴,纤毛浓密;光滑面纤毛较少。太平洋牡蛎唇瓣褶皱面的游离边缘部分和光滑面有大量的球状突起,这是杯状细胞所在处。纤毛和粘液在食物分拣和运输中起重要作用。%The structure of labial palps of Chlamys farreri and Crassostreagigas were studied using light microscopy and scanning electron microscopy. The results show that each labial palp consists of a layer of connective tissue covered on both sides by columnar ciliated epithelium setting on a thin basement membrane. There are many blood spaces within the connective tissues. The epithelum of the labial palps of C.farreri has 2 cell types:columnar ciliated cell and mucous cell, while that of C.gigas consists of columnar ciliated cell,mucous cell as well as eosinophilic cell. Under scanning electron microscopy, the ridged surfaces of the palps of the 2 bivalves are folded into deep ridges and grooves, and the cilia is robust. There are a lot of spherial granules, which are mucous cells, on the smooth surfaces and near the free edge of the ridged surfaces of the palps in C.gigas. The cilia and the mucous cells play important roles in sorting food particles and delivering food to the mouth.

  9. Impact of a sacrificial anode as assessed by zinc accumulation in different organs of the oyster Crassostrea gigas: results from long- and short-term laboratory tests.

    Science.gov (United States)

    Caplat, Christelle; Mottin, Elmina; Lebel, Jean-Marc; Serpentini, Antoine; Barillier, Daniel; Mahaut, Marie-Laure

    2012-05-01

    Sacrificial anodes made of zinc are currently used in marine environments to mitigate marine corrosion as part of CP systems of immerged metallic structures. The aim of this work was to study zinc bioconcentration in the oyster Crassostrea gigas by performing two in vivo tests during different time periods and at different zinc concentrations. The first test was conducted during a period of 10 weeks at a concentration of 0.53 ± 0.04 mg Zn L(-1) to simulate long-term exposure, and a second test was conducted during a 168-hour period at a concentration of 10.2 ± 1.2 mg Zn L(-1) to reproduce short-term exposure. In these experiments, the zinc source was an electrochemical device that included a sacrificial anode to mimic the in situ conditions. During the first 14 days of the long-term experiment, digestive glands of C oysters exhibited bioaccumulation of zinc that varied according to the oysters' reproductive cycle. Both a bioconcentration factor (BCF) of ≤ 13,397 and a zinc accumulation percentage of +297% of zinc occurred in this organ after 10 weeks. The results obtained from the short-term test showed a lower BCF of 405 but a faster bioaccumulation of zinc (starting from the first day) in the same organ. No mortality was observed in long-term assay, but 81.8% of the oysters died at the end of the short-term assay. These results demonstrate the great capacity of C. gigas to accumulate zinc released from the anode, especially when low concentrations are released, as in the case of anode dissolution used as CP. This study confirmed the necessity to monitor this zinc-contamination source in marine environments in relation to the usual oyster consumption by humans (especially in France). No implication for human health of this zinc-contamination source was demonstrated until now, and this was not the purpose of this study; however, zinc remains one of the most abundant nutritionally essential elements in the human body that may affect the human immune

  10. Morfologia e crescimento do músculo estriado esquelético no pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae - DOI: 10.4025/actascibiolsci.v30i2.3640 Morphology and skeletal muscle growth in pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae - DOI: 10.4025/actascibiolsci.v30i3.3640

    Directory of Open Access Journals (Sweden)

    Maeli Dal Pai Silva

    2008-05-01

    Full Text Available O objetivo deste trabalho foi avaliar as características morfológicas e de crescimento do músculo estriado esquelético no pirarucu (Arapaima gigas. Foram utilizados animais em duas fases de crescimento: alevinos, com 50 dias de idade, e juvenis, com um ano de idade. Após eutanásia dos animais, fragmentos musculares das regiões dorsal, lateral cranial e lateral caudal foram coletados e congelados em nitrogênio líquido. Cortes histológicos (10 µm foram submetidos às colorações HE e Tricrômico de Gomori, para a análise morfológica, e NADH-TR, para a análise do metabolismo oxidativo das fibras musculares. Foi calculado o menor diâmetro das fibras musculares brancas nas regiões dorsal e lateral cranial. A musculatura dorsal branca mostrou-se mais desenvolvida e, na musculatura lateral, observaram-se compartimentos distintos: superficial vermelho e profundo branco. Nos alevinos, o crescimento muscular ocorreu predominantemente por hiperplasia das fibras e, nos juvenis, predominou o crescimento muscular por hipertrofia.The aim of this work was to evaluate the morphological and growth characteristics of skeletal muscle tissue in pirarucu (Arapaima gigas using alevins (50 days old and juveniles (1 year old. Muscle samples were collected from dorsal, lateral cranial, and lateral caudal regions, and then frozen in liquid nitrogen. Histological frozen sections (10 µm were stained with HE and Gomori Trichrome for morphological analysis, and NADH-TR to evaluate muscle fiber oxidative metabolism. Morphometric analysis samples were obtained from dorsal and lateral cranial regions, and smallest diameter white fibers were measured. White dorsal muscle was thicker and two muscle fiber compartments were identified in the lateral cranial region: red (superficial and white (deep muscle. Hyperplasia muscle growth predominated in alevins and hypertrophy in juveniles.

  11. Suppression substractive hybridisation (SSH) and real time PCR reveal differential gene expression in the Pacific cupped oyster, Crassostrea gigas, challenged with Ostreid herpesvirus 1.

    Science.gov (United States)

    Renault, T; Faury, N; Barbosa-Solomieu, V; Moreau, K

    2011-07-01

    Virus-induced genes were identified using suppression subtractive hybridisation (SSH) from Pacific cupped oyster, Crassostrea gigas, haemocytes challenged by OsHV-1. A total of 304 clones from SSH forward library were sequenced. Among these sequences, some homologues corresponded to (i) immune related genes (macrophage express protein, IK cytokine, interferon-induced protein 44 or multicopper oxidase), (ii) apoptosis related genes (Bcl-2) and (iii) cell signalling and virus receptor genes (glypican). Molecular characterization and phylogenic analysis of 3 immune-related genes (macrophage expressed protein, multicopper oxidase and immunoglobulin domain cell adhesion molecule) were performed. Finally, quantitative PCR revealed significant changes in the expression of immune related genes (multicopper oxidase, macrophage expressed protein, myeloid differentiation factor 88 and interferon-induced protein 44) in oysters experimentally challenged with OsHV-1. These findings provide a first basis for studying the role of innate immunity in response to viruses in bivalves and identified genes may serve as markers of interest in breeding programs in order to obtain selected oysters presenting OsHV-1 resistance.

  12. Ocean acidification stimulates alkali signal pathway: A bicarbonate sensing soluble adenylyl cyclase from oyster Crassostrea gigas mediates physiological changes induced by CO2 exposure.

    Science.gov (United States)

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Wang, Hao; Jiang, Shuai; Chen, Hao; Wang, Lingling; Song, Linsheng

    2016-12-01

    Ocean acidification (OA) has been demonstrated to have severe effects on marine organisms, especially marine calcifiers. However, the impacts of OA on the physiology of marine calcifiers and the underlying mechanisms remain unclear. Soluble adenylyl cyclase (sAC) is an acid-base sensor in response to [HCO3(-)] and an intracellular source of cyclic AMP (cAMP). In the present study, an ortholog of sAC was identified from pacific oyster Crassostrea gigas (designated as CgsAC) and the catalytic region of CgsAC was cloned and expressed. Similar to the native CgsAC from gill tissues, the recombinant CgsAC protein (rCgsAC) exhibited [HCO3(-)] mediated cAMP-forming activity, which could be inhibited by a small molecule KH7. After 16days of CO2 exposure (pH=7.50), the mRNA transcripts of CgsAC increased in muscle, mantle, hepatopancreas, gill, male gonad and haemocytes, and two truncated CgsAC forms of 45kD and 20kD were produced. Cytosolic CgsAC could be translocated from the cytoplasm and nuclei to the membrane in response to CO2 exposure. Besides, CO2 exposure could increase the production of cAMP and intracellular pH of haemocytes, which was regulated by CgsAC (pocean acidification on marine calcifiers. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. 粗江蓠多糖的提取及光谱分析%Extraction and Analysis of Gracilaria Gigas Harvey Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    孟庆勇; 王亚飞; 揭新明; 东野广智; 张立坚

    2006-01-01

    采用热水浸提和乙醇沉淀的方法提取粗江蓠多糖(gracilaria gigas harvey polysacchrides,GHPS),用苯酚-硫酸法测定糖含量,等离子体原子发射光谱(ICP)测多糖中矿物元素的含量,傅里叶红外光谱仪(FTIR)分析糖类官能团.结果表明:采用热水浸提和乙醇沉淀的方法提取粗江蓠多糖提取率达14.98%,苯酚-硫酸法测得提取物多糖含量为78.2%;ICP测得粗江蓠多糖含Ca,Fe,Mg和S等矿物元素;FTIR分析GHPS有一般糖类物质的特征吸收峰,是一种酸性多糖,同时存在呋喃环和吡喃环.

  14. Iodothyronine deiodinase gene analysis of the Pacific oyster Crassostrea gigas reveals possible conservation of thyroid hormone feedback regulation mechanism in mollusks

    Science.gov (United States)

    Huang, Wen; Xu, Fei; Qu, Tao; Li, Li; Que, Huayong; Zhang, Guofan

    2015-07-01

    Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones (THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop Chlamys farreri. Here, two deiodinases were cloned in the Pacific oyster Crassostrea gigas ( CgDx and CgDy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase cDNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid Capitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of CgDx and CgDy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of CgDx and CgDy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.

  15. Construction of Aspergillus niger integrated with cellulase gene from Ampullaria gigas Spix for improved enzyme production and saccharification of alkaline-pretreated rice straw.

    Science.gov (United States)

    Yang, Peizhou; Zhang, Haifeng; Cao, Lili; Zheng, Zhi; Jiang, Shaotong

    2016-12-01

    Aspergillus niger is an important microorganism that has been used for decades to produce extracellular enzymes. In this study, a novel Aspergillus niger strain integrated with a eukaryotic expression vector harboring the gpd-Shi promoter of shiitake mushrooms and cellulase gene of Ampullaria gigas Spix was engineered to improve cellulase production for the achievement of highly efficient saccharification of agricultural residues. In one strain, designated ACShi27, which exhibited the highest total cellulase expression, total cellulase, endoglucanase, exoglucanase, and xylanase expression levels were 1.73, 16.23, 17.73, and 150.83 U ml(-1), respectively; these values were 14.5, 22.3, 24.6, and 17.3% higher than those of the wild-type Aspergillus niger M85 using wheat bran as an induction substrate. Production of cellulases and xylanase by solid-state fermentation followed by in situ saccharification of ACShi27 was investigated with alkaline-pretreated rice straw as a substrate. After 2 days of enzyme induction at 30 °C, followed by 48 h of saccharification at 50 °C, the conversion rate of carbon polymers into reducing sugar reached 293.2 mg g(-1), which was 1.23-fold higher than that of the wild-type strain. The expression of sestc in Aspergillus niger can improve the total cellulase and xylanase activity and synergism, thereby enhancing the lignocellulose in situ saccharification.

  16. Changes in the composition and diversity of the bacterial microbiota associated with oysters (Crassostrea corteziensis, Crassostrea gigas and Crassostrea sikamea) during commercial production.

    Science.gov (United States)

    Trabal Fernández, Natalia; Mazón-Suástegui, José M; Vázquez-Juárez, Ricardo; Ascencio-Valle, Felipe; Romero, Jaime

    2014-04-01

    The resident microbiota of three oyster species (Crassostrea corteziensis, Crassostrea gigas and Crassostrea sikamea) was characterised using a high-throughput sequencing approach (pyrosequencing) that was based on the V3-V5 regions of the 16S rRNA gene. We analysed the changes in the bacterial community beginning with the postlarvae produced in a hatchery, which were later planted at two grow-out cultivation sites until they reached the adult stage. DNA samples from the oysters were amplified, and 31 008 sequences belonging to 13 phyla (including Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes) and 243 genera were generated. Considering all life stages, Proteobacteria was the most abundant phylum, but it showed variations at the genus level between the postlarvae and the adult oysters. Bacteroidetes was the second most common phylum, but it was found in higher abundance in the postlarvae than in adults. The relative abundance showed that the microbiota that was associated with the postlarvae and adults differed substantially, and higher diversity and richness were evident in the postlarvae in comparison with adults of the same species. The site of rearing influenced the bacterial community composition of C. corteziensis and C. sikamea adults. The bacterial groups that were found in these oysters were complex and metabolically versatile, making it difficult to understand the host-bacteria symbiotic relationships; therefore, the physiological and ecological significances of the resident microbiota remain uncertain.

  17. Anti-Brucella Antibodies in Moose (Alces alces gigas), Muskoxen (Ovibos moschatus), and Plains Bison (Bison bison bison) in Alaska, USA.

    Science.gov (United States)

    Nymo, Ingebjørg Helena; Beckmen, Kimberlee; Godfroid, Jacques

    2016-01-01

    We used an indirect enzyme-linked immunosorbent assay (iELISA) and the rose bengal test (RBT) to test for anti-Brucella antibodies in moose (Alces alces gigas), muskoxen (Ovibos moschatus), and plains bison (Bison bison bison) from various game management units (GMUs) in Alaska, US, sampled from 1982 to 2010. A portion of the sera had previously been tested with the standard plate test (SPT), the buffered Brucella antigen (BBA) card test, and the card test (CARD). No antibody-positive plains bison were identified. Anti-Brucella antibodies were detected in moose (iELISA, n=4/87; RBT, n=4/87; SPT, n=4/5; BBA, n=4/4) from GMU 23 captured in 1992, 1993, and 1995 and in muskoxen (iELISA, n=4/52; RBT, n=4/52; CARD, n=4/35) from GMUs 26A and 26B captured in 2004, 2006, and 2007. A negative effect of infection on the health of individuals of these species is probable. The presence of antibody-positive animals from 1992 to 2007 suggests presence of brucellae over time. The antibody-positive animals were found in northern Alaska, an area with a historically higher prevalence of Brucella-positive caribou, and a spillover of Brucella suis biovar 4 from caribou may have occurred. Brucella suis biovar 4 causes human brucellosis, and transmission from consumption of moose and muskoxen is possible.

