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Sample records for elongatus swaison mollusca

  1. Ultrastructural analysis of the shells of Anodontites trapesialis (Lamarck and Anodontites elongatus (Swaison (Mollusca, Bivalvia, Etherioidea from the Mato Grosso Pantanal Region, Brazil Análise da ultraestrutura das conchas de Anodontites trapesialis (Lamarck e Anodontites elongatus (Swaison (Mollusca, Bivalvia, Etherioidea do Pantanal do Mato Grosso, Brasil

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    Claudia T. Callil

    2005-09-01

    Full Text Available Based on optical and SEM microscopic observations, the projections of the outer surface of the periostracum and inner micro-structures of the shell are described and redefined. The outer surface of the periostracum is practically smooth in both species. Considering a mesoscopic view of the periostracum, A. trapesialis (Lamarck, 1819 presents regular corrugations in the form of radial sequences of arches on the disk region, isolated rays or horizontal sequences of rays on the anterior lower region. A. elongatus presents corrugations formed by series of oblique arches on the disc and oblique rays on the carina. Under SEM, micro ridges were more evident in A. elongatus, but a wide diversity of shapes and patterns of micro fringes were observed in A. trapesialis, especially in young individuals. Considering the profile of the shell layers, the periostracum is relatively thin and apparently simple in A. trapesialis and thinner in A. elongatus. The prismatic layer is thick in both species, consisting of a single series of elongated prisms and wedge-shaped prisms close to the outer surface. The nacreous layer consists of very fine lamellae without pattern or with a slight staircase-like; in A. elongatus this layer is divided by a laminar inclusion of conchiolin. The fringes are abundant and diversified in A. trapesialis, a species less resistant to desiccation due to the presence of a wide intervalvar gap. The existence of a greater density of micro fringes and spikes in juveniles may be related to the orientation of the animal in order to search for an ideal site for development or for escape from regions subject to seasonal droughts, like Pantanal.Projeções da superfície externa do perióstraco e micro estruturas da concha foram redefinidas com base na microscopia óptica e eletrônica de varredura. A superfície do perióstraco é praticamente lisa em ambas espécies. Sob vista mesoscópica, A. trapesialis (Lamarck, 1819 apresenta corruga

  2. Anatomy and systematics of Anodontites Elongatus (Swainson) from Amazon and Parana Basins, Brazil (Mollusca, Bivalvia, Unionoida, Mycetopodidae)

    OpenAIRE

    Simone, Luiz Ricardo L

    1997-01-01

    The anatomy of Anodontiies elongatus (Swainson, 1823), a rare species restricted to the Amazon and Parana Basins, is described by first time, showing a group of conchological and anatomical characters exclusive of this species that may be analyzed to identify it. Diagnosis of A. elongatus: shell long antero-posteriorly, umbones prominent, periostracum opaque and smooth, two posterior radial striae; middle fold of mantle edge veiy tall; gill long antero-posteriorly and short dorso-ventrally, e...

  3. 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

  4. Anatomy and systematics of Anodontites Elongatus (Swainson from Amazon and Parana Basins, Brazil (Mollusca, Bivalvia, Unionoida, Mycetopodidae

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    Luiz Ricardo L Simone

    1997-12-01

    Full Text Available The anatomy of Anodontiies elongatus (Swainson, 1823, a rare species restricted to the Amazon and Parana Basins, is described by first time, showing a group of conchological and anatomical characters exclusive of this species that may be analyzed to identify it. Diagnosis of A. elongatus: shell long antero-posteriorly, umbones prominent, periostracum opaque and smooth, two posterior radial striae; middle fold of mantle edge veiy tall; gill long antero-posteriorly and short dorso-ventrally, extending about a half of it total length beyond visceral mass; palps proportionally small, several furrows in its outer surface; stomach without esophageal transversal ridjp, dorsal hood and gastric shield poorly developed, major typhlosole entering in ddd , posterior pouch of sa³ very-long; style sac reduced, without crystalline style; distal region of intestine and rectum with a well developed typhlosole, "T" in section, other intestinal regions without folds; gonad gonochoristic.

  5. Reproductive biology of the Del Norte salamander (Plethodon elongatus).

    Science.gov (United States)

    Clara A. Wheeler; Hartwell H. Welsh Jr.; Lisa M. Ollivier

    2013-01-01

    We examined seasonal reproductive patterns of the Del Norte Salamander, Plethodon elongatus, in mixed conifer and hardwood forests of northwestern California and southwestern Oregon. Seasonal size differences in reproductive structures suggested that maximum spermatogenic activity occurred during the late summer, with spermatozoa transfer to the...

  6. studies on trace metal concentration pseudotolithus elongatus from ...

    African Journals Online (AJOL)

    DJFLEX

    ecological and human health implications of Lead (Pb) pollution are discussed. KEY WORDS: Trace metals, Lead Pollution, Pseudotolithus elongatus, Mbo coastal waters, Nigeria. INTRODUCTION. Anthropogenic activities which have taken place for the past two decades have greatly impacted on the marine ecosystem ...

  7. De weekdieren van de Nederlandse brakwatergebieden (Mollusca)

    NARCIS (Netherlands)

    Kuijper, W.J.

    2000-01-01

    The molluscs of the brackish waters in the Netherlands (Mollusca) The Netherlands is a river delta rich in brackish waters. The organisms in these waters need to be adapted to extreme conditions, especially large fluctuations in chlorinity. However, several species occur optimally in this habitat.

  8. De tweekleppigen van het Noordzeekanaal (Mollusca: Bivalvia).

    NARCIS (Netherlands)

    Haaren, van T.; Tempelman, D.

    2006-01-01

    The bivalves of the Noordzeekanaal (Mollusca: Bivalvia) In recent years, the macrobenthos of the Noordzeekanaal area, west of Amsterdam, has been surveyed intensively. The area consists of a main, brackish channel and a set of deep sea harbours. It was discovered that several bivalve species were

  9. Uptake of uranium from sea water by Synechococcus elongatus

    International Nuclear Information System (INIS)

    Horikoshi, Takao; Nakajima, Akira; Sakaguchi, Takashi

    1979-01-01

    Basic features of the uranium uptake by Synechococcus elongatus, and the factors affecting it were examined. Synechococcus elongatus was grown in Roux flasks containing 1 liter of culture solution in light (20,000 lux) and with aeration at 30 deg C. Synechococcus cells in the linear growth phase were collected by centrifugation at 6,000 x g for 5 minutes, washed with sea water, and used for the uranium-uptake experiments. The uptake of uranium from sea water containing 1 ppm of the element was strongly affected by the pH of sea water. The optimum uptake was at pH 5. Presence of carbonate ions markedly inhibited and decarbonation of sea water greatly enhanced the uptake. Absorption of uranium by Synechococcus cells was initially rapid, and reached a plateau within 24 hours. The uranium accumulation capacity of Synechococcus cells was increased by heat treatment, the capacity of scalded cells being about twice as much as that of living cells. Most of the uranium absorbed by Synechococcus was found in the inner space of the cells, and only a small amount was present in the cell walls. (Kaihara, S.)

  10. Biological Observations on the Mudskipper Pseudapocryptes elongatus in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Bucholtz, R. H.; Meilvang, A. S.; Cedhagen, Tomas

    2009-01-01

    Aspects of the population biology of the mudskipper, Pseudapocryptes elongatus, (Cuvier, 1816) were studied in Bac Lieu Province in the Lower Mekong Delta, Vietnam, including sex ratio, length–frequency distribution, sexual dimorphism, hepatosomatic index (HSI), female gonadosomatic index (GSI...

  11. Accumulation of cesium-137 by useful mollusca

    International Nuclear Information System (INIS)

    Suzuki, Yuzuru; Nakahara, Motokazu; Nakamura, Ryoichi

    1978-01-01

    There are few data available on the radioactive contamination of marine mollusca, especially cephalopoda. Therefore, in this paper, data obtained on the radioactive contamination of cephalopoda were compared with those on pelecypoda and gastropoda. The uptake and elimination experiments were carried out by means of radioisotope tracer methods, and the concentration factors of 137 Cs due to radioactive fallout were estimated. The contamination of cephalopoda was also compared with those of other marine organisms in terms of concentration factor. The activity ratios in the organs or tissues of octopus were in the range of 3.5 and 12.8 on the 14th day after the beginning of exposure and those of squid were in the range of 8.8 and 10.9 on the 6th day after the commencement of the experiment. The biological half time was 90 days for octopus from the observation over 75 days, while it was 31 days for clam from the results of 75 days' experiment. The concentration factors of 137 Cs due to radioactive fallout were in the range of 3 and 23 for cephalopoda, 7 and 28 for pelecypoda and 24 and 30 for gastropoda, respectively. It was concluded that no difference in the concentration factors was clearly observable among the classes of mollusca, but the values were substantially similar to those of crustaceans and slightly lower than those of marine fish. (auth.)

  12. First Record of Two Gobiid Fishes, Luciogobius elongatus, L. platycephalus (Perciformes: Gobiidae from Korea

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    Seung-Ho Choi

    2014-01-01

    Full Text Available Two species of small gobiid fishes genus Luciogobius, i.e., L. elongatus, L. platycephalus were described as the first records from Korea based on specimens collected from gravel beaches of Gijang-gun, Busan-si, Korea. Luciogobius elongatus is distinguished from congeners by very elongated and naked body, 42-44 vertebrae, 6-7 dorsal soft rays, and no free rays on pectoral fin, and L. platycephalus is characterized by having very depressed head, naked body, 40-41 vertebrae, 10-11 dorsal soft rays, and pectoral fin with only upper 2-4 free rays. We propose the new Korean name “Ga-neun-mi-kkeun-mang-dug”, “Nab-jak-mi-kkeunmang- dug” for L. elongatus and L. platycephalus, respectively.

  13. Development of a sperm cryopreservation protocol for redside dace, Clinostomus elongatus: implications for genome resource banking

    DEFF Research Database (Denmark)

    Butts, Ian A.E.; Mokdad, A.; Trippel, E.A.

    2013-01-01

    Populations of Redside Dace Clinostomus elongatus have declined in many areas across the species’North American range. Therefore, the development of sperm cryopreservation technology would provide an invaluable means of preserving genetic diversity in populations that are in imminent danger...

  14. Collapsing aged culture of the cyanobacterium Synechococcus elongatus produces compound(s toxic to photosynthetic organisms.

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    Assaf Cohen

    Full Text Available Phytoplankton mortality allows effective nutrient cycling, and thus plays a pivotal role in driving biogeochemical cycles. A growing body of literature demonstrates the involvement of regulated death programs in the abrupt collapse of phytoplankton populations, and particularly implicates processes that exhibit characteristics of metazoan programmed cell death. Here, we report that the cell-free, extracellular fluid (conditioned medium of a collapsing aged culture of the cyanobacterium Synechococcus elongatus is toxic to exponentially growing cells of this cyanobacterium, as well as to a large variety of photosynthetic organisms, but not to eubacteria. The toxic effect, which is light-dependent, involves oxidative stress, as suggested by damage alleviation by antioxidants, and the very high sensitivity of a catalase-mutant to the conditioned medium. At relatively high cell densities, S. elongatus cells survived the deleterious effect of conditioned medium in a process that required de novo protein synthesis. Application of conditioned medium from a collapsing culture caused severe pigment bleaching not only in S. elongatus cells, but also resulted in bleaching of pigments in a cell free extract. The latter observation indicates that the elicited damage is a direct effect that does not require an intact cell, and therefore, is mechanistically different from the metazoan-like programmed cell death described for phytoplankton. We suggest that S. elongatus in aged cultures are triggered to produce a toxic compound, and thus, this process may be envisaged as a novel regulated death program.

  15. The distribution of exocrine glands in Lepeophtheirus salmonis and Caligus elongatus (Copepoda: Caligidae)

    NARCIS (Netherlands)

    Bell, S.; Bron, J.E.; Sommerville, C.

    2000-01-01

    The morphology, function and distribution of exocrine glands of copepods have rarely been studied in detail and almost nothing is known about them in the sea lice species L. salmonis and C. elongatus. This study utilised a novel application of a light-microscopy staining technique to reveal a

  16. Bibliographie der Flussperlmuschel Margaritifera Margaritifera (Linnaeus, 1758) [Mollusca: Pelecypoda

    NARCIS (Netherlands)

    Jungbluth, J.H.; Coomans, H.E.; Grohs, H.

    1985-01-01

    Bibliography of the freshwater Pearlmussel Margaritifera margaritifera (Linnaeus, 1758) [Mollusca: Pelecypoda] The freshwater pearlmussel, described by Linnaeus as Mya margaritifera is one of the most important molluscs existing. It belongs with only a few congeneric fossil and recent species to the

  17. Coprorhexy, coprophagy, and coprochaly in the copepods Calanus helgolandicus, Pseudocalanus elongatus, and Oithona similis

    DEFF Research Database (Denmark)

    Iversen, Morten; Poulsen, Louise K.

    2007-01-01

    is mainly thought to be caused by coprophagy (ingestion of fecal pellets) by copepods, and especially by the ubiquitous copepods Oithona spp. We examined fecal pellet ingestion rate and feeding behavior of O. similis and 2 other dominant copepod species from the North Sea (Calanus helgolandicus...... and Pseudocalanus elongatus). All investigations were done with fecal pellets as the sole food source and with fecal pellets offered together with an alternative suitable food source. The ingestion of fecal pellets by all 3 copepod species was highest when offered together with an alternative food source....... No feeding behavior was determined for O. similis due to the lack of pellet capture in those experiments. Fecal pellets offered together with an alternative food source increased the filtration activity by C. helgolandicus and P. elongatus and thereby the number of pellets caught in their feeding current...

  18. Spatial Genetic Structure and Mitochondrial DNA Phylogeography of Argentinean Populations of the Grasshopper Dichroplus elongatus

    OpenAIRE

    Rosetti, Natalia; Remis, Maria Isabel

    2012-01-01

    Many grasshopper species are considered of agronomical importance because they cause damage to pastures and crops. Comprehension of pest population dynamics requires a clear understanding of the genetic diversity and spatial structure of populations. In this study we report on patterns of genetic variation in the South American grasshopper Dichroplus elongatus which is an agricultural pest of crops and forage grasses of great economic significance in Argentina. We use Direct Amplification of ...

  19. Direct Conversion of CO2to α-Farnesene Using Metabolically Engineered Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Lee, Hyun Jeong; Lee, Jiwon; Lee, Sun-Mi; Um, Youngsoon; Kim, Yunje; Sim, Sang Jun; Choi, Jong-Il; Woo, Han Min

    2017-12-06

    Direct conversion of carbon dioxide (CO 2 ) to value-added chemicals by engineering of cyanobacteria has received attention as a sustainable strategy in food and chemical industries. Herein, Synechococcus elongatus PCC 7942, a model cyanobacterium, was engineered to produce α-farnesene from CO 2 . As a result of the lack of farnesene synthase (FS) activity in the wild-type cyanobacterium, we metabolically engineered S. elongatus PCC 7942 to express heterologous FS from either Norway spruce or apple fruit, resulting in detectable peaks of α-farnesene. To enhance α-farnesene production, an optimized methylerythritol phosphate (MEP) pathway was introduced in the farnesene-producing strain to supply farnesyl diphosphate. Subsequent cyanobacterial culture with a dodecane overlay resulted in photosynthetic production of α-farnesene (4.6 ± 0.4 mg/L in 7 days) from CO 2 . To the best of our knowledge, this is the first report of the photosynthetic production of α-farnesene from CO 2 in the unicellular cyanobacterium S. elongatus PCC 7942.

  20. Transcriptome landscape of Synechococcus elongatus PCC 7942 for nitrogen starvation responses using RNA-seq

    Science.gov (United States)

    Choi, Sun Young; Park, Byeonghyeok; Choi, In-Geol; Sim, Sang Jun; Lee, Sun-Mi; Um, Youngsoon; Woo, Han Min

    2016-01-01

    The development of high-throughput technology using RNA-seq has allowed understanding of cellular mechanisms and regulations of bacterial transcription. In addition, transcriptome analysis with RNA-seq has been used to accelerate strain improvement through systems metabolic engineering. Synechococcus elongatus PCC 7942, a photosynthetic bacterium, has remarkable potential for biochemical and biofuel production due to photoautotrophic cell growth and direct CO2 conversion. Here, we performed a transcriptome analysis of S. elongatus PCC 7942 using RNA-seq to understand the changes of cellular metabolism and regulation for nitrogen starvation responses. As a result, differentially expressed genes (DEGs) were identified and functionally categorized. With mapping onto metabolic pathways, we probed transcriptional perturbation and regulation of carbon and nitrogen metabolisms relating to nitrogen starvation responses. Experimental evidence such as chlorophyll a and phycobilisome content and the measurement of CO2 uptake rate validated the transcriptome analysis. The analysis suggests that S. elongatus PCC 7942 reacts to nitrogen starvation by not only rearranging the cellular transport capacity involved in carbon and nitrogen assimilation pathways but also by reducing protein synthesis and photosynthesis activities. PMID:27488818

  1. Cross-amplification of heterologous microsatellite markers in Rhamdia quelen and Leporinus elongatus

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    Nelson Mauricio Lopera-Barrero

    2016-02-01

    Full Text Available Native fish species in Brazil are an asset in fish farming, but their natural stocks have been significantly reduced in recent years. To mitigate this negative impact, studies on fish conservation are being conducted and genetic tools for the discrimination of population parameters are increasingly achieving great importance. Current analysis evaluates a set of microsatellite heterologous primers in the jundiá (Rhamdia quelen and in the piapara (Leporinus elongatus. Samples from the caudal fin of 15 broodstock from each species were analyzed. DNA extraction was performed with NaCl protocol and the integrity of the extracted DNA was checked with agarose gel 1%. Twenty primers developed for Piaractus mesopotamicus, Colossoma macropomum, Prochilodus lineatus, Brycon opalinus and Oreochromis niloticus were evaluated. Cross amplification of four primers of the B. opalinus and P. lineatus species (BoM12, Pli43 and Pli60 in R. quelen and BoM2, Pli43 and Pli60 in L. elongatus was assessed. Primers of P. mesopotamicus, C. macropomum and O. niloticus showed no cross amplification in the two species analyzed. Results revealed the possibility of using the four amplified heterologous primers in genetic studies for R. quelen and L. elongatus.

  2. Bibliographie der Flussperlmuschel Margaritifera Margaritifera (Linnaeus, 1758) [Mollusca: Pelecypoda

    OpenAIRE

    Jungbluth, J.H.; Coomans, H.E.; Grohs, H.

    1985-01-01

    Bibliography of the freshwater Pearlmussel Margaritifera margaritifera (Linnaeus, 1758) [Mollusca: Pelecypoda] The freshwater pearlmussel, described by Linnaeus as Mya margaritifera is one of the most important molluscs existing. It belongs with only a few congeneric fossil and recent species to the distinct family Margaritiferidae. The distribution of the species is Holarctic (figs. 1-2), being known from western, northern and central Europe, and via Siberia to Japan. In North America it is ...

  3. A radioactivity study of mollusca distributed along the Syrian coast

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Ammar, I.; Mamish, S.; Haleem, M. A.

    2006-10-01

    In the present work, radioactivity has been studied in several Mollusca collected from four selected sites(Al Basset, Lattakia, Banise and Tartous) along the Syrian coast. Concentration Factors (CF) of radionuclides (Lead-210, Polonium-210, Uranium Isotopes, Potassium-40 and Cesium-137) in mussels and shells of Mollusca have been calculated in order to determine the species that could be used as Bioindicators for these isotopes. Statistical analysis of the results using the box plot method showed that the mussels of Spondylus spinosus and Chama pacifica can be used as biomonitor for the studied radionuclides in addition to shell of Strombus persicus and Spondylus spinosus. While the mussels of Brachidonta variabilis and Spondylus spinosus have shown good selectivity for Cd and Pb and Pinctada radiate for Zn and Thais haemostoma for Cu. In addition, the migrant Mullusca from the Red Sea, Strombus persicus, can be used as biomonitor for lead, Zn and Cu, Cd, while the shell of Thais haemostoma for lead. However, the importance of the results of the present study that are considered as a baseline data for radionuclides in Mullusca distributed along the Syria coast and it is the only study in the eastern Mediterranean basin, that defined the Mollusca species which could be use as biomonitors for radionuclides. (Authors)

  4. A radioactivity study of mollusca distributed along the Syrian coast

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Ammar, I.; Mamish, S.; Haleem, M. A.

    2008-01-01

    In the present work, radioactivity has been studied in several Mollusca collected from four selected sites (Al Basset, Latakia, Banise and Tartous) along the Syrian coast. Concentration Factors (CF) of radionuclides (Lead-210, Polonium-210, Uranium Isotopes, Potassium-40 and Cesium-137) in mussels and shells of Mollusca have been calculated in order to determine the species that could be used as Bioindicators for these isotopes. Statistical analysis of the results using the box plot method showed that the mussels of Spondylus gaederopus spinosus and Chama pacifica can be used as biomonitor for the studied radionuclides in addition to shell of Strombus decorus persicus and Spondylus gaederopus spinosus. While the mussels of Brachidonta variabilis and Spondylus gaederopus spinosus have shown good selectivity for Cd and Pb and Pinctada radiate for Zn and Thais haemostoma for Cu. In addition, the migrant Mullusca from the Red Sea, Strombus decoruspersicus, can be used as biomonitor for lead, Zn and Cu, Cd, while the shell of Thais haemostoma for lead. However, the importance of the results of the present study that are considered as a baseline data for radionuclides in Mullusca distributed along the Syria coast and it is the only study in the eastern Mediterranean basin, that defined the Mollusca species which could be use as biomonitors for radionuclides. (Authors)

  5. Blueprint for a minimal photoautotrophic cell: conserved and variable genes in Synechococcus elongatus PCC 7942

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    Peretó Juli

    2011-01-01

    Full Text Available Abstract Background Simpler biological systems should be easier to understand and to engineer towards pre-defined goals. One way to achieve biological simplicity is through genome minimization. Here we looked for genomic islands in the fresh water cyanobacteria Synechococcus elongatus PCC 7942 (genome size 2.7 Mb that could be used as targets for deletion. We also looked for conserved genes that might be essential for cell survival. Results By using a combination of methods we identified 170 xenologs, 136 ORFans and 1401 core genes in the genome of S. elongatus PCC 7942. These represent 6.5%, 5.2% and 53.6% of the annotated genes respectively. We considered that genes in genomic islands could be found if they showed a combination of: a unusual G+C content; b unusual phylogenetic similarity; and/or c a small number of the highly iterated palindrome 1 (HIP1 motif plus an unusual codon usage. The origin of the largest genomic island by horizontal gene transfer (HGT could be corroborated by lack of coverage among metagenomic sequences from a fresh water microbialite. Evidence is also presented that xenologous genes tend to cluster in operons. Interestingly, most genes coding for proteins with a diguanylate cyclase domain are predicted to be xenologs, suggesting a role for horizontal gene transfer in the evolution of Synechococcus sensory systems. Conclusions Our estimates of genomic islands in PCC 7942 are larger than those predicted by other published methods like SIGI-HMM. Our results set a guide to non-essential genes in S. elongatus PCC 7942 indicating a path towards the engineering of a model photoautotrophic bacterial cell.

  6. Biological observations on the mudskipper Pseudapocryptes elongatus in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Bucholtz, Rikke Hagstrøm; Meilvang, A. S.; Cedhagen, T.

    2009-01-01

    Aspects of the population biology of the mudskipper, Pseudapocryptes elongatus, (Cuvier, 1816) were studied in Bac Lieu Province in the Lower Mekong Delta, Vietnam, including sex ratio, length-frequency distribution, sexual dimorphism, hepatosomatic index (HSI), female gonadosomatic index (GSI......), gonad histology, fecundity and some observations on post-larvae and juveniles. In the population studied the sex ratio was skewed toward males. Females had a shorter mean length and a lower mean growth rate than males. No mature males or females were observed among mudskippers sampled in estuarine...

  7. Phenotypic Variation and Sexual Size Dimorphism in Dichroplus elongatus (Orthoptera: Acrididae).

    Science.gov (United States)

    Rosetti, N; Remis, M I

    2015-08-01

    Patterns of body size evolution are of particular interest because body size can affect virtually all the physiological and life history traits of an organism. Sexual size dimorphism (SSD), a difference in body size between males and females, is a widespread phenomenon in insects. Much of the variation in SSD is genetically based and likely due to differential selection acting on males and females. The importance of environmental variables and evolutionary processes affecting phenotypeic variation in both sexes may be useful to gain insights into insect ecology and evolution. Dichroplus elongatus Giglio-Tos is a South American grasshopper widely distributed throughout Argentina, Uruguay, most of Chile, and southern Brazil. In this study, we analyzed 122 adult females of D. elongatus collected in eight natural populations from central-east Argentina. Females show large body size variation among the analyzed populations and this variation exhibits a strong relationship with fecundity. Our results have shown that larger females were more fecund than smaller ones. We found that ovariole number varied along a latitudinal gradient, with higher ovariole numbers in populations from warmer locations. A considerable female-biased SSD was detected. SSD for three analyzed morphometric traits scaled isometrically. However, SSD for thorax length displayed a considerable variation across the studied area, indicating a larger relative increase in female size than in male size in warmer environmental conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Der Wert von Befestigungsanlagen für den Erhalt der Biodiversität am Beispiel der Schnecken (Mollusca: Gastropoda)

    NARCIS (Netherlands)

    Kobialka, H.; Kappes, H.

    2010-01-01

    Significance of fortifications for biodiversity conservation: The example of terrestrial gastropods (Mollusca: Gastropoda) Significance of fortifications for biodiversity conservation: The example of terrestrial gastropods (Mollusca: Gastropoda) The different microhabitats of the walls of historical

  9. The structure of allophycocyanin from Thermosynechococcus elongatus at 3.5 Å resolution

    Energy Technology Data Exchange (ETDEWEB)

    Murray, James William; Maghlaoui, Karim; Barber, James, E-mail: j.barber@imperial.ac.uk [Division of Molecular Biosciences, Imperial College, Exhibition Road, London SW7 2AZ (United Kingdom)

    2007-12-01

    The crystal structure of a light-harvesting protein that interacts with photosystem II is reported. Cyanobacteria and red algae use light-harvesting pigments bound by proteins to capture solar radiation and to channel excitation energy into their reaction centres. In most cyanobacteria, a multi-megadalton soluble structure known as the phycobilisome is a major light-harvesting system. Allophycocyanin is the main component of the phycobilisome core, forming a link between the rest of the phycobilisome and the reaction-centre core. The crystal structure of allophycocyanin from Thermosynechococcus elongatus (TeAPC) has been determined and refined at 3.5 Å resolution to a crystallographic R value of 26.0% (R{sub free} = 28.5%). The structure was solved by molecular replacement using the allophycocyanin structure from Spirulina platensis as the search model. The asymmetric unit contains an (αβ) monomer which is expanded by symmetry to a crystallographic trimer.

  10. Blind dating - mate finding in planktonic copepods. II. The pheromone cloud of Pseudocalanus elongatus

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Bagøien, E.; Thygesen, Uffe Høgsbro

    2005-01-01

    as an almost spherical cloud with a very heterogeneous internal structure. This is very different from the long, distinct pheromone trails deposited by females of many cruising copepods and appears to be characteristic of hovering females. We estimate the encounter cross-section area of the pheromone plume...... of P. elongatus and find that it enhances the mate encounter probability by a factor of about 40, and we show that this area increases in proportion to the rate at which pheromones are released. We also show that pheromone clouds are affected by—but still quite robust to—turbulence, with the encounter...... cross section declining with the turbulent dissipation rate raised to a power of 1/2. The sensitivity of mate encounter rates to turbulence is similar among copepods that produce pheromone trails and pheromone clouds....

  11. Spatial genetic structure and mitochondrial DNA phylogeography of Argentinean populations of the grasshopper Dichroplus elongatus.

    Science.gov (United States)

    Rosetti, Natalia; Remis, Maria Isabel

    2012-01-01

    Many grasshopper species are considered of agronomical importance because they cause damage to pastures and crops. Comprehension of pest population dynamics requires a clear understanding of the genetic diversity and spatial structure of populations. In this study we report on patterns of genetic variation in the South American grasshopper Dichroplus elongatus which is an agricultural pest of crops and forage grasses of great economic significance in Argentina. We use Direct Amplification of Minisatellite Regions (DAMD) and partial sequences of the cytochrome oxydase 1 (COI) mitochondrial gene to investigate intraspecific structure, demographic history and gene flow patterns in twenty Argentinean populations of this species belonging to different geographic and biogeographic regions. DAMD data suggest that, although genetic drift and migration occur within and between populations, measurable relatedness among neighbouring populations declines with distance and dispersal over distances greater than 200 km is not typical, whereas effective gene flow may occur for populations separated by less than 100 km. Landscape analysis was useful to detect genetic discontinuities associated with environmental heterogeneity reflecting the changing agroecosystem. The COI results indicate the existence of strong genetic differentiation between two groups of populations located at both margins of the Paraná River which became separated during climate oscillations of the Middle Pleistocene, suggesting a significant restriction in effective dispersion mediated by females and large scale geographic differentiation. The number of migrants between populations estimated through mitochondrial and DAMD markers suggest that gene flow is low prompting a non-homogeneous spatial structure and justifying the variation through space. Moreover, the genetic analysis of both markers allows us to conclude that males appear to disperse more than females, reducing the chance of the genetic loss

  12. Spatial genetic structure and mitochondrial DNA phylogeography of Argentinean populations of the grasshopper Dichroplus elongatus.

    Directory of Open Access Journals (Sweden)

    Natalia Rosetti

    Full Text Available Many grasshopper species are considered of agronomical importance because they cause damage to pastures and crops. Comprehension of pest population dynamics requires a clear understanding of the genetic diversity and spatial structure of populations. In this study we report on patterns of genetic variation in the South American grasshopper Dichroplus elongatus which is an agricultural pest of crops and forage grasses of great economic significance in Argentina. We use Direct Amplification of Minisatellite Regions (DAMD and partial sequences of the cytochrome oxydase 1 (COI mitochondrial gene to investigate intraspecific structure, demographic history and gene flow patterns in twenty Argentinean populations of this species belonging to different geographic and biogeographic regions. DAMD data suggest that, although genetic drift and migration occur within and between populations, measurable relatedness among neighbouring populations declines with distance and dispersal over distances greater than 200 km is not typical, whereas effective gene flow may occur for populations separated by less than 100 km. Landscape analysis was useful to detect genetic discontinuities associated with environmental heterogeneity reflecting the changing agroecosystem. The COI results indicate the existence of strong genetic differentiation between two groups of populations located at both margins of the Paraná River which became separated during climate oscillations of the Middle Pleistocene, suggesting a significant restriction in effective dispersion mediated by females and large scale geographic differentiation. The number of migrants between populations estimated through mitochondrial and DAMD markers suggest that gene flow is low prompting a non-homogeneous spatial structure and justifying the variation through space. Moreover, the genetic analysis of both markers allows us to conclude that males appear to disperse more than females, reducing the chance of the

  13. Single particle analysis of thylakoid proteins from Thermosynechococcus elongatus and Synechocystis 6803 : Localization of the CupA subunit of NDH-1

    NARCIS (Netherlands)

    Folea, I. Mihaela; Zhang, Pengpeng; Nowaczyk, Marc M.; Ogawa, Teruo; Aro, Eva-Marl; Boekema, Egbert J.; Aro, Eva-Mari

    The larger protein complexes of the cyanobacterial photosynthetic membrane of Thermosynechoccus elongatus and Synechocystis 6803 were studied by single particle electron microscopy after detergent solubilization, without any purification steps. Besides the "standard" L-shaped NDH-1L complex, related

  14. ParA-like protein influences the distribution of multi-copy chromosomes in cyanobacterium Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Watanabe, Satoru; Noda, Aska; Ohbayashi, Ryudo; Uchioke, Kana; Kurihara, Ami; Nakatake, Shizuka; Morioka, Sayumi; Kanesaki, Yu; Chibazakura, Taku; Yoshikawa, Hirofumi

    2018-01-01

    While many bacteria, such as Escherichia coli and Bacillus subtilis, harbour a single-copy chromosome, freshwater cyanobacteria have multiple copies of each chromosome per cell. Although it has been reported that multi-copy chromosomes are evenly distributed along the major axis of the cell in cyanobacterium Synechococcus elongatus PCC 7942, the distribution mechanism of these chromosomes remains unclear. In S. elongatus, the carboxysome, a metabolic microcompartment for carbon fixation that is distributed in a similar manner to the multi-copy chromosomes, is regulated by ParA-like protein (hereafter ParA). To elucidate the role of ParA in the distribution of multi-copy chromosomes, we constructed and analysed ParA disruptant and overexpressing strains of S. elongatus. Our fluorescence in situ hybridization assay revealed that the parA disruptants displayed an aberrant distribution of their multi-copy chromosomes. In the parA disruptant the multiple origin and terminus foci, corresponding to the intracellular position of each chromosomal region, were aggregated, which was compensated by the expression of exogenous ParA from other genomic loci. The parA disruptant is sensitive to UV-C compared to the WT strain. Additionally, giant cells appeared under ParA overexpression at the late stage of growth indicating that excess ParA indirectly inhibits cell division. Screening of the ParA-interacting proteins by yeast two-hybrid analysis revealed four candidates that are involved in DNA repair and cell membrane biogenesis. These results suggest that ParA is involved in the pleiotropic cellular functions with these proteins, while parA is dispensable for cell viability in S. elongatus.

  15. Digalactosyldiacylglycerol is essential in Synechococcus elongatus PCC 7942, but its function does not depend on its biosynthetic pathway.

    Science.gov (United States)

    Maida, Eri; Awai, Koichiro

    2016-09-01

    Digalactosyldiacylglycerol (DGDG) is a major component of thylakoid membranes, occupying approximately 20% of the membrane system. This lipid composition is conserved from cyanobacteria to the chloroplasts of terrestrial plants, suggesting that DGDG is important for the function of photosynthetic membranes. Here we isolated the gene for DGDG synthase in the cyanobacterium Synechococcus elongatus PCC 7942 (7942dgdA) and found that this gene is essential for this species. 7942dgdA could be knocked out only when genes for cyanobacterial or plant DGDG synthases were expressed, indicating that the important factor was not the specific synthetic pathway but the lipid product. Lack of DGDG could not be compensated by the other membrane lipids in S. elongatus PCC 7942 or by glucosylgalactosyldiacylglycerol synthesized by the β-GlcT gene of Chloroflexus aurantiacus. These results reveal that DGDG has an indispensable role in S. elongatus PCC 7942 and that the second galactose molecule is key. Conservation and distribution of the galactolipid synthetic pathway among oxygenic phototrophs is discussed. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Growth engineering of Synechococcus elongatus PCC 7942 for mixotrophy under natural light conditions for improved feedstock production.

    Science.gov (United States)

    Sarnaik, Aditya; Pandit, Reena; Lali, Arvind

    2017-09-01

    Synechococcus elongatus PCC 7942 has been widely explored as cyanobacterial cell factory through genetic modifications for production of various value-added compounds. However, successful industrial scale-ups have not been reported for the system predominantly due to its obligate photoautotrophic metabolism and use of artificial light in photobioreactors. Hence, engineering the organism to perform mixotrophy under natural light could serve as an effective solution. Thus, we applied a genetically engineered strain of Synechococcus elongatus PCC 7942 expressing heterologous hexose transporter gene (galP) to perform mixotrophy under natural light in a temperature controlled environmental chamber (EC). We systematically studied the comparative performances of these transformants using autotrophy and mixotrophy, which showed 3.4 times increase in biomass productivity of mixotrophically grown transformants over autotrophs in EC. Chlorophyll a yield was found to have decreased in mixotrophic conditions, possibly indicating reduced dependency on light for energy metabolism. Although pigment yield decreases under mixotrophy, titer was found to have improved due to increased biomass productivity. Carotenoid analysis showed that zeaxanthin is the major carotenoid produced by the species which is essential for photoprotection. Our work thus demonstrates that mixotrophy under temperature controlled natural light can serve as the viable solution to improve biomass productivity of Synechococcus elongatus PCC 7942 and for commercial production of natural or engineered value added compounds from the system. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1182-1192, 2017. © 2017 American Institute of Chemical Engineers.

  17. Using a Microfluidic Gradient Generator to Characterize BG-11 Medium for the Growth of Cyanobacteria Synechococcus elongatus PCC7942

    Directory of Open Access Journals (Sweden)

    Chih-Chun Yang

    2015-11-01

    Full Text Available The photosynthetic cyanobacterium Synechococcus elongatus PCC7942 has recently gained great attention for its ability to directly convert CO2 into renewable chemicals upon genetic engineering. Thus, it is of great interest to increase the growth speed and lower the medium requirement for cultivating this cyanobacterium. The cultivation medium of Synechococcus elongatus PCC7942 has been developed, which consists of many inorganic and metal ingredients with a specific composition, known as the BG-11 medium. In this work, we analyzed the concentration effect of each ingredient and identified the absolutely essential components in BG-11 medium for cyanobacteria growth using the concentration gradient generator chip (CGGC fabricated by MEMS technology. As shown by our results, removal of the individual component sodium nitrate, potassium phosphate, or magnesium sulfate from the BG-11 medium led to severe growth inhibition of Synechococcus elongatus PCC7942. Contrary to our expectation, increasing concentration of the crucial ingredients showed either insignificant or negative impact on cell growth. Overall, standard growth could be achieved without supplementation of ethylenediaminetetraacetic acid (EDTA disodium, sodium carbonate, or sodium citrate to the culture medium. Further improvement of the CGGC-based microfluidic system based on this preliminary study may broaden its application range to analyze more complicated correlations.