  18. A Preliminary Study on the Pattern, the Physiological Bases and the Molecular Mechanism of the Adductor Muscle Scar Pigmentation in Pacific Oyster Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Wenchao Yu

    2017-09-01

    Full Text Available The melanin pigmentation of the adductor muscle scar and the outer surface of the shell are among attractive features and their pigmentation patterns and mechanism still remains unknown in the Pacific oyster Crassostrea gigas. To study these pigmentation patterns, the colors of the adductor muscle scar vs. the outer surface of the shell on the same side were compared. No relevance was found between the colors of the adductor muscle scars and the corresponding outer surface of the shells, suggesting that their pigmentation processes were independent. Interestingly, a relationship between the color of the adductor muscle scars and the dried soft-body weight of Pacific oysters was found, which could be explained by the high hydroxyl free radical scavenging capacity of the muscle attached to the black adductor muscle scar. After the transcriptomes of pigmented and unpigmented adductor muscles and mantles were studied by RNAseq and compared, it was found that the retinol metabolism pathway were likely to be involved in melanin deposition on the adductor muscle scar and the outer surface of the shell, and that the different members of the tyrosinase or Cytochrome P450 gene families could play a role in the independent pigmentation of different organs.

  19. Chromosomal organization of simple sequence repeats in the Pacific oyster (Crassostrea gigas): (GGAT)4, (GT)7 and (TA)10 chromosome patterns

    Indian Academy of Sciences (India)

    K. Bouilly; R. Chaves; A. Leitão; A. Benabdelmouna; H. Guedes-Pinto

    2008-08-01

    Chromosome identification is essential in oyster genomic research. Fluorescence in situ hybridization (FISH) offers new opportunities for the identification of oyster chromosomes. It has been used to locate satellite DNAs, telomeres or ribosomal DNA sequences. However, regarding chromosome identification, no study has been conducted with simple sequence repeats (SSRs). FISH was used to probe the physical organization of three particular SSRs, (GGAT)4, (GT)7 and (TA)10 onto metaphase chromosomes of the Pacific oyster, Crassostrea gigas. Hybridization signals were observed in all the SSR probes, but the distribution and intensity of signals varied according to the oligonucleotide repeat. The intercalary, centromeric and telomeric bands were observed along the chromosomes, and for each particular repeat every chromosome pair presented a similar pattern, allowing karyotypic analysis with all the SSRs tested. Our study is the first in mollusks to show the application of SSR in situ hybridization for chromosome identification and karyotyping. This technique can be a useful tool for oyster comparative studies and to understand genome organization in different oyster taxa.

  20. Decursin in Angelica gigas Nakai (AGN) Enhances Doxorubicin Chemosensitivity in NCI/ADR-RES Ovarian Cancer Cells via Inhibition of P-glycoprotein Expression.

    Science.gov (United States)

    Choi, Hyeong Sim; Cho, Sung-Gook; Kim, Min Kyoung; Kim, Min Soo; Moon, Seung Hee; Kim, Il Hwan; Ko, Seong-Gyu

    2016-12-01

    Angelica gigas Nakai (AGN, Korean Dang-gui) is traditionally used for the treatment of various diseases including cancer. Here, we investigated multidrug-resistant phenotype-reversal activities of AGN and its compounds (decursin, ferulic acid, and nodakenin) in doxorubicin-resistant NCI/ADR-RES ovarian cancer cells. Our results showed that a combination of doxorubicin with either AGN or decursin inhibited a proliferation of NCI/ADR-RES cells. These combinations increased the number of cells at sub-G1 phase when cells were stained with Annexin V-fluorescein isothiocyanate. We also found that these combinations activated caspase-9, caspase-8, and caspase-3 and increased cleaved PARP level. Moreover, an inhibition of P-glycoprotein expression by either AGN or decursin resulted in a reduction of its activity in NCI/ADR-RES cells. Therefore, our data demonstrate that decursin in AGN inhibits doxorubicin-resistant ovarian cancer cell proliferation and induces apoptosis in the presence of doxorubicin via blocking P-glycoprotein expression. Therefore, AGN would be a potentially novel treatment option for multidrug-resistant tumors by sensitizing to anticancer agents. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Hemocyte parameters of the Pacific oyster Crassostrea gigas a year after the Hebei Spirit oil spill off the west coast of Korea

    Science.gov (United States)

    Donaghy, Ludovic; Hong, Hyun-Ki; Lee, Hee-Jung; Jun, Je-Cheon; Park, Young-Je; Choi, Kwang-Sik

    2010-12-01

    In marine bivalves, hemocytes support various physiological functions, including immune defense, nutrient transport, shell repair, and homeostatic maintenance. Although the effects of marine contaminants on the immunological functions of bivalves have been extensively investigated, the impacts of oil spills are not well understood. Therefore, we investigated hemocyte parameters in the Pacific oyster Crassostrea gigas 13 months after the Hebei Spirit oil spill (December 2007) off the west coast of Korea. The parameters studied included hemocyte concentration and mortality, relative proportion of hemocyte populations, and immunological functions such as phagocytosis and oxidative activity using flow cytometry. These immune-related parameters in oysters damaged by the oil spill were also compared to control oysters that were collected from an area unaffected by the spill. The flow cytometry study indicated that granulocyte population, phagocytic capacity, and reactive oxygen species production in oysters exposed to crude oil 13 months prior were depressed compared to the unexposed control oysters. Our data suggest that immunocompetence in oysters affected by the oil spill had not fully recovered 1 year after the accident, although more detailed studies on the physiology and disease resistance should be performed.

  2. A novel junctional adhesion molecule A (CgJAM-A-L) from oyster (Crassostrea gigas) functions as pattern recognition receptor and opsonin.

    Science.gov (United States)

    Liu, Conghui; Wang, Mengqiang; Jiang, Shuai; Wang, Lingling; Chen, Hao; Liu, Zhaoqun; Qiu, Limei; Song, Linsheng

    2016-02-01

    Junctional adhesion molecule (JAM), a subfamily of immunoglobulin superfamily (IgSF) with a couple of immunoglobulin domains, can act as regulator in homeostasis and inflammation of vertebrates. In the present study, a structural homolog of JAM-A (designated CgJAM-A-L) was screened out from oyster, Crassostrea gigas, through a search of JAM-A D1 domain (N-terminal Ig domain in JAM-A). The cDNA of CgJAM-A-L was of 1188 bp encoding a predicted polypeptide of 395 amino acids. The immunoreactive area of CgJAM-A-L mainly distributed over the plasma membrane of hemocytes. After Vibro splendidus or tumor necrosis factor (CgTNF-1) stimulation, the mRNA transcripts of CgJAM-A-L in hemocytes increased significantly by 4.46-fold and 9.00-fold (p oyster hemocytes towards Gram-negative bacteria V. anguillarum and yeast P. pastoris were significantly enhanced after the incubation of rCgJAM-A-L, and even increased more significantly after the pre-incubation of rCgJAM-A-L with microbes (p oyster. Moreover, as the most primitive specie with homolog of JAMs, the information of CgJAM-A-L in oyster would provide useful clues for the evolutionary study of JAMs and immunoglobulins.

  3. Alkali- or acid-induced changes in structure, moisture absorption ability and deacetylating reaction of β-chitin extracted from jumbo squid (Dosidicus gigas) pens.

    Science.gov (United States)

    Jung, Jooyeoun; Zhao, Yanyun

    2014-01-01

    Alkali- or acid-induced structural modifications in β-chitin from squid (Dosidicus gigas, d'Orbigny, 1835) pens and their moisture absorption ability (MAA) and deacetylating reaction were investigated and compared with α-chitin from shrimp shells. β-Chitin was converted into the α-form after 3h in 40% NaOH or 1-3 h in 40% HCl solution, and α-chitin obtained from NaOH treatment had higher MAA than had native α-chitin, due to polymorphic destructions. In contrast, induced α-chitin from acid treatment of β-chitin had few polymorphic modifications, showing no significant change (P>0.05) in MAA. β-Chitin was more susceptible to alkali deacetylation than was α-chitin, and required a lower concentration of NaOH and shorter reaction time. These results demonstrate that alkali- or acid-treated β-chitin retained high susceptibility toward solvents, which in turn resulted in good biological activity of β-chitosan for use as a natural antioxidant and antimicrobial substance or application as edible coatings and films for various food applications.

  4. Functional properties of protein from frozen mantle and fin of jumbo squid Dosidicus gigas in function of pH and ionic strength.

    Science.gov (United States)

    Rocha-Estrada, J G; Córdova-Murueta, J H; García-Carreño, F L

    2010-10-01

    Functional properties of protein from mantle and fin of the jumbo squid Dosidicus gigas were explained based on microscopic muscle fiber and protein fractions profiles as observed in SDS-PAGE. Fin has higher content of connective tissue and complex fiber arrangement, and we observed higher hardness of fin gels as expected. Myosin heavy chain (MHC) was found in sarcoplasmic, myofibril and soluble-in-alkali fractions of mantle and only in sarcoplasmic and soluble-in-alkali fractions of fin. An additive effect of salt concentration and pH affected the solubility and foaming properties. Fin and mantle proteins yielded similar results in solubility tests, but significant differences occurred for specific pH and concentrations of salt. Foaming capacity was proportional to solubility; foam stability was also affected by pH and salt concentration. Hardness and fracture strength of fin gels were significantly higher than mantle gels; gels from proteins of both tissues reached the highest level in the folding test. Structural and molecular properties, such as MHC and paramyosin solubility, arrangement of muscle fibers and the content of connective tissue were useful to explain the differences observed in these protein properties. High-strength gels can be formed from squid mantle or fin muscle. Fin displayed similar or better properties than mantle in all tests.

  5. ESP-102, a Combined Herbal Extract of Angelica gigas, Saururus chinensis, and Schisandra chinensis, Changes Synaptic Plasticity and Attenuates Scopolamine-Induced Memory Impairment in Rat Hippocampus Tissue

    Directory of Open Access Journals (Sweden)

    Hyun-Bum Kim

    2016-01-01

    Full Text Available ESP-102, an extract from Angelica gigas, Saururus chinensis, and Schisandra chinensis, has been used as herbal medicine and dietary supplement in Korea. Despite the numerous bioactivities in vitro and in vivo studies, its effects on neuronal networks remain elusive. To address the neuronal effect, we examined synaptic plasticity in organotypic hippocampal slice culture with multielectrode array. Our results showed an increase in excitatory postsynaptic potential (EPSP, indicating the induction of long-term potentiation (LTP, in the presence of ESP-102. In addition, the neuroprotective effect of ESP-102 was also tested by application of scopolamine to the hippocampal slice. Interestingly, ESP-102 competitively antagonized the preventative LTP effect induced by scopolamine. The scopolamine-induced reduction in brain-derived neurotrophic factor (BDNF and GluR-2 expression was also rescued by ESP-102. In terms of mode of action, ESP-102 appears to act on the presynaptic region independent of AMPA/NMDA receptors. Based on these findings, ESP-102 can be suggested as a novel herbal ingredient with memory enhancing as well as neuroprotective effects.

  6. Net ion fluxes in the facultative air-breather Hoplosternum littorale (tamoata) and the obligate air-breather Arapaima gigas (pirarucu) exposed to different Amazonian waters.

    Science.gov (United States)

    Baldisserotto, Bernardo; Copatti, Carlos E; Gomes, Levy C; Chagas, Edsandra C; Brinn, Richard P; Roubach, Rodrigo

    2008-12-01

    Fishes that live in the Amazon environment may be exposed to several kinds of water: black water (BW), acidic black water (pH 3.5) (ABW) and white water (WW), among others. The aim of the present study was to analyze net ion fluxes in the facultative air-breather Hoplosternum littorale (tamoata) and the obligate air-breather Arapaima gigas (pirarucu) exposed to different types of water. Fishes were acclimated in well water and later placed in individual chambers containing one type of water for ion flux measurements. After 4 h, the water in the chambers was replaced by a different type of water. The transfer of both species to ABW (independent of previous water exposure) increased net ion loss. Tamoatas transferred from ABW to BW or WW presented a net ion influx, but pirarucus showed only small changes on net ion efflux. These results allow us to conclude that tamoatas and pirarucus present differences in terms of ion regulation but that the general aspects of the ion flux are similar: (1) exposure to ABW led to net ion loss; (2) transfer from BW to WW or vice-versa induced only minor changes on net ion fluxes. These observations demonstrate that any osmoregulatory difficulties encountered by either species during changes between these latter two waters can be easily overcome.

  7. ESP-102, a Combined Herbal Extract of Angelica gigas, Saururus chinensis, and Schisandra chinensis, Changes Synaptic Plasticity and Attenuates Scopolamine-Induced Memory Impairment in Rat Hippocampus Tissue

    Science.gov (United States)

    Kim, Hyun-Bum; Hwang, Eun-Sang; Choi, Ga-Young; Lee, Seok; Park, Tae-Suk; Lee, Cheol-Won; Lee, Eun-Suk; Kim, Young-Choong; Kim, Sang Seong; Lee, Sung-Ok; Park, Ji-Ho

    2016-01-01

    ESP-102, an extract from Angelica gigas, Saururus chinensis, and Schisandra chinensis, has been used as herbal medicine and dietary supplement in Korea. Despite the numerous bioactivities in vitro and in vivo studies, its effects on neuronal networks remain elusive. To address the neuronal effect, we examined synaptic plasticity in organotypic hippocampal slice culture with multielectrode array. Our results showed an increase in excitatory postsynaptic potential (EPSP), indicating the induction of long-term potentiation (LTP), in the presence of ESP-102. In addition, the neuroprotective effect of ESP-102 was also tested by application of scopolamine to the hippocampal slice. Interestingly, ESP-102 competitively antagonized the preventative LTP effect induced by scopolamine. The scopolamine-induced reduction in brain-derived neurotrophic factor (BDNF) and GluR-2 expression was also rescued by ESP-102. In terms of mode of action, ESP-102 appears to act on the presynaptic region independent of AMPA/NMDA receptors. Based on these findings, ESP-102 can be suggested as a novel herbal ingredient with memory enhancing as well as neuroprotective effects. PMID:27298627

  8. A Low-cost 4 Bit, 10 Giga-samples-per-second Analog-to-digital Converter Printed Circuit Board Assembly for FPGA-based Backends

    Science.gov (United States)

    Jiang, Homin; Yu, Chen-Yu; Kubo, Derek; Chen, Ming-Tang; Guzzino, Kim

    2016-11-01

    In this study, a 4 bit, 10 giga-samples-per-second analog-to-digital converter (ADC) printed circuit board assembly (PCBA) was designed, manufactured, and characterized for digitizing radio telescopes. For this purpose, an Adsantec ANST7120A-KMA flash ADC chip was used. Together with the field-programmable gate array platform, developed by the Collaboration for Astronomy Signal Processing and Electronics Research community, the PCBA enables data acquisition with a wide bandwidth and simplifies the intermediate frequency section. In the current version, the PCBA and the chip exhibit an analog bandwidth of 10 GHz (3 dB loss) and 20 GHz, respectively, which facilitates second, third, and even fourth Nyquist sampling. The following average performance parameters were obtained from the first and second Nyquist zones of the three boards: a spurious-free dynamic range of 31.35/30.45 dB, a signal-to-noise and distortion ratio of 22.95/21.83 dB, and an effective number of bits of 3.65/3.43, respectively.