  18. Metabolic engineering of cyanobacteria for photosynthetic 3-hydroxypropionic acid production from CO2 using Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Lan, Ethan I; Chuang, Derrick S; Shen, Claire R; Lee, Annabel M; Ro, Soo Y; Liao, James C

    2015-09-01

    Photosynthetic conversion of CO2 to chemicals using cyanobacteria is an attractive approach for direct recycling of CO2 to useful products. 3-Hydroxypropionic acid (3 HP) is a valuable chemical for the synthesis of polymers and serves as a precursor to many other chemicals such as acrylic acid. 3 HP is naturally produced through glycerol metabolism. However, cyanobacteria do not possess pathways for synthesizing glycerol and converting glycerol to 3 HP. Furthermore, the latter pathway requires coenzyme B12, or an oxygen sensitive, coenzyme B12-independent enzyme. These characteristics present major challenges for production of 3 HP using cyanobacteria. To overcome such difficulties, we constructed two alternative pathways in Synechococcus elongatus PCC 7942: a malonyl-CoA dependent pathway and a β-alanine dependent pathway. Expression of the malonyl-CoA dependent pathway genes (malonyl-CoA reductase and malonate semialdehyde reductase) enabled S. elongatus to synthesize 3 HP to a final titer of 665 mg/L. β-Alanine dependent pathway expressing S. elongatus produced 3H P to final titer of 186 mg/L. These results demonstrated the feasibility of converting CO2 into 3 HP using cyanobacteria. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  19. Diversidade genética de três estoques de piapara (Leporinus elongatus, utilizando RAPD = Genetic diversity of three stocks of piapara (Leporinus elongatus, using RAPD

    Directory of Open Access Journals (Sweden)

    Patrícia Cristina Gomes

    2008-04-01

    Full Text Available Recentemente a produção aquícola brasileira tem apresentado grandeprogresso. Dentre as espécies nativas cultivadas no Brasil, a piapara (Leporinus elongatus tem sido amplamente preconizada. Com objetivo de avaliar os programas de repovoamento, foram analisadas a variabilidade e a divergência genética de três estoques de piapara com a técnica de RAPD (Random Amplified Polymorphic. O primeiro estoque pertence à Estação de Aquicultura e Hidrologia da Duke Energy International (A; o segundo, à piscicultura de Rolândia (B e o terceiro, ao Programa de Repovoamento dos Rios do Paraná (C. Os dezprimers para RAPD utilizados produziram 105 fragmentos polimórficos, conferindo um polimorfismo de 98,1% para os três estoques avaliados. A porcentagem de locos polimórficos e índice de Shannon foi superior para o estoque A. Porém, todos valores foram elevados, indicando alta diversidade intrapopulacional. Os valores de Gst indicam que houvebaixa diferenciação genética entre os estoques A x B e moderada diferenciação entre os demais. O Nm foi maior entre os estoques A x B. A distância genética e o dendrograma indicam que os estoques A x B são menos distantes geneticamente.Latelly, aquiculture production in Brazil has made great strides. Among the native species cultivated in Brazil, piapara (Leporinus elogatus has been widely praised. With the objective of evaluating restocking programs, the variability and genetic divergence ofthree piapara stocks were analyzed using the RAPD (Random Amplified Polymorphic DNA technique. The first stock belongs to the Aquiculture and Hydrology Station of Duke Energy International (A; the second one belongs to a fish farm in the city of Rolândia(B; and the third to the River Restocking Program of Paraná (C. The ten primers used for RAPD produced 105 polymorphic loci, conferring a polymorphism of 98.1% for the three evaluated stocks. Polymorphic loci percentage and Shannon index were higher for stock A

  20. CRISPR/Cas9 mediated targeted mutagenesis of the fast growing cyanobacterium Synechococcus elongatus UTEX 2973.

    Science.gov (United States)

    Wendt, Kristen E; Ungerer, Justin; Cobb, Ryan E; Zhao, Huimin; Pakrasi, Himadri B

    2016-06-23

    As autotrophic prokaryotes, cyanobacteria are ideal chassis organisms for sustainable production of various useful compounds. The newly characterized cyanobacterium Synechococcus elongatus UTEX 2973 is a promising candidate for serving as a microbial cell factory because of its unusually rapid growth rate. Here, we seek to develop a genetic toolkit that enables extensive genomic engineering of Synechococcus 2973 by implementing a CRISPR/Cas9 editing system. We targeted the nblA gene because of its important role in biological response to nitrogen deprivation conditions. First, we determined that the Streptococcus pyogenes Cas9 enzyme is toxic in cyanobacteria, and conjugational transfer of stable, replicating constructs containing the cas9 gene resulted in lethality. However, after switching to a vector that permitted transient expression of the cas9 gene, we achieved markerless editing in 100 % of cyanobacterial exconjugants after the first patch. Moreover, we could readily cure the organisms of antibiotic resistance, resulting in a markerless deletion strain. High expression levels of the Cas9 protein in Synechococcus 2973 appear to be toxic and result in cell death. However, introduction of a CRISPR/Cas9 genome editing system on a plasmid backbone that leads to transient cas9 expression allowed for efficient markerless genome editing in a wild type genetic background.

  1. The stringent response regulates adaptation to darkness in the cyanobacterium Synechococcus elongatus.

    Science.gov (United States)

    Hood, Rachel D; Higgins, Sean A; Flamholz, Avi; Nichols, Robert J; Savage, David F

    2016-08-16

    The cyanobacterium Synechococcus elongatus relies upon photosynthesis to drive metabolism and growth. During darkness, Synechococcus stops growing, derives energy from its glycogen stores, and greatly decreases rates of macromolecular synthesis via unknown mechanisms. Here, we show that the stringent response, a stress response pathway whose genes are conserved across bacteria and plant plastids, contributes to this dark adaptation. Levels of the stringent response alarmone guanosine 3'-diphosphate 5'-diphosphate (ppGpp) rise after a shift from light to dark, indicating that darkness triggers the same response in cyanobacteria as starvation in heterotrophic bacteria. High levels of ppGpp are sufficient to stop growth and dramatically alter many aspects of cellular physiology, including levels of photosynthetic pigments and polyphosphate, DNA content, and the rate of translation. Cells unable to synthesize ppGpp display pronounced growth defects after exposure to darkness. The stringent response regulates expression of a number of genes in Synechococcus, including ribosomal hibernation promoting factor (hpf), which causes ribosomes to dimerize in the dark and may contribute to decreased translation. Although the metabolism of Synechococcus differentiates it from other model bacterial systems, the logic of the stringent response remains remarkably conserved, while at the same time having adapted to the unique stresses of the photosynthetic lifestyle.

  2. Morphology, chemistry and function of the postpharyngeal gland in the South American digger wasps Trachypus boharti and Trachypus elongatus.

    Directory of Open Access Journals (Sweden)

    Gudrun Herzner

    Full Text Available Microbes pose severe threats to animals as competitors or pathogens and strongly affect the evolution of life history traits like parental care. Females of the European beewolf Philanthus triangulum, a solitary digger wasp, provision their offspring with paralyzed honeybees and embalm them with the secretion from large postpharyngeal glands (PPG that contain mainly unsaturated hydrocarbons. This coating changes the physico-chemical properties of the prey surface, causes a reduction of water condensation and retards growth of mold fungi. Here we examined the closely related South American genus Trachypus, which shows a life-history similar to Philanthus. We investigated whether Trachypus spp. also possess PPGs and embalm larval provisions. Using histological methods and 3D reconstructions we show that Trachypus boharti and T. elongatus possess PPGs that are similar to P. triangulum but somewhat smaller. The ultrastructure of the gland epithelium suggests that the gland content is at least partly sequestered from the hemolymph. Chemical analyses using gas chromatography / mass spectrometry revealed that both the cuticle and PPGs of Trachypus contain mainly unsaturated long-chain hydrocarbons. The gland of T. boharti additionally contains long-chain ketones. The hydrocarbons from the PPG of T. elongatus occurred on prey bees excavated from nests in the field but not on conspecific control bees. While the embalming only slightly elevated the amount of hydrocarbons on prey bees, the proportion of unsaturated hydrocarbons, which is crucial for the antifungal effect, was significantly increased. The Trachypus species under study possess PPGs that are very similar to the PPG of P. triangulum with regard to morphology, ultrastructure and chemistry. Moreover, we provide clear evidence that T. elongatus females embalm their prey, presumably as a means of prey preservation. The observed differences among Trachypus and Philanthus in gland size and prey

  3. Morphology, Chemistry and Function of the Postpharyngeal Gland in the South American Digger Wasps Trachypus boharti and Trachypus elongatus

    Science.gov (United States)

    Herzner, Gudrun; Kaltenpoth, Martin; Poettinger, Theodor; Weiss, Katharina; Koedam, Dirk; Kroiss, Johannes; Strohm, Erhard

    2013-01-01

    Microbes pose severe threats to animals as competitors or pathogens and strongly affect the evolution of life history traits like parental care. Females of the European beewolf Philanthus triangulum, a solitary digger wasp, provision their offspring with paralyzed honeybees and embalm them with the secretion from large postpharyngeal glands (PPG) that contain mainly unsaturated hydrocarbons. This coating changes the physico-chemical properties of the prey surface, causes a reduction of water condensation and retards growth of mold fungi. Here we examined the closely related South American genus Trachypus, which shows a life-history similar to Philanthus. We investigated whether Trachypus spp. also possess PPGs and embalm larval provisions. Using histological methods and 3D reconstructions we show that Trachypus boharti and T. elongatus possess PPGs that are similar to P. triangulum but somewhat smaller. The ultrastructure of the gland epithelium suggests that the gland content is at least partly sequestered from the hemolymph. Chemical analyses using gas chromatography / mass spectrometry revealed that both the cuticle and PPGs of Trachypus contain mainly unsaturated long-chain hydrocarbons. The gland of T. boharti additionally contains long-chain ketones. The hydrocarbons from the PPG of T. elongatus occurred on prey bees excavated from nests in the field but not on conspecific control bees. While the embalming only slightly elevated the amount of hydrocarbons on prey bees, the proportion of unsaturated hydrocarbons, which is crucial for the antifungal effect, was significantly increased. The Trachypus species under study possess PPGs that are very similar to the PPG of P. triangulum with regard to morphology, ultrastructure and chemistry. Moreover, we provide clear evidence that T. elongatus females embalm their prey, presumably as a means of prey preservation. The observed differences among Trachypus and Philanthus in gland size and prey embalming may have

  4. CRISPR interference (CRISPRi) for gene regulation and succinate production in cyanobacterium S. elongatus PCC 7942.

    Science.gov (United States)

    Huang, Chun-Hung; Shen, Claire R; Li, Hung; Sung, Li-Yu; Wu, Meng-Ying; Hu, Yu-Chen

    2016-11-15

    Cyanobacterium Synechococcus elongatus PCC 7942 holds promise for biochemical conversion, but gene deletion in PCC 7942 is time-consuming and may be lethal to cells. CRISPR interference (CRISPRi) is an emerging technology that exploits the catalytically inactive Cas9 (dCas9) and single guide RNA (sgRNA) to repress sequence-specific genes without the need of gene knockout, and is repurposed to rewire metabolic networks in various procaryotic cells. To employ CRISPRi for the manipulation of gene network in PCC 7942, we integrated the cassettes expressing enhanced yellow fluorescent protein (EYFP), dCas9 and sgRNA targeting different regions on eyfp into the PCC 7942 chromosome. Co-expression of dCas9 and sgRNA conferred effective and stable suppression of EYFP production at efficiencies exceeding 99%, without impairing cell growth. We next integrated the dCas9 and sgRNA targeting endogenous genes essential for glycogen accumulation (glgc) and succinate conversion to fumarate (sdhA and sdhB). Transcription levels of glgc, sdhA and sdhB were effectively suppressed with efficiencies depending on the sgRNA binding site. Targeted suppression of glgc reduced the expression to 6.2%, attenuated the glycogen accumulation to 4.8% and significantly enhanced the succinate titer. Targeting sdhA or sdhB also effectively downregulated the gene expression and enhanced the succinate titer ≈12.5-fold to ≈0.58-0.63 mg/L. These data demonstrated that CRISPRi-mediated gene suppression allowed for re-directing the cellular carbon flow, thus paving a new avenue to rationally fine-tune the metabolic pathways in PCC 7942 for the production of biotechnological products.

  5. The potential of Synechococcus elongatus UTEX 2973 for sugar feedstock production.

    Science.gov (United States)

    Song, Kuo; Tan, Xiaoming; Liang, Yajing; Lu, Xuefeng

    2016-09-01

    It is important to obtain abundant sugar feedstocks economically and sustainably for bio-fermentation industry, especially for producing cheap biofuels and biochemicals. Besides plant biomass, photosynthetic cyanobacteria have also been considered to be potential microbe candidates for sustainable production of carbohydrate feedstocks. As the fastest growing cyanobacterium reported so far, Synechococcus elongatus UTEX 2973 (Syn2973) might have huge potential for bioproduction. In this study, we explored the potentials of this strain as photo-bioreactors for sucrose and glycogen production. Under nitrogen-replete condition, Syn2973 could accumulate glycogen with a rate of 0.75 g L(-1) day(-1) at the exponential phase and reach a glycogen content as high as 51 % of the dry cell weight (DCW) at the stationary phase. By introducing a sucrose transporter CscB, Syn2973 was endowed with an ability to secrete over 94 % sucrose out of cells under salt stress condition. The highest extracellular sucrose productivity reached 35.5 mg L(-1) h(-1) for the Syn2973 strain expressing cscB, which contained the similar amounts of intracellular glycogen with the wild type. Potassium chloride was firstly proved to induce sucrose accumulation as well as sodium chloride in Syn2973. By semi-continuous culturing, 8.7 g L(-1) sucrose was produced by the cscB-expressing strain of Syn2973 in 21 days. These results support that Syn2973 is a promising candidate with great potential for production of sugars.

  6. Comparative genomics of vesicomyid clam (Bivalvia: Mollusca chemosynthetic symbionts

    Directory of Open Access Journals (Sweden)

    Girguis Peter R

    2008-12-01

    Full Text Available Abstract Background The Vesicomyidae (Bivalvia: Mollusca are a family of clams that form symbioses with chemosynthetic gamma-proteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a reduced gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. Recently, two vesicomyid symbiont genomes were sequenced, illuminating the possible nutritional contributions of the symbiont to the host and making genome-wide evolutionary analyses possible. Results To examine the genomic evolution of the vesicomyid symbionts, a comparative genomics framework, including the existing genomic data combined with heterologous microarray hybridization results, was used to analyze conserved gene content in four vesicomyid symbiont genomes. These four symbionts were chosen to include a broad phylogenetic sampling of the vesicomyid symbionts and represent distinct chemosynthetic environments: cold seeps and hydrothermal vents. Conclusion The results of this comparative genomics analysis emphasize the importance of the symbionts' chemoautotrophic metabolism within their hosts. The fact that these symbionts appear to be metabolically capable autotrophs underscores the extent to which the host depends on them for nutrition and reveals the key to invertebrate colonization of these challenging environments.

  7. Preliminary Data of the Shell Morphometry of Populations of Zebrina detrita (Mollusca: Gastropoda: Pulmonata from Bulgaria

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    Antonia Z. Gospodinova

    2015-12-01

    Full Text Available Six populations of Zebrina detrita Müller, 1774 (Mollusca: Gastropoda: Pulmonata occuring in different habitats, regions and altitude were studied by shell morphology. The width and height of the shell and its aperture were measured, and also the last whorl height. Their proportions were calculated. Some differences in the shell size were registered in populations situated at different altitude.

  8. First occurrence of the Kentish Snail Monacha cantiana (Mollusca: Gastropoda: Hygromiidae) in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Hlaváč, Jaroslav; Peltanová, A.

    2010-01-01

    Roč. 9, - (2010), s. 11-15 ISSN 1336-6939 Institutional research plan: CEZ:AV0Z30130516 Keywords : Monacha cantiana * Hygromiidae * first record * distribution Subject RIV: EG - Zoology http://mollusca.sav.sk/pdf/9/9.Hlavac-Peltanova.pdf

  9. A numerical investigation of phytoplankton and Pseudocalanus elongatus dynamics in the spring bloom time in the Gdańsk Gulf

    Science.gov (United States)

    Dzierzbicka-Głowacka, Lidia

    2005-01-01

    A nutrient-phytoplankton-zooplankton-detritus (1D-NPZD) `phytoplankton {Phyt} and Pseudocalanus elongatus {Zoop} dynamics in the spring bloom time in the Gdańsk Gulf. The 1D-NPZD model consists of three coupled, partial second-order differential equations of the diffusion type for phytoplankton {Phyt}, zooplankton {Zoop}, nutrients {Nutr} and one ordinary first-order differential equation for benthic detritus pool {Detr}, together with initial and boundary conditions. In this model, the {Zoop} is presented by only one species of copepod ( P. elongatus) and {Zoop} is composed of six cohorts of copepods with weights ( Wi) and numbers ( Zi); where Zoop= limit∑i=16W iZ i. The calculations were made for 90 days (March, April, May) for two stations at Gdańsk Gulf with a vertical space step of 0.5m and a time step of 900 s. The flow field and water temperature used as the inputs in the biological model 1D-NPZD were reproduced by the prognostic numerical simulation technique using hydrographic climatological data. The results of the numerical investigations described here were compared with the mean observed values of surface chlorophyll- a and depth integrated P. elongatus biomass for 10 years, 1980-1990. The slight differences between the calculated and mean observed values of surface chlorophyll- a and zooplankton biomass are ca. 10-60 mg C m -3 and ca. 5-23 mg C m -2, respectively, depending on the location of the hydrographic station. The 1D-NPZD model with a high-resolution zooplankton module for P. elongatus can be used to describe the temporal patterns for phytoplankton biomass and P. elongatus in the centre of the Gdańsk Gulf.

  10. Effect of the ration processing on the apparent digestibility values of nutrients for the piau (Leporinus elongatus Efeito do tipo de ração sobre a digestibilidade aparente dos nutrientes para piau (Leporinus elongatus

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    Priscila Vieira Rosa Logato

    2009-06-01

    Full Text Available The experiment carried out at National Center for Research in Tropical Fish Pirassununga, SP, aiming to determine the effect of the ration processing on the apparent digestibility coefficients of the ingredients for the piau (L. elongatus. A total of 600 males of piau were utilized, allotted into six ponds of 300L. The applied treatments were: grinder processed ration, pelleting ration and extruded ration, utilizing rations with 32% crude protein and 3400 Kcal DE.Kg-1. The experiment was in a randomized blocks design with three treatments, three blocks and two replicates. The data were submitted to variance analysis by the SAEG computational package and the means of the treatments compared by SNK test (5% of significance. The results showed that there were significant differences among the digestibility coefficients of both protein and energy for the pelleted and extrused rations (P0.05.O experimento foi realizado no Centro Nacional de Pesquisa de Peixes Tropicais de Pirassununga, SP, objetivando-se determinar o efeito do processamento da ração sobre os coeficientes de digestibilidade aparente dos ingredientes para o piau (L. elongatus. Foram utilizados 600 machos de piau, distribuídos em seis tanques de 300 L. Os tratamentos aplicados foram: ração farelada, ração peletizada e ração extrusada, formuladas com 32% de PB e 3400 Kcal ED/Kg. O delineamento experimental foi em blocos casualizados, com três tratamentos, três blocos e duas repetições por tratamento. As análises estatísticas foram realizadas pelo SAEG, com as médias comparadas pelo teste SNK (5%. Houve diferenças entre os coeficientes de digestibilidade da proteína bruta e energia para as rações peletizada e extusada (P0,05.

  11. Land snails (Mollusca: Gastropoda of India: status, threats and conservation strategies

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    S. Sen

    2012-09-01

    Full Text Available Land snails form an important component in the forest ecosystem. In terms of number of species, the phylum Mollusca, to which land snails belong, is the largest phylum after Arthropoda. Mollusca provide unique ecosystem services including recycling of nutrients and they provide a prey base for small mammals, birds, snakes and other reptiles. However, land snails have the largest number of documented extinctions, compared to any other taxa. Till date 1,129 species of land snails are recorded from Indian territory. But only basic information is known about their taxonomy and little is known of their population biology, ecology and their conservation status. In this paper, we briefly review status, threats and conservation strategies of land snails of India.

  12. Bioactive substances with anti-neoplastic efficacy from marine invertebrates: Bryozoa, Mollusca, Echinodermata and Urochordata

    Science.gov (United States)

    Sima, Peter; Vetvicka, Vaclav

    2011-01-01

    The marine environment provides a rich source of natural products with potential therapeutic application. This has resulted in an increased rate of pharmaceutical agents being discovered in marine animals, particularly invertebrates. Our objective is to summarize the most promising compounds which have the best potential and may lead to use in clinical practice, show their biological activities and highlight the compounds currently being tested in clinical trials. In this paper, we focused on Bryozoa, Mollusca, Echinodermata and Urochordata. PMID:22087434

  13. Rational ‘correction’ of the amino-acid sequence of RbcX protein from the thermophilic cyanobacterium Thermosynechococcus elongatus dramatically improves crystallization

    International Nuclear Information System (INIS)

    Tarnawski, Miroslaw; Krzywda, Szymon; Szczepaniak, Andrzej; Jaskolski, Mariusz

    2008-01-01

    Recombinant RuBisCO chaperone from T. elongatus, TeRbcX, was aggregated and could not be crystallized. Mutations of an unusual Cys residue in the TeRbcX sequence yielded much better behaved proteins that could rapidly be crystallized. RbcX is a dimeric protein found in cyanobacteria that assists in the assembly of the oligomeric RuBisCO complex. RbcX from the thermophile Thermosynechococcus elongatus (TeRbcX) contains an unusual Cys103 residue in its sequence and when expressed recombinantly the protein aggregates and cannot be crystallized. Site-directed mutagenesis of Cys103 to either Arg or Ala produced non-aggregating proteins that could be readily crystallized in several crystal forms. Synchrotron-radiation X-ray diffraction data were collected to 1.96 Å resolution and formed the basis of crystal structure analysis of TeRbcX

  14. Identification of small droplets of photosynthetic squalene in engineered Synechococcus elongatus PCC 7942 using TEM and selective fluorescent Nile red analysis.

    Science.gov (United States)

    Choi, Sun Young; Sim, Sang Jun; Choi, Jong-Il; Woo, Han Min

    2018-03-12

    To identify microbial squalene that has been widely used in various industrial applications, intracellular formation of photosynthetic squalene was investigated using the previously engineered Synechococcus elongatus PCC 7942 strain. Unlike the proposed localization of squalene in the membrane bilayer, small droplets were identified in the cytoplasm of S. elongatus PCC 7942 as squalene using transmission electron microscopy analysis. Determination of the diameters of the squalene droplets with manual examination of 1,016 droplets in different squalene-producing strains indicated larger squalene droplets in larger cells. Based on the observation of a sole droplet of squalene in a cyanobacterium, fluorescent Nile red was used for the selective staining of squalene. The fluorescent intensities were correlated with squalene contents determined using gas chromatography-mass spectrometry. Photosynthetic squalene was identified as a small droplet in S. elongatus PCC 7942 and this non-invasive quantitative method could be useful to promote high-throughput strain development for squalene production. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  15. Distribución del género Diplodon (Mollusca: Bivalvia: Hyriidae en territorio Argentino mediante el uso de Colecciones Biológicas

    Directory of Open Access Journals (Sweden)

    Santiago Hernán Torres

    2013-10-01

    Full Text Available Los bivalvos nacaríferos dulciacuícolas (“náyades”, son especies infaunales, endémicas de la RegiónNeotropical, pertenecientes a las familias Hyriidae (Swaison, 1840 y Etheriidae (Swaison, 1840. La alteración del ambiente y la competencia con especies invasoras como Corbicula fluminea (Müller, 1774 y Limnoperna fortunei (Dunker, 1857, impactan sobre las poblaciones naturales. En esta comunicación, se presenta el inicio de un Proyecto de investigación sobre la distribución geográfica de las especies del género Diplodon en la Argentina. Estas especies son un componente importante de la infauna de los cuerpos lóticos y lénticos, viviendo en fondos limosos, limo-arenosos, excepcionalmente en sustratos duros, con un régimen nutricio filtrador, teniendo un papel importante como recicladores de materia orgánica. Conocer la distribución de los bivalvos pertenecientes al género Diplodon en el territorio Argentino permitirá el reconocimiento de potenciales áreas prioritarias para su conservación. Sobre la base de la bibliografía disponible y los ejemplares de las especies del genero Diplodon depositados en la Colección Malacológica del Museo de La Plata (FCNyM-UNLP, se confeccionó una matriz de datos que incluye la identificación del ejemplar, la colección en que se encuentra depositado, el número de catálogo, la localidad y la fecha de colecta. Cada localidad fue ubicada mediante el uso de cartas geográficas de Argentina y revisiones bibliográficas en imágenes satelitales de GoogleEarth, asignando las coordenadas para cada punto. Como resultado del trabajo se obtiene la distribución de estas especies nativas y se discute el grado de solapamiento con las dos especies de bivalvos invasores y el impacto de actividades humanas. 

  16. The mitochondrial genome of the sipunculid Phascolopsis gouldii supports its association with Annelida rather than Mollusca

    Energy Technology Data Exchange (ETDEWEB)

    Boore, Jeffrey L.; Staton, Joseph

    2001-09-01

    We have determined the sequence of about half (7470 nts) of the mitochondrial genome of the sipunculid Phascolopsis gouldii, the first representative of this phylum to be so studied. All of the 19 identified genes are transcribed from the same DNA strand. The arrangement of these genes is remarkably similar to that of the oligochaete annelid Lumbricus terrestris. Comparison of both the inferred amino acid sequences and the gene arrangements of a variety of diverse metazoan taxa reveals that the phylum Sipuncula is more closely related to Annelida than to Mollusca. This requires reinterpretation of the homology of several embryological features and of patterns of animal body plan evolution.

  17. Fine structure of the creeping larva of Loxosomella murmanica: additional evidence for a clade of Kamptozoa (Entoprocta) and Mollusca

    DEFF Research Database (Denmark)

    Haszprunar, Gerhard; Wanninger, Andreas Wilhelm Georg

    2008-01-01

    intercrossing. The present results and previous findings, in particular the chitinous, non-moulted cuticle, the sinus circulatory system, and a number of neural features shared by Kamptozoa and Mollusca, provide substantial evidence for a direct sister-group relationship between these phyla. In addition...

  18. Cenozoic Molluscan types from Java (Indonesia) in the Martin Collection (Division of Cenozoic Mollusca), National Museum of Natural History, Leiden

    NARCIS (Netherlands)

    Hoek Ostende, van den L.W.; Leloux, J.; Wesselingh, F.P.; Winkler Prins, C.F.

    2002-01-01

    An inventory of type material in the ‘Martin Collection’ at the Division of Cenozoic Mollusca of the National Museum of Natural History, Leiden, The Netherlands has been made. In total 1842 lots containing over 5700 type specimens of 912 species were encountered. The status of the types is outlined.

  19. Crystal structure at 1.5Å resolution of the PsbV2 cytochrome from the cyanobacterium Thermosynechococcus elongatus.

    Science.gov (United States)

    Suga, Michihiro; Lai, Thanh-Lan; Sugiura, Miwa; Shen, Jian-Ren; Boussac, Alain

    2013-10-01

    PsbV2 is a c-type cytochrome present in a very low abundance in the thermophilic cyanobacterium Thermosynechococcus elongatus. We purified this cytochrome and solved its crystal structure at a resolution of 1.5Å. The protein existed as a dimer in the crystal, and has an overall structure similar to other c-type cytochromes like Cytc6 and Cytc550, for example. However, the 5th and 6th heme iron axial ligands were found to be His51 and Cys101, respectively, in contrast to the more common bis-His or His/Met ligands found in most cytochromes. Although a few other c-type cytochromes were suggested to have this axial coordination, this is the first crystal structure reported for a c-type heme with this unusual His/Cys axial coordination. Previous spectroscopic characterizations of PsbV2 are discussed in relation to its structural properties. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  20. In vivo features of signal transduction by the essential response regulator RpaB from Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Moronta-Barrios, Félix; Espinosa, Javier; Contreras, Asunción

    2012-05-01

    The NblS-RpaB signalling pathway, the most conserved two-component system in cyanobacteria, regulates photosynthesis and acclimatization to a variety of environmental conditions and is involved in negative regulation of high-light-induced genes. However, relevant regulatory details of the NblS-RpaB signalling pathway remain to be elucidated. We recently showed that the response regulator RpaB is regulated by specific (de)phosphorylation from the histidine kinase NblS and that RpaB and its phosphorylatable residue Asp56 are both required for viability of Synechococcus elongatus PCC 7942. We show here that the phosphorylated form of RpaB is present in cells growing under standard laboratory conditions and that high light stress affected the ratio of phosphorylated to non-phosphorylated RpaB. It also decreased the amount of rpaB transcripts without appreciably changing the total levels of RpaB. Quantitative Western blotting and confocal microscopy analyses were consistent with RpaB being a very abundant regulator, with nucleoid localization. A genetically engineered RpaB-GFP (green fluorescent protein) fusion protein rescued lethality of the rpaB null mutant, indicating that it was functional. This is, to our knowledge, the first study demonstrating in a cyanobacterium, and for a two-component response regulator, that the in vivo ratio of phosphorylated to non-phosphorylated protein changes in response to environmental conditions.

  1. ppGpp Controls Global Gene Expression in Light and in Darkness in S. elongatus

    Directory of Open Access Journals (Sweden)

    Anna M. Puszynska

    2017-12-01

    Full Text Available The bacterial and plant stringent response involves production of the signaling molecules guanosine tetraphosphate and guanosine pentaphosphate ((pppGpp, leading to global reorganization of gene expression. The function of the stringent response has been well characterized in stress conditions, but its regulatory role during unstressed growth is less studied. Here, we demonstrate that (pppGpp-deficient strains of S. elongatus have globally deregulated biosynthetic capacity, with increased transcription rate, translation rate, and cell size in unstressed conditions in light and impaired viability in darkness. Synthetic restoration of basal guanosine tetraphosphate (ppGpp levels is sufficient to recover transcriptional balance and appropriate cell size in light and to rescue viability in light/dark conditions, but it is insufficient to enable efficient dark-induced transcriptional shutdown. Our work underscores the importance of basal ppGpp signaling for regulation of cyanobacterial physiology in the absence of stress and for viability in energy-limiting conditions, highlighting that basal (pppGpp level is essential in cyanobacteria in the environmental light/dark cycle.

  2. Delignification and detoxification of peanut shell bio-waste using an extremely halophilic laccase from an Aquisalibacillus elongatus isolate.

    Science.gov (United States)

    Rezaie, Rezvan; Rezaei, Shahla; Jafari, Nasrin; Forootanfar, Hamid; Khoshayand, Mohammad Reza; Faramarzi, Mohammad Ali

    2017-11-01

    Lignocellulose bioconversion is a harsh process requiring the use of surfactants and organic solvents. Consequently, the incorporation of laccases in this bioconversion requires the bioprospecting of enzymes that can remain stable under extreme conditions. An extracellular, highly stable laccase was produced by the halophilic isolate Aquisalibacillus elongatus in submerged liquid culture fermentation. Statistical and non-statistical strategies gave the highest enzymatic activity (8.02 U mL -1 ) following addition of glucose (1.7 g L -1 ), copper sulfate (0.8 g L -1 ), urea (15 g L -1 ), and CaCl 2 (0.8 g L -1 ). The enzyme, after purification using a synthetic affinity support, delignified a peanut shell substrate by 45%. A pH of 8.0 and a temperature of 35 °C were optimal for delignification of this bio-waste material. Addition of [Bmim][PF 6 ], 1,4-dioxane, acetone, and HBT promoted this bio-waste delignification. Bio-treatment in the presence of 50% [Bmim][PF 6 ] gave a maximal lignin removal of 87%. The surfactants tested had no significant effects on the delignification yield. The laccase also detoxified the toxic phenols found in peanut shell waste. The high catalytic efficiency of this enzyme against a lignocellulosic sample under extreme conditions suggests the suitability of this laccase for industrial applications.

  3. Trace metals in different species of mollusca, water and sediments from Taiwan coastal area.

    Science.gov (United States)

    Hung, T C; Meng, P J; Han, B C; Chuang, A; Huang, C C

    2001-08-01

    Since October 1994, a long-term program of Asia/Pacific Mussel Watch: Taiwan Regional Studies has been carried out. The results indicate that trace metal contents in mollusca varied among 30 different species and the environments (water and sediments) along the Taiwan coast. The orders of bioaccumulation of trace metals in mollusca were: Cu (over 200 microg/g), Thais clavigera > Isognomon legumen > Clibanarius rivescens > Crassostrea gigas; Zn (over 700 microg/g), Moruta granulata > C. gigas > Asiatica cypraea arabica > T. clavigera; Cd (over 5 microg/g), Trochus hanleyanus > Acanthopleura japonica > Nerita albicilla > Patella flexuosa; Pb (over 2 microg/g), P. flexuosa > C. gigas > T. hanleyanus > T. clavigera > C. gigas > Capiyulum mitella; Ni (over 10 microg/g), Meretrix lusoria > Philine sp. > Littoraria scabra > Tridacna squamosa > T. hanleyanus; Cr (over 30 microg/g), Littoraria undulata > T. hanleyanus > N. albicilla > Nerita chamaelor > M. granulata; As (over 20 microg/g), Perna viridis > L. scabra; and Sn (over 5 microg/g), P. viridis > L. undulata> C. mitella> C. gigas. Their seasonal and regional variations as well as their correlation are evaluated and discussed.

  4. Metabolic engineering of Synechococcus elongatus PCC 7942 for improvement of 1,3-propanediol and glycerol production based on in silico simulation of metabolic flux distribution.

    Science.gov (United States)

    Hirokawa, Yasutaka; Matsuo, Shingo; Hamada, Hiroyuki; Matsuda, Fumio; Hanai, Taizo

    2017-11-25

    Production directly from carbon dioxide by engineered cyanobacteria is one of the promising technologies for sustainable future. Previously, we have successfully achieved 1,3-propanediol (1,3-PDO) production using Synechococcus elongatus PCC 7942 with a synthetic metabolic pathway. The strain into which the synthetic metabolic pathway was introduced produced 3.48 mM (0.265 g/L) 1,3-PDO and 14.3 mM (1.32 g/L) glycerol during 20 days of incubation. In this study, the productivities of 1,3-PDO were improved by gene disruption selected by screening with in silico simulation. First, a stoichiometric metabolic model was applied to prediction of cellular metabolic flux distribution in a 1,3-PDO-producing strain of S. elongatus PCC 7942. A genome-scale model of S. elongatus PCC 7942 constructed by Knoop was modified by the addition of a synthetic metabolic pathway for 1,3-PDO production. Next, the metabolic flux distribution predicted by metabolic flux balance analysis (FBA) was used for in silico simulation of gene disruption. As a result of gene disruption simulation, NADPH dehydrogenase 1 (NDH-1) complexes were found by screening to be the most promising candidates for disruption to improve 1,3-PDO production. The effect of disruption of the gene encoding a subunit of the NDH-1 complex was evaluated in the 1,3-PDO-producing strain. During 20 days of incubation, the ndhF1-null 1,3-PDO-producing strain showed the highest titers: 4.44 mM (0.338 g/L) 1,3-PDO and 30.3 mM (2.79 g/L) glycerol. In this study, we successfully improved 1,3-PDO productivity on the basis of in silico simulation of gene disruption.

  5. Construction of a novel d-lactate producing pathway from dihydroxyacetone phosphate of the Calvin cycle in cyanobacterium, Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Hirokawa, Yasutaka; Goto, Ryota; Umetani, Yoshitaka; Hanai, Taizo

    2017-07-01

    Using engineered cyanobacteria to produce various chemicals from carbon dioxide is a promising technology for a sustainable future. Lactate is a valuable commodity that can be used for the biodegradable plastic, polylactic acid. Typically, lactate production using engineered cyanobacteria was via the conversion of pyruvate in glycolysis by lactate dehydrogenase. In cyanobacteria, the metabolic flux in the Calvin cycle is higher than that in glycolysis under photoautotrophic conditions. The construction of a novel lactate producing pathway that uses metabolites from the Calvin cycle could potentially increase lactate productivity in cyanobacteria. In order to develop such a novel lactate production pathway, we engineered a cyanobacterium Synechococcus elongatus PCC 7942 strain that produced lactate directly from carbon dioxide using dihydroxyacetone phosphate (DHAP) via methylglyoxal. We confirmed that wild-type strain of S. elongatus PCC 7942 could produce lactate using exogenous methylglyoxal. A methylglyoxal synthase gene, mgsA, from Escherichia coli was introduced into Synechococcus elongates PCC 7942 for conversion of DHAP to methylglyoxal. This engineered strain produced lactate directly from carbon dioxide. Genes encoding intrinsic putative glyoxalase I, II (Synpcc7942_0638, 1403) and the lactate/H + symporter from E. coli (lldP) were additionally introduced to enhance the production. For higher lactate production, it was important to maintain elevated extracellular pH due to the characteristics of lactate exporting system. In this study, the highest lactate titer of 13.7 mM (1.23 g/l) was achieved during a 24-day incubation with the engineered S. elongatus PCC 7942 strain possessing the novel lactate producing pathway. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  6. Structural basis and target-specific modulation of ADP sensing by the Synechococcus elongatus PII signaling protein.

    Science.gov (United States)

    Zeth, Kornelius; Fokina, Oleksandra; Forchhammer, Karl

    2014-03-28

    PII signaling proteins comprise one of the most versatile signaling devices in nature and have a highly conserved structure. In cyanobacteria, PipX and N-acetyl-L-glutamate kinase are receptors of PII signaling, and these interactions are modulated by ADP, ATP, and 2-oxoglutarate. These effector molecules bind interdependently to three anti-cooperative binding sites on the trimeric PII protein and thereby affect its structure. Here we used the PII protein from Synechococcus elongatus PCC 7942 to reveal the structural basis of anti-cooperative ADP binding. Furthermore, we clarified the mutual influence of PII-receptor interaction and sensing of the ATP/ADP ratio. The crystal structures of two forms of trimeric PII, one with one ADP bound and the other with all three ADP-binding sites occupied, revealed significant differences in the ADP binding mode: at one site (S1) ADP is tightly bound through side-chain and main-chain interactions, whereas at the other two sites (S2 and S3) the ADP molecules are only bound by main-chain interactions. In the presence of the PII-receptor PipX, the affinity of ADP to the first binding site S1 strongly increases, whereas the affinity for ATP decreases due to PipX favoring the S1 conformation of PII-ADP. In consequence, the PII-PipX interaction is highly sensitive to subtle fluctuations in the ATP/ADP ratio. By contrast, the PII-N-acetyl-L-glutamate kinase interaction, which is negatively affected by ADP, is insensitive to these fluctuations. Modulation of the metabolite-sensing properties of PII by its receptors allows PII to differentially perceive signals in a target-specific manner and to perform multitasking signal transduction.

  7. Výsledky průzkumu měkkýšů (Mollusca: Gastropoda, Bivalvia) v okolí města Blatná v jihozápadních Čechách

    Czech Academy of Sciences Publication Activity Database

    Bogusch, P.; Dvořák, L.; Hlaváč, Jaroslav

    2008-01-01

    Roč. 7, - (2008), s. 33-46 ISSN 1336-6939 Institutional research plan: CEZ:AV0Z30130516 Keywords : Mollusca * Gastropoda * Bivalvia * faunistics * Blatná, Bohemia Subject RIV: EG - Zoology http://mollusca.sav.sk/pdf/7/7.Bogusch.pdf

  8. Adjustments to Photosystem Stoichiometry and Electron Transfer Proteins Are Key to the Remarkably Fast Growth of the Cyanobacterium Synechococcus elongatus UTEX 2973

    Directory of Open Access Journals (Sweden)

    Justin Ungerer

    2018-02-01

    Full Text Available At the genome level, Synechococcus elongatus UTEX 2973 (Synechococcus 2973 is nearly identical to the model cyanobacterium Synechococcus elongatus PCC 7942 (Synechococcus 7942 with only 55 single nucleotide differences separating the two strains. Despite the high similarity between the two strains, Synechococcus 2973 grows three times faster, accumulates significantly more glycogen, is tolerant to extremely high light intensities, and displays higher photosynthetic rates. The high homology between the two strains provides a unique opportunity to examine the factors that lead to increased photosynthetic rates. We compared the photophysiology of the two strains and determined the differences in Synechococcus 2973 that lead to increased photosynthetic rates and the concomitant increase in biomass production. In this study, we identified inefficiencies in the electron transport chain of Synechococcus 7942 that have been alleviated in Synechococcus 2973. Photosystem II (PSII capacity is the same in both strains. However, Synechococcus 2973 exhibits a 1.6-fold increase in PSI content, a 1.5-fold increase in cytochrome b6f content, and a 2.4-fold increase in plastocyanin content on a per cell basis. The increased content of electron carriers allows a higher flux of electrons through the photosynthetic electron transport chain, while the increased PSI content provides more oxidizing power to maintain upstream carriers ready to accept electrons. These changes serve to increase the photosynthetic efficiency of Synechococcus 2973, the fastest growing cyanobacterium known.

  9. Analysis of the solution structure of Thermosynechococcus elongatus photosystem I in n-dodecyl-β-D-maltoside using small-angle neutron scattering and molecular dynamics simulation.

    Science.gov (United States)

    Le, Rosemary K; Harris, Bradley J; Iwuchukwu, Ifeyinwa J; Bruce, Barry D; Cheng, Xiaolin; Qian, Shuo; Heller, William T; O'Neill, Hugh; Frymier, Paul D

    2014-05-15

    Small-angle neutron scattering (SANS) and molecular dynamics (MD) simulation were used to investigate the structure of trimeric photosystem I (PSI) from Thermosynechococcus elongatus (T. elongatus) stabilized in n-dodecyl-β-d-maltoside (DDM) detergent solution. Scattering curves of detergent and protein-detergent complexes were measured at 18% D2O, the contrast match point for the detergent, and 100% D2O, allowing observation of the structures of protein/detergent complexes. It was determined that the maximum dimension of the PSI-DDM complex was consistent with the presence of a monolayer belt of detergent around the periphery of PSI. A dummy-atom reconstruction of the shape of the complex from the SANS data indicates that the detergent envelope has an irregular shape around the hydrophobic periphery of the PSI trimer rather than a uniform, toroidal belt around the complex. A 50 ns MD simulation model (a DDM ring surrounding the PSI complex with extra interstitial DDM) of the PSI-DDM complex was developed for comparison with the SANS data. The results suggest that DDM undergoes additional structuring around the membrane-spanning surface of the complex instead of a simple, relatively uniform belt, as is generally assumed for studies that use detergents to solubilize membrane proteins. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes.

    Science.gov (United States)

    Danchin, Etienne G J; Perfus-Barbeoch, Laetitia; Rancurel, Corinne; Thorpe, Peter; Da Rocha, Martine; Bajew, Simon; Neilson, Roy; Guzeeva, Elena Sokolova; Da Silva, Corinne; Guy, Julie; Labadie, Karine; Esmenjaud, Daniel; Helder, Johannes; Jones, John T; den Akker, Sebastian Eves-van

    2017-10-23

    Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. We have used ribonucleic acid sequencing (RNAseq) to generate reference transcriptomes for two economically important nematode species, Xiphinema index and Longidorus elongatus , representative of two genera within the early-branching Clade 2 of the phylum Nematoda. We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. This represents the first in-depth transcriptome analysis from any plant-parasitic nematode of this clade. For each species, we assembled ~30 million Illumina reads into a reference transcriptome. We identified 62 and 104 transcripts, from X. index and L. elongatus , respectively, that were putatively acquired via horizontal gene transfer. By cross-referencing horizontal gene transfer prediction with a phylum-wide analysis of Pfam domains, we identified Clade 2-specific events. Of these, a GH12 cellulase from X. index was analysed phylogenetically and biochemically, revealing a likely bacterial origin and canonical enzymatic function. Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. Our findings underline the importance and the extensiveness of this phenomenon in the evolution of plant-parasitic life styles in this speciose and widespread animal phylum.

  11. The study of desiccation-tolerance in drying leaves of the desiccation-tolerant grass Sporobolus elongatus and the desiccation-sensitive grass Sporobolus pyramidalis.

    Science.gov (United States)

    Ghasempour, Hamid Reza; Kianian, Jahanbakheshe

    2007-03-01

    Hydrated leaves of the resurrection grass Sporobolus elongatus are not desiccation tolerant (DT), but moderate to severe drought stress can induce their DT with the leaves remain attach to drying intact plants. In vivo protein synthesis was studied with SDS-page of extracts of leaves of intact drying plants of S. elongatus (a desiccation-Tolerant grass (DT)) and S. pyramidalis (a desiccation-sensitive species (DS)). Free proline increased in drying leaves. Soluble sugar contents also increased with drying but were less than fully hydrated leaves at 8% RWC. Total protein also showed an increase with an exception at 8% RWC which showed a decrease. SDS-page of extracts of drying leaves of both DT and DS plants were studied as relative water contents (RWC) decreased. In first phase, DT species at 58% RWC (80-51% RWC range), two proteins increased in contents. In the second phase, at 8% (35-4% RWC range) two new bands increased and two bands decreased. In leaves of DS species some bands decreased as drying progressed. Also, as drying advanced free proline increased in DT species. Total protein increased as drying increased but at 8% RWC decreased. All data of results are consistent with current views about studied factors and their roles during drying and induction of desiccation tolerance in DT plants.

  12. Higher ribosomal RNA substitution rates in Bacillariophyceae and Dasycladales than in Mollusca, Echinodermata, and Actinistia-Tetrapoda.

    Science.gov (United States)

    Sorhannus, U

    1996-09-01

    Molecular evolutionary rates within two protistan and three metazoan taxa were estimated using divergence times derived from fossil records. The results indicate that the small-subunit rRNA sequences within Dasycladales (Chlorophyta) and Bacillariophyceae evolved at a rate approximately two to three times faster than that estimated within Echinodermata, Mollusca, and Actinistia-Tetrapoda. It was concluded that this twofold discrepancy demonstrates actual taxonomic differences in the fixation rate of mutations in the small-subunit rRNA.

  13. Biogeography of Crustacea and Mollusca of the Subantarctic and Antarctic regions

    Directory of Open Access Journals (Sweden)

    Angelika Brandt

    1999-12-01

    Full Text Available The Joint Magellan Victor Hensen Campaign in 1994 focused on the biogeographic relationships of the Antarctic and Magellan fauna. The Peracarida and Mollusca sampled at 18 stations in the Beagle Channel by means of an epibenthic sledge were compared with the knowledge about the distribution of species data from the Falkland Islands, South Georgia, Antarctica and the Kerguelen. Peracarida were an important fraction of the macrobenthos and sampled in high numbers. About 105,000 individuals were collected with the epibenthic sledge. Until now about 40 species of Amphipoda, about 42 species of Isopoda, 24 species of Cumacea, eight species of Mysidacea, and 16 species of Tanaidacea were found. 118 mollusc taxa were identified, nine species of Aplacophora, 52 of Gastropoda, five of Scaphopoda and 52 of Bivalvia. Although the species present different distribution trends, the zoogeographic comparison for six larger taxa (four Mollusca and two Peracarida showed that the species similarities decreased from the Magellan region towards the Falkland Islands and from South Georgia to Antarctica. The Magellanic Gastropoda showed similarities with the fauna of the Falkland Islands and South Georgia (31-37 %, whereas the Bivalvia were more similar to the Antarctic fauna (29 %. With regard to Crustacea, 10% of Antarctic Isopoda species were also found in the Magellan region; the Weddell Sea and East Antarctica, and South Georgia and the Antarctic Peninsula shared most species of both Cumacea and Isopoda, whereas the lowest similarities were shown between Bellingshausen and Weddell Sea for the Isopoda, and interestingly between the Magellan region and South Georgia for the Cumacea. The highest degree of endemism of the Isopoda and Cumacea was found in the Magellan region, where as a consequence of the opening of the Drake Passage many new species seem to have evolved in these taxa.

  14. Effects of Reduced and Enhanced Glycogen Pools on Salt-Induced Sucrose Production in a Sucrose-Secreting Strain of Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Qiao, Cuncun; Duan, Yangkai; Zhang, Mingyi; Hagemann, Martin; Luo, Quan; Lu, Xuefeng

    2018-01-15

    Sucrose and glycogen syntheses in cyanobacteria share the common precursor glucose-1-phosphate. It is generally assumed that lowering glycogen synthesis could drive more carbon toward sucrose synthesis that can be induced by salt stress among cyanobacteria. By using a theophylline-dependent riboswitch system, the expression of glgC , a key gene in glycogen synthesis, was downregulated in a quantitative manner in a sucrose-secreting strain of Synechococcus elongatus PCC 7942. We observed that the stepwise suppression of glycogen synthesis limited rather than stimulated sucrose production in the salt-stressed cells, suggesting that glycogen could serve as a carbon pool for the synthesis of sucrose. Accordingly, we generated glycogen-overproducing strains, but the increased glycogen pool alone did not stimulate sucrose production, indicating that alternative steps limit the carbon flux toward the synthesis of sucrose. Consistent with previous studies that showed that sucrose-phosphate synthase (SPS) catalyzes the rate-limiting step in sucrose synthesis, the combination of glycogen overproduction and sps overexpression resulted in increased sucrose production. Our results indicate that the glycogen and sucrose pools are closely linked in Synechococcus elongatus PCC 7942, and we propose that enhancing the glycogen pool could be a promising strategy for the improvement of sucrose production by cyanobacteria in the presence of a strong sucrose synthesis sink. IMPORTANCE Many cyanobacteria naturally synthesize and accumulate sucrose when stressed by NaCl, which provides novel possibilities for obtaining sugar feedstock by engineering of cyanobacteria. It has been assumed that glycogen synthesis competes with sucrose synthesis for the carbon flux. However, our results showed that the suppression of glycogen synthesis decreased rather than stimulated sucrose production in a sucrose-secreting strain of Synechococcus elongatus PCC 7942. This result suggests that glycogen could

  15. Seasonal changes in food quantity and quality of the common North Sea copepods Temora longicornis and Pseudocalanus elongatus: a bioassay approach

    DEFF Research Database (Denmark)

    Koski, Marja; Dutz, Jörg; Klein Breteler, W.

    2010-01-01

    We evaluated the food quantity and quality over a seasonal cycle for the development and egg production of the common North Sea copepods Temora longicornis and Pseudocalanus elongatus, using a bioassay approach. Seston was sampled from December to October from a well-mixed water column...... of the Marsdiep (Dutch Wadden Sea) and fed to cultured copepods at a constant temperature of 15 degrees C, thus excluding seasonal effects of temperature, body size, age, and maternal nutrition. Copepod response was evaluated by measuring egg production and juvenile development, while the seston quantity...... and quality were measured as the concentrations of chl a, specific phytoplankton pigments, particulate organic carbon (POC), particulate organic nitrogen (PON), fatty acids, and sterols. The egg production of both copepods was low when feeding on seston collected in winter, but increased to peak values...

  16. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes

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    Etienne G.J. Danchin

    2017-10-01

    Full Text Available Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. We have used ribonucleic acid sequencing (RNAseq to generate reference transcriptomes for two economically important nematode species, Xiphinema index and Longidorus elongatus, representative of two genera within the early-branching Clade 2 of the phylum Nematoda. We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. This represents the first in-depth transcriptome analysis from any plant-parasitic nematode of this clade. For each species, we assembled ~30 million Illumina reads into a reference transcriptome. We identified 62 and 104 transcripts, from X. index and L. elongatus, respectively, that were putatively acquired via horizontal gene transfer. By cross-referencing horizontal gene transfer prediction with a phylum-wide analysis of Pfam domains, we identified Clade 2-specific events. Of these, a GH12 cellulase from X. index was analysed phylogenetically and biochemically, revealing a likely bacterial origin and canonical enzymatic function. Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. Our findings underline the importance and the extensiveness of this phenomenon in the evolution of plant-parasitic life styles in this speciose and widespread animal phylum.

  17. Distribución geográfica, prevalencia e intensidad de las infecciones de Gregarina ronderosi (Eugregarinorida: Gregarinidae en Dichroplus elongatus (Orthoptera: Acrididae

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    Christian Bardi

    2016-01-01

    Full Text Available regarina ronderosi es un parásito obligado del tracto digestivo del acrídido plaga Dichroplus elongatus y una de las únicas dos eugregarinas de acrídidos argentinos descriptas con su ciclo de vida completo. Dada la falta de conocimiento acerca de aspectos epizootiológicos fundamentales de las infecci- ones causadas por eugregarinas en acrídidos de Argentina, el objetivo de esta contribución es iniciar el registro de la distribución geográfica de G. ronderosi en la región Pampeana, su prevalencia natural y la intensidad de las infecciones en condiciones naturales. Para ello, se colectaron ejemplares de D. elongatus (2008 – 2012 en distintos puntos de la región Pampeana. Se obtuvieron y analizaron un total de 4084 ejemplares provenientes de cuarenta y dos localidades. La prevalen- cia promedio de G. ronderosi para el total de localidades con presencia (diecisiete localidades fue de 29,7 ± EE 6,6% (n = 1071. El total de individuos infectados (n = 396 fue categorizado respecto de la intensidad de las infecciones: tres (0,8% presentaron infecciones muy fuertes, ochenta (20% fuerte, doscientos diez (53% moderadas y ciento tres (26% infecciones leves. Se ha ampliado la distribución ge- ográfica conocida, se han registrado prevalencias elevadas que sugieren la ocur - rencia de epizootias y se han registrado por primera vez en condiciones naturales infecciones de G. ronderosi categorizadas como Fuertes y Muy Fuertes.

  18. Proximate composition, mineral content and fatty acid profile of two marine fishes from Cameroonian coast: Pseudotolithus typus (Bleeker, 1863 and Pseudotolithus elongatus (Bowdich, 1825

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    J.M. Njinkoue

    2016-10-01

    Full Text Available Background: Knowledge of chemical composition of fish from Cameroon is poor. The genera Pseudotolithus are nutritionally and economically important in Cameroon. Thus the knowledge on their chemical composition could help in functional food elaboration. Purpose: In this study, Proximate composition, fatty acid profiles and mineral composition were determined in two fish species, Pseudotolithus typus and Pseudotolithus elongatus from Cameroonian coasts. Basic procedure: AOAC standard method was used. Fatty acids were identified by GC/MS as N-acylpyrolidides. Mineral compositions were determined by atomic absorption spectrophotometry for Ca, Na, K, Mg, Fe, Zn, Cu, Mn, and by UV spectrophotometry for phosphorus (P. Main finding: Results indicated that chemical composition was not similar in the two fish species. Results also showed that water is the main constituent in the edible parts and in the bones with 76.17% to 78.24% and 51.21% to 55.28% respectively. Pseudotolithus typus and Pseudotolithus elongatus were good sources of proteins with 16.17% and 13.4% respectively. All the fish analyzed for fat were lean with fat contents less than 0.5%. These species of fish were poor in ω6PUFA and were rich in ω3PUFA with about one third of total fatty acids. The main ω3 fatty acids were eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. The most abundant main elements were the potassium in the edible parts (1.39% and calcium in the bones (18.26%. The most abundant trace elements were Zn and Fe in the edible parts and in the bones. Principal conclusion: The Na/K ratio values and ω3 fatty acids contents suggest that consumption of these two fish species could be recommended to prevent cardiovascular diseases. Keywords: Proximal composition, Mineral content, Fatty acid profiles, Pseudotolithus typus, Pseudotolithus elongates

  19. Cytogenetic markers as diagnoses in the identification of the hybrid between Piauçu (Leporinus macrocephalus and Piapara (Leporinus elongatus

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    Fábio Porto-Foresti

    2008-01-01

    Full Text Available The genetic monitoring of interspecific hybrids involves the application of methodologies able to provide an easy and indubitable genetic characterization of both parental and hybrid individuals. In the present work, cytogenetic techniques were used to identify a hybrid lineage of "Piaupara" in order to caracterize them in relation to the parental species, Leporinus macrocephalus (piauçu and L. elongatus (piapara. The cytogenetic analysis revealed that L. macrocephalus presented 2n = 54 chromosomes and a nucleolar organizer regions (NOR at the telomere of the long arm of the submetacentric chromosome pair 2. Analysis of constitutive heterochromatin (C-banding revealed a conspicuous block at the pericentromeric region on the long arm of a submetacentric chromosome pair. L. elongatus presented the same diploid number, 2n = 54, and a karyotypic formula similar to that of L. macrocephalus. The NORs were also at the telomere of the long arm of the submetacentric pair 2, which was morphologically different from that of L. macrocephalus. Heterochromatic blocks were observed at both telomeres of a submetacentric chromosome pair. The hybrid "Piaupara" presented the same diploid number (2n = 54 and karyotypic formula as the parental species and there were no visible differences between parental and hybrid individuals. Differently from the Giemsa staining, NOR- and C-banding analysis showed marked differences which allowed the identification of the hybrids by the different morphology and/or size of the chromosomes carrying the NORs and patterns of heterochromatin distribution in their chromosomes. Such genetic studies are important for fish culture since they can provide tools for monitoring natural and artificial hybridization. They are also useful in biological conservation programmes and in the proper management of natural and reared fish stocks.

  20. Mollusca: Bivalvia

    African Journals Online (AJOL)

    1987-06-05

    Jun 5, 1987 ... During spermatogenesis the pattern of nuclear chrornatin condensation is granular. The acrosome is formed by a single Golgi body. and the five large mitochondria of the mid-piece are probably formed by fusion of several small mitochondria. Die struktuur van die spermatozoa en spermatogenese in Solen ...

  1. Quitones (Mollusca: Polyplacophora de El Salvador, América Central

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    Cedar I García-Ríos

    2007-03-01

    Full Text Available En El Salvador se habían registrado los poliplacóforos Chaetopleura lurida (Sowerby, 1832; Ischnochiton guatemalensis (Thiele, 1910; Ceratozona angusta (Thiele, 1909; Chiton stokesii (Broderip, 1832 y Acantochitona exquisita (Pilsbry, 1893. Recolectamos quitones en aguas someras de El Salvador en julio del 2002, agragando a la lista a Lepidochitona beanii (Carpenter, 1857; Ischnochiton dispar (Sowerby, 1832; Stenoplax limaciformis (Sowerby, 1832; Callistochiton expressus (Carpenter, 1865; Acanthochitona arragonites (Carpenter, 1867; Acanthochitona ferreirai (Lyons, 1988 y Acanthochitona hirudiniformis (Sowerby, 1832. Ampliamos la distribución documentada de I. dispar hacia el norte y describimos brevemente una especie innominada de Lepidochitona.Chitons (Mollusca: Polyplacophora from El Salvador, Central America. Collections of 11 species of shallow water Polyplacophora from El Salvador were made in July 2002. Previously only five species had been documented in El Salvador: Chaetopleura lurida (Sowerby, 1832; Ischnochiton guatemalensis (Thiele, 1910; Ceratozona angusta (Thiele, 1909; Chiton stokesii (Broderip, 1832 and Acantochitona exquisita (Pilsbry, 1893. Of these, I. guatemalensis and A. exquisita were not collected in this census. Seven other species are reported here for El Salvador for the first time: Lepidochitona beanii (Carpenter, 1857; Ischnochiton dispar (Sowerby, 1832; Stenoplax limaciformis (Sowerby, 1832; Callistochiton expressus (Carpenter, 1865; Acanthochitona arragonites (Carpenter, 1867; A. ferreirai (Lyons, 1988 and A. hirudiniformis (Sowerby, 1832. The known geographic distribution of I. dispar is extended to the north. An un-named species of Lepidochitona is briefly described. Rev. Biol. Trop. 55 (1: 171-176. Epub 2007 March. 31.

  2. Pomacea canaliculata (Mollusca, Gastropoda) in Patagonia: potential role of climatic change in its dispersion and settlement.

    Science.gov (United States)

    Darrigran, G; Damborenea, C; Tambussi, A

    2011-02-01

    Pomacea canaliculata (Lamarck, 1822) (Mollusca Gastropoda) shows a large native distribution range in South America, reaching as far south as 37º S (Buenos Aires, Argentina). This species was deliberately introduced into Southeast Asia around 1980 and subsequently underwent a rapid intentional or accidental dispersal into many countries in the region. It was also introduced into North and Central America and Hawaii. In this contribution we record the presence of P. canaliculata in Patagonia, assessing the possible influence of climatic change in the new establishment of this species there. Three samplings (between September 2004 and April 2005) were carried out at 38º 58' 20.2" S-68º 11' 27.3" W. In the sampling we found two adult specimens of P. canaliculata and numerous egg clutches. Pomacea canaliculata is naturally distributed in the Plata and Amazon Basins. The southern boundary of this species has been established as the isotherms of 14 ºC and 16 ºC in Buenos Aires province, and precipitations of 900 to 600 mm/year. This study also analysed variations in annual temperature and precipitation in Patagonia. Average temperatures show an increase over the years, although not constantly. Important modifications in precipitation regime in northern Patagonia, triggered by global climatic changes, could be beneficial for the settlement of populations of P. canaliculata in this new area, where precipitation increased enough to reach values similar to those in the southernmost area of distribution of this species.

  3. Pomacea canaliculata (Mollusca, Gastropoda in Patagonia: potential role of climatic change in its dispersion and settlement

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    G. Darrigran

    Full Text Available Pomacea canaliculata (Lamarck, 1822 (Mollusca Gastropoda shows a large native distribution range in South America, reaching as far south as 37º S (Buenos Aires, Argentina. This species was deliberately introduced into Southeast Asia around 1980 and subsequently underwent a rapid intentional or accidental dispersal into many countries in the region. It was also introduced into North and Central America and Hawaii. In this contribution we record the presence of P. canaliculata in Patagonia, assessing the possible influence of climatic change in the new establishment of this species there. Three samplings (between September 2004 and April 2005 were carried out at 38º 58' 20.2" S-68º 11' 27.3" W. In the sampling we found two adult specimens of P. canaliculata and numerous egg clutches. Pomacea canaliculata is naturally distributed in the Plata and Amazon Basins. The southern boundary of this species has been established as the isotherms of 14 ºC and 16 ºC in Buenos Aires province, and precipitations of 900 to 600 mm/year. This study also analysed variations in annual temperature and precipitation in Patagonia. Average temperatures show an increase over the years, although not constantly. Important modifications in precipitation regime in northern Patagonia, triggered by global climatic changes, could be beneficial for the settlement of populations of P. canaliculata in this new area, where precipitation increased enough to reach values similar to those in the southernmost area of distribution of this species.

  4. The Histopathology of the Infection of Tilapia rendalli and Hypostomus regani (Osteichthyes by Lasidium Larvae of Anodontites trapesialis (Mollusca, Bivalvia

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    Silva-Souza Ângela Teresa

    2002-01-01

    Full Text Available It is described the histopathology of the infection of Tilapia rendalli (Osteichthyes, Perciformes, Cichlidae and Hypostomus regani (Osteichthyes, Siluriformes, Loricariidae by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia, Mycetopodidae. The larvae were encysted within the epidermis of the host, being surrounded by a thin hyaline membrane, 3-6 µm thick, of parasite origin. A proliferative host cell reaction did not occur. The histopathology of the infection shows that the lesions induced by the parasites are minimal. However, the numerous small lesions produced by the release of the larvae may provide optimal conditions for the infection by opportunistic pathogens, namely fungus, which may eventually cause the death of the host.

  5. The histopathology of the infection of Tilapia rendalli and Hypostomus regani (Osteichthyes) by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia).

    Science.gov (United States)

    Silva-Souza, Angela Teresa; Eiras, Jorge C

    2002-04-01

    It is described the histopathology of the infection of Tilapia rendalli (Osteichthyes, Perciformes, Cichlidae) and Hypostomus regani (Osteichthyes, Siluriformes, Loricariidae) by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia, Mycetopodidae). The larvae were encysted within the epidermis of the host, being surrounded by a thin hyaline membrane, 3-6 microm thick, of parasite origin. A proliferative host cell reaction did not occur. The histopathology of the infection shows that the lesions induced by the parasites are minimal. However, the numerous small lesions produced by the release of the larvae may provide optimal conditions for the infection by opportunistic pathogens, namely fungus, which may eventually cause the death of the host.

  6. MOLLUSCA' BIODIVERSITY (GASTROPODA AND BIVALVIA AS A BIO INDICATOR OF QUALITY OF WATER IN THE COASTAL ISLAND OF TUNDA ISLAND, BANTEN

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    Indria Wahyuni

    2017-07-01

    Full Text Available The research has been done on Juli 2017 in the coastal region of Tunda Island. This study aims to determine the Biodiversity of Mollusca (Gastropoda and Bivalvia As Bioindicator of Water Quality In Coastal Area of Tunda Island, Banten. Sampling consists of 2 observation stations, namely the mangrove coastal area (3 transects and the seagrass coastal area (2 transects determined by purposive sampling. The observation of each station is done by using the quadratic transect method with 100 m transect line distance, and in each transect line there are 5 observation plots measuring 1m2 x 1m2. The data analysis includes density, biodiversity, bio-indicators of water quality based on diversity index. Result of research on 5 transect found 45 type Mollusca which represent 2 class, that is Gastropoda class of 29 species Gastropoda joined in 14 Family. As for Bivalvia class found 16 species incorporated in 9 families. The total density of Mollusca is 541.2 ind / m2 which consists of 392.4 ind / m2 for Gastropoda class and 148.8 ind / m2 for Bivalvia class. Mollusca diversity was calculated using the diversity index of Shannon-Wienner (H '. The results of diversity index ranged from 3.1356 - 3.3314 with high category. Bioindicator of aquatic quality using diversity index indicates that the coastal area of Tunda Island belongs to a very mildly polluted category.

  7. On Dichelyne (Cucullanellus elongatus (Tornquist, 1931 Petter, 1974: South American correlated species (Nematoda, Cucullanidae and some other helminths of micropogonias furnieri (Desmarest, 1823 (Pisces, Sciaenidae Sobre Dichelyne (Cucullanellus elongatus (Tornquist, 1931 Petter, 1974: espécies sul americanas correlatas (Nematoda, Cucullanidae e alguns outros helmintos de Micropogonias furnieri (Desmarest, 1823(Pisces, Sciaenidae

    Directory of Open Access Journals (Sweden)

    J. Júlio Vicente

    1989-09-01

    Full Text Available Dichelyne (Cucullanellus elongatus (Tomquist, 1931 Petter, 1974, from Venezuela, of which D.(C. amaurincai (Freitas, Vicente & Ibáñez, 1969 Petter, 1974 is proposed as a junior synonym, is redescribed and comments on the present status of the remaining species under the group, namely D.(C. dichelyneformes (Szidat, 1950 Petter, 1974, D.(C. rodriguesi (Pinto, Fábio & Noronha, 1970 Petter, 1974 and D.(C. travassosi (Guimarães & Cristofaro, 1974, occuring in South America are made. Dollfusentis chandleri Golvan, 1969 (Acanthocephala, Illiosentidae, Poecilancistrium caryophyllum (Diesing, 1850(Cestoidea, Otobothriidae and Callitetrarhynchus gracilis (Rudolphi, 1819(Cestoidea, Dasyrhynchidae as well as larval forms of Echinocephalus sp. (Nematoda, Gnathostomatidae and Contracaecum sp. (Nematoda, Anisakidae are also reported.Dichelyne (Cucullanellus elongatus (Tornquist, 1931 Petter, 1974, da Venezuela, da qual D.(C. amaurincai (Freitas, Vicente & Ibáñez, 1969 Petter, 1974 é proposta como sinônimo junior, é descrita, e são feitos comentários sobre a atual situação das outras espécies do mesmo grupo, ocorrendo na América do Sul, a saber: D.(C. dichelyneformes (Szidat, 1950 Petter, 1974, D.(C. rodriguesi (Pinto, Fábio & Noronha, 1971 Petter, 1974 e D.(C. travassosi (Guimarães & Cristofaro, 1974. Dollfusentis chandleri Golvan, 1969 (Acantochephala, Illiosentidae, Poecilancistrium cariophyllum (Diesing, 1850 (Cestoidea, Otobothriidae e Callitetrarhynchus gracilis (Rudolphi, 1819 (Cestoidea, Dayrhynchidae bem como formas larvares de Exhinocephalus sp. (Nematoda, Gnathostomatidae e Contracaecum sp. (Nematoda, Anisakidae são também assinaladas.

  8. Diversidad y microestructura de quitones (Mollusca: Polyplacophora del Caribe de Costa Rica

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    Cedar I García-Ríos

    2011-03-01

    Full Text Available Los poliplacóforos asociados a los arrecifes de coral en la costa caribeña de Costa Rica han sido poco estudiados. El examen del cascajo de coral acumulado en el sublitoral somero, en cuatro estaciones de colección, localizadas en la Provincia de Limón reveló una diversidad de quitones mayor a la documentada. Anteriormente se habían registrado ocho especies para el Caribe costaricense: Ischnochiton erythronotus (C.B. Adams, 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon, 1886; S. purpurascens (C.B. Adams, 1845; Acanthopleura granulata (Gmelin, 1791; Chiton marmoratus Gmelin, 1791; C. tuberculatus Linnaeus, 1758; Acanthochitona rhodea (Pilsbry, 1893. Otras cinco se registran aquí por primera vez: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954; Cryptoconchus floridanus (Dall 1889.Diversity and microstructure of quitons (Mollusca: Polyplacophora from the Caribbean of Costa Rica. The polyplacophorans of the coral reef on the Caribbean coast of Costa Rica have been insufficiently studied. The examination of coral rubble accumulated in the shallow sublitoral waters on four collection stations in Provincia Limón revealed a higher diversity of chitons than was documented. From the country eight species were previously known: Ischnochiton erythronotus (C.B. Adams 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon 1886; S. purpurascens (C.B. Adams 1845; Acanthopleura granulate (Gmelin 1791; Chiton marmoratus Gmelin 1791; C. tuberculatus Linnaeus 1758 and Acanthochitona rhodea (Pilsbry 1893. This study added five more species that are reported here for the first time: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954 and Cryptoconchus floridanus (Dall 1889. Rev. Biol. Trop. 59 (1: 129-136. Epub 2011 March 01.

  9. Homology and homoplasy of swimming behaviors and neural circuits in the Nudipleura (Mollusca, Gastropoda, Opisthobranchia)

    Science.gov (United States)

    Newcomb, James M.; Sakurai, Akira; Lillvis, Joshua L.; Gunaratne, Charuni A.; Katz, Paul S.

    2012-01-01

    How neural circuit evolution relates to behavioral evolution is not well understood. Here the relationship between neural circuits and behavior is explored with respect to the swimming behaviors of the Nudipleura (Mollusca, Gastropoda, Opithobranchia). Nudipleura is a diverse monophyletic clade of sea slugs among which only a small percentage of species can swim. Swimming falls into a limited number of categories, the most prevalent of which are rhythmic left–right body flexions (LR) and rhythmic dorsal–ventral body flexions (DV). The phylogenetic distribution of these behaviors suggests a high degree of homoplasy. The central pattern generator (CPG) underlying DV swimming has been well characterized in Tritonia diomedea and in Pleurobranchaea californica. The CPG for LR swimming has been elucidated in Melibe leonina and Dendronotus iris, which are more closely related. The CPGs for the categorically distinct DV and LR swimming behaviors consist of nonoverlapping sets of homologous identified neurons, whereas the categorically similar behaviors share some homologous identified neurons, although the exact composition of neurons and synapses in the neural circuits differ. The roles played by homologous identified neurons in categorically distinct behaviors differ. However, homologous identified neurons also play different roles even in the swim CPGs of the two LR swimming species. Individual neurons can be multifunctional within a species. Some of those functions are shared across species, whereas others are not. The pattern of use and reuse of homologous neurons in various forms of swimming and other behaviors further demonstrates that the composition of neural circuits influences the evolution of behaviors. PMID:22723353

  10. The Complete Sequence of the Mitochondrial Genome of the Chamberednautilus (Mollusca: Cephalopoda)

    Energy Technology Data Exchange (ETDEWEB)

    Boore, Jeffrey L.

    2005-12-01

    Background: Mitochondria contain small genomes that arephysically separate from those of nuclei. Their comparison serves as amodel system for understanding the processes of genome evolution.Although complete mitochondrial genome sequences have been reported formore than 600 animals, the taxonomic sampling is highly biased towardvertebrates and arthropods, leaving much of the diversity yetuncharacterized. Results: The mitochondrial genome of a cephalopodmollusk, the Chambered Nautilus, is 16,258 nts in length and 59.5 percentA+T, both values that are typical of animal mitochondrial genomes. Itcontains the 37 genes that are typical for animal mtDNAs, with 15 on oneDNA strand and 22 on the other. The arrangement of these genes can bederived from that of the distantly related Katharina tunicata (Mollusca:Polyplacophora) by a switch in position of two large blocks of genes andtranspositions of four tRNA genes. There is strong skew in thedistribution of nucleotides between the two strands. There are an unusualnumber of non-coding regions and their function, if any, is not known;however, several of these demark abrupt shifts in nucleotide skew,suggesting that they may play roles in transcription and/or replication.One of the non-coding regions contains multiple repeats of a tRNA-likesequence. Some of the tRNA genes appear to overlap on the same strand,but this could be resolved if the polycistron were cleaved at thebeginning of the downstream gene, followed by polyadenylation of theproduct of the upstream gene to form a fully paired structure.Conclusions: Nautilus sp. mtDNA contains an expected gene content thathas experienced few rearrangements since the evolutionary split betweencephalopods and polyplacophorans. It contains an unusual number ofnon-coding regions, especially considering that these otherwise often aregenerated by the same processes that produce gene rearrangements. Thisappears to be yet another case where polyadenylation of mitochondrialtRNAs restores

  11. Efficient delivery of large DNA from Escherichia coli to Synechococcus elongatus PCC7942 by broad-host-range conjugal plasmid pUB307.