  9. Seasonality Influence on Biochemical and Hematological Indicators of Stress and Growth of Pirarucu (Arapaima gigas, an Amazonian Air-Breathing Fish

    Directory of Open Access Journals (Sweden)

    Rosiely Felix Bezerra

    2014-01-01

    Full Text Available Environmental factors such as seasonal cycles are the main chronic stress cause in fish increasing incidence of disease and mortality and affecting productive performance. Arapaima gigas (pirarucu is an Amazonian air-breathing and largest freshwater fish with scales in the world. The captivity development of pirarucu is expanding since it can fatten up over 1 kg per month reaching 10 kg body mass in the first year of fattening. This work was conducted in three periods (April to July 2010, August to November 2010, and December 2010 to March 2011 defined according to rainfall and medium temperatures. Seasonality effect analysis was performed on biochemical (lectin activity, lactate dehydrogenase, and alkaline phosphatase activities and hematological (total count of red blood cells, hematocrit, hemoglobin, and hematimetric Wintrobe indexes stress indicators, as well as on growth and wellbeing degree expressed by pirarucu condition factor developed in captivity. All biochemical and hematological stress indicators showed seasonal variations. However, the fish growth was allometrically positive; condition factor high values indicated good state of healthiness in cultivation. These results reinforce the robust feature of pirarucu and represent a starting point for understanding stress physiology and environmental changes during cultivation enabling identification and prevention of fish adverse health conditions.

  10. ESP-102, a Combined Herbal Extract of Angelica gigas, Saururus chinensis, and Schisandra chinensis, Changes Synaptic Plasticity and Attenuates Scopolamine-Induced Memory Impairment in Rat Hippocampus Tissue.

    Science.gov (United States)

    Kim, Hyun-Bum; Hwang, Eun-Sang; Choi, Ga-Young; Lee, Seok; Park, Tae-Suk; Lee, Cheol-Won; Lee, Eun-Suk; Kim, Young-Choong; Kim, Sang Seong; Lee, Sung-Ok; Park, Ji-Ho

    2016-01-01

    ESP-102, an extract from Angelica gigas, Saururus chinensis, and Schisandra chinensis, has been used as herbal medicine and dietary supplement in Korea. Despite the numerous bioactivities in vitro and in vivo studies, its effects on neuronal networks remain elusive. To address the neuronal effect, we examined synaptic plasticity in organotypic hippocampal slice culture with multielectrode array. Our results showed an increase in excitatory postsynaptic potential (EPSP), indicating the induction of long-term potentiation (LTP), in the presence of ESP-102. In addition, the neuroprotective effect of ESP-102 was also tested by application of scopolamine to the hippocampal slice. Interestingly, ESP-102 competitively antagonized the preventative LTP effect induced by scopolamine. The scopolamine-induced reduction in brain-derived neurotrophic factor (BDNF) and GluR-2 expression was also rescued by ESP-102. In terms of mode of action, ESP-102 appears to act on the presynaptic region independent of AMPA/NMDA receptors. Based on these findings, ESP-102 can be suggested as a novel herbal ingredient with memory enhancing as well as neuroprotective effects.

  11. Characteristic and functional analysis of toll-like receptors (TLRs in the lophotrocozoan, Crassostrea gigas, reveals ancient origin of TLR-mediated innate immunity.

    Directory of Open Access Journals (Sweden)

    Yang Zhang

    Full Text Available The evolution of TLR-mediated innate immunity is a fundamental question in immunology. Here, we report the characterization and functional analysis of four TLR members in the lophotrochozoans Crassostreagigas (CgTLRs. All CgTLRs bear a conserved domain organization and have a close relationship with TLRs in ancient non-vertebrate chordates. In HEK293 cells, every CgTLR could constitutively activate NF-κB responsive reporter, but none of the PAMPs tested could stimulate CgTLR-activated NF-κB induction. Subcellular localization showed that CgTLR members have similar and dual distribution on late endosomes and plasma membranes. Moreover, CgTLRs and CgMyD88 mRNA show a consistent response to multiple PAMP challenges in oyster hemocytes. As CgTLR-mediated NF-κB activation is dependent on CgMyD88, we designed a blocking peptide for CgTLR signaling that would inhibit CgTLR-CgMyD88 dependent NF-κB activation. This was used to demonstrate that a Vibrio parahaemolyticus infection-induced enhancement of degranulation and increase of cytokines TNF mRNA in hemocytes, could be inhibited by blocking CgTLR signaling. In summary, our study characterized the primitive TLRs in the lophotrocozoan C. gigas and demonstrated a fundamental role of TLR signaling in infection-induced hemocyte activation. This provides further evidence for an ancient origin of TLR-mediated innate immunity.

  12. CRCP St. Croix Queen Conch Acoustic Tracking Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine protected areas (MPAs) can be highly effective tools for conserving habitats, populations, and sustainable fisheries. The National Park Service (NPS) is...

  13. Evaluación de la toxicidad a dosis repetidas (90 días) por vía oral del concentrado de proteína de pota (Dosidicus gigas), en ratas Sprague dawley

    OpenAIRE

    2009-01-01

    Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Tecnología de Alimentos El potencial tóxico de un concentrado de proteína de calamar gigante (Dosidicus gigas) fue evaluado mediante el estudio de toxicidad de dosis repetidas a 90 días en ratas Sprague Dawley de ambos sexos. Los métodos empleados fueron los descritos por las normas OECD (1998). Se administró por vía oral la dosis de 500, 1000 y 2000 mg/kg/día durante 13 semanas. Se evaluaron los signos tóxicos y peso...

  14. Clonagem, caracterização e análise filogenética das subunidades alfa e beta do hormônio luteinizante de pirarucu (Arapaima gigas)

    OpenAIRE

    Thais Cristina dos Anjos Sevilhano

    2015-01-01

    O Arapaima gigas, conhecido popularmente como pirarucu é uma espécie de peixe pertencente à ordem dos Osteoglossiformes, nativo da Bacia Amazônica e autóctone da Bacia de São Francisco e do Nordeste. É considerado um dos maiores peixes de água doce do mundo, chegando, na fase adulta, a três metros de comprimento e mais de 200 kg de peso, possuindo, portanto, uma grande importância para a alimentação e o comércio da região. Infelizmente esta espécie pertence à lista de animais sobre explorados...

  15. 福寿螺肉提取液抗氧化活性初步研究%Preliminary Study on Antioxidant Activity of Ampullaria gigas Spix Extracts

    Institute of Scientific and Technical Information of China (English)

    张泽宏; 朱丽霞; 胡俊西; 章家恩

    2014-01-01

    Objective]To evaluate the antioxidant capacity of water extracts,60% ethanol ex-tracts and anhydrous ethanol extracts from Ampullaria gigas Spix.[Method]Total antioxidant capacity (A-TOC)assay kits,hydroxyl radical assay kits,resistance to the ultra oxygen anion free radical and superoxide anion free radical assay kits,and the method of determination of reduc-tion ability were used.[Results]The results showed that 60% ethanol extracts were stronger than anhydrous ethanol extracts in inhibition of hydroxyl radical,and water extracts were the strongest.Water extracts were stronger than ethanol extracts in resistance to superoxide anion free radical.Water extracts were stronger than anhydrous ethanol extracts in total antioxidant ca-pacity,and 60% ethanol extracts were the strongest.Water extracts were stronger than anhy-drous ethanol extracts in reduction ability,and 60% ethanol extracts were the strongest.[Con-clusion]Antioxidant ability of the three kinds of extracts showed dose-effect relationship within 15-35 g/L.The antioxidant activity of Ampullaria gigas Spix was obviously well,and the low concentration of ethanol solvent was better than anhydrous ethanol.%【目的】研究福寿螺肉的水提液、无水乙醇提取液、60%乙醇提取液的抗氧化能力。【方法】利用总抗氧化能力(A-TOC)测定试剂盒,羟自由基测定试剂盒,抗超氧阴离子自由基及产生超氧阴离子自由基测试盒,以及测定还原力的方法。【结果】表明:抑制羟基自由基能力60%乙醇提取液比无水乙醇提取液强,水提液抑制羟基自由基能力最强;抗超氧阴离子活性,水提液比乙醇提取液强;总抗氧化能力水提液比无水乙醇提取液强,60%乙醇提取液总抗氧化能力最强;水提液比无水乙醇提取液具有较强的还原力,且60%乙醇提取液还原力最强。【结论】在所选取提取液梯度(15~35 g/L)的范围内,提取液的抗氧化能力

  16. A novel phagocytic receptor (CgNimC) from Pacific oyster Crassostrea gigas with lipopolysaccharide and gram-negative bacteria binding activity.

    Science.gov (United States)

    Wang, Weilin; Liu, Rui; Zhang, Tao; Zhang, Ran; Song, Xuan; Wang, Lingling; Song, Linsheng

    2015-03-01

    Phagocytosis is an evolutionarily conserved process to ingest the invading microbes and apoptotic or necrotic corpses, playing vital roles in defensing invaders and maintenance of normal physiological conditions. In the present study, a new Nimrod family phagocytic receptor with three EGF-like domains was identified in Pacific oyster Crassostrea gigas (designated CgNimC). CgNimC shared homology with other identified multiple EGF-like domain containing proteins. The mRNA transcripts of CgNimC were mainly distributed in mantle and hemocytes. Its relative expression level in hemocytes was significantly (P bacteria Vibrio anguillarum. Different to the NimC in Drosophila and Anopheles gambiae, the recombinant protein of CgNimC (rCgNimC) could bind directly to two gram-negative bacteria V. anguillarum and Vibrio splendidus, but not to gram-positive bacteria Staphylococci aureus, Micrococcus luteus or fungi Yarrowia lipolytica and Pichia pastoris. The affinity of rCgNimC toward M. luteus and Y. lipolytica was enhanced when the microorganisms were pre-incubated with the cell free hemolymph. rCgNimC exhibited higher affinity to lipopolysaccharide (LPS) and relatively lower affinity to peptidoglycan (PGN), while no affinity to glucan (GLU). After the CgNimC receptor was blocked by anti-rCgNimC antibody in vitro, the phagocytic rate of hemocytes toward two gram-negative bacteria V. anguillarum and V. splendidus was reduced significantly (P bacteria, was a novel phagocytic receptor involved in immune response of Pacific oyster. Further, it was speculated that receptors of Nimrod family might function as a phagocytic receptor to recognize PAMPs on the invaders and its recognition could be promoted by opsonization of molecules in hemolymph.

  17. Genetic evidence for the uncoupling of local aquaculture activities and a population of an invasive species--a case study of Pacific oysters (Crassostrea gigas).

    Science.gov (United States)

    Kochmann, Judith; Carlsson, Jens; Crowe, Tasman P; Mariani, Stefano

    2012-01-01

    Human-mediated introduction of nonnative species into coastal areas via aquaculture is one of the main pathways that can lead to biological invasions. To develop strategies to counteract invasions, it is critical to determine whether populations establishing in the wild are self-sustaining or based on repeated introductions. Invasions by the Pacific oyster (Crassostrea gigas) have been associated with the growing oyster aquaculture industry worldwide. In this study, temporal genetic variability of farmed and wild oysters from the largest enclosed bay in Ireland was assessed to reconstruct the recent biological history of the feral populations using 7 anonymous microsatellites and 7 microsatellites linked to expressed sequence tags (ESTs). There was no evidence of EST-linked markers showing footprints of selection. Allelic richness was higher in feral than in aquaculture samples (P = 0.003, paired t-test). Significant deviations from Hardy-Weinberg equilibrium due to heterozygote deficiencies were detected for almost all loci and samples, most likely explained by the presence of null alleles. Relatively high genetic differentiation was found between aquaculture and feral oysters (largest pairwise multilocus F(ST) 0.074, P aquaculture (largest pairwise multilocus F(ST) 0.073, P aquaculture and wild samples using Bayesian clustering approaches. A 10-fold higher effective population size (N(e)) and a high number of private alleles in wild oysters suggest an established self-sustaining feral population. The wild oyster population studied appears demographically independent from the current aquaculture activities in the estuary and alternative scenarios of introduction pathways are discussed.

  18. Food web and fish stock changes in central Chile: comparing the roles of jumbo squid (Dosidicus gigas) predation, the environment, and fisheries

    Science.gov (United States)

    Neira, Sergio; Arancibia, Hugo

    2013-10-01

    We analyzed recent food web and fish stock changes in the central Chile marine ecosystem, comparing the roles of jumbo squid (Dosidicus gigas) as predator, the environment, and fishing. To accomplish this we used food web modeling and the Ecopath with Ecosim software (EwE). The principal fish stocks have experienced wide decadal fluctuations in the past 30 years, including stock collapses of horse mackerel (Trachurus murphyi) and hake (Merluccius gayi), and there was a large influx of jumbo squid during the mid-2000s. We used two EwE models representing the food web off central Chile to test the hypothesis that predation by jumbo squid has been significant in explaining the dynamics of the main fishing resources and other species in the study area. Results indicate that predation by jumbo squid on fish stocks is lower than that of other predators (e.g. hake) and the fishery. Long-term fluctuations (1978-2004) in the biomass of the main fish stocks (as well as other components of the food web) seem to be related to fishing and to variation in primary production, rather than to predation by jumbo squid alone. Jumbo squid seems to play a role as predator rather than prey in the system, but its impacts are low when compared with the impacts of other predators and fishing. Therefore, we conclude that jumbo squid predation on its prey was not the primary force behind the collapse of important fish stocks off central Chile. Future efforts should be directed to better understanding factors that trigger sudden increases in jumbo squid abundance off central Chile, as well as modeling its trophic impacts.

  19. Uranium uptake history, open-system behaviour and uranium-series ages of fossil Tridacna gigas from Huon Peninsula, Papua New Guinea

    Science.gov (United States)

    Ayling, Bridget F.; Eggins, Stephen; McCulloch, Malcolm T.; Chappell, John; Grün, Rainer; Mortimer, Graham

    2017-09-01

    Molluscs incorporate negligible uranium into their skeleton while they are living, with any uranium uptake occurring post-mortem. As such, closed-system U-series dating of molluscs is unlikely to provide reliable age constraints for marine deposits. Even the application of open-system U-series modelling is challenging, because uranium uptake and loss histories can affect time-integrated uranium distributions and are difficult to constrain. We investigate the chemical and isotopic distribution of uranium in fossil Tridacna gigas (giant clams) from Marine Isotope Stage (MIS) 5e (128-116 ka) and MIS 11 (424-374 ka) reefs at Huon Peninsula in Papua New Guinea. The large size of the clams enables detailed chemical and isotopic mapping of uranium using LA-ICPMS and LA-MC-ICPMS techniques. Within each fossil Tridacna specimen, marked differences in uranium concentrations are observed across the three Tridacna growth zones (outer, inner, hinge), with the outer and hinge zones being relatively enriched. In MIS 5e and MIS 11 Tridacna, the outer and hinge zones contain approximately 1 ppm and 5 ppm uranium respectively. In addition to uptake of uranium, loss of uranium appears prevalent, especially in the MIS 11 specimens. The effect of uranium loss is to elevate measured [230Th/238U] values with little effect on [234U/238U] values. Closed-system age estimates are on average 50% too young for the MIS 5e Tridacna, and 25% too young for the MIS 11 Tridacna. A complex, multi-stage uptake and loss history is interpreted for the fossil Tridacna and we demonstrate that they cannot provide independent, reliable geochronological controls on the timing of past reef growth at Huon Peninsula.

  20. A single-CRD C-type lectin from oyster Crassostrea gigas mediates immune recognition and pathogen elimination with a potential role in the activation of complement system.

    Science.gov (United States)

    Li, Hui; Zhang, Huan; Jiang, Shuai; Wang, Weilin; Xin, Lusheng; Wang, Hao; Wang, Lingling; Song, Linsheng

    2015-06-01

    C-type lectins (CTLs), serving as pattern recognition receptors (PRRs), are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins that participate in nonself-recognition and pathogen elimination. In the present study, a single carbohydrate-recognition domain (CRD) CTL was identified from oyster Crassostrea gigas (designated as CgCLec-2). There was only one CRD within the deduced amino acid sequence of CgCLec-2 consisting of 129 amino acid residues. A conserved EPN (Glu246-Pro247-Asn248) motif was found in Ca(2+)-binding site 2 of CgCLec-2. The CgCLec-2 mRNA could be detected in all the examined tissues at different expression levels in oysters. The mRNA expression of CgCLec-2 in hemocytes was up-regulated significantly at 6 h post Vibrio splendidus challenge. The recombinant CgCLec-2 (rCgCLec-2) could bind various Pathogen-Associated Molecular Patterns (PAMPs), including lipopolysaccharide, mannan and peptidoglycan, and displayed strong binding abilities to Vibrio anguillarum, V. splendidus and Yarrowiali polytica and week binding ability to Staphylococcus aureus. It could also enhance the phagocytic activity of oyster hemocytes to V. splendidus and exhibited growth suppression activity against gram-positive bacteria S. aureus but no effect on gram-negative bacteria V. splendidus. Furthermore, the interaction between rCgCLec-2 and rCgMASPL-1 was confirmed by GST Pull down. The results suggested that CgCLec-2 served as not only a PRR in immune recognition but also a regulatory factor in pathogen elimination, and played a potential role in the activation of complement system.

  1. ESP-102, a standardized combined extract of Angelica gigas, Saururus chinensis and Schizandra chinensis, significantly improved scopolamine-induced memory impairment in mice.

    Science.gov (United States)

    Kang, So Young; Lee, Ki Yong; Koo, Kyung Ah; Yoon, Jeong Seon; Lim, Song Won; Kim, Young Choong; Sung, Sang Hyun

    2005-02-25

    We assessed the effects of oral treatments of ESP-102, a standardized combined extract of Angelica gigas, Saururus chinensis and Schizandra chinensis, on learning and memory deficit. The cognition-enhancing effect of ESP-102 was investigated in scopolamine-induced (1 mg/kg body weight, s.c.) amnesic mice with both passive avoidance and Morris water maze performance tests. Acute oral treatment (single administration prior to scopolamine treatment) of mice with ESP-102 (doses in the range of 10 to 100 mg/kg body weight) significantly reduced scopolamine-induced memory deficits in the passive avoidance performance test. Another noteworthy result included the fact that prolonged oral daily treatments of mice with much lower amounts of ESP-102 (1 and 10 mg/kg body weight) for ten days reversed scopolamine-induced memory deficits. In the Morris water maze performance test, both acute and prolonged oral treatments with ESP-102 (single administration of 100 mg/kg body weight or prolonged daily administration of 1 and 10 mg/kg body weight for ten days, respectively, significantly ameliorated scopolamine-induced memory deficits as indicated by the formation of long-term and/or short-term spatial memory. In addition, we investigated the effects of ESP-102 on neurotoxicity induced by amyloid-beta peptide (Abeta25-35) or glutamate in primary cultured cortical neurons of rats. Pretreatment of cultures with ESP-102 (0.001, 0.01 and 0.1 mug/ml) significantly protected neurons from neurotoxicity induced by either glutamate or Abeta25-35. These results suggest that ESP-102 may have some protective characteristics against neuronal cell death and cognitive impairments often observed in Alzheimer's disease, stroke, ischemic injury and other neurodegenerative diseases.

  2. Seasonal changes in mRNA encoding for cell stress markers in the oyster Crassostrea gigas exposed to radioactive discharges in their natural environment

    Energy Technology Data Exchange (ETDEWEB)

    Farcy, Emilie [Laboratoire de Radioecologie de Cherbourg-Octeville, Institut de Radioprotection et de Surete Nucleaire/DEI/SECRE, Cherbourg-Octeville (France); Laboratoire de Biologie et Biotechnologies Marines, Universite de Caen Basse-Normandie, UMR 100 Ifremer, Caen (France); Voiseux, Claire; Fievet, Bruno [Laboratoire de Radioecologie de Cherbourg-Octeville, Institut de Radioprotection et de Surete Nucleaire/DEI/SECRE, Cherbourg-Octeville (France); Lebel, Jean-Marc [Laboratoire de Biologie et Biotechnologies Marines, Universite de Caen Basse-Normandie, UMR 100 Ifremer, Caen (France)

    2007-03-15

    The North Cotentin area (Normandy, France) hosts several nuclear facilities among which the AREVA reprocessing plant of La Hague is responsible for controlled discharges of liquid radioactive wastes into the marine environment. The resulting increase in radioactivity is very small compared to natural radioactivity. However, concerns about environment protection prompted the scientific community to focus on the effects of the chronic exposure to low concentrations of radionuclides in non-human biota. This study contributes to the evaluation of the possible impact of radioactive discharges on the oyster Crassostrea gigas in the field. Real-time polymerase chain reaction was used to quantify the expression levels of genes involved in cell stress in the oyster. They included members of the heat shock protein family (Hsp70, Hsc72, Hsp90), superoxide dismutase (SOD) and metallothionein (MT). Times series measurements were built from periodic samplings in the natural environment in order to characterize the natural variability as well as possible seasonal fluctuations. The genes studied exhibited a general seasonal expression pattern with a peak value in winter. The data inversely correlated with seawater temperature and the nature of the relationship between gene expression and temperature is discussed. In parallel, oysters were collected in four locations on the French shores, exposed or not to radioactive liquid wastes from the nuclear facilities hosted in the North Cotentin. The comparison of data obtained in the reference location on the Atlantic coast (not exposed) and data from oysters of the English Channel (exposed) gave no evidence for any statistical difference. However, because of the complexity of the natural environment, we cannot rule out the possibility that other parameters may have masked the impact of radioactive discharges. This dense set of data is a basis for the use of the expression levels of those genes as biomarkers to address the question of the

  3. Comparative efficiency and yield in different systems and densities at the nursery culture phase of the oyster Crassostrea gigas in southern Brazil

    Directory of Open Access Journals (Sweden)

    Fernando Magalhães Ferreira

    2014-02-01

    Full Text Available This study was conducted to compare different aquaculture systems and seed densities for the nursery phase ofCrassostrea gigas in Brazil. Small oyster seeds (2 mm in height reared in three nursery systems (same area/floor, a lantern net, a bouncing bucket or a floating box were compared with three initial stocking densities (50, 100 and 200 mL of seeds/system floor. As density increased, there was a significant decline in seed growth and yield, mainly in the lantern nets (P=0.0002. Better yields were observed in the box (P=0.005 and bucket systems (P=0.02 under densities of 50 and 100 mL. However, at the highest density, the nursery box system had the highest seed yield when compared to the lantern net and bucket systems (P=0.003. The results showed that the floating box was the most efficient system tested with a survival of 54% at a density of 100 mL. This was more than twice the survival for the same volumes used in the nursery lantern nets (24%, which was the most common culture method in Brazil prior to this experiment (2002. An additional advantage is the reduced cost of starting with 2.0 mm seeds that cost 50% less than the usual 4.0 to 8.0 mm seeds. These results showed the efficiency of the floating box system, which is currently used by over 90% of oyster producers in Brazil.

  4. Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel.

    Science.gov (United States)

    Corzo, Gerardo; Gilles, Nicolas; Satake, Honoo; Villegas, Elba; Dai, Li; Nakajima, Terumi; Haupt, Joachim

    2003-07-17

    Six peptide toxins (Magi 1-6) were isolated from the Hexathelidae spider Macrothele gigas. The amino acid sequences of Magi 1, 2, 5 and 6 have low similarities to the amino acid sequences of known spider toxins. The primary structure of Magi 3 is similar to the structure of the palmitoylated peptide named PlTx-II from the North American spider Plectreurys tristis (Plectreuridae). Moreover, the amino acid sequence of Magi 4, which was revealed by cloning of its cDNA, displays similarities to the Na+ channel modifier delta-atracotoxin from the Australian spider Atrax robustus (Hexathelidae). Competitive binding assays using several 125I-labelled peptide toxins clearly demonstrated the specific binding affinity of Magi 1-5 to site 3 of the insect sodium channel and also that of Magi 5 to site 4 of the rat sodium channel. Only Magi 6 did not compete with the scorpion toxin LqhalphaIT in binding to site 3 despite high toxicity on lepidoptera larvae of 3.1 nmol/g. The K(i)s of other toxins were between 50 pM for Magi 4 and 1747 nM for Magi 1. In addition, only Magi 5 binds to both site 3 in insects (K(i)=267 nM) and site 4 in rat brain synaptosomes (K(i)=1.2 nM), whereas it showed no affinities for either mammal binding site 3 or insect binding site 4. Magi 5 is the first spider toxin with binding affinity to site 4 of a mammalian sodium channel.

  5. High-Throughput Screening of Na(V)1.7 Modulators Using a Giga-Seal Automated Patch Clamp Instrument.

    Science.gov (United States)

    Chambers, Chris; Witton, Ian; Adams, Cathryn; Marrington, Luke; Kammonen, Juha

    2016-03-01

    Voltage-gated sodium (Na(V)) channels have an essential role in the initiation and propagation of action potentials in excitable cells, such as neurons. Of these channels, Na(V)1.7 has been indicated as a key channel for pain sensation. While extensive efforts have gone into discovering novel Na(V)1.7 modulating compounds for the treatment of pain, none has reached the market yet. In the last two years, new compound screening technologies have been introduced, which may speed up the discovery of such compounds. The Sophion Qube(®) is a next-generation 384-well giga-seal automated patch clamp (APC) screening instrument, capable of testing thousands of compounds per day. By combining high-throughput screening and follow-up compound testing on the same APC platform, it should be possible to accelerate the hit-to-lead stage of ion channel drug discovery and help identify the most interesting compounds faster. Following a period of instrument beta-testing, a Na(V)1.7 high-throughput screen was run with two Pfizer plate-based compound subsets. In total, data were generated for 158,000 compounds at a median success rate of 83%, which can be considered high in APC screening. In parallel, IC50 assay validation and protocol optimization was completed with a set of reference compounds to understand how the IC50 potencies generated on the Qube correlate with data generated on the more established Sophion QPatch(®) APC platform. In summary, the results presented here demonstrate that the Qube provides a comparable but much faster approach to study Na(V)1.7 in a robust and reliable APC assay for compound screening.

  6. Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas harvested in the south bay of Santa Catarina island, Brazil Ocorrência de Vibrio spp., estafilococos coagulase positivo e bactérias entéricas em ostras (Crassostrea gigas cultivadas na baía sul da ilha de Santa Catarina, Brasil

    Directory of Open Access Journals (Sweden)

    Roberta Juliano Ramos

    2012-09-01

    Full Text Available The aim of this study was to assess the contamination of oysters (Crassostrea gigas, harvested in six different regions of the South Bay of Santa Catarina Island, with Coliforms at 45 ºC, Escherichia coli, Vibrio spp., positive coagulase staphylococci, and Salmonella sp. over a period of one year. One hundred eighty oyster samples were collected directly from their culture sites and analyzed. Each sample consisted of a pool of 12 oysters. All of the samples analyzed showed absence of Salmonella, 18 (10% samples showed presence of Escherichia coli, 15 (8.3% samples were positive for V. alginolyticus, and Vibriocholerae was detected in 4 samples (2.2%. The counts of positive-coagulase staphylococci varied from O objetivo deste estudo foi avaliar a contaminação de ostras (Crassostrea gigas cultivadas em diferentes regiões da Baía Sul da Ilha de Santa Catarina, por coliformes a 45 ºC, Escherichia coli, Vibrio spp. Estafilococos coagulase positiva e Salmonella sp., durante o período de um ano. Foram analisadas 180 amostras, coletadas diretamente no local de cultivo. Todas as amostras analisadas apresentaram ausência de Salmonella, 18 (10% amostras apresentaram presença de Escherichia coli, 15 (8,3% amostras positivas para Vibrio alginolyticus e V. cholerae foi detectado em 4 amostras (2,2%. As contagens de Estafilococos coagulase positiva variaram de <10 a 1,9 x 102 UFC.g-1, enquanto que as contagens de coliformes a 45 ºC e E. coli variaram de <3 a 1,5 x 102 NMP.g-1 e <3 e 4,3 x 10 NMP.g-1, respectivamente. As contagens de V. parahaemolyticus e V. vulnificus variaram de <3 a 7 NMP.g-1, para ambos os microrganismos, sugerindo um monitoramento tanto destas espécies quanto da temperatura das águas marinhas nas regiões de cultivo. Com base nos resultados das análises microbiológicas, as amostras analisadas mostraram qualidade bacteriológica aceitável, ou seja, dentro dos parâmetros estabelecidos na legislação brasileira.