    Science.gov (United States)

    Itaya, Mitsuhiro; Kusakabe, Hiroko; Sato, Mitsuru; Tomita, Masaru; Sato, Rintaro

    2018-02-06

    Synechococcus elongatus PCC7942, a cyanobacterium that uses light and carbon dioxide to grow, has a high ability to incorporate DNA by transformation. To assess the effective delivery of large DNA in plasmid form, we cloned the endogenous plasmid pANL (46.4 kbp) into a BAC vector of Escherichia coli. The plasmid p38ANL (54.3 kbp) replaced the native plasmid. To assess the delivery of larger DNA into PCC7942, p38ANL was fused to the broad-host-range conjugal transfer plasmid pUB307IP (53.5 kbp). The resulting plasmid pUB307IP501 (107.9 kbp) was transmitted from E. coli to PCC7942 by simple mixing of donor and recipient cultures. PCC7942 transcipients possessed only pUB307IP501, replacing the preexisting pANL. In contrast, the pUB307IP501 plasmid was unable to transform PCC7942, indicating that natural transformation of DNA may be restricted by size limitations. The ability to deliver large DNA by conjugation may lead to genetic engineering in PCC7942. © The Authors 2018. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  12. Isolation, one-step affinity purification, and characterization of a polyextremotolerant laccase from the halophilic bacterium Aquisalibacillus elongatus and its application in the delignification of sugar beet pulp.

    Science.gov (United States)

    Rezaei, Shahla; Shahverdi, Ahmad Reza; Faramarzi, Mohammad Ali

    2017-04-01

    The aim of the present work was to study the ability of a halophilic bacterial laccase to efficient delignification in extreme conditions. Here, a highly stable extracellular laccase showing ligninolytic activity from halophilic Aquisalibacillus elongatus is described. The laccase production was strongly influenced by NaCl and CuSO 4 and under optimal conditions reached 4.8UmL -1 . The monomeric enzyme of 75kDa was purified by a synthetic affinity column with 68.2% yield and 99.8-fold purification. The enzyme showed some valuable features viz. stability against a wide range of organic solvents, salts, metals, inhibitors, and surfactants and specificity to a wide spectrum of substrates diverse in structure and redox potential. It retained more than 50% of the original activity at 25-75°C and pH 5.0-10.0. Furthermore, the enzyme was found to be effective in the delignification of sugar beet pulp in an ionic liquid that makes it useful for industrial applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The complete sequence of the mitochondrial genome of Nautilus macromphalus (Mollusca: Cephalopoda

    Directory of Open Access Journals (Sweden)

    Boore Jeffrey L

    2006-07-01

    Full Text Available Abstract Background Mitochondria contain small genomes that are physically separate from those of nuclei. Their comparison serves as a model system for understanding the processes of genome evolution. Although complete mitochondrial genome sequences have been reported for more than 600 animals, the taxonomic sampling is highly biased toward vertebrates and arthropods, leaving much of the diversity yet uncharacterized. Results The mitochondrial genome of the bellybutton nautilus, Nautilus macromphalus, a cephalopod mollusk, is 16,258 nts in length and 59.5% A+T, both values that are typical of animal mitochondrial genomes. It contains the 37 genes that are almost universally found in animal mtDNAs, with 15 on one DNA strand and 22 on the other. The arrangement of these genes can be derived from that of the distantly related Katharina tunicata (Mollusca: Polyplacophora by a switch in position of two large blocks of genes and transpositions of four tRNA genes. There is strong skew in the distribution of nucleotides between the two strands, and analysis of this yields insight into modes of transcription and replication. There is an unusual number of non-coding regions and their function, if any, is not known; however, several of these demark abrupt shifts in nucleotide skew, and there are several identical sequence elements at these junctions, suggesting that they may play roles in transcription and/or replication. One of the non-coding regions contains multiple repeats of a tRNA-like sequence. Some of the tRNA genes appear to overlap on the same strand, but this could be resolved if the polycistron were cleaved at the beginning of the downstream gene, followed by polyadenylation of the product of the upstream gene to form a fully paired structure. Conclusion Nautilus macromphalus mtDNA contains an expected gene content that has experienced few rearrangements since the evolutionary split between cephalopods and polyplacophorans. It contains an

  14. Recombinant thermoactive phosphoenolpyruvate carboxylase (PEPC) from Thermosynechococcus elongatus and its coupling with mesophilic/thermophilic bacterial carbonic anhydrases (CAs) for the conversion of CO2 to oxaloacetate.

    Science.gov (United States)

    Del Prete, Sonia; De Luca, Viviana; Capasso, Clemente; Supuran, Claudiu T; Carginale, Vincenzo

    2016-01-15

    With the continuous increase of atmospheric CO2 in the last decades, efficient methods for carbon capture, sequestration, and utilization are urgently required. The possibility of converting CO2 into useful chemicals could be a good strategy to both decreasing the CO2 concentration and for achieving an efficient exploitation of this cheap carbon source. Recently, several single- and multi-enzyme systems for the catalytic conversion of CO2 mainly to bicarbonate have been implemented. In order to design and construct a catalytic system for the conversion of CO2 to organic molecules, we implemented an in vitro multienzyme system using mesophilic and thermophilic enzymes. The system, in fact, was constituted by a recombinant phosphoenolpyruvate carboxylase (PEPC) from the thermophilic cyanobacterium Thermosynechococcus elongatus, in combination with mesophilic/thermophilic bacterial carbonic anhydrases (CAs), for converting CO2 into oxaloacetate, a compound of potential utility in industrial processes. The catalytic procedure is in two steps: the conversion of CO2 into bicarbonate by CA, followed by the carboxylation of phosphoenolpyruvate with bicarbonate, catalyzed by PEPC, with formation of oxaloacetate (OAA). All tested CAs, belonging to α-, β-, and γ-CA classes, were able to increase OAA production compared to procedures when only PEPC was used. Interestingly, the efficiency of the CAs tested in OAA production was in good agreement with the kinetic parameters for the CO2 hydration reaction of these enzymes. This PEPC also revealed to be thermoactive and thermostable, and when coupled with the extremely thermostable CA from Sulphurhydrogenibium azorense (SazCA) the production of OAA was achieved even if the two enzymes were exposed to temperatures up to 60 °C, suggesting a possible role of the two coupled enzymes in biotechnological processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Isobutanol production as an alternative metabolic sink to rescue the growth deficiency of the glycogen mutant of Synechococcus elongatus PCC 7942

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    Li, XQ; Shen, CR; Liao, JC

    2014-03-04

    Glycogen synthesis initiated by glucose-1-phosphate adenylyltransferase (glgC) represents a major carbon storage route in cyanobacteria which could divert a significant portion of assimilated carbon. Significant growth retardation in cyanobacteria with glgC knocked out (Delta glgC) has been reported in high light conditions. Here, we knocked out the glgC gene and analyzed its effects on carbon distribution in an isobutanol-producing strain of Synechococcus elongatus PCC7942 and its parental wild-type strain. We showed that isobutanol production was able to partially rescue the growth of Delta glgC mutant where the growth rescue effect positively correlated with the rate of isobutanol production. Using (NaHCO3)-C-14 incorporation analysis, we observed a 28 % loss of total carbon fixation rate in the Delta glgC mutant compared to the wild-type. Upon expression of the isobutanol production pathway in Delta glgC mutant, the total carbon fixation rate was restored to the wild-type level. Furthermore, we showed that 52 % of the total carbon fixed was redirected into isobutanol biosynthesis in the Delta glgC mutant expressing enzymes for isobutanol production, which is 2.5 times higher than that of the wild-type expressing the same enzymes. These results suggest that biosynthesis of non-native product such as isobutanol can serve as a metabolic sink for replacing glycogen to rescue growth and restore carbon fixation rate. The rescue effect may further serve as a platform for cyanobacteria energy and carbon metabolism study.

  16. Development of a high-frequency in vivo transposon mutagenesis system for Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Watabe, Kazuyuki; Mimuro, Mamoru; Tsuchiya, Tohru

    2014-11-01

    Synechocystis sp. PCC 6803 (Synechocystis) is the first sequenced photosynthetic organism and has two advantages: natural transformation and light-activated heterotrophic growth. Such characteristics have mainly promoted reverse genetic analysis in this organism, however, to date approximately 50% of genes are still annotated as 'unknown protein' or 'hypothetical protein'. Therefore, forward genetic analysis is required for the identification of significant genes responsible for photosynthesis and other physiological phenomena among the genes of unknown function. The in vivo transposon mutagenesis system is one of the major methods for random mutagenesis. However, present in vivo transposon mutagenesis systems for cyanobacteria face problems such as relatively low frequency of transposition and repeated transposition in the host cells. In this study, we constructed vectors based on a mini-Tn5-derived vector that was designed to prevent repeated transposition. Our vectors carry a hyperactive transposase and optimized recognition sequence of transposase, which were reported to enhance frequency of transposition. Using the vector, we succeeded in highly frequent transposition (9×10(-3) per recipient cell) in Synechocystis. Transposon insertion sites of 10 randomly selected mutants indicated that the insertion sites spread throughout the genome with low sequence dependency. Furthermore, one of the 10 mutants exhibited the slow-growing phenotype, and the mutant was functionally complemented by using our expression vector. Our system also worked with another model cyanobacterium, Synechococcus elongatus PCC 7942, with high frequency. These results indicate that the developed system can be applied to the forward genetic analysis of a broad range of cyanobacteria. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. Genetic variability of wild populations of Leporinus elongatus in the São Domingos River - MS Brazil: a preliminary view on the construction of the hydroelectric plant

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    Ricardo Pereira Ribeiro

    2016-09-01

    Full Text Available Most of the electricity used in Brazil comes from hydroelectric plants, mainly due to the great availability of its water resources. However, the construction of these plants denotes serious problems related to migration of native fish and the genetic conservation of stocks. Current study evaluates two wild population of Leporinus elongatus (piapara located downstream (Population A - PopA and upstream (Population B - PopB of the Cachoeira Branca before the construction of the São Domingos hydroelectric plant (HPP in the Mato Grosso do Sul State, Brazil. Thirty samples from caudal fins were collected and analyzed for each population. Eighty-nine fragments, including 72 polymorphic ones (80.9%, were analyzed. Low fragments (less than 0.100 in both populations (PopA = 2 and PopB = 3 were identified. Nine fixed fragments (frequency 1.000 (PopA = 3 and PopB = 6, and four exclusive fragments (PopA = 3 and PopB = 1 were also reported. The genetic variability within populations, calculated by Shannon Index and by percentage of polymorphic fragments, indicated high rates of intrapopulation variability (PopA = 0.309 and 61.80% and PopB = 0.392 and 71.90%, respectively. Genetic distance and identity rates (0.089 and 0.915, respectively were different between populations, whilst AMOVA showed that most variations lie within the populations and not between them. Fst and Nm rates showed moderate genetic differentiation with low numbers of migrants. Results reveal populations with high intra-population genetic variability and genetic differentiation, with low gene flow. The passage ladders of São Domingos HPP should control fish transposition to preserve genetic variability.

  18. Combined SAXS/EM based models of the S. elongatus post-translational circadian oscillator and its interactions with the output His-kinase SasA.

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    Rekha Pattanayek

    Full Text Available The circadian clock in the cyanobacterium Synechococcus elongatus is composed of a post-translational oscillator (PTO that can be reconstituted in vitro from three different proteins in the presence of ATP and a transcription-translation feedback loop (TTFL. The homo-hexameric KaiC kinase, phosphatase and ATPase alternates between hypo- and hyper-phosphorylated states over the 24-h cycle, with KaiA enhancing phosphorylation, and KaiB antagonizing KaiA and promoting KaiC subunit exchange. SasA is a His kinase that relays output signals from the PTO formed by the three Kai proteins to the TTFL. Although the crystal structures for all three Kai proteins are known, atomic resolution structures of Kai and Kai/SasA protein complexes have remained elusive. Here, we present models of the KaiAC and KaiBC complexes derived from solution small angle X-ray scattering (SAXS, which are consistent with previous EM based models. We also present a combined SAXS/EM model of the KaiC/SasA complex, which has two N-terminal SasA sensory domains occupying positions on the C-terminal KaiC ring reminiscent of the orientations adopted by KaiB dimers. Using EM we demonstrate that KaiB and SasA compete for similar binding sites on KaiC. We also propose an EM based model of the ternary KaiABC complex that is consistent with the sequestering of KaiA by KaiB on KaiC during the PTO dephosphorylation phase. This work provides the first 3D-catalogue of protein-protein interactions in the KaiABC PTO and the output pathway mediated by SasA.

  19. In vitro kinetics of P700+reduction of Thermosynechococcus elongatus trimeric Photosystem I complexes by recombinant cytochrome c6using a Joliot-type LED spectrophotometer.

    Science.gov (United States)

    Nguyen, Khoa; Vaughn, Michael; Frymier, Paul; Bruce, Barry D

    2017-01-01

    The reduction rate of photo-oxidized Photosystem I (PSI) with various natural and artificial electron donors have been well studied by transient absorption spectroscopy. The electron transfer rate from various donors to P 700 + has been measured for a wide range of photosynthetic organisms encompassing cyanobacteria, algae, and plants. PSI can be a limiting component due to tedious extraction and purification methods required for this membrane protein. In this report, we have determined the in vivo, intracellular cytochrome c 6 (cyt c 6 )/PSI ratio in Thermosynechococcus elongatus (T.e.) using quantitative Western blot analysis. This information permitted the determination of P 700 + reduction kinetics via recombinant cyt c 6 in a physiologically relevant ratio (cyt c 6 : PSI) with a Joliot-type, LED-driven, pump-probe spectrophotometer. Dilute PSI samples were tested under varying cyt c 6 concentration, temperature, pH, and ionic strength, each of which shows similar trends to the reported literature utilizing much higher PSI concentrations with laser-based spectrophotometer. Our results do however indicate kinetic differences between actinic light sources (laser vs. LED), and we have attempted to resolve these effects by varying our LED light intensity and duration. The standardized configuration of this spectrophotometer will also allow a more uniform kinetic analysis of samples in different laboratories. We can conclude that our findings from the LED-based system display an added total protein concentration effect due to multiple turnover events of P 700 + reduction by cyt c 6 during the longer illumination regime.

  20. Sulfite-stress induced functional and structural changes in the complexes of photosystems I and II in a cyanobacterium, Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Kobayashi, Satomi; Tsuzuki, Mikio; Sato, Norihiro

    2015-08-01

    Excess sulfite is well known to have toxic effects on photosynthetic activities and growth in plants, however, so far, the behavior of the photosynthetic apparatus during sulfite-stress has not been characterized as to the responsible proteins or genes. Here, the effects of sulfite on photosystem complexes were investigated in a cyanobacterium, Synechococcus elongatus PCC 7942, a possible model organism of chloroplasts. Culturing of the cells for 24 h in the presence of 10 mM sulfite retarded cell growth of the wild type, concomitantly with synthesis of Chl and phycobilisome repressed. The excess sulfite simultaneously repressed photosynthesis by more than 90%, owing largely to structural destabilization and resultant inactivation of the PSII complex, which seemed to consequently retard the cell growth. Notably, the PsbO protein, one of the subunits that construct the water-splitting system of PSII, was retained at a considerable level, and disruption of the psbO gene led to higher sensitivity of photosynthesis and growth to sulfite. Meanwhile, the PSI complex showed monomerization of its trimeric configuration with little effect on the activity. The structural alterations of these PS complexes depended on light. Our data provide evidence for quantitative decreases in the photosystem complex(es) including their antenna(e), structural alterations of the PSI and PSII complexes that would modulate their functions, and a crucial role of psbO in PSII protection, in Synechococcus cells during sulfite-stress. We suggest that the reconstruction of the photosystem complexes is beneficial to cell survival. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. Assessing metal contamination from construction and demolition (C&D) waste used to infill wetlands: using Deroceras reticulatum (Mollusca: Gastropoda).

    Science.gov (United States)

    Staunton, John A; Mc Donnell, Rory J; Gormally, Michael J; Williams, Chris D; Henry, Tiernan; Morrison, Liam

    2014-11-01

    Large quantities of construction and demolition waste (C&D) are produced globally every year, with little known about potential environmental impacts. In the present study, the slug, Deroceras reticulatum (Mollusca: Gastropoda) was used as the first biomonitor of metals (Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Ti, Tl, V and Zn) on wetlands post infilling with construction and demolition (C&D) waste. The bioaccumulation of As, Ba, Cd, Co, Sb, Se and Tl were found to be significantly elevated in slugs collected on C&D waste when compared to unimproved pastures (control sites), while Mo, Se and Sr had significantly higher concentrations in slugs collected on C&D waste when compared to known contaminated sites (mining locations), indicating the potential hazardous nature of C&D waste to biota. Identifying exact sources for these metals within the waste can be problematic, due to its heterogenic nature. Biomonitors are a useful tool for future monitoring and impact studies, facilitating policy makers and regulations in other countries regarding C&D waste infill. In addition, improving separation of C&D waste to allow increased reuse and recycling is likely to be effective in reducing the volume of waste being used as infill, subsequently decreasing potential metal contamination.

  2. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda in the Museum für Naturkunde, Berlin

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    Abraham Breure

    2013-03-01

    Full Text Available The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum für Naturkunde der Humboldt-Universität zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Z. quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = O. bensoni (Reeve, 1849; Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Bruguière, 1789; Porphyrobaphe (Myiorthalicus dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848; Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909; Orthalicus (Laeorthalicus reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821; Bulimus (Eurytus corticosus Sowerby III, 1895 = Plekocheilus (Eurytus stuebeli Martens, 1885. The taxon Bulimus (Eudioptus psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by Köhler 2007 and a partial list of letters present in the correspondence archives.

  3. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Museum für Naturkunde, Berlin.

    Science.gov (United States)

    Breure, Abraham S H

    2013-01-01

    The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum für Naturkunde der Humboldt-Universität zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Zebra quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = Orthalicus bensoni (Reeve, 1849); Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Bruguière, 1789); Porphyrobaphe (Myiorthalicus) dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848); Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909); Orthalicus (Laeorthalicus) reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821); Bulimus (Eurytus) corticosus Sowerby III, 1895 = Plekocheilus (Eurytus) stuebeli Martens, 1885. The taxon Bulimus (Eudioptus) psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by Köhler 2007) and a partial list of letters present in the correspondence archives.

  4. Comunidades de quitones (Mollusca: Polyplacophora de la Bahía de La Paz, Baja California Sur, México

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    Cedar I García Ríos

    2007-03-01

    Full Text Available A las ocho especies de poliplacóforos registradas en Bahía de la Paz, Baja California Sur, México, o cerca de ella, agregamos a Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata y Acanthochitona arragonites. El análisis de las comunidades estudiadas usando técnicas de ordenación sugiere que podría relacionarse la exposición al oleaje con la riqueza y la diversidad de especies. La comunidad recolectada en condiciones intermedias de exposición al oleaje presentó mayor número de especies y mayor diversidad de acuerdo con el índice de Shannon.Polyplacophoran communities (Mollusca: Polyplacophora at Bahía de La Paz, Baja California Sur, México. Eight species of polyplacophorans have been reported from La Bahía de la Paz, Baja California Sur, Mexico. We add Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata and Acanthochitona arragonites, increasing the known number of species to 15. Ordination analysis of five chiton communities at the site suggests a correlation of wave exposure to species composition and diversity: communities with intermediate wave exposure have more species (richness and higher diversity (Shannon’s index. Rev. Biol. Trop. 55 (1: 177-182. Epub 2007 March. 31.

  5. ON THE PALEOFAUNA INVERTEBRATES (MOLLUSCA, ARTROPODA; INSECTA OF DIATOMITE DEPOSITS OF SHAMB–1 LOCALITY (SISIAN SUITE, EARLY PLEISTOCENE, ARMENIA

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    М. A. Маrjanyan

    2016-01-01

    Full Text Available Aim. The study of fossil insects from diatomaceous sediments of Shamb-1 locality of Sisian Suite (Early Pleistocene. The collection of fossils plants and animals of Institute of Botany of NAS RA and authors' findings served as material for study.Methods. The material is processed and prepared for study by conventional methods in paleontology for prints and fossils of insects from diatomaceous sediments. There are 654 samples studied: 2 samples were with mollusks’ imprints and 652 samples with imprints of insects, from which preserved marks on 291samples allowed to identify them up to order, family, genus and species.Results. The studied material refers to the Mollusca and Arthropoda (Insecta types. Insects are represented by species of orders Orthoptera (2 fam., Homoptera (1 fam., Heteroptera (2 fam., Coleoptera (15 fam., Hymenoptera (2 fam., Diptera (1 fam.. Coleopteras dominate among them and are presented with following species of the family – Carabidae, Dytiscidae, Hydrophilidae, Histeridae, Staphylinidae, Silphidae, Elateridae, Buprestidae, Lampyridae, Scarabaeidae, Chrysomelidae, Tenebrionidae, Coccinellidae, Cerambycidae, Curculionidae.Main conclusions. An analysis of the taxonomic composition of paleofauna was done, which corresponds to the recent fauna and with considering modern ecological characteristics of systematical groups and species. In the investigated location of Shamb-1 a version is suggested about the palaeolandscapes and palaeoclimate in the Early Pleistocene.

  6. The influence of fish cage culture on δ13C and δ15N of filter-feeding Bivalvia (Mollusca

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    E. Benedito

    Full Text Available The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ13C and δ15N in Corbicula fluminea (Mollusca; Bivalvia and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP. Samples of specimens of the bivalve filterer C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ13C and nitrogen (δ15N isotopic value analysis in a mass spectrometer. There were significant differences in the δ13C and δ15N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ13C and δ15N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem.

  7. Mitochondrial gene order evolution in Mollusca: Inference of the ancestral state from the mtDNA of Chaetopleura apiculata (Polyplacophora, Chaetopleuridae).

    Science.gov (United States)

    Guerra, Davide; Bouvet, Karim; Breton, Sophie

    2018-03-01

    The mitochondrial genome architecture of polyplacophorans has been usually regarded as being very ancient in comparison to all mollusks. However, even if some complete chiton mtDNAs have been recently sequenced, thorough studies of their evolution are lacking. To further expand the set of complete chiton mtDNAs and perform such analysis, we sequenced the mitochondrial genome of the Eastern beaded chiton Chaetopleura apiculata (Chaetopleuridae) using next-generation sequencing. With mitochondrial sequences from all available chiton mtDNAs, we also built a phylogeny on which we reconstructed the evolution of gene arrangement in this class. The arrangement of C. apiculata proved to be the most primitive known so far for polyplacophorans. Comparing this gene order to those of other molluscan classes, we found that it most probably is the original gene order of the last common ancestor to all extant Mollusca. The ancient mitochondrial genome organization of C. apiculata is an important information that may help reconstructing the phylogeny of Mollusca and their relationship with other lophotrochozoans. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Diversidade genética de três estoques de piapara (Leporinus elongatus, utilizando RAPD - DOI: 10.4025/actascianimsci.v30i2.4710 Genetic diversity of three stocks of piapara (Leporinus elongatus, using RAPD - DOI: 10.4025/actascianimsci.v30i2.4710

    Directory of Open Access Journals (Sweden)

    Lauro Vargas

    2008-08-01

    Full Text Available Recentemente a produção aquícola brasileira tem apresentado grande progresso. Dentre as espécies nativas cultivadas no Brasil, a piapara (Leporinus elongatus tem sido amplamente preconizada. Com objetivo de avaliar os programas de repovoamento, foram analisadas a variabilidade e a divergência genética de três estoques de piapara com a técnica de RAPD (Random Amplified Polymorphic. O primeiro estoque pertence à Estação de Aquicultura e Hidrologia da Duke Energy International (A; o segundo, à piscicultura de Rolândia (B e o terceiro, ao Programa de Repovoamento dos Rios do Paraná (C. Os dez primers para RAPD utilizados produziram 105 fragmentos polimórficos, conferindo um polimorfismo de 98,1% para os três estoques avaliados. A porcentagem de locos polimórficos e índice de Shannon foi superior para o estoque A. Porém, todos valores foram elevados, indicando alta diversidade intrapopulacional. Os valores de indicam que houve baixa diferenciação genética entre os estoques A x B e moderada diferenciação entre os demais. O Nm foi maior entre os estoques A x B. A distância genética e o dendrograma indicam que os estoques A x B são menos distantes geneticamente.Latelly, aquiculture production in Brazil has made great strides. Among the native species cultivated in Brazil, piapara (Leporinus elogatus has been widely praised. With the objective of evaluating restocking programs, the variability and genetic divergence of three piapara stocks were analyzed using the RAPD (Random Amplified Polymorphic DNA technique. The first stock belongs to the Aquiculture and Hydrology Station of Duke Energy International (A; the second one belongs to a fish farm in the city of Rolândia (B; and the third to the River Restocking Program of Paraná (C. The ten primers used for RAPD produced 105 polymorphic loci, conferring a polymorphism of 98.1% for the three evaluated stocks. Polymorphic loci percentage and Shannon index were higher for stock A

  9. Molecular phylogenetic analysis supports a Gondwanan origin of the Hyriidae (Mollusca: Bivalvia: Unionida) and the paraphyly of Australasian taxa.

    Science.gov (United States)

    Graf, Daniel L; Jones, Hugh; Geneva, Anthony J; Pfeiffer, John M; Klunzinger, Michael W

    2015-04-01

    The freshwater mussel family Hyriidae (Mollusca: Bivalvia: Unionida) has a disjunct trans-Pacific distribution in Australasia and South America. Previous phylogenetic analyses have estimated the evolutionary relationships of the family and the major infra-familial taxa (Velesunioninae and Hyriinae: Hyridellini in Australia; Hyriinae: Hyriini, Castaliini, and Rhipidodontini in South America), but taxon and character sampling have been too incomplete to support a predictive classification or allow testing of biogeographical hypotheses. We sampled 30 freshwater mussel individuals representing the aforementioned hyriid taxa, as well as outgroup species representing the five other freshwater mussel families and their marine sister group (order Trigoniida). Our ingroup included representatives of all Australian genera. Phylogenetic relationships were estimated from three gene fragments (nuclear 28S, COI and 16S mtDNA) using maximum parsimony, maximum likelihood, and Bayesian inference, and we applied a Bayesian relaxed clock model calibrated with fossil dates to estimate node ages. Our analyses found good support for monophyly of the Hyriidae and the subfamilies and tribes, as well as the paraphyly of the Australasian taxa (Velesunioninae, (Hyridellini, (Rhipidodontini, (Castaliini, Hyriini)))). The Hyriidae was recovered as sister to a clade comprised of all other Recent freshwater mussel families. Our molecular date estimation supported Cretaceous origins of the major hyriid clades, pre-dating the Tertiary isolation of South America from Antarctica/Australia. We hypothesize that early diversification of the Hyriidae was driven by terrestrial barriers on Gondwana rather than marine barriers following disintegration of the super-continent. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Mollusca.

    Science.gov (United States)

    Wiklund, Helena; Taylor, John D; Dahlgren, Thomas G; Todt, Christiane; Ikebe, Chiho; Rabone, Muriel; Glover, Adrian G

    2017-01-01

    We present the first DNA taxonomy publication on abyssal Mollusca from the Clarion-Clipperton Zone (CCZ), central Pacific ocean, using material collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise 'AB01' to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration area 'UK-1' in the eastern CCZ. This is the third paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Taxonomic data are presented for 21 species from 42 records identified by a combination of morphological and genetic data, including molecular phylogenetic analyses. These included 3 heterodont bivalves, 5 protobranch bivalves, 4 pteriomorph bivalves, 1 caudofoveate, 1 monoplacophoran, 1 polyplacophoran, 4 scaphopods and 2 solenogastres. Gastropoda were recovered but will be the subject of a future study. Seven taxa matched published morphological descriptions for species with deep Pacific type localities, and our sequences provide the first genetic data for these taxa. One taxon morphologically matched a known cosmopolitan species but with a type locality in a different ocean basin and was assigned the open nomenclature ' cf ' as a precautionary approach in taxon assignments to avoid over-estimating species ranges. One taxon is here described as a new species, Ledella knudseni sp. n. For the remaining 12 taxa, we have determined them to be potentially new species, for which we make the raw data, imagery and vouchers available for future taxonomic study. The Clarion-Clipperton Zone is a region undergoing intense exploration for potential deep-sea mineral extraction. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections.

  11. Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Mollusca

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    Helena Wiklund

    2017-10-01

    Full Text Available We present the first DNA taxonomy publication on abyssal Mollusca from the Clarion-Clipperton Zone (CCZ, central Pacific ocean, using material collected as part of the Abyssal Baseline (ABYSSLINE environmental survey cruise ‘AB01’ to the UK Seabed Resources Ltd (UKSRL polymetallic-nodule exploration area ‘UK-1’ in the eastern CCZ. This is the third paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Taxonomic data are presented for 21 species from 42 records identified by a combination of morphological and genetic data, including molecular phylogenetic analyses. These included 3 heterodont bivalves, 5 protobranch bivalves, 4 pteriomorph bivalves, 1 caudofoveate, 1 monoplacophoran, 1 polyplacophoran, 4 scaphopods and 2 solenogastres. Gastropoda were recovered but will be the subject of a future study. Seven taxa matched published morphological descriptions for species with deep Pacific type localities, and our sequences provide the first genetic data for these taxa. One taxon morphologically matched a known cosmopolitan species but with a type locality in a different ocean basin and was assigned the open nomenclature ‘cf’ as a precautionary approach in taxon assignments to avoid over-estimating species ranges. One taxon is here described as a new species, Ledella knudseni sp. n. For the remaining 12 taxa, we have determined them to be potentially new species, for which we make the raw data, imagery and vouchers available for future taxonomic study. The Clarion-Clipperton Zone is a region undergoing intense exploration for potential deep-sea mineral extraction. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections.

  12. Evaluation of uptake and chronic toxicity of virgin polystyrene microbeads in freshwater zebra mussel Dreissena polymorpha (Mollusca: Bivalvia).

    Science.gov (United States)

    Magni, Stefano; Gagné, François; André, Chantale; Della Torre, Camilla; Auclair, Joëlle; Hanana, Houda; Parenti, Camilla Carla; Bonasoro, Francesco; Binelli, Andrea

    2018-08-01

    Microplastics (MPs), plastic debris smaller than 5mm, are widely found in both marine and freshwater ecosystems. However, few studies regarding their hazardous effects on inland water organisms, have been conducted. For this reason, the aim of our research was the evaluation of uptake and chronic toxicity of two mixtures (MIXs) of virgin polystyrene microbeads (PMs) of 10μm and 1μm in size (MIX 1, with 5×10 5 of 1μmsizePMs/L and 5×10 5 of 10μmsizePMs/L, and MIX 2 with 2×10 6 of 1μmsizePMs/L and 2×10 6 of 10μmsizePMs/L) on freshwater zebra mussel Dreissena polymorpha (Mollusca: Bivalvia) during 6 exposure days. The PM uptake in the mussel body and hemolymph was assessed using confocal microscopy, while the chronic toxicity of PMs was evaluated on exposed mussels using a comprehensive battery of biomarkers of cellular stress, oxidative damage and neuro- genotoxicity. Confocal microscopy analyses showed that MPs concentrated in the gut lumen of exposed mussels, absorbed and transferred firstly in the tissues and then in the hemolymph. The results revealed that PMs do not produce oxidative stress and genetic damage, with the exception of a significant modulation of catalase and glutathione peroxidase activities in mussels exposed to MIX 1. Regarding neurotoxicity, we observed only a significant increase of dopamine concentration in mussels exposed to both MIXs, suggesting a possible implication of this neurotransmitter in an elimination process of accumulated PMs. This research represents a first study about the evaluation of virgin MP toxicity in zebra mussel and more research is warranted concerning the long term neurological effects of virgin MPs. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  13. On Pomacea sordida (Swainson, 1823 (Prosobranchia, Ampullariidae Sobre Pomacea sordida (Swaison, 1823 (Prosobranchia, Ampullariidae

    Directory of Open Access Journals (Sweden)

    Silvana Carvalho Thiengo

    1989-09-01

    Full Text Available A description of Pomacea sordida (Swainson, 1823 collected in Caxias and Nova Iguaçu, state of Rio de Janeiro, is presented. The shell is globose, heavy, whith greenish or horn-colored periostracum and dark spinal bands; apex subelevated, 4-5 moderately shoudered whorls, increasing rather rapidly and separated by deep suture. Aperture large, moderately round, yellowish or violaceous; lip thick and sometimes dark brown; umbilicus large and deep; operculum corneous and heavy, entirely closing the aperture. Ratios: shell width/shell length = 0.81-0.91 (mean 0.86; aperture length/shell length = 0.66-0.75 (mean 0.70. Testis, spermiduct and penis pouch as in Pomacea lineata (Spix, 1827. Seminal vesicle whitish and bean-shaped. Prostate cylindric and narrow, cream in coloar as the testis. Penis whiplike whith a closed circular spermiduct. Penial sheath elongated and tapered, with its distal tip turned to the right; outer basal gland situated on the left; inner median gland rounded; apical gland elongated and wrinkled. Ovary composed of branched whitish tubules lying superficially on the digestive gland; oviduct and seminal receptacle as in P. lineata; albumen gland yellowish - orange. Vestigial male copulatory apparatus (penis and its sheath present in all females examined.Nesse trabalho é apresentada a descrição de Pomacea sordida (Swainson, 1823, coletada em Caxias e Nova Iguaçu, Estado do Rio de Janeiro. Concha globosa, espessa, com perióstraco esverdeado ou castanho e com faixas espirais escuras; ápice pouco elevado, 4-5 giros moderadamente arredondados, crescendo relativamente rápido, separados por suturas profundas. Abertura grande, moderadamente arredondada, amarelada ou violácea; lábio espesso e algumas vezes marrom escuro; umbílico grande e profundo; opérculo córneo e espesso, fechando completamente a abertura. Razões: largura da concha/comprimento da concha=0.81-0.91 (média 0.86; comprimento da abertura/comprimento da concha=0.66-0.75 (média 0.70. Testículo, espermiduto e bolsa do pênis como em Pomacea lineata (Spix, 1827. Vesícula seminal esbranquiçada e em forma de feijão. Próstata cilíndrica e estreita, de cor creme como o testículo. Pênis em forma de chicote, com espermiduto circular e fechado. Bainha do pênis alongada tendo sua largura diminuída da base para a extremidade, sendo esta última voltada para a direita; glândula basal extrema situada à esquerda; glândula mediana interna arredondada; glândula apical alongada e com sulcos. Ovário composto de túbulos brancos ramificados dispostos superficialmente sobre a glândula digestiva verde. Oviduto e receptáculo seminal como em P. lineata; glândula de albume de cor alaranjada; ovos prismáticos e calcáreos de cor alaranjada. Aparelho copulador masculino vestigial (pênis e sua bainha presente em todas as fêmeas examinadas.

  14. First record of Stibarobdella moorei (Annelida, Hirudinea, Piscicolidae a marine leech parasitizing Octopus bimaculatus (Mollusca: Octopodidae from the Mexican Pacific coast

    Directory of Open Access Journals (Sweden)

    López-Peraza D. J.

    2017-12-01

    Full Text Available The occurrence of the parasitic marine leech Stibarobdella moorei (Oka, 1910 (Hirudinea: Piscicolidae along the northwest Mexican Pacific coast is described for the first time. This ectoparasite was collected from the skin of the Octopus bimaculatus (Verril, 1983 (Mollusca: Octopodidae. Stibarobdella loricata (Hardig, 1924 is synonymized with S. moorei as this species resembles other species of the genus based on tubercle patterns and the presence of papillae and a marginal fringe on the oral sucker. The present finding throws new light on the biodiversity and host preference of the ectoparasite and suggests a successful migration to unusual host. The coast of the Pacific Ocean, particularly in the Bay of Los Angeles, Baja California, Mexico is a new geographical distribution area for S. moorei, and O. bimaculatus is a new host reported for this leech. The morphology of this ectoparasite is briefly described.

  15. Fauna Europaea: Mollusca - Bivalvia

    NARCIS (Netherlands)

    Araujo, R.; de Jong, Y.

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The

  16. (Born, 1778) (Mollusca: Bivalvia)

    African Journals Online (AJOL)

    1988-05-27

    May 27, 1988 ... settled animals reached a total length of 19 mm in their first year. ..... showing maximum, mean and minimum growth with the mean growth equation. The curves are extrapolated beyond five years to show the estimated age of the largest individuals .... possibility of differential growth within Dwesa cannot be.

  17. (Lamark) (Mollusca: Bivalvia)

    African Journals Online (AJOL)

    Approximately eight species of burrowing bivalves are fairly common in the .... bombed in an adiabatic bomb calorimeter. Duplicates were ..... the same species. Its initial rate of growth was faster, while that for the fourth and fifth years was much slower. The estimated maximum potential life span of 8 - 9 years for D. hepatica ...

  18. The influence of fish cage culture on δ{sup 13}C and δ{sup 15}N of filter-feeding Bivalvia (Mollusca)

    Energy Technology Data Exchange (ETDEWEB)

    Benedito, E.; Takeda, A.M., E-mail: eva@nupelia.uem.br [Universidade Estadual de Maringa (UEM), PR (Brazil). Nucleo de Pesquisas em Limnologia, Ictiologia e Aquicultura; Figueroa, L. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Ecologia de Ambientes Aquaticos Continentais; Manetta, GI. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Biologia Comparada

    2013-11-15

    The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ{sup 13}C and δ{sup 15}N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filter C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ{sup 13}C and δ{sup 15}N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ{sup 13}C and δ{sup 15}N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem. (author)

  19. A massive ingression of the alien species Mytilus edulis L. (Bivalvia: Mollusca into the Mediterranean Sea following the Costa Concordia cruise-ship disaster

    Directory of Open Access Journals (Sweden)

    E. CASOLI

    2016-03-01

    Full Text Available The Costa Concordia cruise-ship disaster occurred just off the coast of Italy on January 13th, 2012, and entailed the largest marine salvage operation in history. The salvage employed vessels from different European harbours, providing an unexpected means for transporting alien species into the Mediterranean. In this work we identified mussel species using fragments length polymorphism of a nuclear locus and report the first evidence of the transport of the blue mussel, Mytilus edulis Linnaeus, 1758 (Bivalvia: Mollusca, into the Mediterranean Sea, as a part of the fouling community of the hull of an accommodation barge arrived from a NE Atlantic location in October 2012. Furthermore, we describe the rapid growth of this species, under the ASV Pioneer, until its almost total extinction during the summer of 2013, which left a covering of mussel shells on the underlying Posidonia oceanica (Linnaeus Delile, 1813. meadow. This high mortality rate indicated that M. edulis had been exposed to high stress conditions, probably due to different salinity, temperature, and oligotrophic conditions from its place of origin, and there was no spawning event or known settlement on the nearest infralittoral natural habitats. This event reminds us of how the Mediterranean Sea is constantly under alien-species pressure, due to human activities.

  20. O desenvolvimento embrionário da Piapara, Leporinus elongatus (Pisces, Anostomidae, utilizando técnicas de histologia, microscopia eletrônica de varredura e imunológicas empregando marcadores ósseos

    Directory of Open Access Journals (Sweden)

    Erika Z. Sousa

    2014-12-01

    Full Text Available Resumo O desenvolvimento embrionário dos peixes é de grande importância para a piscicultura e na reintrodução de espécies ameaçadas de extinção em seus ambientes, e seu conhecimento constitui uma importante maneira para minimizar doenças e mortalidades dessas espécies. Com o auxílio de técnicas como a Microscopia Eletrônica de Varredura (MEV e a imuno-histoquimica para identificar proteínas ósseas, foi possível avaliar as fases de desenvolvimento com mais riqueza de detalhes, facilitando a compreensão de hábitos e da biologia da espécie. Neste trabalho pudemos observar a ontogenia e osteogênese da Piapara (Leporinus elongatus, desde a fecundação até a fase juvenil, sendo evidenciadas estruturas importantes como o tamanho do vitelo, essencial para a nutrição do embrião; o fechamento do blastóporo, evento principal da embriogênese, que indica as taxas de fertilização; a metamorfose, que indica a formação dos primeiros e principais órgãos do animal e a formação de sua estrutura óssea. As Proteínas Ósseas Morfogenéticas (BMP-2 e BMP-4, moléculas essenciais reguladoras no desenvolvimento embrionário e na formação óssea, foram observadas apenas no estádio larval até o período juvenil, não sendo evidenciadas nos estágios anteriores. Os resultados desse trabalho trouxeram novas informações quanto à biologia do desenvolvimento dessa espécie, que certamente poderão auxiliar no aprimoramento de técnicas reprodutivas visando uma melhora na sua produção seja para fins comerciais ou de repovoamento.

  1. Megafauna of the UKSRL exploration contract area and eastern Clarion-Clipperton Zone in the Pacific Ocean: Annelida, Arthropoda, Bryozoa, Chordata, Ctenophora, Mollusca

    Science.gov (United States)

    Ziegler, Amanda F; Drazen, Jeffrey C; Grischenko, Andrei V; Leitner, Astrid B; Lindsay, Dhugal J; Voight, Janet R; Wicksten, Mary K; Young, Craig M; Smith, Craig R

    2017-01-01

    Abstract Background There is growing interest in mining polymetallic nodules from the abyssal Clarion-Clipperton Zone (CCZ) in the tropical Pacific Ocean. Despite having been the focus of environmental studies for decades, the benthic megafauna of the CCZ remain poorly known. To predict and manage the environmental impacts of mining in the CCZ, baseline knowledge of the megafauna is essential. The ABYSSLINE Project has conducted benthic biological baseline surveys in the UK Seabed Resources Ltd polymetallic-nodule exploration contract area (UK-1). Prior to ABYSSLINE research cruises in 2013 and 2015, no biological studies had been done in this area of the eastern CCZ. New information Using a Remotely Operated Vehicle and Autonomous Underwater Vehicle (as well as several other pieces of equipment), the megafauna within the UK Seabed Resources Ltd exploration contract area (UK-1) and at a site ~250 km east of the UK-1 area were surveyed, allowing us to make the first estimates of megafaunal morphospecies richness from the imagery collected. Here, we present an atlas of the abyssal annelid, arthropod, bryozoan, chordate, ctenophore and molluscan megafauna observed and collected during the ABYSSLINE cruises to the UK-1 polymetallic-nodule exploration contract area in the CCZ. There appear to be at least 55 distinct morphospecies (8 Annelida, 12 Arthropoda, 4 Bryozoa, 22 Chordata, 5 Ctenophora, and 4 Mollusca) identified mostly by morphology but also using molecular barcoding for a limited number of animals that were collected. This atlas will aid the synthesis of megafaunal presence/absence data collected by contractors, scientists and other stakeholders undertaking work in the CCZ, ultimately helping to decipher the biogeography of the megafauna in this threatened habitat. PMID:28874906

  2. Megafauna of the UKSRL exploration contract area and eastern Clarion-Clipperton Zone in the Pacific Ocean: Annelida, Arthropoda, Bryozoa, Chordata, Ctenophora, Mollusca.

    Science.gov (United States)

    Amon, Diva J; Ziegler, Amanda F; Drazen, Jeffrey C; Grischenko, Andrei V; Leitner, Astrid B; Lindsay, Dhugal J; Voight, Janet R; Wicksten, Mary K; Young, Craig M; Smith, Craig R

    2017-01-01

    There is growing interest in mining polymetallic nodules from the abyssal Clarion-Clipperton Zone (CCZ) in the tropical Pacific Ocean. Despite having been the focus of environmental studies for decades, the benthic megafauna of the CCZ remain poorly known. To predict and manage the environmental impacts of mining in the CCZ, baseline knowledge of the megafauna is essential. The ABYSSLINE Project has conducted benthic biological baseline surveys in the UK Seabed Resources Ltd polymetallic-nodule exploration contract area (UK-1). Prior to ABYSSLINE research cruises in 2013 and 2015, no biological studies had been done in this area of the eastern CCZ. Using a Remotely Operated Vehicle and Autonomous Underwater Vehicle (as well as several other pieces of equipment), the megafauna within the UK Seabed Resources Ltd exploration contract area (UK-1) and at a site ~250 km east of the UK-1 area were surveyed, allowing us to make the first estimates of megafaunal morphospecies richness from the imagery collected. Here, we present an atlas of the abyssal annelid, arthropod, bryozoan, chordate, ctenophore and molluscan megafauna observed and collected during the ABYSSLINE cruises to the UK-1 polymetallic-nodule exploration contract area in the CCZ. There appear to be at least 55 distinct morphospecies (8 Annelida, 12 Arthropoda, 4 Bryozoa, 22 Chordata, 5 Ctenophora, and 4 Mollusca) identified mostly by morphology but also using molecular barcoding for a limited number of animals that were collected. This atlas will aid the synthesis of megafaunal presence/absence data collected by contractors, scientists and other stakeholders undertaking work in the CCZ, ultimately helping to decipher the biogeography of the megafauna in this threatened habitat.

  3. Introducción al estudio de los gasterópodos (Mollusca de la laguna de Montcortès (Pallars Sobirà, Cataluña, NE de la península ibérica

    Directory of Open Access Journals (Sweden)

    V. Bros

    2009-01-01

    Full Text Available Introduction to the study of gastropods (Mollusca on the Montcortés lake (Pallars Sobirà, Catlonia, NE of the Iberian peninsulaThe check-list of 50 species of terrestrial gastro­pod and freshwater molluscs in the Montcortès lake (Catalonia, Spain and its environs, pertaining to 24 different families, is shown. Thirty-three species are cited for the first time in the area of study. The unpublished data on their distribution and ecological requirements are contributed. The preliminary results indicate us that the communities of molluscs that accompany to the helofitic vegetation and the higrofits well are formed with elements of high faunistic and ecological interest. Simultaneously, some recommendations for the protection of the malacological fauna of the lake are commented.

  4. Variabilidad temporal de la abundancia de Coralliophila abbreviata y Coralliophila caribaea (Mollusca, Coralliophilidae en un arrecife coralino del Parque Nacional Morrocoy, Venezuela

    Directory of Open Access Journals (Sweden)

    Carlos del Mónaco

    2008-06-01

    Full Text Available C. abbreviata y C. caribaea son moluscos coralívoros del Mar Caribe. Evaluamos la variabilidad temporal de la abundancia y los cambios en la estructura de talla de C. abbreviata y C. caribaea en Cayo Sombrero, Venezuela (septiembre 2004-agosto 2005. Se colocaron transectas fijas de 50 metros de longitud a profundidades de tres y seis metros cada una, paralelas a la costa. Se evaluó mensualmente durante un año la densidad de ambos depredadores y se seleccionaron 30 individuos de C. abbreviata para medirlos cada mes. Las densidades de C. abbreviata en la transecta somera fluctuaron entre 1.78 ind/m² en septiembre y 6.26 ind/m² en mayo; las densidades de C. abbreviata en la transecta profunda estuvieron comprendidas entre 4.23 ind/m² en enero y 7.66 ind/m² en mayo. Las densidades de C. caribaea fluctuaron en la transecta somera entre 0 ind/m² (todos los meses menos septiembre y 0.03 ind/m² (septiembre mientras que la transecta profunda fluctuó entre 0 ind/m² (octubre a marzo y julio y 0.1 ind/m² (abril. La mayoría de los individuos de C. abbreviata midieron entre 12 y 16 mm de longitud. El largo de la mayoría de los individuos de C. caribaea estuvo comprendido entre 10 y 15 mm.Temporary abundance variation of Coralliophila abbreviata and Coralliophila caribaea (Mollusca, Coralliophilidae in a coral reef at Morrocoy National Park. The mollusks Coralliophila abbreviata and C. caribaea are coral predators in the Caribbean Sea . We evaluated the temporal variability of abundance and size structure of C. abbreviata and C. caribaea in Cayo Sombrero, Morrocoy National Park, Venezuelar (September 2004 - August 2005. The density of C. abbreviata and C. caribaea was evaluated monthly by means of two 50- meter long transects paralell to the coast line, at 3 m and 6 m deep; aditionally, 30 individuals of C. abbreviata were collected to measure size. The densities of C. abbreviata at the shallow transect fluctuated between 1.78 ind/m² in

  5. Biodiversidad de gasterópodos terrestres (Mollusca en el Parque Biológico Sierra de San Javier, Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    María José Miranda

    2010-09-01

    Full Text Available Se realizó un inventario y se analizaron parámetros de diversidad de la malacofauna terrestre del Parque Biológico Sierra de San Javier. Se llevaron a cabo muestreos cualitativos y cuantitativos en parcelas de 10x10m tomadas en transectas altitudinales, para un total de 22 169 especímenes recolectados. Las identificaciones taxonómicas se llevaron a cabo a nivel de especie. Se construyó una matriz de especies por parcela para analizar patrones de diversidad y se utilizaron estimadores no paramétricos (ICE, ACE, Chao 1 y Chao 2 para calcular la diversidad del Parque, el grado de completitud del muestreo y la agregación espacial de los datos. Se calcularon los índices de Shannon, Simpson, Whittaker y Jaccard. La riqueza del Parque fue estimada en 32 especies distribuidas en 21 géneros y 13 familias. Solo una especie pertenece a Caenogastropoda, el resto son Pulmonados Stylommatophora y Systellommatophora. La familia más representada fue Charopidae mientras que la especie con mayor abundancia relativa fue Adelopoma tucma. La riqueza y diversidad fue levemente mayor en chaco seco que en bosque húmedo de Yungas. Los valores de diversidad obtenidos fueron elevados en comparación con estudios previos realizados en el noroeste Argentino.Biodiversity of land gastropods (Mollusca in Sierra de San Javier Park, Tucumán, Argentina. Studies related to land mollusk diversity in tropical and subtropical forests are scarce. To assess this, a study on land snail diversity of subtropical cloudforest (Yungas and dry forest (Chaco areas of Sierra de San Javier Park, Tucumán, Argentina, was carried out. Taxonomic identifications were performed to species level and built a species per stations data matrix to analyze diversity patterns on qualitative and quantitative samples processed from 10x10m quadrates in altitudinal transects. Non parametric analysis (ICE, ACE, Chao 1 and Chao 2 were used to estimate the true diversity of the area, as well as the

  6. Marine mollusca of oxygen isotope stages of the last 2 million years in New Zealand. Part 1, Revised generic positions and recognition of warm-water and cool-water migrants

    International Nuclear Information System (INIS)

    Beu, A.G.

    2004-01-01

    Warm-water molluscs were transported to Wanganui Basin from the northeastern North Island during Pleistocene time as planktotrophic larvae. This is not possible at present, so their occurrence in Wanganui Basin correlates with breaches of the Auckland isthmus during high sea levels. The end of Nukumaruan time is clearly defined by the extinction of 29 genera of molluscs (most only locally) during this stage, including 15 at the end. The extinction likely was caused by the initial closure of the Auckland isthmus. Migrants to Wanganui from the northeastern North Island indicate that breaches of the isthmus during interglacials commenced in oxygen isotope stage (OIS) 25, just before the mid-Pleistocene transition (MPT). Appearances of taxa from Australia at Wanganui during OIS 17-9 therefore indicate that warm-water taxa were transported to New Zealand during interglacial maxima after the MPT. The migrants provide the first molluscan biostratigraphy at the OIS scale. The Castlecliffian/Nukumaruan boundary, at the base of Ototoka tephra at Ototoka Beach, Wanganui, falls within OIS 57, with an age of c. 1.63 Ma. It is also dated at 1.63 Ma by the position with respect to the geomagnetic polarity time-scale of three chemically indistinguishable tephra in ODP core 1123. This paper presents the first results of a reassessment of the taxonomy and time ranges of the fossil marine molluscan fauna that occupied New Zealand during the last 2 m.y. (latest Pliocene-Holocene). Time ranges are compiled in oxygen isotope stages rather than in the traditional 'local' (or regional) stages in use in New Zealand. This should provide precision in time ranges of the order of 40,000-100,000 yr, rather than the 0.34-1.3 m.y. duration of New Zealand local stages of the latest Neogene (Nukumaruan, Castlecliffian, and Haweran Stages). The reassessment is aimed also, though, at providing evidence from Mollusca of climate change over this period. Much useful information on paleoclimates can be

  7. Die Aciculidae (Mollusca: Gastropoda Prosobranchia)

    NARCIS (Netherlands)

    Boeters, H.D.; Gittenberger, E.; Subai, P.

    1989-01-01

    Our knowledge concerning the recent and fossil species and subspecies of the Aciculidae is summarized. After some introductionary chapters concerning habitat, anatomy, shell morphology and distribution, both in time and geographical, all taxa are dealt with systematically. In total 56 recent species

  8. Fauna Europaea: Mollusca – Bivalvia

    Directory of Open Access Journals (Sweden)

    Rafael Araujo

    2015-07-01

    European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbicula fluminea and the Dreissenoidea the famous invasive zebra mussel (Dreissena polymorpha. Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species.

  9. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna mussels (Linnaeus, 1758: Mollusca Bivalvia) collected in the coast of Sao Paulo state, Brazil; Avaliacao dos teores de Br, Cl, K, Mg, Mn e V em mexilhoes Perna perna (Linnaeus, 1758: Mollusca Bivalvia) coletados no litoral do estado de Sao Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele

    2012-07-01

    The coastal environment has been heavily altered by multiple environmental impacts of human activities, such as disposal of sewage from urban areas, the release of numerous chemical industries, agriculture and the flow of vessels, which can lead to accidental spills of oil and oil products, fuels and other products transported by sea. In this context, a means of determining concentrations of these potentially toxic substances in the sea water is the biomonitoring by means of different types of bivalves, which have been used by various researchers, in Brazil and other countries. With regard to bivalve mollusks, particularly mussels, their use in monitoring the marine contamination is mainly due to their wide geographic distribution, sessile habit and ability to concentrate toxic metals to 102-105 times in relation to the concentrations detected in water. In the present study, we employed the passive biomonitoring using the Perna perna bivalve mollusk with respect to the elements Br, Cl, K, Mg, Mn and V. These elements were chosen since they can be determined by INAA method (Instrumental Neutron Activation Analysis), by means of short irradiation which provides faster analyzes and also due to their importance from the standpoint of environmental or nutritional studies. The aim of this study was to evaluate the content of Br, Cl, K, Mg, Mn and V in samples of Perna perna mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coastal regions of Sao Paulo subject to anthropogenic contamination (Ponta de Itaipu and Palmas Island, in Santos), comparing the values obtained in sites potentially impacted with the values of the control site in Praia da Cocanha, in Caraguatatuba. The collection points located in Sao Paulo coast are located in the geographical areas 23 Masculine-Ordinal-Indicator 37'S - 45 Degree-Sign 24' W (Caraguatatuba) and 23 Masculine-Ordinal-Indicator 57'S - 46 Masculine-Ordinal-Indicator 20' W (Santos). The collection of organisms

  10. Intragenomic sequence variation at the ITS1 - ITS2 region and at the 18S and 28S nuclear ribosomal DNA genes of the New Zealand mud snail, Potamopyrgus antipodarum (Hydrobiidae: mollusca)

    Science.gov (United States)

    Hoy, Marshal S.; Rodriguez, Rusty J.

    2013-01-01

    Molecular genetic analysis was conducted on two populations of the invasive non-native New Zealand mud snail (Potamopyrgus antipodarum), one from a freshwater ecosystem in Devil's Lake (Oregon, USA) and the other from an ecosystem of higher salinity in the Columbia River estuary (Hammond Harbor, Oregon, USA). To elucidate potential genetic differences between the two populations, three segments of nuclear ribosomal DNA (rDNA), the ITS1-ITS2 regions and the 18S and 28S rDNA genes were cloned and sequenced. Variant sequences within each individual were found in all three rDNA segments. Folding models were utilized for secondary structure analysis and results indicated that there were many sequences which contained structure-altering polymorphisms, which suggests they could be nonfunctional pseudogenes. In addition, analysis of molecular variance (AMOVA) was used for hierarchical analysis of genetic variance to estimate variation within and among populations and within individuals. AMOVA revealed significant variation in the ITS region between the populations and among clones within individuals, while in the 5.8S rDNA significant variation was revealed among individuals within the two populations. High levels of intragenomic variation were found in the ITS regions, which are known to be highly variable in many organisms. More interestingly, intragenomic variation was also found in the 18S and 28S rDNA, which has rarely been observed in animals and is so far unreported in Mollusca. We postulate that in these P. antipodarum populations the effects of concerted evolution are diminished due to the fact that not all of the rDNA genes in their polyploid genome should be essential for sustaining cellular function. This could lead to a lessening of selection pressures, allowing mutations to accumulate in some copies, changing them into variant sequences.                   

  11. Comunidad de moluscos asociados al mejillón verde Perna viridis (Mollusca: Bivalvia y sus relaciones tróficas en la costa norte de la Península de Araya, Estado Sucre, Venezuela

    Directory of Open Access Journals (Sweden)

    Sioliz Villafranca

    2006-12-01

    Full Text Available Perna viridis es un bivalvo procedente del Indo-Pacífico que habita en la zona intermareal y ha invadido varios ecosistemas de la costa norte del estado Sucre, Venezuela. Con la finalidad de realizar un estudio sobre las comunidades de moluscos asociadas a esta especie y sus relaciones tróficas, se llevaron a cabo muestreos bimensuales entre octubre/97 y agosto/98, en un banco natural de mejillones a dos metros de profundidad en la costa norte de la península de Araya (10°40’N -48°63’W. Los organismos fueron recolectados delimitando el área con una cuadrícula de 0.25 m². Se identificaron los organismos hasta la categoría de especies utilizando claves específicas para moluscos y bibliográficamente se les determinó categoría trófica.Se capturó un total de 1 235 individuos de P. viridis y asociados a la especie 3 163 especímenes pertenecientes al phylum Mollusca, contenidos en tres clases: Bivalvia,Gastropoda y Polyplacophora. Éstas estuvieron representadas por 50 especies correspondientes a 10 órdenes, 24 familias; para los gasterópodos se contabilizaron 25 especies, para los bivalvos 22 y tres para los poliplacóforos. Del total de las especies, 40% fueron filtradoras, 26% carnívoras, 24% herbívoras y el 10% restante presentó dos categorías.De las filtradoras las más representativas fueron: Perna perna, Musculus lateralis, Crassostrea rhizophorae y Ostrea equestris; en el grupo de los carnívoros dominaron tres especies de la familia Columbellidae:Mitrella lunata, Anachis obesa y Nitidella ocellata y para el grupo de los herbívoros destacaron dos especies de la familia Fisurellidae: Diodora cayenensis y D. minuta. Se registraron dos especies filtradoras-detritívoras, y tres especies herbívoras-filtradoras representantes del género C repidula. El alto porcentaje de filtradores sería un indicativo de que dentro de este sistema probablemente hay una mayor disponibilidad de fracciones alimenticias para este grupo

  12. Immunocytochemical study of the distribuition of endocrine cells in the pancreas of the Brazilian sparrow species Zonotrichia Capensis Subtorquata (Swaison, 1837

    Directory of Open Access Journals (Sweden)

    AA Nascimento

    Full Text Available In the present study, we investigated types of pancreatic endocrine cells and its respective peptides in the Brazilian sparrow species using immunocytochemistry. The use of polyclonal specific antisera for somatostatin, glucagon, avian pancreatic polypeptide (APP, YY polypeptide (PYY and insulin, revealed a diversified distribution in the pancreas. All these types of immunoreactive cells were observed in the pancreas with different amounts. Insulin- Immunoreactive cells to (B cells were most numerous, preferably occupying the central place in the pancreatic islets. Somatostatin, PPA, PYY and glucagon immunoreactive cells occurred in a lower frequency in the periphery of pancreatic islets.

  13. Analysis of the complete Fischoederius elongatus (Paramphistomidae, Trematoda) mitochondrial genome.

    Science.gov (United States)

    Yang, Xin; Zhao, Yunyang; Wang, Lixia; Feng, Hanli; Tan, Li; Lei, Weiqiang; Zhao, Pengfei; Hu, Min; Fang, Rui

    2015-05-20

    Fischoederius elongates is an important trematode of Paramphistomes in ruminants. Animals infected with F. elongates often don't show obvious symptoms, so it is easy to be ignored. However it can cause severe economic losses to the breeding industry. Knowledge of the mitochondrial genome of F. elongates can be used for phylogenetic and epidemiological studies. The complete mt genome sequence of F. elongates is 14,120 bp in length and contains 12 protein-coding genes, 22 tRNA genes, two rRNA genes and two non-coding regions (LNR and SNR). The gene arrangement of F. elongates is the same as other trematodes, such as Fasciola hepatica and Paramphistomum cervi. Phylogenetic analyses using concatenated amino acid sequences of the 12 protein-coding genes by Maximum-likelihood and Neighbor-joining analysis method showed that F. elongates was closely related to P. cervi. The complete mt genome sequence of F. elongates should provide information for phylogenetic and epidemiological studies for F. elongates and the family Paramphistomidae.

  14. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna mussels (Linnaeus, 1758: Mollusca Bivalvia) collected in the coast of Sao Paulo state, Brazil

    International Nuclear Information System (INIS)

    Seo, Daniele

    2012-01-01

    The coastal environment has been heavily altered by multiple environmental impacts of human activities, such as disposal of sewage from urban areas, the release of numerous chemical industries, agriculture and the flow of vessels, which can lead to accidental spills of oil and oil products, fuels and other products transported by sea. In this context, a means of determining concentrations of these potentially toxic substances in the sea water is the biomonitoring by means of different types of bivalves, which have been used by various researchers, in Brazil and other countries. With regard to bivalve mollusks, particularly mussels, their use in monitoring the marine contamination is mainly due to their wide geographic distribution, sessile habit and ability to concentrate toxic metals to 102-105 times in relation to the concentrations detected in water. In the present study, we employed the passive biomonitoring using the Perna perna bivalve mollusk with respect to the elements Br, Cl, K, Mg, Mn and V. These elements were chosen since they can be determined by INAA method (Instrumental Neutron Activation Analysis), by means of short irradiation which provides faster analyzes and also due to their importance from the standpoint of environmental or nutritional studies. The aim of this study was to evaluate the content of Br, Cl, K, Mg, Mn and V in samples of Perna perna mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coastal regions of São Paulo subject to anthropogenic contamination (Ponta de Itaipu and Palmas Island, in Santos), comparing the values obtained in sites potentially impacted with the values of the control site in Praia da Cocanha, in Caraguatatuba. The collection points located in São Paulo coast are located in the geographical areas 23º 37'S - 45° 24' W (Caraguatatuba) and 23º 57'S - 46º 20' W (Santos). The collection of organisms was performed in all seasons of the year, beginning in spring 2008 and ending in winter 2009. The samples

  15. Lorentz Spengler's descriptions of chitons (Mollusca: Polyplacophora)

    NARCIS (Netherlands)

    Kaas, P.; Knudsen, J.

    1992-01-01

    The present paper deals with an important Danish paper on the Polyplacophora, published in 1797 by Lorentz Spengler: Udförlig Beskrivelse over det mangeskallede Konkylie-Slaegt, af Linnaeus kaldet Chiton; med endeel nye Arter og Varieteter. -Skrivter af Naturhistorie-Selskabet, 4e Bind, Ie Hefte,

  16. Systematics, phylogeny and zoogeography of Bulimulinae (Mollusca)

    NARCIS (Netherlands)

    Breure, A.S.H.

    1979-01-01

    In this publication a revision is given of the genera of the subfamily Bulimulinae (Gastropoda, Pulmonata, Bulimulidae). The morphological variation of the shell, radula, pallial organs and genitalia is analized and 21 character transition series are recognized. In the systematical part the

  17. Short Communication Myosotella myosotis (Mollusca: Ellobiidae ...

    African Journals Online (AJOL)

    Myosotella myosotis is shown to be a well-established alien species in South Africa. Discovered in Port Elizabeth more than 100 years ago, it was initially thought to be indigenous and was described under two different names, but subsequent taxonomic work has demonstrated that these are synonyms of the variable and ...

  18. Perfil de lípidos y ácidos grasos de Perna viridis, mejillón verde (Mollusca: Bivalvia en el oriente venezolano y la costa oeste de Trinidad

    Directory of Open Access Journals (Sweden)

    Tamar Koftayan

    2011-03-01

    Full Text Available Los lípidos totales fueron extraídos, identificados y cuantificados por gravimetría, mediante TLC/FID (sistema Iatroscan. Los ácidos grasos de los lípidos totales, fosfolípidos y triacilgliceroles fueron identificados y cuantificados por cromatografía de gases. Las mayores concentraciones de lípidos totales se presentaron en las muestras de Los Cedros, La Brea y Chaguaramas con valores de 7.92, 7.74 y 7.53%; respectivamente y los valores mínimos en las de La Restinga (6.08%. En la composición lípidica, las muestras de Chacopata presentaron la menor concentración de fosfolípidos (48.86% y los máximos valores de colesterol (38.87% y triacilgliceroles (12.26%, y las muestras de La Esmeralda y Río Caribe exhibieron concentraciones máximas de fosfolípidos (88.71-84.93%, respectivamente y mínimas de colesterol (6.50-4.42%. En los lípidos totales, los ácidos grasos saturados se encontraron entre 15.04 y 65.55%, con máximos en muestras de La Esmeralda y mínimos en Chacopata y los poliinsaturados estuvieron entre 7.80 y 37.18%, con máximos valores en la Brea y mínimos en la Esmeralda. En los fosfolípidos, la concentración de ácidos grasos saturados estuvo entre 38.81 y 48.68% para las muestras de Chaguaramas y Chacopata, respectivamente; los ácidos grasos poliinsaturados se encontraron entre no detectado y 34.51%, con altas concentraciones en muestras de Los Cedros (27.97% y Chaguaramas (34.51%. En los triacilgliceroles, la composición de ácidos grasos saturados variaron entre 14.27 y 53.80%, con baja concentración en Chacopata y alta concentración en La Restinga; los ácidos grasos poliinsaturados estuvieron entre 4.66 y 35.55%, con valores menores en las muestras de Chacopata (4.66% y mayores en Chaguaramas. El consumo frecuente de Perna viridis es recomendable, debido a su alto contenido de fosfolípidos y ácidos grasos insaturados.Lipid and fatty acid profile of Perna viridis, Green Mussel (Mollusca: Bivalvia in

  19. Biodiesel production using blue-green cyanobacterium Synechococcus elongatus PCC 7942

    NARCIS (Netherlands)

    Voshol, Gerben

    2015-01-01

    Due to concerns about global climate change and diminishing supplies of petroleum, there is a need to develop a clean sustainable alternative. The two main alternative fuels are bioethanol and biodiesel. Production of these biofuels using cyanobacteria is a new promising development. I describe the

  20. Cd2+ Effect on Photosynthetic Apparatus in Synechococcus elongatus and Spinach (Spinacia oleracea L.)

    Czech Academy of Sciences Publication Activity Database

    Nováková, Marie; Matějová, E.; Sofrová, D.

    2004-01-01

    Roč. 42, č. 3 (2004), s. 425-430 ISSN 0300-3604 R&D Projects: GA ČR GA525/02/0301 Institutional research plan: CEZ:AV0Z5038910 Keywords : cyanobacteria * heavy metals * photochemical activity Subject RIV: ED - Physiology Impact factor: 0.734, year: 2004

  1. Effects of Irregular Bimetallic Nanostructures on the Optical Properties of Photosystem I from Thermosynechococcus elongatus

    Directory of Open Access Journals (Sweden)

    Imran Ashraf

    2015-07-01

    Full Text Available The fluorescence of photosystem I (PSI trimers in proximity to bimetallic plasmonic nanostructures have been explored by single-molecule spectroscopy (SMS at cryogenic temperature (1.6 K. PSI serves as a model for biological multichromophore-coupled systems with high potential for biotechnological applications. Plasmonic nanostructures are fabricated by thermal annealing of thin metallic films. The fluorescence of PSI has been intensified due to the coupling with plasmonic nanostructures. Enhancement factors up to 22.9 and 5.1 are observed for individual PSI complexes coupled to Au/Au and Ag/Au samples, respectively. Additionally, a wavelength dependence of fluorescence enhancement is observed, which can be explained by the multichromophoric composition of PSI.

  2. A sneak preview of the daily life of S. elongatus by MS-based proteomics

    NARCIS (Netherlands)

    Leite Guerreiro, A.C.

    2016-01-01

    Circadian rhythms are self-sustained and adjustable cycles, typically entrained with light/dark and/or temperature cycles. These rhythms are present in animals, plants, fungi and several bacteria. The central mechanism behind these ‘pacemakers’ and the connection to the circadian regulated pathways

  3. Chitons (Mollusca, Polyplacophora from Alacranes Reef, Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Adriana Reyes-Gómez

    2017-04-01

    Full Text Available This study represents the first comprehensive chiton study from Alacranes Reef, the largest reef system in the Gulf of Mexico. Nine chiton species were found in seven localities within the area, in the intertidal and subtidal to 12 m depth. SEM examination of C. janeirensis, A. hemphilli, T. schrammi and C. floridanus, showed variations in the sculpture and radular teeth morphology when compared to specimens of the same species from Florida Keys, Bahamas and Puerto Rico. The distribution ranges of T. schrammi, L. liozonis and S. floridana are extended into the south-western area of the Gulf of Mexico. Altogether, combining previous literature and the present survey, reports eleven chiton species which have now been recorded within the Alacranes reef area.

  4. A new and unusual species of Parachiton (Mollusca ...

    African Journals Online (AJOL)

    The intermediate valves are granulose with the granules arranged in widely spaced, longitudinal rows on the central area of the valves. There are 20–31 longitudinal rows on the central areas of the intermediate valves. Variability in the morphology of the tail valve is shown. Keywords: chiton taxonomy, Lepidopleurina, ...

  5. Variation in foraging activity of Acanthochitona garnoti (Mollusca ...

    African Journals Online (AJOL)

    ; x = 182 rnm). Chitons on the boulder beach travelled greater distances (x = 367 mm) during foraging than those from aeolian shores (x = 105 mm). It is suggested that this IS a result of boulder beach chitons having further to travel to find a ...

  6. Parasitism by a Digenea in Lucina pectinata (Mollusca: Lucinidae

    Directory of Open Access Journals (Sweden)

    M. M. Ribeiro

    2017-06-01

    Full Text Available Abstract Lucina pectinata is an important economic resource in the Brazilian coast. This study reports parasitism caused by a Digenea in this species. The specimens (n = 470 were collected in December 2012 in a mangrove swamp of the Cachoeira River estuary, Bahia, Brazil. They were measured along the anterior-posterior axis (length, and after macroscopic analysis for parasites and diseases cuts of 5 mm were fixated in Carnoy’s solution and processed by routine histology technique wherein sessions of 7 μm were stained with Harris hematoxylin and eosin (H&E. The tissues were examined using an optical microscope. The mean length of L. pectinata was 4.0 ± 0.53 cm. Microscopic analysis showed sporocysts containing both germ balls as cercariae of an unidentified Digenea (Platyhelminthes, these in various stages of development. The prevalence was 1.48% (7/470. In a parasitized specimen was macroscopic evidence of tissue densification of gills. The sporocysts were observed in mantle, gills, digestive gland and gonads, with evident alteration/destruction of tissues, including parasitic castration. There were no other parasites found, which is probably related to inaccessibility and chemical conditions in which lives L. pectinata, i.e., between 10 and 20 cm in mangrove sediment.

  7. Chitons (Mollusca, Polyplacophora) from Alacranes Reef, Yucatan, Mexico

    Science.gov (United States)

    Reyes-Gómez, Adriana; Ortigosa, Deneb; Simões, Nuno

    2017-01-01

    Abstract This study represents the first comprehensive chiton study from Alacranes Reef, the largest reef system in the Gulf of Mexico. Nine chiton species were found in seven localities within the area, in the intertidal and subtidal to 12 m depth. SEM examination of C. janeirensis, A. hemphilli, T. schrammi and C. floridanus, showed variations in the sculpture and radular teeth morphology when compared to specimens of the same species from Florida Keys, Bahamas and Puerto Rico. The distribution ranges of T. schrammi, L. liozonis and S. floridana are extended into the south-western area of the Gulf of Mexico. Altogether, combining previous literature and the present survey, reports eleven chiton species which have now been recorded within the Alacranes reef area. PMID:28769624

  8. Morphological and molecular diversity of Unionidae (Mollusca, Bivalvia from Portugal

    Directory of Open Access Journals (Sweden)

    Reis, J.

    2013-06-01

    Full Text Available Freshwater mussels from the family Unionidae are known to exhibit a high level of ecological phenotypic plasticity that is reflected in their shell shape. This variation has caused uncertainty on systematics and taxonomy of the group. Several naiad populations from nine river basins from Portugal were analyzed genetically, using two mitochondrial gene fragments (16SrRNA and Cytochrome Oxidase I and morphologically, using ANOVA analyses of shell dimmensions. Molecular phylogenetic analyses were used to revise the systematics and to infer an evolutionary hypothesis for the family at the western-most Atlantic Iberian Peninsula. Genetic and morphological data were in agreement and supported the occurrence of 5 species in the region: Anodonta anatina, Anodonta cygnea, Potomida littoralis, Unio tumidiformis and Unio delphinus. The differentiation of all these species, except A. cygnea, is thought to have taken place during the isolation of the Iberian Peninsula and formation of the current river basins in the Tertiary. The possibility of A. cygnea being a relatively recent introduction is discussed. Basic morphometric measures of the shell proved to be useful to separate Unio species, but also seem to be strongly affected by environmental conditions. The high intra-specific morphologic variation was partially related to the species’ high level of phenotypic plasticity, but seems to have an important role in evolutionary processes.Las náyades de la familia Unionidae tienen gran plasticidad fenotípica, lo que se refleja en la forma de su concha. Esta variabilidad morfológica ha sido causa de gran confusión en la taxonomía y sistemática del grupo. Se han estudiado, genética y morfológicamente, numerosas poblaciones de náyades provenientes de nueve cuencas hidrográficas portuguesas. Para ello se han analizando dos fragmentos de genes mitocondriales (ARNr 16S y Citocromo Oxidasa I así como diferentes variables morfológicas de la concha. Se han realizado además análisis filogenéticos para conocer la sistemática de la familia e inferir una hipótesis evolutiva de su distribución en el oeste de la península Ibérica. Los datos genéticos y morfológicos sugieren la existencia de cinco especies: Anodonta anatina, Anodonta cygnea, Potomida littoralis, Unio tumidiformis y Unio delphinus. La diferenciación de estas especies, con la excepción de A. cygnea, ha ocurrido durante el aislamiento de la península Ibérica y posterior formación de las actuales cuencas hidrográficas en el Terciario. Se discute la posibilidad de que la presencia de A. cygnea se deba a una introducción reciente. Los datos morfométricos analizados pueden ser útiles para separar las especies del género Unio, pero son también dependientes de las condiciones ambientales. La elevada variabilidad morfológica dentro de cada especie está relacionada con su plasticidad fenotípica, pero tiene a su vez un importante papel en el proceso evolutivo.