  7. Comparison of phenotypic traits of four shell color families of the Pa-cific oyster (Crassostrea gigas)%长牡蛎4种壳色家系子代的表型性状比较

    Institute of Scientific and Technical Information of China (English)

    丛日浩; 李琪; 葛建龙; 孔令锋; 于红

    2014-01-01

    本研究分析了长牡蛎(Crassostrea gigas)白壳色、黑壳色、金壳色和紫壳色4种壳色家系各生长阶段的表型性状及成贝生长和存活性状基因型与环境的互作效应。结果表明,浮游阶段10日龄后,金壳色和紫壳色家系壳高显著高于白壳色家系和对照组(P0.05);420日龄紫壳色家系存活率显著高于其他家系(P0.05)。研究表明长牡蛎壳色与其生长和存活性状关联显著,成贝阶段生长和存活性状的基因型与环境互作效应相对较弱,不会对长牡蛎在两海区的育种效果产生显著影响。%Color polymorphism is relatively common in marine shellfish. Shell color affects the visual perception of products which, in turn, influences consumer preference and product value. The shell color of marine mollusks is a ge-netically-based phenotypic trait and is therefore amenable to artificial selection. Furthermore, distinctive pigment colors or color patterns in several marine shellfish species are controlled by genes segregated at only one or two loci. The ge-netic control of shell pigment was recently determined for Crassostrea gigas, and the narrow-sense heritability of left-shell pigmentation was estimated at 0.59 ± 0.19. To increase the value of C. gigas sold as“singles”for the half-shell market, there has been a recent increase in interest in selective breeding for desirable shell colors in C. gigas. In par-ticular, research has focused on the relationship between shell color and phenotypic traits in C. gigas and the effect of genotype-environment interactions on adult fitness. Four shell color families (white, black, golden, and purple) and the control group were established by separately selecting corresponding parents in Rushan Bay, Weihai of Shandong Province. The larvae, spat, and adults were reared following standard practices, and the rearing conditions were identi-cal between families to minimize environmental effects. We measured the growth

  8. Differential response of benthic macrofauna to the formation of novel oyster reefs ( Crassostrea gigas, Thunberg) on soft and rocky substrate in the intertidal of the Bay of Brest, France

    Science.gov (United States)

    Lejart, Morgane; Hily, Christian

    2011-01-01

    When the Pacific oyster ( Crassostrea gigas, Thunberg) was introduced into France for aquaculture in the mid-sixties, it was initially confined to the sites where it was farmed. Subsequent global warming most likely facilitated the establishment of wild populations throughout the French coastline. This phenomenon of spread has become so great that oyster reefs have recently appeared in sheltered estuaries, on both soft and hard substrate. The present study examined two such sites in the Bay of Brest, Brittany. It is the first to investigate the impacts of this new substrate on the biocoenosis of uncolonised intertidal habitats in France. Increased species richness and abundance of intertidal macrofauna were observed in the presence of oyster reefs on both, mud (4 and 20 fold respectively) and rock (5 fold for both). The dominance of suspension feeders in mud changed to carnivores in reefs and their underlying sediment. Calculation of biotic coefficients (BC) of the soft-bottom fauna revealed only a slight organic enrichment, and the organic and silt composition in the sediment beneath oyster reefs were not significantly different from that on bare sites. On rock, the dominance of grazers remained unchanged between bare rock and oyster reef, while reef on rock was also characterised by deposit and detritic feeders. C. gigas is suspected to cause a homogenisation of coastal habitats with an impoverishment of overall quality but we detected only 11 common species between reefs on mud (60 species) and those on rock (55 species).

  9. Heat Shock Protein Augmentation of Angelica gigas Nakai Root Hot Water Extract on Adipogenic Differentiation in Murine 3T3-L1 Preadipocytes.

    Science.gov (United States)

    Lumbera, Wenchie Marie L; Dela Cruz, Joseph; Yang, Seung-Hak; Hwang, Seong Gu

    2016-03-01

    There is a high association of heat shock on the alteration of energy and lipid metabolism. The alterations associated with thermal stress are composed of gene expression changes and adaptation through biochemical responses. Previous study showed that Angelica gigas Nakai (AGN) root extract promoted adipogenic differentiation in murine 3T3-L1 preadipocytes under the normal temperature condition. However, its effect in heat shocked 3T3-L1 cells has not been established. In this study, we investigated the effect of AGN root hot water extract in the adipogenic differentiation of murine 3T3-L1 preadipocytes following heat shock and its possible mechanism of action. Thermal stress procedure was executed within the same stage of preadipocyte confluence (G0) through incubation at 42°C for one hour and then allowed to recover at normal incubation temperature of 37°C for another hour before AGN treatment for both cell viability assay and Oil Red O. Cell viability assay showed that AGN was able to dose dependently (0 to 400 μg/mL) increase cell proliferation under normal incubation temperature and also was able to prevent cytotoxicity due to heat shock accompanied by cell proliferation. Confluent preadipocytes were subjected into heat shock procedure, recovery and then AGN treatment prior to stimulation with the differentiation solution. Heat shocked preadipocytes exhibited reduced differentiation as supported by decreased amount of lipid accumulation in Oil Red O staining and triglyceride measurement. However, those heat shocked preadipocytes that then were given AGN extract showed a dose dependent increase in lipid accumulation as shown by both evaluation procedures. In line with these results, real-time polymerase chain reaction (RT-PCR) and Western blot analysis showed that AGN increased adipogenic differentiation by upregulating heat shock protection related genes and proteins together with the adipogenic markers. These findings imply the potential of AGN in heat

  10. Big defensins, a diverse family of antimicrobial peptides that follows different patterns of expression in hemocytes of the oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Rafael D Rosa

    Full Text Available BACKGROUND: Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. FINDINGS: Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3 that are encoded by distinct genomic sequences. All Cg-BigDefs contain a hydrophobic N-terminal domain and a cationic C-terminal domain that resembles vertebrate β-defensins. Both domains are encoded by separate exons. We found that big defensins form a group predominantly present in mollusks and closer to vertebrate defensins than to invertebrate and fungi CSαβ-containing defensins. Moreover, we showed that Cg-BigDefs are expressed in oyster hemocytes only and follow different patterns of gene expression. While Cg-BigDef3 is non-regulated, both Cg-BigDef1 and Cg-BigDef2 transcripts are strongly induced in response to bacterial challenge. Induction was dependent on pathogen associated molecular patterns but not damage-dependent. The inducibility of Cg-BigDef1 was confirmed by HPLC and mass spectrometry, since ions with a molecular mass compatible with mature Cg-BigDef1 (10.7 kDa were present in immune-challenged oysters only. From our biochemical data, native Cg-BigDef1 would result from the elimination of a prepropeptide sequence and the cyclization of the resulting N-terminal glutamine residue into a pyroglutamic acid. CONCLUSIONS: We provide here the first report showing that big defensins form a family

  11. Compositional and Textural Analysis of Maar-Diatreme Volcanic Deposits at Hopi Buttes Volcanic Field (AZ) Using GigaPan Panoramic and Thermal Infrared Imagery

    Science.gov (United States)

    Lee, R.; Graettinger, A. H.; Weinell, M.; Hughes, C. G.

    2016-12-01

    Basaltic maar-diatreme volcanoes are produced when rising magma interacts with groundwater and produces a maar crater at the ground surface. This crater is underlain by a diatreme, a downward-tapering conical structure filled with a mixture of fragments of intruded magma, fractured host rock, and clasts recycled through repeated discrete subsurface explosions. The debris of the diatreme records the mixing processes caused by subsurface explosions and is the source for ejected material that forms maar tephra rings. Determining the variable depths and lateral locations of these explosions and how energy is dissipated in the subsurface is critical to understanding how maar-diatreme eruptions progress. The Hopi Buttes Volcanic Field (HBVF) in the Navajo Nation, Arizona, USA, contains several diatremes and incised tephra rings with heterolithic clasts 10 mm - 10 m in size, and are well-exposed near-vertical to vertical outcrops. Our ability to measure the length scales and distribution of textures produced by subsurface explosions in these diatremes is limited by the physical accessibility of the exposures, due to both the verticality of the outcrops and the cultural sensitivity of the site. Quantifying the number and locations of explosions is dependent on our ability to investigate the full diatreme outcrop, and not just what can be accessed through traditional field observations. We present a novel field and computer-based technique for both quantitatively and qualitatively characterizing the composition and texture of maar-diatreme deposits in vertical outcrops. This technique uses a combination of field-collected multispectral thermal infrared (TIR) image data and visible wavelength GigaPan imagery to characterize the compositional and textural variations over a whole outcrop. To increase the spatial and spectral resolution of the TIR data, a super-resolution technique will be applied. The technique provides a simple and efficient method to augment the study of the

  12. Validation of housekeeping genes as internal controls for studying gene expression during Pacific oyster (Crassostrea gigas) development by quantitative real-time PCR.

    Science.gov (United States)

    Du, Yishuai; Zhang, Linlin; Xu, Fei; Huang, Baoyu; Zhang, Guofan; Li, Li

    2013-03-01

    Hatchery-reared larvae of the Pacific oyster (Crassostrea gigas) often suffer from massive mortality induced by Ostreid herpesvirus 1 (OsHV-1) infection, indicating the importance of better understanding of oyster immune defense systems. The accuracy of measurements of gene expression levels based on quantitative real-time PCR assays relies on the use of housekeeping genes as internal controls; however, few studies have focused on the selection of such internal controls. In this study, we conducted a comprehensive investigation of internal control genes during oyster development in virus-infected and uninfected samples. Transcriptome data for 38 developmental stages were downloaded and the gene expression patterns were classified into 30 clusters. A total of 317 orthologs of classical housekeeping genes in the oyster genome were annotated. After combining the expression profiles and oyster housekeeping gene dataset, 14 candidate internal controls were selected for further investigation: Elongation factor-1α (EF-1α), 18S rRNA (18S), 28S rRNA (28S), Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), β-actin (ACT), Ribosomal protein L7 (RL7), Ribosomal protein L27 (RL27), Ribosomal protein L36 (RL36), Ribosomal protein S18 (RS18), Heterogeneous nuclear ribonucleoprotein A2/B1 (RO21), Eukaryotic translation elongation factor 2 (EF2), Ubiquitin-conjugating enzyme E2D2 (UBCD1), S-phase kinase-associated protein 1 (SKP1) and Heterogeneous nuclear ribonucleoprotein Q (HNRPQ). RNA was extracted from oyster larvae infected with OsHV-1 (group A; GA), and OsHV-1 free larvae (group B; GB). The expression levels of the 14 candidate internal controls were studied in GA and GB larvae by real-time PCR. Their expression stabilities were further analyzed using the GeNorm program. RL7 and RS18 were the most stable genes in both OsHV-1 infected (GA) and uninfected (GB) larvae. These results suggest that RL7 and RS18 could be used as internal controls for studying gene expression in

  13. Spatial synchronies in the seasonal occurrence of larvae of oysters (Crassostrea gigas) and mussels (Mytilus edulis/galloprovincialis) in European coastal waters

    Science.gov (United States)

    Philippart, Catharina J. M.; Amaral, Ana; Asmus, Ragnhild; van Bleijswijk, Judith; Bremner, Julie; Buchholz, Fred; Cabanellas-Reboredo, Miguel; Catarino, Diana; Cattrijsse, André; Charles, François; Comtet, Thierry; Cunha, Alexandra; Deudero, Salud; Duchêne, Jean-Claude; Fraschetti, Simonetta; Gentil, Franck; Gittenberger, Arjan; Guizien, Katell; Gonçalves, João M.; Guarnieri, Giuseppe; Hendriks, Iris; Hussel, Birgit; Vieira, Raquel Pinheiro; Reijnen, Bastian T.; Sampaio, Iris; Serrao, Ester; Pinto, Isabel Sousa; Thiebaut, Eric; Viard, Frédérique; Zuur, Alain F.

    2012-08-01

    Reproductive cycles of marine invertebrates with complex life histories are considered to be synchronized by water temperature and feeding conditions, which vary with season and latitude. This study analyses seasonal variation in the occurrence of oyster (Crassostrea gigas) and mussel (Mytilus edulis/galloprovincialis) larvae across European coastal waters at a synoptic scale (1000s of km) using standardised methods for sampling and molecular analyses. We tested a series of hypotheses to explain the observed seasonal patterns of occurrence of bivalve larvae at 12 European stations (located between 37°N and 60°N and 27°W and 18°E). These hypotheses included a model that stated that there was no synchronisation in seasonality of larval presence at all between the locations (null hypothesis), a model that assumed that there was one common seasonality pattern for all stations within Europe, and various models that supposed that the variation in seasonality could be grouped according to specific spatial scales (i.e., latitude, large marine ecosystems and ecoregions), taxonomic groups, or several combinations of these factors. For oysters, the best models explaining the presence/absence of larvae in European coastal waters were (1) the model that assumed one common seasonal pattern, and (2) the one that, in addition to this common pattern, assumed an enhanced probability of occurrence from south to north. The third best model for oysters, with less empirical support than the first two, stated that oysters reproduced later in the south than in the north. For mussels, the best models explaining the seasonality in occurrence of larvae were (1) the model that assumed four underlying trends related to large marine ecosystems, and (2) the one that assumed one common seasonal pattern for larvae occurrence throughout Europe. Such synchronies in larval occurrences suggest that environmental conditions relevant to bivalve larval survival are more or less similar at large

  14. Vibriosis induced by experimental cohabitation in Crassostrea gigas: evidence of early infection and down-expression of immune-related genes.