  9. Parasitism by a Digenea in Lucina pectinata (Mollusca: Lucinidae).

    Science.gov (United States)

    Ribeiro, M M; Oliveira, J B; Boehs, G

    2018-02-01

    Lucina pectinata is an important economic resource in the Brazilian coast. This study reports parasitism caused by a Digenea in this species. The specimens (n = 470) were collected in December 2012 in a mangrove swamp of the Cachoeira River estuary, Bahia, Brazil. They were measured along the anterior-posterior axis (length), and after macroscopic analysis for parasites and diseases cuts of 5 mm were fixated in Carnoy's solution and processed by routine histology technique wherein sessions of 7 μm were stained with Harris hematoxylin and eosin (H&E). The tissues were examined using an optical microscope. The mean length of L. pectinata was 4.0 ± 0.53 cm. Microscopic analysis showed sporocysts containing both germ balls as cercariae of an unidentified Digenea (Platyhelminthes), these in various stages of development. The prevalence was 1.48% (7/470). In a parasitized specimen was macroscopic evidence of tissue densification of gills. The sporocysts were observed in mantle, gills, digestive gland and gonads, with evident alteration/destruction of tissues, including parasitic castration. There were no other parasites found, which is probably related to inaccessibility and chemical conditions in which lives L. pectinata, i.e., between 10 and 20 cm in mangrove sediment.

  10. Recharacterization of Synapterpes (S. hanleyi (Pfeiffer (Mollusca, Gastropoda, Stylommatophora, Subulinidae

    Directory of Open Access Journals (Sweden)

    Norma Campos Salgado

    1999-01-01

    Full Text Available Synapterpes (S. hanleyi (Pfeiffer, 1846 is characterized by anatomy, synonymy and geographical distribution. Shell and soft parts were studied and important taxonomic characters evaluated and illustrated. These studies give conditions to characterize the species and include it in the genus Synapterpes Pilsbry, 1896 and distinguish S. hanleyi from the other species of Synapterpes s.s. known only by their shells, respectively from Brazil and Colombia: S.(S. coronatus (Pfeiffer, 1846 and S.(S. wallisi (Mousson, 1869.

  11. In situ growth rate of Solen cylindraceus (Mollusca: Euheterodonta ...

    African Journals Online (AJOL)

    Growth lines of this species are too indistinct and irregular to be of any use. This study, therefore, adopted a more direct method of monitoring the shell length of individuals, by caging them in situ. Shell measurements were taken from the individuals in cages and the surrounding environment at monthly intervals for one year.

  12. Abundance and diversity of Mollusca in the Beagle Channel

    Directory of Open Access Journals (Sweden)

    Katrin Linse

    1999-12-01

    Full Text Available The malacofauna of the Beagle Channel caught by an epibenthic sledge during the Joint Magellan Victor Hensen Campaign in 1994 was investigated. At 11 locations 16 samples were taken on a transect through the Channel. Species of Aplacophora, Polyplacophora, Gastropoda, Scaphopoda and Bivalvia were identified and quantified. Their horizontal and vertical distribution was described and possible reasons due to their feeding mode discussed. The exact number of specimens collected was 35,084 yielding 107,208 molluscs/ 1000 m2.

  13. On Pomacea canaliculata (Lamarck, 1822 (Mollusca; Pilidae: Ampullariidae

    Directory of Open Access Journals (Sweden)

    Silvana C. Thiengo

    1993-03-01

    Full Text Available This paper deals with the morphology of Pomacea caniculata (Lamarck, 1822 collected at Corrientes, Argentina. Comparison is made with Pomacea lineata (Spix, 1827 and Pomacea sordida (Swainson, 1823. The shell is globose, heavy, with greenish or horn-colored periostracum and dark spiral bands; apex subelevated, 5-6 whorls increasing rather rapidly and separated by very deep suture. Aperture large, rounded to subelongated; lip sometimes reddish; umbilicus large and deep; operculum corneous, entirely closing the aperture. Ratios: shell width/shell length = 0.78-0.96 (mean 0.86; aperture length/shell length = 0.68-0.77 (mean 0.72. Radula similar to other congeneric species. Testis and spermiduct as in P. lineata and P. sordida; prostate cylindric and short, cream in color as the testis. Penial sheath straight bearing a central outer gland deeply embedded in the tissue of its basal portion and a large wrinkled gland occupying 2/3 of the distal tip of its inner surface; the rigth margin of the sheath overlaps the left one until 2/3 of its proximal end. Female reproductive apparatus similar to that P. lineata; vestigial male copulatory apparatus (penis and its sheath present in all females examined.

  14. The Mollusca inhabiting rice fields in northern Cameroon and their ...

    African Journals Online (AJOL)

    A systematic account is given of the freshwater gastropod and bivalve fauna of Ouro-Doukoudje, northern Cameroon, based on a survey conducted from July 2000 to June 2001 at 12 sites in rice fields spanning 800 ha. In total, 14 species were encountered, one of them (Burnupia sp.) being a first record for the area.

  15. Phylogenetic relationships among superfamilies of Neritimorpha (Mollusca: Gastropoda).

    Science.gov (United States)

    Uribe, Juan E; Colgan, Don; Castro, Lyda R; Kano, Yasunori; Zardoya, Rafael

    2016-11-01

    Despite the extraordinary morphological and ecological diversity of Neritimorpha, few studies have focused on the phylogenetic relationships of this lineage of gastropods, which includes four extant superfamilies: Neritopsoidea, Hydrocenoidea, Helicinoidea, and Neritoidea. Here, the nucleotide sequences of the complete mitochondrial genomes of Georissa bangueyensis (Hydrocenoidea), Neritina usnea (Neritoidea), and Pleuropoma jana (Helicinoidea) and the nearly complete mt genomes of Titiscania sp. (Neritopsoidea) and Theodoxus fluviatilis (Neritoidea) were determined. Phylogenetic reconstructions using probabilistic methods were based on mitochondrial (13 protein coding genes and two ribosomal rRNA genes), nuclear (partial 28S rRNA, 18S rRNA, actin, and histone H3 genes) and combined sequence data sets. All phylogenetic analyses except one converged on a single, highly supported tree in which Neritopsoidea was recovered as the sister group of a clade including Helicinoidea as the sister group of Hydrocenoidea and Neritoidea. This topology agrees with the fossil record and supports at least three independent invasions of land by neritimorph snails. The mitochondrial genomes of Titiscania sp., G. bangueyensis, N. usnea, and T. fluviatilis share the same gene organization previously described for Nerita mt genomes whereas that of P. jana has undergone major rearrangements. We sequenced about half of the mitochondrial genome of another species of Helicinoidea, Viana regina, and confirmed that this species shares the highly derived gene order of P. jana. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Octopus tetricus (Mollusca: Cephalopoda as an ecosystem engineer

    Directory of Open Access Journals (Sweden)

    David Scheel

    2014-12-01

    Full Text Available The Sydney octopus (Octopus tetricus occurs in unusual numbers on a shell bed of its prey remains that have accumulated as an extended midden where additional octopuses excavate dens. Here, O tetricus are ecosystem engineers, organisms that modulate availability of resources to other species and to their own species by causing physical state changes in materials. A community of invertebrate grazers and scavengers has developed on the shell bed. Fishes are attracted to the shell bed in numbers significantly greater than in nearby habitats. Large predators, including wobbegong sharks, were attracted to and fed on concentrations of fish, inhibiting the activities of the original engineers, the octopuses. Positive feedbacks included the accumulation of shell debris, increasing shelter availability for additional octopuses and aggregating fish. Negative feedbacks included reductions of nearby prey size and availability, aggression among octopuses, and predator limitation to octopus activity that would otherwise maintain the shell bed.

  17. Vanadium, rubidium and potassium in Octopus vulgaris (Mollusca: Cephalopoda

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    Sónia Seixas

    2005-06-01

    Full Text Available The levels of vanadium, rubidium and potassium were determined in Octopus vulgaris caught during commercial fishing activities at three locations (Cascais, Santa Luzia and Viana do Castelo in Portugal in autumn and spring. We determined the concentration of these elements in digestive gland, branchial heart, gills, mantle and arms in males and females. At least five males and five females were assessed for each season/location combination. Elemental concentrations were determined by Particle Induced X-ray Emission (PIXE. Vanadium was detectable only in digestive gland and branchial heart samples. Its concentration was not correlated with total weight, total length or mantle length. There were no differences in concentrations of V, Rb and K between sexes. There were significant differences in vanadium concentrations in branchial hearts in autumn between samples from Viana do Castelo and those from the other two sites. We found a significant positive relationship between the concentration of vanadium and those of potassium and rubidium in branchial hearts. Branchial hearts appear to play an important role in decontamination of V.

  18. Intramantle Inking: A Stress Behavior in Octopus bimaculoides (Mollusca: Cephalopoda)

    Science.gov (United States)

    Toll, Ronald B

    2011-01-01

    Several Pacific 2-spot octopuses (Octopus bimaculoides) shipped from California and held in a recirculating seawater system at Illinois College exhibited an unusual postshipping stress behavior not previously documented in the literature. Ink, normally ejected into the surrounding seawater, was uncharacteristically retained in the mantle cavity. We describe the resulting behaviors, discuss successful resuscitation efforts, and briefly consider the possible role(s) that ink may have played in the death of one octopus. PMID:22330791

  19. Notes on some land and freshwater Mollusca from Auvergne, France

    NARCIS (Netherlands)

    Bruggen, van A.C.

    1957-01-01

    From August 16 till September 1, 1955, Dr. H. C. Blöte, Mr. J. J. Barkman, and the present author were the leaders of an excursion of students in biology of the University at Leiden to Central France. For some two weeks the party was hospitably lodged in the "Station Biologique" in the village

  20. Gundlachia dutrae: n. sp. from northwest Brazil (Mollusca: Basommatophora: Ancylidae

    Directory of Open Access Journals (Sweden)

    Sonia Barbosa dos Santos

    1994-06-01

    Full Text Available A new species of Gundlachia, Gundlachia dutrae is described from northwest Brazil. It is distinguishable from other congenerie species by characteristics of the shell, radula and internal organs. Shell relatively high. Aperture near-circular; periostracum dark brown without periostracal hairs. Apex slightly inclined to the right, projected but not hooked, with an apical depression surrounted by a sculpture of well-marked irregular punctations. Shell surface with prominent radial sculpture. No septate specimens were observed. Ratios (n= 59: shell width/shell lenght = 0,66- 0,79 (mean 0,73; shell height/shell length = 0,32- 0,45 ( mean 0,37; shell height/shell width = 0,43- 0,63 (mean 0,51. Body of normal ancylid type; mantle pigmentation dark brown or black, concentrated along the mantle collar. The dorsal surface of the right anterior muscle is elongated and medially constricted. The left anterior and the posterior muscles are almost elliptical. Adhesive area is V-shaped. Pseudobranch unpigmented bearing a very small and thin dorsal lobe. Ovotestis with more than 25 unbranched diverticula. Ovispermiduct with seminal vesicle rather developed. Elongated nidamental gland continous with the glandular wall of the uterus. Nidamental gland appendix ending into a bulbous swelling Spermathecal body almost rounded. Well-developed prostate with five long diverticula. Ejaculatory complex with long glandular flagellum, without a penis or true ultra-penis. "Penis sheath" developed. "Ultra-penis" projected as a tube inside the lumem of prepuce, with a slit between "ultra-penis" and "penis sheath". Rachidian tooth tetracuspid, with two median cusps assymmetrical and aculeated. Lateral teeth tricuspid, with a reduced endocon and a prominent mesocon. A well marked gap occurs between meso and ectocon. Marginal teeth similar to lateral ones. Jaw T-shaped, with about 28 dorsal plates.

  1. Mortality of the abalone Haliotis mariae (Haliotidae: Mollusca in aquaculture

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    Gilha Yoon

    2015-01-01

    Full Text Available The Omani abalone, Haliotis mariae, is the only species of abalone found in Omani waters. Given the rarity of this species and the high price it can fetch on the market (US$ 150 kg-1 dry weight, the wild abalone fishery in the Dhofar region has been regarded as a valuable income source for the past decade. The present study was undertaken set to investigate the mortality of abalone held at the Mirbat Research Center, through bacteriological and histopathological based investigations and challenge tests. Only the adult wild abalone that had been kept for a year in the hatchery, visually, appeared to be clear of disease symptoms. Infected individuals typically were swollen around the mouth, had fluid tinged with blood, bubbles in the intestines, and, very weak adhesive strength. The foot area (muscle of diseased animals was noticeably very soft and individuals that were seen lying upside down on the bottom of the tank subsequently died. On dissection, the intestinal organs released bubbles and a foul smelling odour. Identification of the isolated bacteria using various identification methods indicated that individuals were infected with Staphylococcus sciuri. Histopathology of infected individuals revealed spongiosis of the tissues with evident bacterial infection. Neither of these histopathological conditions were seen in healthy abalone. The study concludes that the bacterium Staphylococcus sciuri may be the likely cause of abalone mortalities.

  2. The Genus Theba (Mollusca: Gastropoda: Helicidae), Systematics and Distribution

    NARCIS (Netherlands)

    Gittenberger, E.; Ripken, Th. E.J.

    1987-01-01

    Our knowledge concerning taxonomy and zoogeography of the fossil and recent species of the helicid genus Theba is summarized and enlarged. The fossil T. arinagae spec. nov. is described from Gran Canaria. The recent T. andalusica spec. nov. and T. sacchii spec. nov. are described from the

  3. Parasites in Bulinus senegalensis (Mollusca: Planorbidae) and their detection.

    Science.gov (United States)

    Wright, C A; Rollinson, D; Goll, P H

    1979-08-01

    Isoelectric focusing studies on enzyme variation between populations of the snail Bulinus senegalensis revealed that parasitic infections in the snails contributed additional bands of enzyme activity, particularly in the glucose phosphate isomerase (GPI) and malate dehydrogenase (MDH) systems. The patterns due to the parasite enzymes were, in most cases, clearly distinct from those of the host and different from each other. Parasites encountered included Schistosoma haematobium, S. bovis, Paramphistomum microbothrium, another amphistome probably belonging to the group which infect amphibians, Echinostoma revolutum, another echinostome (probably Echinoparyphium sp.), strigeids, xiphidiocercariae (these were resolved into 3 distinct types by the enzyme data) and ciliate protozoa. The 7 host populations which were examined showed marked differences in both the prevalence and variety of their parasitic infections and these variations were tentatively related to environmental differences in their respective habitats and to the nature of human contact patterns. Seasonal changes in the parasite fauna were also noted and some of the implications of the parasite load on the host population are briefly mentioned.

  4. Miocene Vetigastropoda and Neritimorpha (Mollusca, Gastropoda) of central Chile

    Science.gov (United States)

    Nielsen, Sven N.; Frassinetti, Daniel; Bandel, Klaus

    2004-09-01

    Species of Vetigastropoda (Fissurellidae, Turbinidae, Trochidae) and one species of Neritimorpha (Neritidae) from the Navidad area, south of Valparaı´so, and the Arauco Peninsula, south of Concepción, are described. Among these, the Fissurellidae comprise Diodora fragilis n. sp., Diodora pupuyana n. sp., two additional unnamed species of Diodora, and a species resembling Fissurellidea. Turbinidae are represented by Cantrainea sp., and Trochidae include Tegula (Chlorostoma) austropacifica n. sp., Tegula (Chlorostoma) chilena n. sp., Tegula (Chlorostoma) matanzensis n. sp., Tegula (Agathistoma) antiqua n. sp., Bathybembix mcleani n. sp., Gibbula poeppigii [Philippi, 1887] n. comb., Diloma miocenica n. sp., Fagnastesia venefica [Philippi, 1887] n. gen. n. comb., Fagnastesia matanzana n. gen. n. sp., Calliostoma mapucherum n. sp., Calliostoma kleppi n. sp., Calliostoma covacevichi n. sp., Astele laevis [Sowerby, 1846] n. comb., and Monilea riorapelensis n. sp. The Neritidae are represented by Nerita (Heminerita) chilensis [Philippi, 1887]. The new genus Fagnastesia is introduced to represent low-spired trochoideans with a sculpture of nodes below the suture, angulated whorls, and a wide umbilicus. This Miocene Chilean fauna includes genera that have lived at the coast and in shallow, relatively warm water or deeper, much cooler water. This composition therefore suggests that many of the Miocene formations along the central Chilean coast consist of displaced sediments. A comparison with different fossil and Recent faunas from around the Pacific and South America indicates that the vetigastropod and neritid fauna from the Miocene of Chile has only minor affinities with taxa living near New Zealand, Argentina, and the tropical eastern Pacific at that time.

  5. Primer registro de Dondice parguerensis (Mollusca: Favorinidae para Venezuela First record of Dondice parguerensis (Mollusca: Favorinidae in Venezuela

    Directory of Open Access Journals (Sweden)

    Joany Mariño

    2011-06-01

    Full Text Available Se cita por primera vez para Venezuela el aeolidaceo Dondice parguerensis Brandon y Cutress, 1985, parásito de los cnidarios Cassiopea xamachana Bigelow, 1892 y Cassiopea frondosa (Pallas, 1774, hasta ahora sólo conocido de Puerto Rico, Panamá y Bermudas.The presence of the aeolidacean Dondice parguerensis Brandon and Cutress, 1985, parasite of the cnidaria Cassiopea xamachana Bigelow, 1892 and Cassiopea frondosa (Pallas, 1774 is recorded for the first time in Venezuela. It was previously recorded in Puerto Rico, Panama and Bermuda.

  6. Photophysiological and photosynthetic complex changes during iron starvation in Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Fraser, Jared M; Tulk, Sarah E; Jeans, Jennifer A; Campbell, Douglas A; Bibby, Thomas S; Cockshutt, Amanda M

    2013-01-01

    Iron is an essential component in many protein complexes involved in photosynthesis, but environmental iron availability is often low as oxidized forms of iron are insoluble in water. To adjust to low environmental iron levels, cyanobacteria undergo numerous changes to balance their iron budget and mitigate the physiological effects of iron depletion. We investigated changes in key protein abundances and photophysiological parameters in the model cyanobacteria Synechococcus PCC 7942 and Synechocystis PCC 6803 over a 120 hour time course of iron deprivation. The iron stress induced protein (IsiA) accumulated to high levels within 48 h of the onset of iron deprivation, reaching a molar ratio of ~42 IsiA : Photosystem I in Synechococcus PCC 7942 and ~12 IsiA : Photosystem I in Synechocystis PCC 6803. Concomitantly the iron-rich complexes Cytochrome b6f and Photosystem I declined in abundance, leading to a decrease in the Photosystem I : Photosystem II ratio. Chlorophyll fluorescence analyses showed a drop in electron transport per Photosystem II in Synechococcus, but not in Synechocystis after iron depletion. We found no evidence that the accumulated IsiA contributes to light capture by Photosystem II complexes.

  7. Integrity and activity of photosystem 2 complexes isolated from the thermophilic cyanobacterium Synechococcus elongatus using various detergents

    Czech Academy of Sciences Publication Activity Database

    Šetlíková, Eva; Sofrová, D.; Prášil, Ondřej; Budáč, Petr; Koblížek, Michal; Šetlík, Ivan

    1999-01-01

    Roč. 37, č. 2 (1999), s. 183-200 ISSN 0300-3604. [Regional Photosynthesis Workshop /2./. Lipno, 31.01.1999-03.02.1999] R&D Projects: GA ČR GA206/96/1266; GA ČR GA206/98/P110; GA MŠk VS96085; GA MŠk ME 138 Grant - others:NATO(EC) LG970388 Subject RIV: ED - Physiology Impact factor: 0.734, year: 1999

  8. Crystal structure of the Psb28 accessory factor of Thermosynechococcus elongatus photosystem II at 2.3 angstrom

    Czech Academy of Sciences Publication Activity Database

    Bialek, W.; Wen, S.; Michoux, F.; Bečková, Martina; Komenda, Josef; Murray, J. W.; Nixon, P. J.

    2013-01-01

    Roč. 117, 1-3 (2013), s. 375-383 ISSN 0166-8595 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : Assembly factor * Psb28 * Psb28-2 Subject RIV: EE - Microbiology, Virology Impact factor: 3.185, year: 2013

  9. Distribucion arborea de los gastropodos cerithidea montagnei (mollusca potamidae y littorina Spp. (Mollusca, Littorinidae en el manglar de Mata de Limón, Costa Rica

    Directory of Open Access Journals (Sweden)

    Édgar Suarez B

    2016-03-01

    Full Text Available En el manglar de Mata de Limón, Puntarenas, Costa Rica, se estudió la distribución y preferencia por el susbtrato arbóreo de gastrópodos C. montagnei y Littorina spp. en cuatro especies de mangle, según la cantidad de moluscos observados en cada árbol y la cantidad de árboles con presencia o ausencia de ellos, en el período de setiembre de 1982 a junio de 1983. El orden de preferencia mostrado por ambos grupos de moluscos fue: 1 Rhizophora mangle, 2 Avicennia germinans, 3Pelliciera rhizophorae y 4 Laguncularia racemosa. Se discuten las posibles razones de esta preferencia. Cerithidea montagnei presentó una mayor distribución horizontal, así como una mayor abundancia respecto de Littorina spp.

  10. Ocorrência do bivalve exótico Mytilopsis leucophaeta (Conrad (Mollusca, Bivalvia, no Brasil Occurrence of exotic bivalve Mytilopsis leucophaeta (Conrad (Mollusca, Bivalvia, in Brazil

    Directory of Open Access Journals (Sweden)

    José R. B. de Souza

    2005-12-01

    Full Text Available O molusco Mytilopsis leucophaeta (Conrad, 1831, natural da América do Norte, foi localizado no litoral de Pernambuco, Brasil, em 2004, trazido provavelmente por água de lastro de navios. Na região, sua distribuição atualmente abrange zonas estuarinas adjacentes ao Porto do Recife. Os organismos foram encontrados restritos à região entre-marés, formando agregados densos com até 176.800 ind./m².The mussel Mytilopsis leucophaeta (Conrad, 1831 is native to North America. It was found at Pernambuco Coast, northeastern Brazil, in 2004, probably brought by ships' ballast water. The distribution of this species has been now spread to estuarial area near Recife Harbour. They showed a clumped distribution with a maximum of 176,800 ind./m² only in the intertidal zone.

  11. Hermaphroditism among dioecious Tagelus plebeius (Lightfoot, 1786) (Mollusca, Psammobiidae) and Iphigenia brasiliana (Lamarck, 1818) (Mollusca, Donacidae) on the Cachoeira River estuary, Ilhéus, Bahia, Brazil.

    Science.gov (United States)

    Ceuta, L O; Boehs, G; Santos, J J B

    2010-02-01

    The samples of Tagelus plebeius and Iphigenia brasiliana were manually collected on the Cachoeira River estuary region (Ilhéus, BA, Brazil) between August 2005 and August 2006, with a periodicity of 15 days, with 20 animals collected/sampled, performing 500 samples from each species. The animals were measured, eviscerated and kept in solution of Davidson and after 24-30 hours, they were transferred to ethanol 70%. The material was processed for routine histology, with paraffin embedding, obtaining 7 microm thick slices, stained with Harris hematoxilin and Eosin (HE). By light microscopy analysis, 2 cases of hermaphroditism (0.4%) in T. plebeius samples and one case (0.2%) in I. brasiliana were registered with predominance of female over male follicles.

  12. Especies nuevas del género Gibberula (Mollusca: Cystiscidae de Cuba y Venezuela New species of the genus Gibberula (Mollusca: Cystiscidae from Cuba and Venezuela

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    José Espinosa

    2011-03-01

    Full Text Available Se describen 3 especies nuevas de moluscos marinos: Gibberula palmasola sp. n., recolectada en la vegetación asociada a rocas rodeadas de sedimentos blandos en una laguna costera cercada por mangle en la península de Guanahacabibes, Cuba, y caracterizada por presentar, el animal vivo, la cabeza negra y una distribución típica de bandas negras y pardas con lunares anaranjados en el manto bajo la concha; Gibberula dosmosquises sp. n., recolectada en fondos rocosos del Caribe insular de Venezuela, se caracteriza por una discreta coloración del manto y un patrón de manchas en el pie, y Gibberula thetisae sp. n, proveniente de los pastos marinos del golfo de Batabanó, Cuba, con 3 pliegues en la columela, el último muy débil, y un labio externo casi cortante, caracteres que permiten separarla de todas las demás especies conocidas en el área antillana, aunque se desconozca la anatomía del animal. Se discute la lista de especies válidas del género para Cuba y Venezuela, y se hacen adiciones y consideraciones al complejo de especies en torno a Gibberula ubitaensis Espinosa y Ortea, 2000.Three new species of marine molluscs are described. Gibberula palmasola new species, collected in vegetation associated with rocks surrounded by soft sediments in a coastal lagoon surrounded by mangroves in Guanahacabibes Peninsula, Cuba, and characterized by a black head and typical distribution of black and brown bands and orange spots in the mantle. Gibberula dosmosquises new species, collected in rocky bottoms of a Caribbean island from Venezuela, characterized by a simple staining in the mantle and a pattern of spots on the foot, and Gibberula thetisae new species, from sea grass in the gulf of Batabano, Cuba, with shell having 3 columellar folds, the last very weak, and a sharp outer lip; although, its anatomy is not known, these conchological characters separate it from all other known species in the Antilles. Aditionally, the list of valid species for Cuba and Venezuela is discussed and some considerations about Gibberula ubitaensis Espinosa y Ortea, 2000 species complex are given.

  13. Observations on the morphology of Pomacea lineata (Spix, 1827 (Mollusca, Ampullariidae Observações sobre a morfologia de Pomacea lineata (Spix, 1827 (Mollusca, Ampullaridae

    Directory of Open Access Journals (Sweden)

    Silvana Carvalho Thiengo

    1987-12-01

    Full Text Available This paper deals with the morpholgy of Pomacea lineata (Spix, 1827 collected at its type locality. The shell is globose, moderately heavy, horn-colored with brown spiral bands; apex subelevated; 4 - 5 rounded whorls increasing in diameter rather rapidly, separated by deep suture. Aperture large and ovoid; outer lip sharp; umbilicus narrow and deep; operculum concentric, corneous. Ratios: shell width/shell length = 0.74 - 0.83 (mean 0.78; spire length/shell length = 0.10 - 0.18 (mean 0.13; aperture length/shell length = 0.70 - 0.77 (mean 0.73. The animal is longisiphonate. Renal organ brownish with marked invagination at its right edge. Ureter elongated with its long axis transverse to the main axis of the kidney. The radula is taenioglossate (2.1.1.1.2 and has on average 35 transverse rows of teeth. The form and arrangement of the radula teeth are nearly the same as in other Ampullariidae. The testis is cream-colored and lies in the first three whorls of the spire. Spermiduct uniformly narrow, running to the base of the spire. Seminal vesicle whitish, slightly pressed dorsoventrally. Prostate cylindric and thick, similar in color to the testis. Penis whiplike, with a closed circular spermiduct. Penis pouch ovoid completely envelping the penis. Penis sheath elongated, broad prosimally, tapering distally. Its inner surface shows a longitudinal channel along its proximal half and two glands, one on the middle and the other apical. Ovary composed of branched whitish tubules situated on the surface of the digestive gland. Oviduct slender running along the columellar axis toward the base of the spire. Seminal receptalble tubiform, thick-walled and rounded proximally. Albumen gland large, pink, enclosing the receptacle and the spiral capsule gland. Vestigial male copulatory apparatus (penis and its sheath present in all females examined.Neste trabalho e estudada a morfologia de Pomacea lineata (Spix, 1827 baseada em material coletado na localidade-tipo. Concha com espessura moderada, globosa, castanha, com faixas espirais castanhas-escuras; ápice pouco elevado, 4-5 giros arredondados crescendo rapidamente em diâmetro, separados por suturas profundas. Abertura grande oval; lábio externo simples; umbigo pequeno e profundo; opérculo concêntrico, córneo. Razão: largura da concha/comprimento da concha = 0.74 - 0.83 (média 0.78; comprimento da espira/comprimento da concha = 0.10 - 0.18 (média 0.13; comprimento da abertura/comprimento da concha = 0.70 - 0.77 (média 0.73. Animal com sifão bem desenvolvido. A rádula é tenioglossa (2.1.1.1.2 e tem em média 35 fileiras transversais de dentes. A forma e a disposição dos dentes radulares são semelhantes ao padrão dos ampularídeos. Rim de cor castanha apresentando uma invaginação acentuada na parede direita. Ureter alongado e transversal ao eixo principal do rim. Testículo constituído por uma massa cor creme, ocupando as três primeiras voltas da espira. Espermiduto estreito e uniforme, correndo para a base da espira. Vesícula seminal esbranquiçada levemente achatada dorso-ventralmente. Próstata cilíndrica e compacta com coloração semelhante à do testículo. Pênis em forma de chicote com canal espermático fechado e de contorno circular. Bolsa do pênis ovalada, envolvendo-o completamente. Bainha do pênis alongada tendo sua largura diminuída gradualmente da base para a extremidade; sua superfície interna apresenta um canal mediano em sua metade proximal e duas glândulas, uma mediana e outra apical. Ovário constituído por túbulos ramificados branco-amarelados situados superficilamente sobre a glândula digestiva. Oviduto estreito correndo pelo eixo columelar até a base da espira. Receptáculo seminal tubular com parede espessa e extremidade proximal alargada. Glândula de albume volumosa e rosada envolvendo o receptáculo seminal e a glândula da casca em espiral. Vestígio do aparelho copulador masculino (pênis e sua bainha presente em todas as fêmeas examinadas.

  14. Protein (Cyanobacteria): 74944 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available in tlr1014 Thermosynechococcus elongatus BP-1 MCSVGLLLVPALLPYSLAQTSPRTDVIAPWEITTYARVVLEIEPIRQKYYRQAQAAFQGQVPSNACFGMNPQHIPSGLEAICASYGWEAIQVLKKYNMSLEQFNAITLRAQQDSTLSRRIQAEMLRLQQP ...

  15. Protein (Cyanobacteria): 64998 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available syc2491_c Synechococcus elongatus PCC 6301 MRPLTLEPHDQRSVLRLLIGAAWLDGDMQPEERNYLKGLLEKHRLAADPEFQDLMTRTTPISPAVFEQWLTAYLRQHPRREDVEALLEQISSVIYADSLIDAREAAVLCEIEQELEHRPALRLLDRLQTFFHHCLVMS ...

  16. [Reproductive aspects of Pomacea flagellata (Mollusca: Ampullariidae) at Bacalar lagoon, Quintana Roo, México].

    Science.gov (United States)

    Oliva-Rivera, José J; Ocaña, Frank A; Navarrete, Alberto de Jesús; Carrillo, Rosa M de Jesús; Vargas-Espósitos, Abel A

    2016-12-01

    The freshwater snail Pomacea flagellata is native from Southeastern Mexico. Studies about this species are scarce and none has treated their reproduction. This snail has been exploited at Bacalar lagoon for many years, leading to a significant decrease in their abundance and currently, a permanent ban was proposed by the government. This work aimed to assess the temporal variations of mating frequency and the abundance of egg clutches of P. flagellata at Bacalar lagoon, as well as their relation with snails density and environmental variables. Sampling was done during the three climatic seasons: Rainy (July, August and September/2012), North or Cold fronts (December/2012 and January and February/2013) and Dry (March, April and May/2013) in 12 sampling stations located along the Bacalar lagoon. On each station a transect of 100 m length was set parallel to the edge, and the number of fresh egg clutches (pink color) laid over vegetation, rocks or manmade structures, were counted. In the water, three 50 x 2 m transects were set and the number of snails were counted as well as the mating frequency. Density of snails varied significantly among seasons, decreasing from the rainy to the dry season. There were no significant differences of snail abundance among months, nested in climatic seasons (ANOVA, p>0.05). During the rainy season the mating frequency was significantly higher than in the Norths, meanwhile in the dry season no mating were registered (Kruskal-Wallis, p˂0.05). Eggs clutches appeared from July to March. Density of egg clutches presented no differences between the Rainy and the North seasons (2.72 and 2.93 clutches/m, respectively), nonetheless during the dry season abundance of egg masses was significantly lower (0.1 clutches/m) (H, p˂0.05). Mating frequency was related with snail abundance (rs= 0.26; pBacalar lagoon is related with the warmer months and with higher rainfall. This finding is relevant to support the management of this resource in the region, so that to implement any management arrangement they must be aware that a temporal ban is necessary during the reproductive season at least.

  17. Using DNA barcoding to differentiate invasive Dreissena species (Mollusca, Bivalvia

    Directory of Open Access Journals (Sweden)

    Jonathan Marescaux

    2013-12-01

    Full Text Available The zebra mussel (Dreissena polymorpha and the quagga mussel (Dreissena rostriformis bugensis are considered as the most competitive invaders in freshwaters of Europe and North America. Although shell characteristics exist to differentiate both species, phenotypic plasticity in the genus Dreissena does not always allow a clear identification. Therefore, the need to find an accurate identification method is essential. DNA barcoding has been proven to be an adequate procedure to discriminate species. The cytochrome c oxidase subunit 1 mitochondrial gene (COI is considered as the standard barcode for animals. We tested the use of this gene as an efficient DNA barcode and found that it allow rapid and accurate identification of adult Dreissena individuals.

  18. Using DNA barcoding to differentiate invasive Dreissena species (Mollusca, Bivalvia).

    Science.gov (United States)

    Marescaux, Jonathan; Van Doninck, Karine

    2013-12-30

    The zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena rostriformis bugensis) are considered as the most competitive invaders in freshwaters of Europe and North America. Although shell characteristics exist to differentiate both species, phenotypic plasticity in the genus Dreissena does not always allow a clear identification. Therefore, the need to find an accurate identification method is essential. DNA barcoding has been proven to be an adequate procedure to discriminate species. The cytochrome c oxidase subunit I mitochondrial gene (COI) is considered as the standard barcode for animals. We tested the use of this gene as an efficient DNA barcode and found that it allow rapid and accurate identification of adult Dreissena individuals.

  19. The genus Alvania on the Canary islands and Madeira (Mollusca: Gastropoda), part 2 [final part

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Hoenselaar, H.J.

    1998-01-01

    Five Alvania species from the Canary Islands and the Madeira Archipelago are revised. A new species to science, A. johannae is described and for three species lectotypes are designated. Altogether 13 littoral alvaniids are presently known from this area. Doubtful records are enumerated and a list of

  20. Acanthochitona terezae sp. n., um novo poliplacóforo da costa brasileira (Mollusca, Polyplacophora

    Directory of Open Access Journals (Sweden)

    Orlando Guerra Júnior

    1983-12-01

    Full Text Available O autor descreve uma nova espécie de poliplacóforo (Acanthochitona terezae para o litoral brasileiro, apresenta dados sobre sua morfologia e discute aspectos biogeográficos.The author describes a new species of chiton (Acanthochitona terezae from the coast of Brazil, adducing data on its morphology and biogeographic aspects.

  1. Fine structure and immunocytochemistry of a new chemosensory system in the Chiton larva (Mollusca: Polyplacophora)

    DEFF Research Database (Denmark)

    Haszprunar, Gerhard; Friedrich, Stefan; Wanninger, Andreas

    2002-01-01

    Combined electron microscopy and immunocytochemistry of the larvae of several polyplacophoran species (Chiton olivaceus, Lepidochitona aff. corrugata, Mopalia muscosa) revealed a sensory system new to science, a so-called "ampullary system." The cells of the "ampullary system" are arranged in four...

  2. Chitons (Mollusca: Polyplacophora) from the Seychelles with description of a new species

    NARCIS (Netherlands)

    Kaast, P.

    1996-01-01

    Notes are given on nine chiton species, collected mainly during the 'Oceanic Reefs' Expedition to the Seychelles (1992-1993), with some biogeographical observations. Ischnochiton goudi (family Ischnochitonidae) is described as a new species.