    Science.gov (United States)

    De Decker, Sophie; Saulnier, Denis

    2011-02-01

    The understanding of reciprocal interactions between Crassostrea gigas and Vibrio sp., whether these be virulent or avirulent, is vital for the development of methods to improve the health status of cultured oysters. We describe an original non-invasive experimental infection technique using cohabitation, designed to explore these interactions. Using real-time PCR techniques we examined the dynamics of virulent and avirulent Vibrio sp. in oyster hemolymph and tank seawater, and made a parallel study of the expression of four genes involved in oyster immune defense: Cg-BPI, Cg-EcSOD, Cg-IκB, Cg-TIMP. No mortality occurred in control animals, but oysters put in cohabitation for 2-48 h with animals previously infected by two Vibrio pathogens suffered mortalities from 2 to 16 days post-cohabitation. Our results show that virulent Vibrio infect healthy individuals after only 2 h of cohabitation, with values ranging from 4.5 x 10² to 2 x 10⁴ cells ml⁻¹ hemolymph. Simultaneously, an approximate ten-fold increase of the total Vibrio population was observed in control animals, with a 6.6-78.5-fold up-expression of targeted genes. In contrast, oysters exposed to harmful bacteria had mean expression levels strongly down-regulated by a factor of 9.2-29 (depending on the gene) compared with control animals. Although oysters were still found to be infected by virulent Vibrio after 6-48 h of cohabitation, no significant differences were noted when comparing levels of each transcript in control and infected oysters at the same sampling times during this period: the important differences were noted before 6 h cohabitation. Taken together, our data support (1) the hypothesis that virulent Vibrio disturbs the immune response of this invertebrate host both rapidly and significantly, although this occurs specifically during an early and transient period during the first 6 h of cohabitation challenge, and that (2) expression of targeted genes is not correlated with vibriosis

  15. Estudos etnoictiológicos sobre o pirarucu Arapaima gigas na Amazônia Central Ethnoictiology studies on Pirarucu (Arapaima mock-ups in Central Amazon

    Directory of Open Access Journals (Sweden)

    Liane Galvão de Lima

    2012-09-01

    Full Text Available O presente estudo visou identificar saberes comuns entre o conhecimento científico e o conhecimento local sobre a ecologia e biologia do pirarucu (Arapaima gigas, contribuindo com informações úteis para a implementação e consolidação de projetos de manejo participativo pesqueiro na região. Foram realizadas 57 entrevistas semi-estruturadas, com pescadores profissionais de Manaus e pescadores de subsistência de Manacapuru durante o período de junho a dezembro do ano de 2002. Foi observado que os pescadores profissionais possuem informações igualmente precisas e abrangentes em relação aos saberes dos pescadores ribeirinhos de subsistência nos aspectos de reprodução, predação, migração, crescimento e mortalidade. Os aspectos que não são equivalentes entre os pescadores profissionais comerciais citadinos e ribeirinhos de subsistência são nos aspectos de tipo de alimentação e no tamanho de recrutamento pesqueiro. Concluímos que os pescadores da Amazônia central possuem os conhecimentos necessários que possibilitam o manejo participativo do pirarucu, como um profundo saber nos aspectos comportamentais, biológicos e ecológicos desta espécie, podendo assim contribuir de fato com a participação de gestão nos recursos pesqueiros locais.Present study it aimed at to identify to know common between scientific knowledge and local knowledge on ecology and biology of pirarucu (Arapaima mock-ups, contributing with useful information for implementation and consolidation of projects of participative handling fishing boat in region. 57 half-structuralized interviews had been carried through, with fishing of Manaus and Manacapuru during period of June to December of year 2002. It was observed that professional fishermen also have accurate and comprehensive information in relation to knowledge of subsistence fishermen in coastal aspects of reproduction, predation, migration, growth and mortality. Aspects that are not equivalent

  16. Interspecific hybridization between two oysters Crassostrea gigas and C.ariakensis%太平洋牡蛎与近江牡蛎的种间杂交

    Institute of Scientific and Technical Information of China (English)

    张跃环; 郭希明; 王昭萍; 闫喜武; 姚托; 虞志飞; 霍忠明; 于瑞海; 李晓喻; 李雅林

    2012-01-01

    To evaluate whether heterosis can be obtained from hybridization between Crassostrea gigas and C. ariakensis, a 2×2 factorial cross experiment was conducted between these two species in May 2010. Heterosis was first examined by comparing growth and survival of the two reciprocal hybrid crosses (GA and AG) with that of the two parental crosses (GG and AA). Gametic compatibility between the two species was asymmetric with GA crosses having higher fertilization success than AG crosses. In the hybrid crosses, GA offspring were significantly larger than AG offspring. Larval growth of interspecific crosses was similar to that of the maternal species during the first nine days, indicating dominant maternal effects. Beyond larval day 9, however, we observed asymmetry in single parent heterosis for growth and survival for both larvae and spat. GA crosses had good success in metamorphosis, while AG crosses produced only 72 spat. Heterosis was positive for GA hybrids but negative for AG hybrids, with the exception of higher AG survival during the grow-out stage. Maternal origin had a dominant effect on heterosis of both growth and survival, while the interaction between maternal origin and mating type was the second significant factor impacting growth heterosis during the first several days. After that, mating type emerged as an independent factor influencing growth heterosis for the rest of the larval stage. Genetic analysis confirmed that the spat of reciprocal crosses contained DNA from both species. Our study indicates that interspecific hybridization between female C. gigas and male C. ariakensis may be a promising method for genetic improvement of these two species for aquaculture.%为了评估太平洋牡蛎与近江牡蛎能否产生远缘杂种优势,于2010年5月,以成熟的两种牡蛎亲本为材料开展了2×2远缘杂交研究,由长牡蛎自繁组GG(Crassostrea gigas♀×C.gigas♂)、近江牡蛎自繁组AA(C

  17. 响应面法优化秘鲁鱿鱼(Dosidicus gigas)肌肉盐溶蛋白的提取和凝胶形成条件%Response Surface Optimization of Conditions for Extraction and Gel Preparation of Salt-soluble Proteins from Dosidicus gigas Muscle

    Institute of Scientific and Technical Information of China (English)

    金淼; 周逸; 徐亦及; 唐剑波; 杨文鸽; 张进杰

    2013-01-01

    The effect of extraction and gel preparation conditions of salt-soluble protein from Dosidicus gigas on its gel characteristics were discussed.Using respond surface methodology,the effects of KCl concentration,pH and lowtemperature heating time on the water holding capacity(WHC) and texture characteristics of salt-soluble protein gel from squid meat were studied.Result:(1) The effect of KCl concentration on the WHC of gel was extremely significant; the effect of KCl concentration and low-temperature heating time on the hardness of gel was significant ; both the effect of pH on the WHC and low-temperature heating time on the stickiness of gel were significant.(2) Response surface and contour were graphed with the WHC,hardness and stickiness of gel as the response value,the optimal extraction and gel preparation conditions of salt-soluble proteins from Dosidicus gigas muscle were 0.16mol· L-1 KCl,pH7.10 and 55min of low-temperature heating time,respectively.Experimentally,these conditions produced a salt-soluble protein gel with a WHC of 88.00%,hardness of 510.00 g,stickiness of-11.00 g,confirming the model prediction.%探讨了秘鲁鱿鱼肉盐溶蛋白的提取及凝胶形成条件对其凝胶特性的影响.采用响应面分析法,研究KCl浓度、pH值和低温加热时间对鱿鱼肉盐溶蛋白凝胶保水性和质构特性的影响.结果显示:(1)提取液KCl浓度对保水性影响极其显著,对硬度影响显著;提取液pH值对保水性影响显著;低温加热时间对硬度和粘性影响显著;(2)在分析各因素显著性及其交互作用的基础上,确定鱿鱼肉盐溶蛋白提取和凝胶形成的适宜条件为:KCl浓度0.16 mol·L-1、pH 7.10、40℃加热55min,此时凝胶保水性、硬度、粘性分别达到88.00%、510.00g、-ll.00g,与模型预测值相符.

  18. Study of the impact of radionuclides discharges from nuclear industry in the northern Cotentin area on the oyster Crassostrea gigas: expression of cellular stress molecular markers; Etude de l'impact des radionucleides rejetes par les installations nucleaires du Nord Cotentin sur l'huitre creuse Crassostrea gigas: analyse de l'expression de marqueurs moleculaires de stress

    Energy Technology Data Exchange (ETDEWEB)

    Farcy, E

    2006-11-15

    This thesis explores the potential radiological impact of radionuclide discharges from the nuclear industry on the Pacific oyster, Crassostrea gigas. One of the major goals of this research was to identify markers that could be used to monitor the effects of low-level chronic irradiation. We decided to focalize on the expression of stress-induced genes involved in the regulation of cellular stress, focusing on transcription. First, homology cloning was used to identify four new cDNAs encoding stress markers. Then data collected at various sites enabled to evidence that mRNA levels for each of the genes of interest naturally vary to a significant degree, based on individual differences and seasonal factors. Comparing oysters from exposed sites with those from a reference site located on the Atlantic coast did not suggest any relationship between mRNA levels changes and the oysters exposure to liquid radioactive waste from the A.R.E.V.A. reprocessing plant. In the environment, we found that those radionuclide releases resulted in a very small increase in radioactivity in oysters, especially compared with their natural radioactivity. In the laboratory, by exposing the oysters to higher radionuclide concentrations than those found in the environment, we were able to identify two genes as potential candidates for studying the effects of chronic exposure to low doses of ionizing radiations in the oyster: genes encoding MT and MXR. We confirmed that transcriptional induction of these two genes occurs in response to high doses of acute irradiation. Finally, the comparison between environmental results and the laboratory results underlined the complementarity of these two approaches. In particular, it revealed that seasonal variations in mRNA levels probably have a significant effect on the stress response. (author)

  19. Les risques conchylicoles en Baie de Quiberon. Première partie : le risque de mortalité virale du naissain d’huître creuse Crassostra gigas. Rapport final du projet Risco 2010-2013

    OpenAIRE

    Mazurie, Joseph; Stanisiere, Jean-yves; Langlade, Aime; Bouget, Jean-francois; Dumas, Franck; Treguier, Cathy; Leclerc,Emilie; Ravaud, Emilie; Quinsat, Kevin; Gabellec, Raoul; Retho, Michael; Cochet, Helene; Dreano, Alain

    2013-01-01

    L’étude « Risco », labellisée Pôle Mer et financée par la Région Bretagne, mobilise à la fois des socio-économistes, des biologistes et des professionnels. Elle vise à comprendre et gérer les facteurs de mortalités massives d’huîtres creuses (Crassostrea gigas) enregistrées par les concessionnaires de baie de Quiberon (France, 56), à partir de 2006 sur les huîtres adultes et 2008 sur le naissain. Le protocole engagé en 2010, avec un volet expérimental basé sur le suivi mensuel de lots d’huîtr...

  20. 9-10月秘鲁外海茎柔鱼摄食习性的初步研究%Preliminary study on feeding behavior of jumbo flying squid (Dosidicus gigas)off Peru during September and October

    Institute of Scientific and Technical Information of China (English)

    贾涛; 李纲; 陈新军; 刘必林; 钱卫国

    2010-01-01

    茎柔鱼(Dosidicus gigas)是大洋性重要经济头足类之一,在食物链中起着重要作用.通过对2009年9-10月秘鲁外海采集的383尾茎柔鱼胃含物进行分析与研究,以了解调查期间茎柔鱼摄食习性的时空变化特性.研究认为,摄食等级在9-10月份间存在极显著差异(P0.05).但昼夜消化水平差异极显著(P0.05).

  1. Recovery of wild Pacific oyster, Crassostrea gigas in terms of reproduction and gametogenesis two-years after the Hebei Spirit Oil Spill Accident off the West Coast of Korea

    Science.gov (United States)

    Mondol, Mostafizur Rahman; Keshavmurthy, Shashank; Lee, Hee-Jung; Hong, Hyun-Ki; Park, Heung-Sik; Park, Sang-Rul; Kang, Chang-Keun; Choi, Kwang-Sik

    2015-12-01

    The Hebei Spirit oil spill in December 2007 at Taean off the west coast of Korea was the largest oil tanker accident in Korea. However, the impact of the spill on physiology of benthic animals remains largely unknown. Two-years after the accident, we compared reproductive effort and annual gametogenesis of the wild Pacific oyster Crassostrea gigas, residing at oil spill site with a control oyster population in Incheon Bay, North-West coast of Korea. Results showed that the oyster sampled from the oil spill site showed a significantly higher (279.0 mg standard animal-1, Panimal-1, Panimal-1, Panimal-1, Panimal-1, Panimal-1, Pphysiological status to normal level after two years of the oil spill accident.

  2. Aplicación de la Espectrometría de Masas Maldi tof/tof a la Endocrinología, Inmunología y Patología del paiche Arapaima gigas

    OpenAIRE

    Cueva Távara, Mario David

    2016-01-01

    RESUMEN El pez amazónico gigante “paiche” Arapaima gigas es una especie prometedora para la piscicultura tropical debido a sus características anatómicas, sin embargo, su completa domesticación es problemática debido a la falta de información biológica. Los progresos recientes en el campo de la biotecnología molecular, llamados “omicas”, están revolucionando la ictiología básica y aplicada; en particular la proteómica por espectrometría doble masa MALDI TOF/TOF, que permite la detección...

  3. Paralarvae of the complex Sthenoteuthis oualaniensis-Dosidicus gigas (Cephalopoda: Ommastrephidae) in the northern limit of the shallow oxygen minimum zone of the Eastern Tropical Pacific Ocean (April 2012)

    Science.gov (United States)

    Sánchez-Velasco, Laura; Ruvalcaba-Aroche, Erick D.; Beier, Emilio; Godínez, Victor M.; Barton, Eric D.; Díaz-Viloria, Noe; Pacheco, María. R.

    2016-03-01

    The three-dimensional distribution of the paralarvae of the complex Sthenoteuthis oualaniensis-Dosidicus gigas (Cephalopoda: Ommastrephidae) was analyzed at the northern limit of the shallow oxygen minimum zone in the Eastern Tropical Pacific in April 2012. The upper limit of the oxygen minimum water (˜44 µmol/kg or 1 mL/L) rises from ˜100 m depth in the entrance of the Gulf of California to ˜20 m depth off Cabo Corrientes. Most of the paralarvae of this complex, dominated by D. gigas, were concentrated in the Gulf entrance, between the thermocline (˜20 to ˜50 m depth) and the sea surface, in the warmest (>19°C) oxygenated (>176 µmol/kg) layer. The highest abundance of paralarvae was detected in an anticyclonic eddy (˜120 km diameter and >500 m deep), which contained lower-salinity water (<35 g/kg), consistent with formation in the California Current. Lower paralarvae abundance was recorded further south off Cabo Corrientes, where hypoxic layers were elevated as water shoaled nearshore. Almost no paralarvae were found in the north of the study area beyond the strong salinity front (˜34.8-35.4 g/kg) that bounded the anticyclone. These results showed an affinity of the paralarvae for lower-salinity, oxygenated water, illustrated by the influence of the mesoscale anticyclonic eddy and the salinity front in their distribution. Based on this study, it can be concluded that the expansion of the depth range of hypoxic water observed in the Eastern Tropical Pacific may be increasing environmental stress on the paralarvae by vertically restricting their habitat, and so affecting their survival.

  4. 东太平洋不同海区茎柔鱼渔业生物学的初步研究%Comparison of fishery biology for Dosidicus gigas from three different areas in the Eastern Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    陈新军; 李建华; 刘必林; 李纲; 钱卫国

    2012-01-01

    根据我国鱿钓船多年在秘鲁、智利和哥斯达黎加外海生产调查所采集的茎柔鱼样本,对3个不同作业海区茎柔鱼渔业生物学特性进行比较分析。研究表明,秘鲁、智利和哥斯达黎加外海茎柔鱼胴长范围分别为209~1 149 mm、166~837 mm和204~429 mm,优势胴长分别为250~400 mm、300~450 mm和250~350 mm,对应的渔获物中雌雄性比平均值分别为3.87∶1、2.50∶1、3.75∶1。根据胴长组成以及性成熟,认为秘鲁外海存在大型、中型和小型3个群体,智利外海以中型群体为主体并存在少量的大型群体,哥斯达黎加外海以小型群体为主体并存在少量的中型群体。秘鲁和智利外海茎柔鱼体重与胴长关系式的生长参数b值为3.06~3.17,而哥斯达黎加外海为2.57~2.63。秘鲁和智利外海茎柔鱼性腺成熟度均以Ⅰ级和Ⅱ级为主,而哥斯达黎加外海则以Ⅱ、Ⅲ和Ⅳ级为主。各月间摄食等级差异变化较为显著,但基本上以0~2级为主体。研究表明,3个海区茎柔鱼种群结构和生物学特性总体上有所差异。研究亮点:首次对秘鲁、智利和哥斯达黎加外海3个不同作业海区茎柔鱼渔业生物学特性进行比较分析,研究认为秘鲁外海存在大型、中型和小型3个群体,智利外海以中型群体为主体并存在少量的大型群体,哥斯达黎加外海以小型群体为主体并存在少量的中型群体。生长参数存在差异,各月间摄食等级差异变化较为显著。研究表明,3个海区茎柔鱼种群结构和生物学特性总体上有所差异。%According to the sampled squid,Dosidicus gigas,collected from the fishing and survey by Chinese squid fishing boats for many years off EEZ of Peru,Chile and Costa Rica,the biological characteristics of D.gigas form three different fishing areas are compared.The results indicated that their mantle lengths of D.gigas off EEZ of Peru,Chile and Costa Rica ranged from 209

  5. Stock assessment and management of Dosidicus gigas in the Southeast Pacific Ocean with Schaefer model%基于 Schaefer 模型的东南太平洋茎柔鱼资源评估和管理

    Institute of Scientific and Technical Information of China (English)

    许骆良; 陈新军; 汪金涛; 官文江

    2015-01-01

    Dosidicus gigas is one of the important economic cephalopod in the world.It is widely distributed in the east of Pacific Ocean.Nowadays the yield of Dosidicus gigas occupies more than 50% of the total yield of squid in China mainland.In 2012 ,the yearly catch in China mainland reached 221.1 thousand tons,the number of fishing vessels are more than 250.It is necessary to assess the stock for making the fishery sustainable.Unfortunately lit-tle work is done in this field.The stock assessment and risk analysis of alternative management strategies for Dosi-dicus gigas in the Southeast Pacific Ocean were carried out by using a Bayesian Schaefer model,in which two sce-narios,standard scenario and sensitivity analysis scenario,are considered.The Schaefer model was chosen because of the lack of age-data of Dosidicus gigas and also because the migration mechanism and stock structure of the squid was very complex which was not completely understood by us.In many cases,Schaefer model performed better than many other more complex models such as age-data based models or metapopulation model.For parameters K and q in standard scenario,the posterior distribution are approximately normal distributed.It is totally different with the prior distribution which is set to be uniform distribution.Compared with the two scenarios,the results of posterior distribution of the three parameters are similar .The study indicated that the data of yearly yield and CPUE provided sufficient information for the valuation of model parameters.Under standard scenario,the MSY (maximum sustainable yield)is 1.429 million tons.To maintain MSY,the biomass and fishing mortality should be 2.147 million tons and 0.682,respectively.Under sensitivity analysis scenario,the MSY is 1.525 million tons.To maintain MSY,the biomass and fishing mortality should be 2.296 million tons and 0.691,respectively.Under both scenarios,the fishing mortalities and yearly catches from 2003 to 2012 were lower than reference points F0

  6. Nervous and muscle system development in Phascolion strombus (Sipuncula)

    DEFF Research Database (Denmark)

    Wanninger, Andreas; Koop, Demian; Bromham, Lindell

    2005-01-01

    Recent interpretations of developmental gene expression patterns propose that the last common metazoan ancestor was segmented, although most animal phyla show no obvious signs of segmentation. Developmental studies of non-model system trochozoan taxa may shed light on this hypothesis by assessing...

  7. 秘鲁鱿鱼(Dosidicus gigas)冻品加工期间肌肉蛋白特性的变化%Changes ,of biochemical properties of muscle protein during the process of Dosidicus gigas frozen goods

    Institute of Scientific and Technical Information of China (English)

    金淼; 周逸; 徐亦及; 唐剑波; 杨文鸽; 徐培芳

    2012-01-01

    Study on the changes of biochemical properties,including the content of myofibrillar protein,total thiol and active thioI,Ca^2+-ATPase activity,textural properties from Dosidicus gigas muscle during the process. The results showed:After processed,the content of myofibrillar protein,total thiol and active thioI,Ca^2+-ATPase activity,springiness declined to 84.58% ,69.95% ,67.69% ,74.12% and 79.67%, respectively. The content of myofibrillar protein decreased obviously during the soaking with deacid agent and the second quick freezing, reduced to 92.08% and 84.58% ,total thiol and active thiol,Ca^2+-ATPase activity,cohusiveness decreased obviously during the soaking with deacid agent. Compared with the raw material,the corresponding indicators reduced to 72.44% ,73.39% ,78.82% and 44.10% respectively. Springiness decreased obviously during the second quick freezing,reduced to 79.67%. During the process of Dosidicus gigas frozen goods,soaking with deacid agent and quick freezing had a great influence on the denaturation of myofibrillar protein from Dosidicus gigas muscle.%以肌原纤维蛋白含量、总巯基和活性巯基含量、Ca^2+-ATPase活性、质构特性为测定指标,研究秘鲁鱿鱼冻品在加工过程中蛋白特性的变化,确定引起秘鲁鱿鱼蛋白变性的主要生产环节。经过5个不同阶段的加工,鱿鱼肌原纤维蛋白含量、总巯基和活性巯基含量、Ca^2+-ATPase活性、弹性分别下降为原材料的84.58%、69.95%和67.69%、74.12%、79.67%:肌原纤维蛋白含量在鱿鱼去酸浸泡及第二次速冻阶段下降幅度较大,分别下降为原材料的92.08%和84.58%:总巯基和活性巯基含量、Ca2+^-ATPase活性、凝聚性在去酸剂浸泡阶段下降幅度最大.分别下降为原材料的72.44%和73.39%、78.82%、44.10%;弹性在第二次速冻后下降幅度最大,下降为原材料的79.67%。在加工过程中,去酸

  8. Molecular cloning and characterization of nacrein gene in Pacific oyster (Crassostrea gigas)%长牡蛎nacrein基因的克隆、结构及进化分析

    Institute of Scientific and Technical Information of China (English)

    宋小瑞; 王晓通; 李莉; 张国范

    2015-01-01

    首次在长牡蛎(Crassostrea gigas)中克隆得到一种新的贝壳基质蛋白nacrein-like protein F3的全长cDNA序列。nacrein-like protein F3基因cDNA全长1499bp,其中编码区长度为1242bp,编码一条含413个氨基酸残基的多肽链。氨基酸序列比对和结构域分析均表明其为合浦珠母贝(Pinctada fu-cata)nacrein的同源蛋白,含有1个保守的α-碳酸酐酶结构域,但由于重复结构域的插入,α-碳酸酐酶结构域被间隔成2个亚结构域。系统进化分析显示nacrein-like protein F3与贻贝(Mytilus californianus) nacrein-like protein进化关系最近。此外,在软体动物中,双壳纲nacrein-like proteins进化速度相对较快,推测与寒武纪时期剧烈的环境变化有关,如影响贝壳形成的海水化学变化。%The full length cDNA sequence of nacrein-like protein F3 was cloned from Pacific oyster (Crassostrea gigas) for the first time. Nacrein-like protein F3 cDNA has 1499 bp, containing a 1242 bp CDS that encod a peptide of 413 amino acids. Multiple alignment and conserved domain analysis showed that this peptide is a homolog of nacrein (Pinctada fucata), containing a carbonic anhydrase (CA) domain, which is flanked by inserted repeat se-quences. Phylogenetic analysis indicated that nacrein-like protein F3 is more closely related to nacrein-like protein inMytilus californianus than other nacrein-like proteins. Moreover, the nacrein-like proteins in bivalves seem to evolve relatively fast, which is presumably caused by the fast changing Cambrian environment, especially the ma-rine chemical composition, which can affect shell biomineralization.

  9. Rapid method for controlling the correct labeling of products containing common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas) by fast real-time PCR.

    Science.gov (United States)

    Espiñeira, Montserrat; Vieites, Juan M

    2012-12-15

    The TaqMan real-time PCR has the highest potential for automation, therefore representing the currently most suitable method for screening, allowing the detection of fraudulent or unintentional mislabeling of species. This work describes the development of a real-time polymerase chain reaction (RT-PCR) system for the detection and identification of common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas). This technique is notable for the combination of simplicity, speed, sensitivity and specificity in an homogeneous assay. The method can be applied to all kinds of products; fresh, frozen and processed, including those undergoing intensive processes of transformation. This methodology was validated to check how the degree of food processing affects the method and the detection of each species. Moreover, it was applied to 34 commercial samples to evaluate the labeling of products made from them. The methodology herein developed is useful to check the fulfillment of labeling regulations for seafood products and to verify traceability in commercial trade and for fisheries control. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. A Carbonic Anhydrase Serves as an Important Acid-Base Regulator in Pacific Oyster Crassostrea gigas Exposed to Elevated CO2: Implication for Physiological Responses of Mollusk to Ocean Acidification.

    Science.gov (United States)

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Qiu, Limei; Wang, Lingling; Zhang, Anguo; Song, Linsheng

    2017-02-01

    Carbonic anhydrases (CAs) have been demonstrated to play an important role in acid-base regulation in vertebrates. However, the classification and modulatory function of CAs in marine invertebrates, especially their responses to ocean acidification remain largely unknown. Here, a cytosolic α-CA (designated as CgCAII-1) was characterized from Pacific oyster Crassostrea gigas and its molecular activities against CO2 exposure were investigated. CgCAII-1 possessed a conserved CA catalytic domain, with high similarity to invertebrate cytoplasmic or mitochondrial α-CAs. Recombinant CgCAII-1 could convert CO2 to HCO3(-) with calculated activity as 0.54 × 10(3) U/mg, which could be inhibited by acetazolamide (AZ). The mRNA transcripts of CgCAII-1 in muscle, mantle, hepatopancreas, gill, and hemocytes increased significantly after exposure to elevated CO2. CgCAII-1 could interact with the hemocyte membrane proteins and the distribution of CgCAII-1 protein became more concentrated and dense in gill and mantle under CO2 exposure. The intracellular pH (pHi) of hemocytes under CO2 exposure increased significantly (p ocean acidification and participate in acid-base regulation. Such cytoplasmic CA-based physiological regulation mechanism might explain other physiological responses of marine organisms to OA.

  11. 粗江蓠多糖对辐射损伤小鼠NK细胞的影响%Effect of Gracilaria Gigas Harvey Polysaccharides (GHPS) on Natural Killer Cells Activity in Mice with Radiation Injury

    Institute of Scientific and Technical Information of China (English)

    王亚飞; 孟庆勇

    2009-01-01

    目的:研究粗江蓠多糖(Gracilaria Gigas Harvey Polysaccharides, GHPS)对辐射损伤小鼠NK细胞的影响.方法:采用60Co γ射线5Gy全身照射小鼠制造辐射损伤模型,通过乳酸脱氢酶释放法检测不同剂量(10mg/kg,20mg/kg,40mg/kg)的GHPS对辐射损伤小鼠NK细胞杀伤靶细胞能力的影响.结果:辐射对照组小鼠接受60Co γ射线5Gy照射后,NK细胞的活性显著低于正常对照组(P<0.01).经腹腔注射(10、20、40 )mg/kg GHPS,再接受γ射线5Gy照射后,小鼠NK细胞活性明显高于辐射对照组(P<0.01),并有剂量依赖性.结论:5Gy γ射线可以抑制小鼠NK细胞杀伤靶细胞的活性,而GHPS对辐射损伤小鼠的NK细胞有保护作用.

  12. The expulsive and attractive effects of 16 species of plants on Golden Apple Snails(Ampullaria gigas Spix)%16种植物对福寿螺的趋避效果研究

    Institute of Scientific and Technical Information of China (English)

    徐武兵; 钟秋华; 李林峰; 郭荣荣; 章家恩; 罗明珠

    2010-01-01

    于实验室内通过自制的八边形分室趋避试验装置观察研究了16种植物对福寿螺(A mpullaria gigas Spix)的趋避效果.结果表明:福寿螺具有沿壁爬行的偏好性,沿壁爬行的福寿螺数量平均为非沿壁爬行福寿螺数的3.77倍.同时发现,在所选的16种植物中,白千层(Melaleuca leucadendra L)、扶桑(Hibiscus rosa-sinensis L.)2种植物对福寿螺有较大的吸引作用;金叶假连翘(Duranta repens cv.Dwarf Yellow)、木麻黄(Casuarina equisetifolia L)、红龙草(A lternanthera dentata cv.Ruliginosa)、鸭脚木[Schefflera octophylla(Lour.)Harms]、剑麻(Agave Sisalana Perrine)5种植物对福寿螺有一定的驱赶作用.

  13. Decursin Isolated from Angelica gigas Nakai Rescues PC12 Cells from Amyloid β-Protein-Induced Neurotoxicity through Nrf2-Mediated Upregulation of Heme Oxygenase-1: Potential Roles of MAPK

    Directory of Open Access Journals (Sweden)

    Li Li

    2013-01-01

    Full Text Available Decursin (D, purified from Angelica gigas Nakai, has been proven to exert neuroprotective property. Previous study revealed that D reduced Aβ25‒35-induced cytotoxicity in PC12 cells. Our study explored the underlying mechanisms by which D mediates its therapeutic effects in vitro. Pretreatment of cells with D diminished intracellular generation of ROS in response to Aβ25‒35. Western blot revealed that D significantly increased the expression and activity of HO-1, which was correlated with its protection against Aβ25‒35-induced injury. Addition of ZnPP, an HO-1 competitive inhibitor, significantly attenuated its protective effect in Aβ25‒35-treated cells, indicating the vital role of HO-1 resistance to oxidative injury. Moreover, D induced Nrf2 nuclear translocation, the upstream of HO-1 expression. While investigating the signaling pathways responsible for HO-1 induction, D activated ERK and dephosphorylated p38 in PC12 cells. Addition of U0126, a selective inhibitor of ERK, blocked D-induced Nrf2 activation and HO-1 induction and meanwhile reversed the protection of D against Aβ25‒35-induced cell death. These findings suggest D augments cellular antioxidant defense capacity through both intrinsic free radical scavenging activity and activation of MAPK signal pathways that leads to Nrf2 activation, and subsequently HO-1 induction, thereby protecting the PC12 cells from Aβ25‒35-induced oxidative cytotoxicity.