  3. Diversidad y microestructura de quitones (Mollusca: Polyplacophora del Caribe de Costa Rica

    Directory of Open Access Journals (Sweden)

    Cedar I García-Ríos

    2011-03-01

    Full Text Available Los poliplacóforos asociados a los arrecifes de coral en la costa caribeña de Costa Rica han sido poco estudiados. El examen del cascajo de coral acumulado en el sublitoral somero, en cuatro estaciones de colección, localizadas en la Provincia de Limón reveló una diversidad de quitones mayor a la documentada. Anteriormente se habían registrado ocho especies para el Caribe costaricense: Ischnochiton erythronotus (C.B. Adams, 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon, 1886; S. purpurascens (C.B. Adams, 1845; Acanthopleura granulata (Gmelin, 1791; Chiton marmoratus Gmelin, 1791; C. tuberculatus Linnaeus, 1758; Acanthochitona rhodea (Pilsbry, 1893. Otras cinco se registran aquí por primera vez: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954; Cryptoconchus floridanus (Dall 1889.

  4. The first observations of Ischnochiton (Mollusca, Polyplacophora movement behaviour, with comparison between habitats differing in complexity

    Directory of Open Access Journals (Sweden)

    Kiran Liversage

    2017-12-01

    Full Text Available Most species of Ischnochiton are habitat specialists and are almost always found underneath unstable marine hard-substrata such as boulders. The difficulty of experimenting on these chitons without causing disturbance means little is known about their ecology despite their importance as a group that often contributes greatly to coastal species diversity. In the present study we measured among-boulder distributional patterns of Ischnochiton smaragdinus, and used time-lapse photography to quantify movement behaviours within different habitat types (pebble substrata and rock-platform. In intertidal rock-pools in South Australia, I. smaragdinus were significantly overdispersed among boulders, as most boulders had few individuals but a small proportion harboured large populations. I. smaragdinus individuals emerge from underneath boulders during nocturnal low-tides and move amongst the inter-boulder matrix (pebbles or rock-platform. Seventy-two percent of chitons in the pebble matrix did not move from one pebble to another within the periods of observation (55–130 min but a small proportion moved across as many as five pebbles per hour, indicating a capacity for adults to migrate among disconnected habitat patches. Chitons moved faster and movement paths were less tortuous across rock-platform compared to pebble substrata, which included more discontinuities among substratum patches. Overall, we show that patterns of distribution at the boulder-scale, such as the observed overdispersion, must be set largely by active dispersal of adults across the substratum, and that differing substratum-types may affect the degree of adult dispersal for this and possibly other under-boulder chiton species.

  5. Embryonic development of nudibranch species (Mollusca: Opisthobranchia in the Gulf of Thailand

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    Pattira Kasamesiri

    2014-12-01

    Full Text Available Objective: To find the possible way to predict the mode of embryonic development of nudibranchs, focusing on egg mass characteristics, embryonic development, and shell patterns of the veligers. Methods: Eight species of nudibranch were collected in the eastern part of the Gulf of Thailand. The specimens were allowed to copulate and lay their egg masses under laboratory conditions. Embryonic development was monitored under a light microscope with a digital camera every day until hatching. Results: Most of the species of nudibranch collected had a single larva in each egg capsule that developed, except for Jorunna funebris, which had 1-4 larvae in each egg capsule. All the specimens had the same pattern of cell division and hatching into the water column during the veliger form. However, the species developed at different rates in each stage. Conclusions: All species in the current study had planktotrophic development except Doriprismatica atromarginata, which showed lecithotrophic development. Based on embryonic development among the nudibranchs that showed planktotrophic development, Jorunna funebris appeared to be the most advantageous species for culture development with regard to utilization and conservation in the future.

  6. Freshwater Pea Clams Pisidium C. Pfeiffer (Mollusca, Bivalvia From The Alpine Areas of Bulgaria

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    Dilian G. Georgiev

    2016-12-01

    Full Text Available Distributional data for 3 Pisidium species was provided from 19 alpine lakes and 1 dam in Rila and Pirin Mts. (Bulgaria. Most widely distributed was P. casertanum. The species P. globulare and P. obtusale are new records to the area.

  7. Thermal tolerance of the adult Asiatic clam Corbicula manilensis (Mollusca:Bivalvia)

    International Nuclear Information System (INIS)

    Mattice, J.S.; Dye, L.L.

    1975-01-01

    Knowledge of the thermal tolerance of Corbicula manilensis is important for antifouling at water intakes and protection below discharges. Groups of 20 clams were acclimated to temperatures ranging between 5 and 32 0 C and exposed continuously to higher temperatures (24-39 0 C), continuously to lower temperatures (2 to 20 0 C), or for 30 minutes to temperatures between 37 and 43 0 C. Mortality was determined by lack of response to prying open the valves. Exposure to temperatures between 40 (5 0 C Acclimation) and 43 0 C (30 0 C Acclimation) for 30 minutes caused 100 per cent mortality. For continuous exposures, upper tolerance limits (50 per cent) were between 24 (5 0 C Acclimation) and 34 0 C (30 0 Acclimation) and lower tolerance limits were between 2 (15 0 C Acclimation) and 12 0 C (30 0 C Acclimation). Relationships between acclimation and resistance temperatures were linear. The upper incipient lethal temperature was 34 0 C. Use of results at 24 and 48 hours (and 96 hours for long-term heat stress) yielded significant overestimates of tolerance limits. (U.S.)

  8. Systematic reviews on the Mesodesmatidae (Mollusca, Bivalvia) I. The Genus Monterosatus Beu, 1971

    NARCIS (Netherlands)

    Rooij-Schuiling, de L.A.

    1977-01-01

    In trying to identify a small Mesodesma from West Irian, New Guinea, much material in the collections of several museums was studied. As a guide for the identification I at first used the revision of the Mesodesmatidae by Lamy (1914), which is based exclusively on the collections of the Parisian

  9. A new alien snail species from the Eger stream, Hungary (Mollusca, Ampullariidae

    Directory of Open Access Journals (Sweden)

    Frisóczki, B.

    2016-11-01

    Full Text Available Our macrozoobenthon samplings carried out in the Eger stream during 2015–2016 resulted in recording an alien species Marisa cornuarietis (Linneaus, 1758 the giant ramshorn snail which has not been reported so far from outdoorwaters in Hungary. Here we report on collecting several specimens from the urban section of the stream close to the outflow of the Eger thermal spa.

  10. New species of Rissoidae from the Cape Verde Islands (Mollusca: Gastropoda) Part 1

    OpenAIRE

    Moolenbeek, R.G.; Rolán, E.

    1988-01-01

    Sediment samples collected at the Cape Verde Islands contained many interesting micromolluscs. Amongst them, four new species of the family Rissoidae ( Alvania peli, A. nicolauensis, A. stocki and A. planciusi).

  11. Patterns of Diversity of the Rissoidae (Mollusca: Gastropoda) in the Atlantic and the Mediterranean Region

    OpenAIRE

    Sérgio P. Ávila; Jeroen Goud; António M. de Frias Martins

    2012-01-01

    The geographical distribution of the Rissoidae in the Atlantic Ocean and Mediterranean Sea was compiled and is up-to-date until July 2011. All species were classified according to their mode of larval development (planktotrophic and nonplanktotrophic), and bathymetrical zonation (shallow species—those living between the intertidal and 50 m depth, and deep species—those usually living below 50 m depth). 542 species of Rissoidae are presently reported to the Atlantic Ocean and the Mediterranean...

  12. Patterns of diversity of the Rissoidae (Mollusca: Gastropoda) in the Atlantic and the Mediterranean region.

    Science.gov (United States)

    Ávila, Sérgio P; Goud, Jeroen; de Frias Martins, António M

    2012-01-01

    The geographical distribution of the Rissoidae in the Atlantic Ocean and Mediterranean Sea was compiled and is up-to-date until July 2011. All species were classified according to their mode of larval development (planktotrophic and nonplanktotrophic), and bathymetrical zonation (shallow species--those living between the intertidal and 50 m depth, and deep species--those usually living below 50 m depth). 542 species of Rissoidae are presently reported to the Atlantic Ocean and the Mediterranean Sea, belonging to 33 genera. The Mediterranean Sea is the most diverse site, followed by Canary Islands, Caribbean, Portugal, and Cape Verde. The Mediterranean and Cape Verde Islands are the sites with higher numbers of endemic species, with predominance of Alvania spp. in the first site, and of Alvania and Schwartziella at Cape Verde. In spite of the large number of rissoids at Madeira archipelago, a large number of species are shared with Canaries, Selvagens, and the Azores, thus only about 8% are endemic to the Madeira archipelago. Most of the 542-rissoid species that live in the Atlantic and in the Mediterranean are shallow species (323), 110 are considered as deep species, and 23 species are reported in both shallow and deep waters. There is a predominance of nonplanktotrophs in islands, seamounts, and at high and medium latitudes. This pattern is particularly evident in the genera Crisilla, Manzonia, Onoba, Porosalvania, Schwartziella, and Setia. Planktotrophic species are more abundant in the eastern Atlantic and in the Mediterranean Sea. The results of the analysis of the probable directions of faunal flows support the patterns found by both the Parsimony Analysis of Endemicity and the geographical distribution. Four main source areas for rissoids emerge: Mediterranean, Caribbean, Canaries/Madeira archipelagos, and the Cape Verde archipelago. We must stress the high percentage of endemics that occurs in the isolated islands of Saint Helena, Tristan da Cunha, Cape Verde archipelago and also the Azores, thus reinforcing the legislative protective actions that the local governments have implemented in these islands during the recent years.

  13. A new Indo-Pacific Zebina species (Mollusca: Gastropoda: Rissoidae)

    OpenAIRE

    Sleurs, W.J.; Van Goethem, J.L.

    2002-01-01

    A new, widespread, but uncommon Indo-Pacific rissoinine species, Zebina ( ? Zebina) malagazzae sp. nov. is described. It is compared with its morphologically closest relative, the tropical Eastern Pacific species Zebina axeliana (STRONG & HERTLEIN, 1951 ), with the holotype of Zebina constricta LASERON, 1956 from Christmas Island and with Zebina ( ?Zebina) japonica (WEINKAUFF, 1881).

  14. Anesthesia of Biomphalaria spp. (Mollusca, Gastropoda: sodium pentobarbital is the drug of choice

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    RL Martins-Sousa

    2001-04-01

    Full Text Available The anesthetic effect of some water-soluble anesthesic or narcotic drugs currently used in mice was tested in molluscs of the Biomphalaria genus. Sodium thiopental was very toxic to the snails resulting in high rates of mortality in all the treatment schedules tested. Cetamine base, at concentration of 0.25 mg/ml of water, resulted in partial snail anesthesia (40% of snails were anesthetized only after 20 h of exposition. The association of Cetamine base with Tiazine chloridrate did not improve the anesthesic effect, and higher concentrations of these drugs were toxic to the snails. Sodium pentobarbital at 0.4 mg/ml in water for 8 h was the best treatment schedule to anesthetize Biomphalaria snails. In this schedule, the snails were anesthetized without any toxic effect. The procedure provides a powerful tool for in vivo studies that demande a complete state of snail anesthesia.

  15. Comparative morphology among representatives of main taxa of Scaphopoda and basal protobranch Bivalvia (Mollusca

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    Luiz Ricardo L. Simone

    2009-01-01

    Full Text Available This study deals with detailed morphology and anatomy of 4 species of Scaphopoda and 5 species of protobranch Bivalvia. Both classes are traditionally grouped in the taxon Diasoma, which has been questioned by different methodologies, such as molecular and developmental. This study is developed under a phylogenetic methodology with the main concern in performing it in an intelligible and testable methodology. The analyzed Scaphopoda species came from the Brazilian coast and belong to the family Dentaliidae [(1 Coccodentalium carduus; (2 Paradentalium disparile] and Gadiliidae; [(3 Polyschides noronhensis, n. sp. from Fernando de Noronha Archipelago; (4 Gadila braziliensis]. These species represent the main branches of the class Scaphopoda. From protobranch bivalves, representatives of the families Solemyidae [(5 Solemya occidentalis, from Florida; S. notialis, n. sp. from S.E. Brazil], Nuculanidae [(6 Propeleda carpentieri from Florida], and Nuculidae [(7 Ennucula puelcha, from south Brazil] are included. These species represent the main branches of the basal Bivalvia. The descriptions on the anatomy of S. occidentalis and of P. carpentieri are published elsewhere. The remaining are included here, for which a complete taxonomical treatment is performed. Beyond these species, representatives of other taxa are operationally included as part of the ingroup (indices are then shared with them, as a procedure to test the morphological monophyly of Diasoma. These taxa are: two lamellibranch bivalves [(8 Barbatia - Arcidae; (9 Serratina - Tellinidae; both published elsewhere;, and Propilidium (10 Patellogastropoda, and (11 Nautilus, basal Cephalopoda, based on basal taxa. The effective outgroups are (12 Neopilina (Monoplacophora and (13 Hanleya (Polyplacophora. The phylogenetic analysis based on morphology revealed that the taxon Diasoma is supported by 14 synapomorphies, and is separated from Cyrtosoma (Gastropoda + Cephalopoda. Although they are not the main goal of this paper, the taxa Scaphopoda and Bivalvia are supported by 8 and by 7 synapomorphies respectively. The taxon Protobranchia resulted paraphyletic. Both scaphopod orders resulted monophyletic. The obtained cladogram is: ((((Coccodentalium carduus - Paradentalium disparile (Polyschides noronhensis - Gadila brasiliensis ((Solemya occidentalis - S. notialis (Propeleda carpenteri (Ennucula puelcha (Barbatia cancellaria - Serratina capsoides (Propilidium curumim - Nautilus pompilius - Lolliguncula brevis.Este estudo analisa a morfologia e anatomia detalhadas de 4 espécies de Scaphopoda e 5 espécies de bivalves protobrânquios. Ambas as classes são tradicionalmente agrupadas no táxon Diasoma, o qual vem sendo questionado por diferentes metodologias, tais como molecular e de desenvolvimento. Este estudo é desenvolvido sob uma metodologia filogenética, a qual a maior preocupação é fornecer um procedimento inteligível e testável. As espécies de Scaphopoda analisadas provieram da costa brasileira e pertencem à família Dentaliidae [(1 Coccodentalium carduus; (2 Paradentalium disparile] e Gadilidae [(3 Polyschides noronhensis, n. sp. do Arquipélago de Fernando de Noronha; (4 Gadila braziliensis]. Estas espécies representam os ramos principais da classe Scaphopoda. Dos bivalves protobrânquios, representantes das famílias Solemyidae [(5 Solemya occidentalis, da Flórida; S. notialis, n. sp. do S.E. Brasil], Nuculanidae [(6 Propeleda carpentieri, da Flórida] e Nuculidae [(7 Ennucula puelcha, do sul do Brasil] são incluídos. Estas espécies representam os principais ramos dos bivalves basais. As descrições anatômicas de S. occidentalis e de P. carpentieri estão sendo publicadas em outro artigo, as das demais espécies estão incluídas neste, o qual também inclui um completo tratamento taxonômico. Além dessas espécies, representantes de outros táxons são operacionalmente incluídos como parte do ingroup (então os índices são compartilhados com eles, um procedimento visando testar a monofilia morfológica de Diasoma. Esses táxons são 2 bivalves lamelibrânquios [(8 Barbatia - Arcidae; (9 Serratina - Tellinidae; ambos publicados em artigos a parte]; Propilidium (10 Patellogastropoda e (11 Nautilus, Cephalopoda basal, baseados em táxons basais. Os outgroups efetivos são (12 Neopilina (Monoplacophora e (13 Hanleya (Polyplacophora. A análise filogenética baseada na morfologia revelou que o táxon Diasoma é suportado por 14 sinapomorfias, sendo separada de Cyrtosoma (Gastropoda + Cephalopoda. Embora não sendo o principal enfoque do presente artigo, os táxons Scaphopoda e Bivalvia são suportados por 8 e por 7 sinapomorfias respectivamente. O táxon Protobranchia resultou parafilético. O cladograma obtido é: ((((Coccodentalium carduus - Paradentalium disparile (Polyschides noronhensis - Gadila brasiliensis ((Solemya occidentalis - S. notialis (Propeleda carpenteri (Ennucula puelcha (Barbatia cancellaria - Serratina capsoides (Propilidium curumim - Nautilus pompilius - Lolliguncula brevis.

  16. Ingestion Rates and Absorption Efficiencies of Abra ovata(Mollusca: Bivalvia) Fed on Macrophytobenthic Detritus

    Science.gov (United States)

    Charles, F.; Grémare, A.; Amouroux, J. M.

    1996-01-01

    Ingestion and absorption were investigated in the deposit-feeding bivalve Abra ovatafed on 14C-formaldehyde-labelled detritus derived from 11 macrophytes: Posidonia oceanica, Cystoseira compressa, Padina pavonica, Stypocaulon scoparium, Colpomenia sinuosa, Cystoseira mediterranea, Dilophus spiralis, Rissoella verruculosa, Ulva rigida, Corallina elongata andCodium vermilara . Labelling efficiency ranged from 3·2 (R. verruculosa ) to 53·0% (C. sinuosa) depending on the detritus. The stability of the labelling also varied among detritus types, and was negatively correlated with labelling efficiency. For all types of detritus, the exchanges of radioactivity between compartments were dominated by the transfer between particulate organic matter (POM) and bivalves. These transfers resulted from the interactions between the processes of ingestion, defaecation, and recycling of faeces. The coexistence of these processes together with the occasional lack of stability of the label complicated the actual determination of ingestion rates and absorption efficiencies, which necessitated the use of mathematical modelling. The model was initially composed of five compartments: Detritus, Bivalves, Dissolved organic matter (DOM), CO 2, and Faeces. Two first-order time delays were introduced to account for the production of faeces and CO 2by the bivalves. These delays resulted in the subdivision of the Bivalves compartment into three subcompartments: bivIng, bivDig, and bivAbs. The model also accounts for differences in utilization rates of detritus and faeces by the bivalves. It simulates the exchange of radioactivity between compartments and allows the quantification of ingestion and absorption efficiencies. Our results show large differences in both ingestion rates and absorption efficiencies of A. ovatafed on different types of detritus. Ingestion rates ranged between 0·16 ( C. mediterraneaand D. spiralis) and 8·65 μgOM mgDW -1 h -1( U. rigida). Absorption efficiencies ranged between 0·5 ( C. sinuosa) and 11·4% ( C. elongata). These results were related to the main characteristics of the detritus by using a principal component analysis. Results show a negative effect of both protein and phenolic contents on ingestion rates, and a negative effect of phenolic contents on absorption efficiencies, in good agreement with the existing literature.

  17. Replication and recovery of nuclear DNA in UV-irradiated eggs of Lymnaea stagnalis (Mollusca, Gastropoda)

    NARCIS (Netherlands)

    Labordus, V.; Deumer, H.

    1982-01-01

    Synchronized and oriented egg cells of L. stagnalis have been irradiated with UV light during the G2 phase of the 2nd cleavage cycle; next the egg cells were treated with caffeïne (3 × 10−3M) for varying periods during the 2nd and the 3rd cleavage cycle. In a second experiment the egg cells were

  18. Geochemical and Crystallographic Study of Turbo Torquatus (Mollusca: Gastropoda) From Southwestern Australia

    Science.gov (United States)

    Roger, L. M.; George, A. D.; Shaw, J.; Hart, R. D.; Roberts, M. P.; Becker, T.; Evans, N. J.; McDonald, B. J.

    2018-01-01

    Shells of the marine gastropod Turbo torquatus were sampled from three different locations along the Western Australian coastline, namely Marmion Lagoon (31°S), Rottnest Island (32°S), and Hamelin Bay (34°S). Marmion Lagoon and Rottnest Island have similar sea surface temperature ranges that are ˜1°C warmer than Hamelin Bay, with all sites influenced by the warm southward flowing Leeuwin Current. The shells were characterized using crystallographic, spectroscopic, and geochemical analyses. Shell mineral composition varies between the three sites suggesting the influence of sea surface temperature, oxygen consumption, and/or bedrock composition on shell mineralogy and preferential incorporation and/or elemental discrimination of Mg, P, and S. Furthermore, T. torquatus was found to exert control over the incorporation of most, if not all, the elements measured here, suggesting strong biological regulation. At all levels of testing, the concentrations of Li varied significantly, which indicates that this trace element may not be a suitable environmental proxy. Variation in Sr concentration between sites and between specimens reflects combined environmental and biological controls suggesting that Sr/Ca ratios in T. torquatus cannot be used to estimate sea surface temperature without experimentally accounting for metabolic and growth effects. The mineral composition and microstructure of T. torquatus shells may help identify sea surface temperature variations on geological time scales. These findings support the previously hypothesized involvement of an active selective pathway across the calcifying mantle of T. torquatus for most, if not all, the elements measured here.

  19. Is Galba schirazensis (Mollusca, Gastropoda) an intermediate host of Fasciola hepatica (Trematoda, Digenea) in Ecuador?

    Science.gov (United States)

    Caron, Yannick; Celi-Erazo, Maritza; Hurtrez-Boussès, Sylvie; Lounnas, Mannon; Pointier, Jean-Pierre; Saegerman, Claude; Losson, Bertrand; Benítez-Ortíz, Washington

    2017-01-01

    Fasciolosis is a widely distributed disease in livestock in South America but knowledge about the epidemiology and the intermediate hosts is relatively scarce in Ecuador. For three months, lymnaeid snails were sampled (n = 1482) in Pichincha Province at two sites located in a highly endemic area. Snails were identified (based on morphology and ITS-2 sequences) and the infection status was established through microscopic dissection and a multiplex polymerase chain reaction (PCR)-based technique. Techniques based on morphology were not useful to accurately name the collected snail species. Comparison with available DNA sequences showed that a single snail species was collected, Galba schirazensis. Live rediae were observed in 1.75% (26/1482) and Fasciola sp. DNA was detected in 6% (89/1482) of collected snails. The COX-1 region permitted identification of the parasite as Fasciola hepatica. The relative sensitivity and specificity of the microscope study, compared to PCR results, were 25.84% and 99.78%, respectively. The mean size of the snails recorded positive for F. hepatica through crushing and microscopy was significantly higher than the mean size of negative snails, but there was no such difference in PCR-positive snails. The role of G. schirazensis as an intermediate host of F. hepatica in Ecuador is discussed and the hypothesis of an adaptation of the parasite to this invasive snail is proposed. For the first time, an epidemiological survey based on molecular biology-based techniques assessed the possible role of lymnaeid snails in the epidemiology of fasciolosis in Ecuador. © Y. Caron et al., published by EDP Sciences, 2017.

  20. Is Galba schirazensis (Mollusca, Gastropoda an intermediate host of Fasciola hepatica (Trematoda, Digenea in Ecuador?

    Directory of Open Access Journals (Sweden)

    Caron Yannick

    2017-01-01

    Full Text Available Fasciolosis is a widely distributed disease in livestock in South America but knowledge about the epidemiology and the intermediate hosts is relatively scarce in Ecuador. For three months, lymnaeid snails were sampled (n = 1482 in Pichincha Province at two sites located in a highly endemic area. Snails were identified (based on morphology and ITS-2 sequences and the infection status was established through microscopic dissection and a multiplex polymerase chain reaction (PCR-based technique. Techniques based on morphology were not useful to accurately name the collected snail species. Comparison with available DNA sequences showed that a single snail species was collected, Galba schirazensis. Live rediae were observed in 1.75% (26/1482 and Fasciola sp. DNA was detected in 6% (89/1482 of collected snails. The COX-1 region permitted identification of the parasite as Fasciola hepatica. The relative sensitivity and specificity of the microscope study, compared to PCR results, were 25.84% and 99.78%, respectively. The mean size of the snails recorded positive for F. hepatica through crushing and microscopy was significantly higher than the mean size of negative snails, but there was no such difference in PCR-positive snails. The role of G. schirazensis as an intermediate host of F. hepatica in Ecuador is discussed and the hypothesis of an adaptation of the parasite to this invasive snail is proposed. For the first time, an epidemiological survey based on molecular biology-based techniques assessed the possible role of lymnaeid snails in the epidemiology of fasciolosis in Ecuador.

  1. Mollusca of the Magellan Region. A checklist of the species and their distribution

    Directory of Open Access Journals (Sweden)

    Katrin Linse

    1999-12-01

    Full Text Available The Molluscan species collected during the Victor Hensen Joint Magellan Campaign 1994 served as the basis for this species list. The list was then completed by literature data on the distribution of molluscs around the Falkland Islands, the other Scotia Arc Islands, Antarctica and the Kerguelen Islands. 397 Magellan species are known: 10 species of Aplacophora, 250 species of Gastropoda, 6 species of Scaphopoda and 131 species of Bivalvia. Polyplacophora and Cephalopoda are not included because both taxa need revision.

  2. Phylogenetic Diversity of Cephalopoda (Animalia:Mollusca) Along the Saudi Arabian Red Sea Coastline

    KAUST Repository

    Byron, Gordon

    2016-12-01

    Although the Red Sea presents a unique environment with high temperature and salinity, it remains an area that is understudied. This lack of information is reflected in many areas, one which is biodiversity. Despite increasing work on biodiversity throughout the Red Sea and an increase in Cephalopoda studies, Cephalopoda in the Red Sea remain underrepresented, which is especially pronounced in molecular analyses. Members of the class Cephalopoda are considered to be major contributors to coral reef ecosystems, serving as part of the food chain and exhibiting population increases due to targeted teleost fisheries and global climate change. In order to assess the biodiversity of Cephalopoda in the Saudi Arabian Red Sea, 87 specimens were collected from 25 reef locations between 17°N and 28°N latitude, as well as from the largest fish market in the Kingdom of Saudi Arabia. Taxonomic identification of specimens was determined using morphological comparisons with previously reported species in the Red Sea and the molecular barcoding region Cytochrome Oxidase I. 84 Red Sea sequences were compared with sequences from GenBank and analyzed using a complement of Neighbor-Joining, Maximum-Likelihood, and Bayesian inference trees. Species complexes were also investigated for Sepia pharaonis and Sepioteuthis lessoniana, which had been previously reported. From 17 cuttlefish, our study yielded three species, two of which matched previously reported species in GenBank. In addition, two distinct clades of Sepia pharaonis were identified. Of 35 squid collected, four species were identified, one of which did not match any other accepted species in literature, while Sepioteuthis lessoniana in the Red Sea formed a distinct clade. From 30 different specimens a total of five genera of Octopoda were present, forming six distinct species. Five Octopoda species collected did not match previously reported species, although many specimens were paralarvae or juveniles, so morphologically we could not compare to previously described species in the Red Sea. Cephalopoda fisheries in the Red Sea is low, and as their populations increase worldwide, this could be a viable fishery for Saudi Arabia. As such, further investigation into the role which cephalopods play in supporting biodiversity in the Red Sea is essential.

  3. The shallow-water chitons (Mollusca, Polyplacophora of Caldera, Region of Atacama, northern Chile

    Directory of Open Access Journals (Sweden)

    Juan Francisco Araya

    2015-03-01

    Full Text Available The Molluscan species of the northern littoral of Chile have been sparsely studied. This work reviews for the first time the diversity of polyplacophoran molluscs around the port of Caldera, in the Region of Atacama (26°45’49”S; 70°45’17”W to 27°20’23”S; 70°56’46”W, northern Chile. Eleven species were found in this study: Acanthopleura echinata (Barnes, 1824; Callistochiton pulchellus (Gray, 1828; Calloplax vivipara (Plate, 1899, Chaetopleura peruviana (Lamarck, 1819; Chiton cumingsii Frembly, 1827; Chiton granosus Frembly, 1827; Chiton magnificus Deshayes, 1827; Enoplochiton niger (Barnes, 1824, Radsia barnesii (Gray, 1828, Tonicia atrata (G. B. Sowerby II, 1840 and Tonicia chilensis (Frembly, 1827. All of the species occurring in the area have distributions in the southeastern Pacific Ocean, from Ecuador to central Chile, and three of them are species endemic to the Chilean coasts (Calloplax vivipara, Radsia barnesii, and Tonicia atrata. This diversity of species is comparable to that of better surveyed faunas of central and southern Chile or Patagonia. Of the eleven species recorded, the geographic distribution records for Callistochiton pulchellus, Radsia barnesii and Tonicia atrata are extended, and Calloplax vivipara is found alive again after 40 years, filling a gap in its known distribution. Illustrations of living specimens in their habitat, distribution records and a taxonomic key for all the studied taxa are also provided.

  4. One hundred years after Pinctada: an update on alien Mollusca in Tunisia

    Directory of Open Access Journals (Sweden)

    M. ANTIT

    2011-04-01

    The occurrence of aliens in Tunisia is balanced between presumably Lessepsian species of tropical Indo-Pacific origin, and species from other sources including species from the Tropical Atlantic introduced through shipping. Nevertheless there is a prevalence of Lessepsian species towards the Gulf of Gabes in the south, whereas the shipping activity in Tunis harbour may be the main pathway of introduction in the north.

  5. Molluscicidal activity of some marine substances against the snail Biomphalaria glabrata (Mollusca, Planorbidae).

    Science.gov (United States)

    Miyasato, P A; Kawano, T; Freitas, J C; Berlinck, R G S; Nakano, E; Tallarico, L F

    2012-05-01

    Freshwater snails of the genus Biomphalaria play a major role as intermediate hosts of Schistosoma mansoni, the etiologic agent of schistosomiasis. While Biomphalaria spp. control by molluscicides is one of the main strategies to reduce the snail population in infected areas, there are few effective molluscicides commercially available. Natural products may be considered as potentially useful and safe molluscicides. We have evaluated the molluscicidal activity of 12 extracts from ten marine organisms on adult and embryonic stages of Biomphalaria glabrata. Only extracts of the red algae Liagora farinosa and of the sponge Amphimedon viridis presented molluscicidal activity. Lethal concentration (LC)(50) values obtained were 120 μg/mL for L. farinosa CH(2)Cl(2) extract (apolar fraction) and 20 μg/mL for A. viridis extract and halitoxin. The polar alga fraction and halitoxin had no effect on B. glabrata embryos. The algae apolar fraction was active on B. glabrata in all embryonic development stages, with LC(50) values for blastulae at 42 μg/mL, gastrulae at 124 μg/mL, trochophore at 180 μg/mL, and veliger at 222 μg/mL. This is the first report of extracts from marine organisms which presented molluscicidal activity.

  6. The influence of thymol+DMSO on survival, growth and reproduction of Bradybaena similaris (Mollusca: Bradybaenidae

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    Paula Ferreira

    2011-04-01

    Full Text Available Bradybaena similaris (Férussac, 1821, commonly known as the Asian trampsnail, is a terrestrial snail native to Asia, introduced in other regions of the world. In Brazil, populations of this land snail are distributed from the state of Amapá in the North to Rio Grande do Sul in the South. This species acts as an intermediate host for parasites and is a difficult-to-control agricultural pest as well, causing great losses to crops and ornamental plant cultivation. This land snail is easily reared in the laboratory and has been successfully used as a biological model in studies that aim at verifying molluscicidal effects of plant extracts. Several studies have demonstrated that B. similaris, like many other species of land and freshwater snails, is physiologically adapted to survival over transitory unfavorable environmental conditions. Moreover, this species seems to have a life history strategy characterized by a short life span and a maximal opportunistic reproductive effort during transient favorable periods. Such biological features may potentially lead to the inefficacy of control attempts and, simultaneously, make this species able to repopulate sites previously treated with biocides. For this reason, studies that aim at verifying the effect of molluscicides on the reproduction, growth and survival of molluscs are greatly required. Molluscicides of plant origin may represent a safe and effective way of controlling these animals. Thymol is a substance of plant origin which has bactericidal, fungicidal and anti-inflammatory properties and has been presented as a promissory biocide of mollusc species. The aim of this work was to assess the molluscicidal property of thymol in combination with DMSO against eggs and adults of B. similaris. During 120 days, we evaluated the effect of thymol+DMSO at different concentrations (2.5 g/L and 5 g/L on the hatching success, hatchling survival, growth and reproduction of B. similaris under laboratory conditions. We tested thymol+DMSO on 160 eggs, 160 10-day-old and 160 30-day-old juveniles. The results showed that thymol+DMSO (5 g/L and 2.5 g/L affected hatching success, acting as an ovicide. The tests with 10-day-old juveniles showed that thymol+DMSO at 2.5 g/L and 5 g/L caused 90 and 100% of mortality, respectively. For the 30-day-old juveniles, thymol+DMSO caused 87.5% of mortality at 5 g/L, and 75% at 2.5 g/L. With regard to growth, the results were not significant. The 10-day-old individuals treated with thymol+DMSO showed only one reproductive event during the 120 days of the experiment. Thymol+DMSO showed molluscicidal and residual activity, which makes evident its potential for controlling snails, and consequently, snail-borne diseases.

  7. Melanoides tuberculata (Mollusca: Thiaridae) harboring renicolid cercariae (Trematoda: Renicolidae) in Brazil.

    Science.gov (United States)

    Pinto, H A; Melo, A L

    2012-08-01

    Melanoides tuberculata , naturally infected by gymnocephalous cercariae, were found in aquatic collections from Belo Horizonte, Minas Gerais, Brazil. After morphological characterization, larvae were used for experimental infection of Poecilia reticulata. Metacercariae were obtained from the liver of these fish, which were also found to be naturally infected in the same locality. The morphology and biology of the developmental stages of trematodes we obtained were characteristic of Renicola sp. This is the first record of renicolid cercariae and metacercariae in Brazil.

  8. Nonhemocyte sources of selected lysosomal enzymes in Biomphalaria glabrata, B. tenagophila and B. straminea (Mollusca: Pulmonata

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    Gary E. Rodrick

    1981-09-01

    Full Text Available The specific activities of acid phosphatase, alkaline phosphatase, β-glucuronidase, lysozymes, glutamate-oxalacetate transaminase and glutamate-pyruvate transaminate were determined in the head-foot and digestive gland of Brazilian Biomphalaria glabrata (Touros, B. tenagophila (Caçapava and B. straminea (Monsenhor Gil. All six enzymes were detected inthe 3000g supernatant. Both cytoplasmic enzymes, glutamate-oxalacetate and glutamate-pyruvate transaminase exhibited the highest specific activities. In the case of the four hydrolytic enzymes assayed, β-glucuronidase exhibited the highest specific activity while lysozyme showed the lowest activity. All six enzymes are thought to be produced by cells within the head-foot and digestive gland of B. glabrata, B. tenagophila and B. straminea.Foram determinadas, na massa cefalopedal e na glândula digestiva de Biomphalaria glabrata de Touros (Rio Grande do Norte B. tenagophila de Cacapava (Sao Paulo e B. straminea de Monsenhor Gil (Piauí, as atividades específicas das seguintes enzimas: fosfatase acida, fosfatase alcalina, beta-glucuronidase, lisozima, transaminase glutâmico-oxalacetica e transaminase glutâmico-piruvica. As seis enzimas referidas foram detectadas no sobrenadante a 3000g. Ambas as enzimas citoplasmaticas - transaminases glutamico-oxalacetica e glutamico-piruvica - mostraram as atividades específicas mais altas. No caso das quatro enzimas hidrolíticas, a beta-glucuronidase revelou a mais alta atividade específica, enquanto a lisozima revelou a mais baixa. E admitido que todas as seis enzimas sao produzidas por celulas presentes na massa cefalopedal e na glândula digestiva das tres especies de moluscos examinadas.

  9. Spermatozoa and spermatogenesis in the northern quahaug Mercenaria mercenaria (Mollusca, Bivalvia)

    Science.gov (United States)

    Ying, Xue-Ping; Yang, Wan-Xi; Dahms, Hans-U.; Lin, Zhihua; Chai, Xueliang

    2008-12-01

    We studied the ultrastructure of spermatogenesis and spermatozoa in the northern quahaug, the clam Mercenaria mercenaria. Spermatogenetic cells gradually elongate. Mitochondria gradually fuse and increase in size and electron density. During spermatid differentiation, proacrosomal vesicles migrate towards the presumptive anterior pole of the nucleus and eventually form the acrosome. The spermatozoon of M. mercenaria is of a primitive type. It is composed of head, mid-piece, and tail. The acrosome shows a subacrosomal space with a short conical contour. The slightly curved nucleus of the spermatozoon contains fine-grained dense chromatin. The middle piece consists of a centriolar complex which is surrounded by four mitochondria. The flagellum has a standard “9 + 2” microtubular structure. The ultrastructure of spermatozoa and spermatogenesis of M. mercenaria shares a number of features with other species of the family Veneridae. M. mercenaria may be a suitable model species for further investigations into the mechanisms of spermatogenesis in the Bivalvia.

  10. First record of subterranean rissoidean gastropod assemblages in Southeast Asia (Mollusca, Gastropoda, Pomatiopsidae

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    Jozef Grego

    2018-03-01

    Full Text Available In February 2017 we investigated several caves and karstic springs in Laos for the presence of underground freshwater gastropod species. We report previously unrecorded freshwater gastropod assemblages in the largest cave in Laos, Tham Khon Dôn, and in the third largest cave, Pha Soung, in Khammouane Province, with single finds in Na Li Cave (Khammouane Province, an unnamed cave near Vieng Thong (Bolikhamsay Province and a small karst spring near Phonsavan (Xianghouan Province. All 15 species recorded and described herein are new to science. Four species are assigned to the new genus Pseudoiglica: P. pseudoiglica sp. n., P. olsavskyi sp. n., P. kameniari sp. n., and P. phonsavanica sp. n. Three species are assigned to the new genus Thamkhondonia: T. moureti sp. n., T. vacquiei sp. n., and T. smidai sp. n. Eight species are assigned to the genus Tricula Benson, 1843: T. valenasi sp. n., T. davisi sp. n., T. spelaea sp. n., T. lenahani sp. n., T. reischuetzorum sp. n., T. phasoungensis sp. n., T. bannaensis sp. n., and T. viengthongensis sp. n.