  14. Mortality and growth of cobalt-60 gamma-irradiated adult Pacific oyster, Crassotrea gigas%60Co-γ射线对成体长牡蛎生长的影响及致死效应

    Institute of Scientific and Technical Information of China (English)

    刘晓; 彭小明; 张国范; 赵敏; 郭希明

    2005-01-01

    Effects of ionizing irradiation of 60Co-γ ray on mortality and growth of one year-old Pacific oysters ( Crassotrea gigas ) were studied. Irradiation was conducted at 4℃ and without sea water, and the survival, shell length, shell width, whole wet weight and condition index of irradiated oysters were measured. A biphasic dose response effect of 660Co-γ irradiation on Pacific oyster with high stimulatory response dose range to 100 Gy, and strong hormesis effects had been observed. Gamma ray induced mortality happened within 90 days after irradiation, and the relation between dosage ( D ) and mortality at 90 days could be described by the equation of M90 = 0.0041D2- 0. 1816D (R2= 0. 9958) with an LD50/90 of 135 Gy, indicating that the Pacific oyster has strong resistance to 60Co-γ irradiation. Growth in shell length, shell width and whole wet weight of Pacific oyster were also enhanced by 60 Gy of 60Co-γ ray. The condition index was also enhanced by 60Co-γ irradiation in the dosage range from 40 to 100 Gy, with the maximum stimulatory response of 2.5 fold of control value at the 40 Gy dosage, suggesting that the accelerating effects of γ ray on growth of the Pacific oyster led to increase in dry meat. Results of this study showed that ionizing irradiation might be useful in the improvement of production traits in shellfish.

  15. Preliminary study on the influence of water temperature on the recruitment of Dosidicus gigas%海洋水温对茎柔鱼资源补充量影响的初探

    Institute of Scientific and Technical Information of China (English)

    徐冰; 陈新军; 李建华

    2012-01-01

    茎柔鱼是短生命周期种类,其资源量极易受到海洋环境变化的影响。根据2003-2010年我国鱿钓船队在东南太平洋公海的生产统计和海洋表面温度(SST)、Nino 1+2 SSTA等资料,利用灰色关联度方法,分析了茎柔鱼作业渔场和产卵场最适表层水温范围占总面积的比例(分别用PF和PS来表示),以及它们与Nino 1+2SSTA的关系,进而探讨了PF和PS与单位捕捞努力量渔获量(CPUE)的关系,研究海洋环境变化对茎柔鱼资源补充量(用CPUE来表示)的影响。结果表明,2003-2010年PF和PS比值最大的分别集中在9-11月和12月-翌年1月。PS与Nino 1+2 SSTA的灰色关联度要高于PF与Nino 1+2 SSTA的值,由此推测厄尔尼诺等事件对PS的影响较为显著。同时,分析结果表明PS与CPUE的灰色关联度较高,在时间上呈现连续性,11月至翌年2月均在0.4左右。研究认为,拉尼娜事件会增大作业渔场最适表层水温面积比例,并形成广泛的上升流,从而有利于茎柔鱼索饵与生长,也利于茎柔鱼资源补充量的增加;反之则不利于茎柔鱼资源补充量的发生。%Dosidicus gigas is a short-lived species and its recruitments would be affected by change of environmental conditions.Based on the fishing data collected by Chinese squid jigger fleets,and sea surface temperature(SST) and Nino 1+2 SSTA data,in the high sea waters of Southeastern Pacific Ocean from 2003 to 2010,the grey correlations between the proportion of favorable SST in the fishing ground and spawning ground(indicated by PF and PS,respectively) are analyzed,and the relationship between PF,PS and CPUE are also analyzed to evaluate the effect of changable environment on recruitment of D.gigas respectively.The results indicated that the largest proportions of favorable SST in fishing ground are from September to November,and from December to January of the next year for the spawning ground.The grey correlation between the

  16. Improvement in antiproliferative activity of Angelica gigas Nakai by solid dispersion formation via hot-melt extrusion and induction of cell cycle arrest and apoptosis in HeLa cells.

    Science.gov (United States)

    Jiang, Yunyao; Piao, Jingpei; Cho, Hyun-Jong; Kang, Wie-Soo; Kim, Hye-Young

    2015-01-01

    Angelica gigas Nakai (AGN) is one of the most popular herbal medicines and widely used as a functional food product. In this study, AGN was firstly processed by a low-temperature turbo mill and a hot melting extruder to reduce particle size and form solid dispersion (SD). Anticancer activity against HeLa cells was then examined. AGN-SD based on Soluplus was formed via hot-melt extrusion (HME) and showed the strongest cytotoxic effect on HeLa cells. In addition, the possible mechanism of cell death induced by AGN-SD on HeLa cells was also investigated. AGN-SD decreased cell viability, induced apoptosis, increased the production of reactive oxygen species, regulated the expression of Bcl-2 and Bax, and induced G2/M phase arrest in HeLa cells. This study suggested that AGN-SD based on Soluplus and the method to improve antiproliferative effect by SD formation via HME may be suitable for application in the pharmaceutical industry.

  17. EPR studies of the Mo-enzyme aldehyde oxidoreductase from Desulfovibrio gigas: an application of the Bloch-Wangsness-Redfield theory to a system containing weakly-coupled paramagnetic redox centers with different relaxation rates.

    Science.gov (United States)

    González, Pablo J; Barrera, Guillermo I; Rizzi, Alberto C; Moura, José J G; Passeggi, Mario C G; Brondino, Carlos D

    2009-10-01

    Electron transfer proteins and redox enzymes containing paramagnetic redox centers with different relaxation rates are widespread in nature. Despite both the long distances and chemical paths connecting these centers, they can present weak magnetic couplings produced by spin-spin interactions such as dipolar and isotropic exchange. We present here a theoretical model based on the Bloch-Wangsness-Redfield theory to analyze the dependence with temperature of EPR spectra of interacting pairs of spin 1/2 centers having different relaxation rates, as is the case of the molybdenum-containing enzyme aldehyde oxidoreductase from Desulfovibrio gigas. We analyze the changes of the EPR spectra of the slow relaxing center (Mo(V)) induced by the faster relaxing center (FeS center). At high temperatures, when the relaxation time T(1) of the fast relaxing center is very short, the magnetic coupling between centers is averaged to zero. Conversely, at low temperatures when T(1) is longer, no modulation of the coupling between metal centers can be detected.

  18. PRELIMINARY STUDY ON FISHERIES BIOLOGY OF DOSIDICUS GIGAS IN THE WATERS NEAR THE EQUATOR OF EASTERN PACIFIC OCEAN%东太平洋赤道附近海域茎柔鱼(Dosidicus gigas)渔业生物学的初步研究

    Institute of Scientific and Technical Information of China (English)

    陈新军; 李建华; 易倩; 刘必林; 杨铭霞; 陆化杰

    2012-01-01

    Based on the samples of 1178 squids in total from Chinese squid jigging vessels near the equator of the eastern Pacific in 2011, the biological characteristics of Dosidicus gigas were studied. The results showed that the range of mantle length was from 201 to 421mm and the average attained 290mm, the dominant mantle length ranged from 260 to 320mm. Body weight was from 200g to 2650g and the average attained 1000g, the dominant body weight ranged from 600 to 1000g. The equation of the relationship between mantle length and body weight was fitted by power exponent. The sexual ratio of female to male was 2.59 : 1. The sexual maturity stage dominated I and II. The length and weight of nidamental gland of D. gigas increased with the growth of gland maturity. And the mantle length of first maturity of females was 397.2mm. The feeding stage dominated 0-1. It can be found that D. gigas near the equator is obvious different from that in the Gulf of California and waters off Chile, Peru and Costa Rica. We can conclude that the population of D. gigas near the equator of the eastern Pacific belongs to small group.%根据2011年东太平洋赤道附近海域探捕期间采集的1178尾茎柔鱼样本,进行了茎柔鱼的生物学特性研究。结果表明:茎柔鱼胴长范围为201-421mm,平均胴长为290mm,优势胴长为260—320mm;体重范围为200-2650g,平均体重为1000g,优势体重为600-1000g;胴长与体重关系呈幂指数关系;雌、雄性比为2.59:1;性腺成熟度以I、Ⅱ期为主;缠卵腺长和缠卵腺重随着性腺的成熟而逐步增大;雌性初次性成熟胴长为397.2mm;摄食等级以0—1级为主;与其它海域相比,该海域茎柔鱼个体差异明显,主要为小型群体。

  19. Primary studies on the population genetic structure of Dosidicus gigas in the high seas of eastern Pacific Ocean%东太平洋公海茎柔鱼种群遗传结构初步研究

    Institute of Scientific and Technical Information of China (English)

    闫杰; 许强华; 陈新军; 李纲; 刘必林

    2011-01-01

    The jumbo flying squid(Dosidicus gigas)is commercially important fishery species in the world. Assessment of population genetic diversity levels of jumbo flying squid is fundamental to the conservation and management of this species. The samples derived from the Chinese squid jigging vessel were collected from the eastern Pacific waters(81.9°-94.9°W,8.9°N -11.3°S)from July to October 2009. By using 724 bp fragment of mitochondrial cytochrome b gene ( Cyt b), we analyzed the sequence variations and population genetic structures for 155 samples collected from seven sites of Peru and three sites of Costa Rica. In total, 16 variable sites were acquired, and all of them were parsimony sites. 43 haplotypes were identified from 155 individuals. Analysis of mtDNA Cyt b sequences of jumbo flying squids from the ten localities revealed that the mean haplotypic diversity was 0. 873, while the nucleotide diversity was 0.003 69. 6 haplotypes were shared by all the populations, while Peru population possessed the highest haplotypes (n = 20). The AMOVA test of D. Gigas revealed that 82. 70% of the genetic variation occurred within populations. FST analysis suggested that significant genetic differentiations were found between the partial Peru populations and the Costa Rica populations, and even between partial Peru populations. However, no significant genetic differentiations were detected between Costa Rica populations.%根据2009年7月到10月我国大型鱿钓渔船在东太平洋(81.9°~94.9°W,8.9°N~11.3°S)秘鲁和哥斯达黎加外海作业期间采集的样本,利用线粒体DNA细胞色素b基因的724 bp部分序列,分析了采自秘鲁7个采样点和哥斯达黎加3个采样点的155个个体的序列多样性与种群遗传结构.结果显示,724 bp片段中发现了16个变异位点,155个个体出现43个单倍型.序列多样性分析结果揭示,155个个体的平均单倍型多样性指数为0.873,核苷酸多样性指数为0.003 69.群体间共享6

  20. 秘鲁外海茎柔鱼渔场时空分布分析%Spatial and Temporal Distribution of Fishing Ground for Dosidicus giga s in the Offshore Waters of Peru

    Institute of Scientific and Technical Information of China (English)

    徐冰; 陈新军; 钱卫国; 田思泉

    2011-01-01

    Jumbo flying squid, Dosidicus gigas, distributed in the waters of Peru, is an important economic squid. Understanding of the spatial and temporal variations in the distribution of this squid is useful to rational utilization of its resources. In this study, based on the fishing data and sea surface temperature (SST) collected by Chinese squid fleets in the waters off Peru from 2003 to 2004 and from 2006 to 2009, the methods of spatial distance and aggregative analysis were used to study the spatial and temporal variations in fishing ground for Dosidicus gigas. The result indicated that there were some differences on the gravity between years. It was found that the position of longitude showed westward move with months, whereas its latitude showed northward shift from January to June and southward shift from July to December. The cluster analysis showed that four groups are divided, I. E. (2003, (2006 and 2008)), (2004, (2007 and 2009)) respectively. The results indicated that the gravities of catch between 2006 and 2009 are different. The former's weight position of catch is 82°23'W and 12°53'S and the tatter's weight position of catch is 81°47 W and 14°27' S, which have 1. 5 degrees of latitude difference. The results showed that the monthly difference in fishing ground may be caused by the migration of jumbo flying squid, and the annual difference in fishing ground may be related to the changes of marine environment.%秘鲁外海茎柔鱼是重要的经济性种类,掌握其渔场时空分布规律有助于资源的合理利用.本文根据2003-2004年和2006-2009年我国鱿钓船在秘鲁外海的生产统计和海洋表面温度(SST)等资料,使用空间距离和聚类分析的方法,对其各年间渔场时空分布进行分析比较.结果表明,各年产量重心的分布都存在一定差异,产量重心在经度上随月份整体上呈现向西移动的趋势,在纬度方向上1~6月整体上呈向北移动的趋势,7~12月则表现出向南移

  1. Inheritance of mantle pigmentation in selected families of the Pacific oyster Crassostrea gigas%长牡蛎外套膜色遗传规律初步研究

    Institute of Scientific and Technical Information of China (English)

    王庆志; 李琪; 丛日浩; 孔宁; 孔令锋; 于红

    2015-01-01

    比较了长牡蛎(Crassostrea gigas)不同外套膜色家系的受精率与孵化率, 不同生长阶段的生长与存活及外套膜色在子代个体中的分布规律.结果表明, 不同家系的卵径、受精率和孵化率无显著差异(P>0.05); 壳高在 60 和 150 日龄稚贝阶段略有差异(P0.05); 不同生长阶段的存活率差异不显著(P>0.05).外套膜纯黑 BB 家系的子代外套膜基本全部为4 级着色; 外套膜纯黄 YY1 家系子代的外套膜基本全部为 1 级着色, YY2 家系子代的外套膜黄色与黑色比例约为 3:1, 符合孟德尔分离定律.由此推测长牡蛎外套膜色可能由一个主效基因控制, 且黄色对黑色具有显性上位效应.研究结果可以为长牡蛎外套膜色的人工选育提供理论依据.%In the interest of increasing the value of the Pacific oyster (Crassostrea gigas) sold as "singles" for the half-shell market, we explored the feasibility of modifying mantle pigmentation through selective breeding. The experimental 12 full-sib families of pedigreed oysters were investigated for growth, survival and mantle pigmentation. Initial investigations showed the trait was complex and best described as 1-4 degrees. At 350 and 450 days old, no significant survival and shell height difference were found among different families (P>0.05) which showed that the performance traits of growth and survival were not correlated with mantle pigmentation. The distributions of pigmentation levels among individuals within full-sib families were further examined. High within-family variation in mantle pigmentation that in the hybrid and control families was normally and continuously distributed. However, offspring within three BB families, the 4 degree mantle was dominant absolutely. Furthermore, offspring within YY2 family segregated into phenotypically distinct "lighter" and "darker"mantle groups in a 3:1 ratio supporting the hypothesis that a single major gene is segregating in these families

  2. 秘鲁鱿鱼和日本海鱿鱼营养成分分析与评价%Analysis and Evaluation of Nutritional Compositions of Dosidicus gigas and Onychoteuthis borealijaponicus okada

    Institute of Scientific and Technical Information of China (English)

    杨宪时; 王丽丽; 李学英; 黄洪亮; 迟海

    2013-01-01

    以秘鲁鱿鱼(Dosidicus gigas)和日本海鱿鱼(Onychoteuthis borealijaponicus okada)为原料,对其胴体的营养成分进行了分析比较与评价.研究表明,秘鲁鱿鱼和日本海鱿鱼都是低脂肪高蛋白食品,两者的蛋白质、脂肪、灰分含量均相近,水分含量前者显著高于后者(P<0.05).两者的磷P、锌Zn、铜Cu含量没有显著性差别,日