  11. Pseudoglessula Libera, a new Subulinid land snail from Guinea, West Africa (Mollusca, Gastropoda Pulmonata)

    NARCIS (Netherlands)

    Solem, A.; Bruggen, van A.C.

    1976-01-01

    Study of some land snails collected in Guinea, West Africa, by Ms. Diane deVry has led to the description of a new species, Pseudoglessula libera. It is currently known only from several localities near Conakry, but probably has a wide distribution. Detailed comparisons with previously described

  12. Trachygystis (Dendrotrichia) sylvicola, a new subgenus and species from Rhodesia (Mollusca, Gastropoda Pulmonata: Endodontidae)

    NARCIS (Netherlands)

    Bruggen, van A.C.; Verdcourt, B.

    1965-01-01

    In 1959 the first author (A.C.v.B.) discovered a peculiar snail of the pulmonate family Endodontidae in Rhodesia; on a subsequent expedition more specimens were obtained, so that a series is now available for description. The species undoubtedly belongs to the genus Trachycystis Pilsbry, 1893, but a

  13. Neuromuscular development of Aeolidiella stephanieae Valdéz, 2005 (Mollusca, Gastropoda, Nudibranchia)

    DEFF Research Database (Denmark)

    Kristof, Alen; Klussmann-Kolb, Annette

    2010-01-01

    data on opisthobranch gastropods we investigated the neuromuscular development in the nudibranch Aeolidiella stephanieae Valdéz, 2005 using immunocytochemistry as well as F-actin labelling in conjunction with confocal laser scanning microscopy (cLSM). RESULTS: The ontogenetic development of Aeolidiella...

  14. A tropical Atlantic species of Melibe Rang, 1829 (Mollusca, Nudibranchia, Tethyiidae

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    Erika Espinoza

    2013-07-01

    Full Text Available A new species of Melibe is described based on two specimens collected in Florida. This new species is well differentiated morphologically and genetically from other species of Melibe studied to date. The four residue deletions in the cytochrome c oxidase subunit 1 protein found in all previously sequenced tropical species of Melibe sequenced (and Melibe rosea are also present in this new species. These deletions do not appear to affect important structural components of this protein but might have fitness implications. This paper provides the first confirmed record of Melibe in the tropical western Atlantic Ocean.

  15. Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia

    Science.gov (United States)

    Foon, Junn Kitt; Clements, Gopalasamy Reuben; Liew, Thor-Seng

    2017-01-01

    Abstract Limestone hills are now gaining global conservation attention as hotspots for short-range endemic species. Levels of land snail endemism can be high at limestone hills, especially at hill clusters that are geographically isolated. In the State of Perak, Peninsular Malaysia, limestone hills have been opportunistically surveyed for land snails in the past, but the majority have yet to be surveyed. To address this knowledge gap, we systematically surveyed the terrestrial malacofauna of 12 limestone hills that, based on our opinion, are a representation of the limestone land snail assemblages within the State. Our inventory yielded high sampling completeness (>85%). We found 122 species of land snails, of which 34 species were unique to one of the surveyed hills. We identified 30 species that are potentially new to science. The number of land snail species recorded at each hill ranged between 39 and 63 species. Four of the sampled limestone hills namely, Prk 01 G. Tempurung, Prk 55 G. Pondok, Prk 47 Kanthan, and Prk 64 Bt Kepala Gajah, have high levels of species richness and unique species, representing 91% of the total species recorded in this study. We identified two clusters of limestone hills in central Perak with distinct differences in land snail species composition – a northern hill cluster on elevated granite bedrock and southern hill cluster in a low-lying valley surrounded by alluvial soils. As limestone hills continue to be quarried to meet the cement demand, the four identified limestone hills, along with other hills from the two clusters, warrant urgent conservation attention in order to maintain high species diversity within Perak’s terrestrial malacofauna. PMID:28769723

  16. Biogeographical homogeneity in the eastern Mediterranean Sea - I: the opisthobranchs (Mollusca: Gastropoda from Lebanon

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    F. CROCETTA

    2013-07-01

    Full Text Available A reviewed knowledge of the opisthobranch species from Lebanon (eastern Mediterranean Sea, based on literature records (scattered throughout various papers published over a period of more than 150 years and recently collected material (1999-2002 within the CEDRE framework and other samples, is presented, yielding a total number of 35 taxa recorded from the Lebanese shores identified to species level. Special emphasis has mainly been given to the alien species, for which scattered notes are also given. The known opisthobranch biota is composed of 22 native (~ 63%, 12 alien (~ 34% and one cryptogenic (~ 3% taxa. Eleven of these (Berthella aurantiaca, B. ocellata, Aplysia fasciata, Felimare picta, Felimida britoi, F. luteorosea, F. purpurea, Phyllidia flava, Dendrodoris grandiflora, D. limbata and Aeolidiella alderi constitute new records for the Lebanese fauna, whilst the examined material of a further seven species (Elysia grandifolia, Pleurobranchus forskalii, Aplysia dactylomela, Bursatella leachii, Syphonota geographica, Goniobranchus annulatus, Flabellina rubrolineata anecdotally cited from Lebanon on the basis of the samples here studied, is here first explained. One additional taxon belonging to the genus Haminoea has been identified to genus level only. Despite the searching effort poning the basis of the material analyzed here, data reported clearly suggest that strong investments are still needed for a better understanding of the eastern Mediterranean opisthobranch fauna.

  17. The genus Acanthochitona (Mollusca: Polylacophora in the Mediterranean Sea: morphological and molecular data

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    Antonio Bonfitto

    2011-02-01

    Full Text Available This work represents an attempt to resolve the confused and contradictory taxonomy of Mediterranean chitons of the genus Acanthochitona by analysing morphological (SEM observations of aesthetes, radula and girdle and molecular data (COI, 12S, ITS1. Both analyses support the validity of the three species, Acanthochitona fascicularis, A. crinita and A. oblonga, the latter two of which were previously considered as synonymous.

  18. The opisthobranch gastropods (Mollusca: Heterobranchia) from Venezuela: an annotated and illustrated inventory of species.

    Science.gov (United States)

    Gutiérrez, Manuel Caballer; Ortea, Jesús; Rivero, Nelsy; Tucker, Gabriela Carias; Malaquias, Manuel António E; Narciso, Samuel

    2015-10-29

    The Caribbean waters of Venezuela are composed by a large variety of habitats, with over 2800 km of coastline, islands, and islets. This area is a transitional zone between two main biogeographic provinces, the Caribbean and the Brazilian, separated by the fresh water outflows of the Orinoco and Amazon rivers, and is therefore expected to be an area of high species diversity. However, concerning the study of molluscs, Venezuela is probably the poorest known region in the Caribbean. The best compilation of opisthobranch species known in Venezuela was produced almost a decade ago, mentioning the occurrence of 57 species, plus seven determined only to genus level. In this work, 134 species are reported for Venezuela (71 are illustrated), representing about 40 % of the entire diversity of opisthobranchs known in the Caribbean. Among the species occurring in Venezuela, 49 have here the southern limit of their distribution range and only one the northern limit. Forty-six species are recorded for the first time to the country and one is a new record for the Caribbean Sea, namely Placida cremoniana. In addition, the distribution and ecology of the species are given based in literature and new data.

  19. Redescription of Dicyemennea eledones (Wagener, 1857) (Phylum Dicyemida) from Eledone cirrhosa (Lamarck, 1798) (Mollusca: Cephalopoda: Octopoda).

    Science.gov (United States)

    Souidenne, Dhikra; Florent, Isabelle; Dellinger, Marc; Romdhane, Mohamed Salah; Grellier, Philippe; Furuya, Hidetaka

    2016-11-01

    Dicyemids are common parasites found in the kidneys of many cephalopods. Species identification previously relied on old species descriptions containing considerable confusions, casting doubt on taxonomy and identification. Detailed morphological description and genotyping of all developmental stages are required for an exact taxonomy. To this end, we undertook the redescription of the dicyemid Dicyemennea eledones (Wagener, 1857), infecting the cephalopod Eledone cirrhosa (Lamarck). Samples were collected off Concarneau in the Bay of Biscay, France, and off La Goulette in the Gulf of Tunis, Tunisia. Dicyemennea eledones is a large species, with adults reaching c.7,000 μm in length. The vermiform stages are characterised by having 23 peripheral cells, a conical calotte and an axial cell that extends to the base of the propolar cells. An anterior abortive axial cell is present in vermiform embryos. Infusoriform embryos consist of 37 cells; a single nucleus is present in each urn cell and the refringent bodies, which were not always seen, are possibly liquid. For the first time, an 18S rDNA sequence is generated for D. eledones, illustrating genetic differences with the other dicyemid 18S rDNA sequences available in databases. This sequence can now be used for D. eledones barcoding, making the identification of the species easier and more reliable.

  20. Old and sticky—adhesive mechanisms in the living fossil Nautilus pompilius (Mollusca, Cephalopoda)

    Science.gov (United States)

    von Byern, Janek; Wani, Ryoji; Schwaha, Thomas; Grunwald, Ingo; Cyran, Norbert

    2012-01-01

    Nautiloidea is the oldest group within the cephalopoda, and modern Nautilus differs much in its outer morphology from all other recent species; its external shell and pinhole camera eye are the most prominent distinguishing characters. A further unique feature of Nautilus within the cephalopods is the lack of suckers or hooks on the tentacles. Instead, the animals use adhesive structures present on the digital tentacles. Earlier studies focused on the general tentacle morphology and put little attention on the adhesive gland system. Our results show that the epithelial parts on the oral adhesive ridge contain three secretory cell types (columnar, goblet, and cell type 1) that differ in shape and granule size. In the non-adhesive aboral epithelium, two glandular cell types (cell types 2 and 3) are present; these were not mentioned in any earlier study and differ from the cells in the adhesive area. The secretory material of all glandular cell types consists mainly of neutral mucopolysaccharide units, whereas one cell type in the non-adhesive epithelium also reacts positive for acidic mucopolysaccharides. The present data indicate that the glue in Nautilus consists mainly of neutral mucopolysaccharides. The glue seems to be a viscous carbohydrate gel, as known from another cephalopod species. De-attachment is apparently effectuated mechanically, i.e., by muscle contraction of the adhesive ridges and tentacle retraction. PMID:22221553

  1. Sea Hare Aplysia punctata (Mollusca: Gastropoda) Can Maintain Shell Calcification under Extreme Ocean Acidification.

    Science.gov (United States)

    Carey, Nicholas; Dupont, Sam; Sigwart, Julia D

    2016-10-01

    Ocean acidification is expected to cause energetic constraints upon marine calcifying organisms such as molluscs and echinoderms, because of the increased costs of building or maintaining shell material in lower pH. We examined metabolic rate, shell morphometry, and calcification in the sea hare Aplysia punctata under short-term exposure (19 days) to an extreme ocean acidification scenario (pH 7.3, ∼2800 μatm pCO 2 ), along with a group held in control conditions (pH 8.1, ∼344 μatm pCO 2 ). This gastropod and its congeners are broadly distributed and locally abundant grazers, and have an internal shell that protects the internal organs. Specimens were examined for metabolic rate via closed-chamber respirometry, followed by removal and examination of the shell under confocal microscopy. Staining using calcein determined the amount of new calcification that occurred over 6 days at the end of the acclimation period. The width of new, pre-calcified shell on the distal shell margin was also quantified as a proxy for overall shell growth. Aplysia punctata showed a 30% reduction in metabolic rate under low pH, but calcification was not affected. This species is apparently able to maintain calcification rate even under extreme low pH, and even when under the energetic constraints of lower metabolism. This finding adds to the evidence that calcification is a largely autonomous process of crystallization that occurs as long as suitable haeomocoel conditions are preserved. There was, however, evidence that the accretion of new, noncalcified shell material may have been reduced, which would lead to overall reduced shell growth under longer-term exposures to low pH independent of calcification. Our findings highlight that the chief impact of ocean acidification upon the ability of marine invertebrates to maintain their shell under low pH may be energetic constraints that hinder growth of supporting structure, rather than maintenance of calcification.

  2. Reproductive cycle of Glycymeris nummaria (Mollusca: Bivalvia from Mali Ston Bay, Adriatic Sea, Croatia

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    Marija Crnčević

    2013-06-01

    Full Text Available The reproductive cycle of the dog cockle, Glycymeris nummaria (Glycymerididae, was studied using specimens collected monthly from Mali Ston Bay, southeastern Adriatic Sea over the period from January to December 2010. We analysed sex ratios, gonad developmental stages, and oocyte diameters using standard histological techniques. There were no differences in the overall sex ratio and no difference in shell length with respect to sex. Results of a size-frequency analysis of oocyte diameters agreed with a qualitative analysis of gonadal developmental stages, confirming the occurrence of one annual spawning peak from May to July. A significant correlation was identified between mean gonad indices of males and females and condition index. This study provides the first data on the reproductive characteristics of G. nummaria, providing necessary information for the future sustainable management of its potential fishery.

  3. Especies bentónicas de Opisthobranchia (Mollusca: Gastropoda presentes en el litoral del norte peruano

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    Katia Nakamura

    2013-05-01

    Full Text Available El presente trabajo muestra las especies bentónicas de Opisthobranchia registradas para el norte del Perú. El trabajo se basa en la recopilación de la literatura científica disponible para el área de interés. Se presentan las 17 especies reportadas para dicha zona, clasificadas dentro del Grupo Informal Opisthobranchia en 6 clados, 12 familias y 14 géneros. A pesar del alto potencial de diversidad que se le otorga a la costa norte peruana, el número de especies registradas es bajo, debido principalmente al escaso número de exploraciones e investigaciones realizadas.

  4. Stunting of the penis in Heleobia parchappii (Mollusca: Cochliopidae) and its relationship with parasitism.

    Science.gov (United States)

    Merlo, Matías J; Parietti, Manuela; Etchegoin, Jorge A

    2017-02-08

    Penis anatomy is used to discriminate species of gastropods belonging to the family Cochliopidae; however, this characteristic may be affected by the presence of parasites. To evaluate the possible effect of parasites on penis length and number of papillae in Heleobia parchappii, 195 males were collected from the Nahuel Rucá Lagoon, Argentina. Male snails were only infected by trematode digeneans (total prevalence 45.13%). Three out of 9 species of digeneans registered showed prevalence values higher than 10%: Microphallus szidati, M. simillimus, and Notocotylidae sp. 1. The penis length of non-parasitized males and those parasitized by M. szidati and M. similimus increased with increased snail length; however, this increase was lower in infected snails. In the case of snails infected with Notocotylidae sp. 1, no relationship between shell length and penis length was apparent. Differences in the life cycles of these 3 digeneans could explain the null or lower penis growth rate in relation to host body growth. In contrast, no change was observed in the number of penial papillae of H. parchappii when these snails were infected by larval digeneans compared to those that were not infected. This indicates that penial papillae may be a more stable characteristic than penis length to discriminate between species within the Cochliopidae. The study of penial papillae should be central in the taxonomy and identification of new species within the Cochliopidae, as well as in previously described species.

  5. Biomphalaria obstructa (Morelet, 1849: a study of topotypic specimens (Mollusca: pulmonata: planorbidae

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    W. Lobato Paraense

    1990-12-01

    Full Text Available A description of Biomphalaria obstructa (Morelet, 1849, based on specimens collected at its type locality - isla del carmen, state of Campeche, Mexico - is presented. The Shell is small, 13 mm in diameter, 3.5 mm in width and with 5.75 whorls in the largest specimen, thin, moderately lustrous and translucent, horn-colored. Whorls increasing regularly (neither slowly nor rapidly in diameter, rounded on the periphery side, bluntly angular on the left. Suture well-marked, deeper on the left. Right side widely concave, with first whorl deeply situated and partly hidden by the next. Left side shallower than right one, largely flattened, with first whorl plaintly visible. Aperture roundly heart-shaped, usually in the same plane as the body whorl but somewhat deflected to the left (less frequently to the right in some specimens. Peristome sharp, seldom blunt; a distinct callus on the parietal wall. A number of young shells develop one set (seldom more of apertural lamellae which tend to be resorbed as the shell grows. Absence of renal ridge. Ovotestis with about 70 mostly unbrached diverticula. Seminal vesicle beset with well-developed knoblike to fingerlike diverticula. Vaginal pouch more or less developed. Spermatheca club-shaped when empty, egg-shaped when full, and with intermediate forms between those extremes. Spermathecal body usually somewhat longer than the duct. Prostate with 7 to 20 (mean 12.06 ± 2.51 usually short diverticula which give off plumpish branches spreading out in a fan shape and overlapping to some extent their immediate neighbors. Foremost prostatic diverticulum nearly always partially or completely inserted between the spermathecal body and the uterine wall. Penial sheath consistently narrower and shorter than the prepuce. Muscular coat of the penis consisting of an inner longitudinal and an outer circular layers. Ratios between organ lengths: caudal to cephalic parts of female duct = 0.55 to 1.37 (mean 0.85 +- 0.17; cephalic parte of female duct to penial complex = 1.36 to 2.81 ((mean 1.90 +- 0.33; penial sheath to prepuce = 042 to 0.96 (mean 0.67 +- 0.13. Comparison with Morelet’s type specimens of Planorbis orbiculus and P. retusus points to the identity of those nominal species with B. obstructa.

  6. Holoplanktonic mollusks (Mollusca: Gastropoda) from the Gulf of California, México

    OpenAIRE

    Angulo Campillo, Orso; Aceves Medina, Gerardo; Avendaño Ibarra, Raymundo

    2011-01-01

    We compiled a checklist of holoplanktonic mollusks obtained from seven oceanographic surveys performed between 2005 and 2007 in the Gulf of California, México. The checklist comprises five orders, 15 families, 28 genera and 62 species, including 39 new records and two range extensions within the Gulf.

  7. Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca, Gastropoda, Pulmonata, Onchidiidae).

    Science.gov (United States)

    Dayrat, Benoît; Goulding, Tricia C; Apte, Deepak; Bhave, Vishal; Joseph Comendador; Qua Ng, Ngô Xuân; Tan, Siong Kiat; Tan, Shau Hwai

    2016-01-01

    In an effort to clarify the species diversity of onchidiid slugs, the taxonomy of the genus Onchidium Buchannan, 1800 is revised using an integrative approach. New, fresh specimens were collected in a large number of places, including type localities. The genus Onchidium is redefined here as a clade including only three species which are strongly supported by both morphological and molecular data. All three species were already named: the type species Onchidium typhae Buchannan, 1800, Onchidium stuxbergi (Westerlund, 1883), and Onchidium reevesii (J.E. Gray, 1850). With the exception of a re-description of Onchidium typhae published in 1869, all three species are re-described here for the first time. First-hand observations on the color variation of live animals in their natural habitat are provided. The anatomy of each species is described. Important nomenclatural issues are addressed. In particular, Labella Starobogatov, 1976 is regarded as a junior synonym of Onchidium and Labella ajuthiae (Labbé, 1935) and Onchidium nigrum (Plate, 1893) are regarded as junior synonyms of Onchidium stuxbergi . The nomenclatural status of several other species names is discussed as well. Many new records are provided across South-East Asia and precise ranges of geographic distributions are provided for the genus Onchidium and its three species. Distinctive features that help distinguish the genus Onchidium from other onchidiids are provided, as well as an identification key for the three species.

  8. The Marine Mollusca of St. Martin, Lesser Antilles, collected by H.J. Krebs

    NARCIS (Netherlands)

    Coomans, H.E.

    1963-01-01

    In 1864 an anonymous list of species of the West Indian marine mollusks was published in Denmark. There were only twenty copies printed, seven of which were lost during transportation to the West Indies (CLENCH et al., 1947—1948, p. 23). The author was HENDRIK JOHANNES KREBS (1821—1907), Fig. 117, a

  9. Invertebrate shells (mollusca, foraminifera) as pollution indicators, Red Sea Coast, Egypt

    Science.gov (United States)

    Youssef, Mohamed; Madkour, Hashem; Mansour, Abbas; Alharbi, Wedad; El-Taher, Atef

    2017-09-01

    To assess the degree of pollution and its impact on the environment along the Red Sea Coast, the most abundant nine species of recent benthic foraminifera and three species of molluscan shells have been selected for the analysis of Fe, Mn, Zn, Cu, Pb, Ni, Co, and Cd concentrations. The selected foraminiferal species are: Textularia agglutinans, Amphispsorus hemprichii, Sorites marginalis, Peneroplis planatus, Borelis schlumbergeri, Amphistegina lessonii, Ammonia beccarii, Operculina gaimairdi, and Operculinella cumingii. The selected molluscan shells are: Lambis truncata and Strombus tricornis (gastropods) and Tridacana gigas (bivalves). The inorganic material analysis of foraminifera and molluscs from the Quseir and Safaga harbors indicates that foraminifera tests include higher concentrations of heavy metals such as Fe and Mn than molluscan shells. These results are supported by the black tests of porcelaneous foraminifera and reflect iron selectivity. The Cd and Pb concentrations in molluscan shells are high in the El Esh Area because of oil pollution at this site. The Cu, Zn, and Ni concentrations in the studied invertebrates are high at Quseir Harbor and in the El Esh Area because of the strong influence of terrigenous materials that are rich in these metals. The heavy metal contamination is mostly attributed to anthropogenic sources.

  10. Nanostructure and crystallography of aberrant columnar vaterite in Corbicula fluminea (Mollusca).

    Science.gov (United States)

    Frenzel, Max; Harrison, Richard J; Harper, Elizabeth M

    2012-04-01

    Both the crystallographic and nanostructural organisation of aberrant columnar vaterite occurring in Corbicula fluminea were characterised in detail for the first time using electron microscopic and X-ray powder diffraction techniques. At the millimetre scale, only a confinement of the otherwise randomly oriented c-axis to the growth surface is observed. Domains of 100 or more individual vaterite columns with common c-axis orientation exist within this disordered material. Each column behaves as a single crystal on the scale of EBSD measurements, but is internally composed of smaller irregularly shaped and slightly misaligned crystalline units (0.3-1.3μm in dimension). These are in turn partitioned by porous boundaries into rounded nanodomains, up to 600nm in size. The geometry of the nanodomains and their respective boundaries might suggest formation by the accretion of vesicles. In addition to crystallographic textures, this observation indicates formation under significant biological control with wider implications for possible causes of the condition. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Comet assay comparison of different Corbicula fluminea (Mollusca tissues for the detection of genotoxicity

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    Janaina Rigonato

    2005-09-01

    Full Text Available The comet assay was used to study the sensitivity of the widely distributed freshwater bivalve mollusk Corbicula fluminea to the DNA-damaging alkylating-agent methylmethane sulfonate (MMS. This study was undertaken to ascertain if C. fluminea is a good bioindicator of pollutants in aquatic environments and identify which C. fluminea tissue is most effective and practical for genotoxicity studies. The mollusks were exposed to 0.6, 1.2 or 2.4 X 10-4 M MMS for 40 min and their hemolymph, gill tissue and digestive gland tissue assessed for the level of DNA damage and the time needed for the tissues to recovery. Regression analysis showed a direct linear dose-response relationship between MMS concentration and the number of damaged cells for hemolymph and digestive gland tissue but a quadratic relationship for gill tissue, which made the interpretation the gill tissue results difficult. The basal level of DNA damage to gill tissue was very high, possibly because gill is the organs most directly exposed to environmental toxins and mutagenic agents. Although all three types of tissue produced useful results, hemolymph and digestive gland tissue produced more reproducible and reliable results. Hemolymph was the best sample type in that it was easy to obtain and handle, while gill tissue required more manipulation to obtain cell suspensions. Our results indicate that C. fluminea is an optimal bioindicator for the determination genotoxic contaminants in aquatic environments.

  12. Genetics and shell morphometrics of assimineids (Mollusca, Caenogastropoda, Truncatelloidea) in the St Lucia Estuary, South Africa.

    Science.gov (United States)

    Miranda, Nelson A F; van Rooyen, Ryan; MacDonald, Angus; Ponder, Winston; Perissinotto, Renzo

    2014-01-01

    The Assimineidae are a family of amphibious microgastropods that can be mostly found in estuaries and mangroves in South Africa. These snails often occur in great numbers and are ecologically important to the St Lucia Estuary, which forms a crucial part of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Genetic and shell morphometric analyses were conducted on individuals collected from nine localities distributed from the northern lake regions to the southern lake and the mouth of the St Lucia estuarine lake. Mitochondrial (COI) and nuclear (28S) DNA was used to construct Bayesian Inference, Neighbour-joining, Maximum Parsimony and Maximum Likelihood trees. Principal Component Analysis and Cluster Analysis were performed on standard shell parameter data. Results indicate that two different taxa are present in St Lucia. The taxon comprising individuals from the South Lake and St Lucia Estuary Mouth is identified as Assiminea cf. capensis Bartsch, in accordance with the latest taxonomic consensus. The taxon comprising assimineid individuals from False Bay, North Lake and South Lake, is here tentatively named "Assiminea" aff. capensis (Sowerby). These two taxa exhibit patterns of spatial overlap that appear to vary depending on environmental parameters, particularly salinity. The need to resolve the complex taxonomy of assimineids is highlighted.

  13. Food intake and growth in Macoma balthica (mollusca) in the laboratory

    Science.gov (United States)

    Hummel, H.

    Groups of Macoma balthica were kept during 4-week periods in an experimental set up at a constant temperature and food concentration. Food concentrations (expressed in particulate organic carbon) for the different groups ranged from 0 to 16 mg C·I -1. The experiment was repeated 6 times, viz. in different months, and the temperatures were changed accordingly to correspond with levels found in the field. The rates of food intake, water clearance and growth were followed throughout the experiment. The flagellate Isochrysis galbana served as food. With increasing food concentration all 3 rates (food intake, water clearance and growth) increased up to maximum to decrease again at high food concentrations. Such bell-shaped relationships were observed in all seasons. The dependence of growth on food concentration was similar in all seasons. Zero growth or weight losses were observed at food concentrations below 1.3 mg C·I -1, and maximum growth rates were reached at food concentrations between 5 and 7 mg C·I -1. The daily maintenance ration amounted to about 1.2% of the body weight. Seasonal differences were observed in the relationships of the rates of both water clearance and food intake with food concentration. During the winter and spring the optimum curves for these relationships reached their maximum at food concentrations of 8 to 10 mg C·I -1. During summer and early autumn the optimum curves were shifted to lower food concentrations, around 2 to 4 mg C·I -1, probably as an adaptation to low food concentrations observed in the field during these periods.

  14. A checklist of land snails from the west coast islands of Sabah, Borneo (Mollusca, Gastropoda)

    Science.gov (United States)

    Phung, Chee-Chean; Yu, Fred Tuh Yit; Liew, Thor-Seng

    2017-01-01

    Abstract Sabah, situated in one of the world’s biodiversity hotspots, has the largest number of islands in Malaysia with more than 500 of various sizes and degrees of isolation. However, information on the islands’ biodiversity is limited. This study provides an up-to-date checklist of land snail species found on 24 west coast islands in Sabah. A total of 67 species (nearly 20% of the total number of land snail species in the state) representing 37 genera and 19 families is enumerated based on systematic field surveys of 133 sampling plots, BORNEENSIS database records and species checklists published between 2000 and 2016. The number of species on the islands ranges from four to 29. Labuan Island has the highest number of species (29), followed by Tiga Island (25), Mantanani Besar Island (24) and Gaya Island (23). However, the populations of some land snail species may have declined as several previously recorded species on the islands were not found in a recent systematic field sampling. This checklist is provided as a baseline inventory for future island land snail studies and to better inform biodiversity conservation plans of marine parks and other islands on the Sabah west coast. PMID:28769672

  15. Multi-species generalist predation on the stochastic harvested clam Tivela mactroides (Mollusca, Bivalvia)

    Science.gov (United States)

    Turra, Alexander; Fernandez, Wellington S.; Bessa, Eduardo; Santos, Flavia B.; Denadai, Márcia R.

    2015-12-01

    Top-down control is an important force modulating the abundance of prey and structuring marine communities. The harvested trigonal clam Tivela mactroides is hypothesized to be part of the diet of a variety of marine organisms, with its stock influencing predator abundance and being influenced by them. Here we analyzed the diet of potential predators of T. mactroides in Caraguatatuba Bay, northern coast of São Paulo State, Brazil, to identify the main consumers of this marine resource, and also to address the importance of this clam in the diet of each predator. Samples were taken year-round by trawls; all specimens collected were identified and measured and the food items identified and quantified. Twenty-one species consumed T. mactroides, whose importance in the diet varied greatly in both the volume ingested and the frequency of occurrence (pompano Trachinotus carolinus > blue crab Callinectes danae > starfish Astropecten marginatus). Top-down influence on T. mactroides was also dependent on the abundance of consumers (yellow catfish Cathorops spixii > rake stardrum Stellifer rastrifer > barred grunt Conodon nobilis > A. marginatus). Considering the mean volume ingested, the frequency of occurrence of T. mactroides in the diet, and the relative abundance of consumers, the predators that most influenced T. mactroides were T. carolinus, A. marginatus, and C. danae, in decreasing order. Large numbers of small-sized individuals of T. mactroides (<10 mm) were generally preyed upon by A. marginatus, which may have a stronger effect on clam abundance in comparison to C. danae and T. carolinus, which preyed upon larger clams. In conclusion, the results of this study indicate that predators' consumption of T. mactroides in Caraguatatuba Bay can influence its stocks, mainly due to the type and/or abundance of predator species, the volume and number of individuals of T. mactroides preyed upon, and the temporal variations in the abundance of predators.

  16. DNA barcoding reveals neritid diversity (Mollusca: Gastropoda) diversity in Malaysian waters.

    Science.gov (United States)

    Chee, S Y; Mohd Nor, Siti Azizah

    2016-05-01

    This is the first study to identify and determine the phylogenetics of neritids found in Malaysia. In total, twelve species from the family Neritidae were recorded. Ten species were from the genus Nerita and two species were from the genus Neritina. DNA barcodes were successfully assigned to each species. Although some of these species were previously reported in the region, three are only presently reported in this study. The dendrogram showed Nerita and Neritina strongly supported in their respective monophyletic clades. Phylogenetic positions of some species appeared unstable in the trees. This could be due to the differences in a small number of nucleotides, thus minimizing genetic variation between each specimen and species.

  17. The phylogenetic position of Neritimorpha based on the mitochondrial genome of Nerita melanotragus (Mollusca: Gastropoda).

    Science.gov (United States)

    Castro, Lyda R; Colgan, D J

    2010-11-01

    This is the first report of the mitochondrial gene order and almost-complete DNA sequence of a representative of the Neritimorpha, the highest-ranking gastropod clade lacking such data. Mitochondrial gene order in Nerita is largely plesiomorphic. Its only difference from the cephalopod Octopus vulgaris is a tRNA transposition shared by Vetigastropoda and Caenogastropoda. Genome arrangements were not informative enough to resolve the evolutionary relationships of Neritimorpha, Vetigastropoda and Caenogastropoda. The sister-group taxon of Neritimorpha varied in sequence-based analyses. Some suggested that Neritimorpha is the sister group of Caenogastropoda plus Heterobranchia and some that Neritimorpha and Caenogastropoda are sister groups. No analysis significantly supported the hypothesis that Vetigastroda is more closely related to Caenogastropoda than is Neritimorpha. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. High accumulation of cobalt-60 by the particular organ or part of some species in mollusca

    International Nuclear Information System (INIS)

    Yoshida, Katsuhiko

    1981-01-01

    A large amounts of samples in marine Cephalopoda and Tridacna were sampled in north west pacific ocean, near Japan. The samples were separated into organs or parts for determination of Co-60 concentration. A peculiar accumulation of Co-60 by the branchial heart of Octopus was also recognized in field condition, but it had become apparent that branchial heart of squid had not same ability. Liver of Cephalopoda had the ability to highly accumulate the Co-60 and specific activity of squid was one order highter than Octopus. The concentration of Cobalt-60 in visceral muss kidney of Tridacna maxima lineally increased with increasing shell length but that in other soft parts was kept constant. After examination of the other papers it was assumed that Co-60 highly accumulated in these organs was transfered by the food chain. (author)

  19. New records for the shallow-water chiton fauna (Mollusca, Polyplacophora of the Azores (NE Atlantic

    Directory of Open Access Journals (Sweden)

    Sérgio Ávila

    2013-06-01

    Full Text Available Published records, original data from recent field work on all of the islands of the Azores (NE Atlantic, and a revision of the entire mollusc collection deposited in the Department of Biology of the University of the Azores (DBUA were used to compile a checklist of the shallow-water Polyplacophora of the Azores. Lepidochitona cf. canariensis and Tonicella rubra are reported for the first time for this archipelago, increasing the recorded Azorean fauna to seven species.

  20. [Mollusc diversity in an Arca zebra (Mollusca: Bivalvia) community, Chacopata, Sucre, Venezuela].

    Science.gov (United States)

    Prieto, A S; Ruiz, L J; García, N; Alvarez, M

    2001-06-01

    The diversity of a subtidal epifaunal mollusk community was studied from September, 1990 to September, 1991 in Chacopata, Sucre State, Venezuela. There were 40 species (24 bivalves and 16 gastropods). The diversity indexes (H' = 2.087, J' = 0.392, 1/D = 0.528) were low when compared with other tropical zones. Monthly diversity reached its maximum in September, 1990 (1.63 bits/ind.) and July, 1991 (1.60 bits/ind.); minimum diversity occurred in June, 1991 (0.52 bits/ind.). A Log series model applied to species abundance data showed a straight line with a diversity index alpha of 5.56. Of 40 species identified, the turkeywing Arca zebra was dominant (69% in number of individuals and 72% of biomass) followed by Pinctada imbricata, Modiolus squamosus, Chama macerophyla and Anadara notabilis. The predatory snails Phyllonotus pomum, Chicoreus brevifrons and Murex recurvirostris seemed to have trophic relationships with A. zebra. The total mean biomass in wet weight (469.20 +/- 263 g m-2, shell included) was high which indicates that A. zebra, a species with a rapid growth rate, occupies a central role in the assemblage as an efficient filter feeder that converts planktonic food into available biomass, supporting one of the most important fisheries in Venezuela.

  1. On the morphology of Laevapex vazi n. sp. from Brazil (Mollusca: Pulmonata: Basommatophora: Ancylidae

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    Sonia Barbosa dos Santos

    1989-01-01

    Full Text Available A description of Laevapex vazi n. sp. based on 8 specimens collectec in Ourinhos, state of São Paulo, is presented. Shell thin, diaphanous, with a light brown periostracum and moderately elliptical opening. Apex not pointed, smooth, situated on the right posterior region of the shell, inclined to the right often reaching the edge of the shell or extending beyond it. Concentric lines clearly visible; radial striation not visible or when perceptible very thin, here and there. Ratios: shell width/shell lenght = 0,60 - 0,67 (mean = 0,63; shell height/shell length = 0,50 - 0,61 (mean = 0,55; shell height/shell width = 0,33 - 0,40 (mean = 0,35. Body of normal ancylid type; mantle pigmentation concentrated on the left side; three muscles are seen: a round posterior one on the left side, an elliptical muscle on the right anterior side and an almost almond-shaped one on the left anterior side. Tentacles with a medium core of black pigment. Pseudobranch two-lobed and folded, the dorsal lobe smaller than the vetral one. Ovotestis with 20 unbranched diverticula, around a short collecting canal. Ovispermiduct with an enlargement with several round outpocketings constituting the seminal vesicle. Carrefour as a round sac. Albumen gland almost cylindrical with several acinous diverticula. Elongated nidamental gland continous with the galndular wall of the uterus; uterus flattened and thin-walled. Spermathecal body almost rounded. Pear-shaped prostate without diverticula. Penial complex without flagellum but with well-developed ultra-penis and penis. Jaw horseshoe shaped. Radular forma 20.1.20; raquidian tooth quadricuspid, asymmetrical. The genus Laevapex Walker, 1903 is recorded for the first time in Brazil. It is easily distinguished from South American Gundlachia Pfeiffer, 1849 by its penial complex. Laevapex vazi is dedicated to Dr. Jorge Faria Vaz, from SUCEN-SP, who have been sent to me the specimens.

  2. Variações anatômicas em Lymnaea columella (Mollusca, Gastropoda

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    Marlene T. Ueta

    1977-12-01

    Full Text Available Foram estudadas variações anatômicas de espécimes de L. columella coletados de diferentes criadouros situados em diversos Municípios do Estado de São Paulo: Campinas, Americana, Atibaia, Pirassununga, Caçapava e Taubaté. As comparações morfométricas foram baseadas em estudos do aparelho genital, rim e rádula. Foram medidos, para cada criadouro, os comprimentos do conjunto útero-vagina, dueto da espermateca, prepúcio e bainha do pênis. Foram ainda calculados os índices de relação entre bainha do pênis/prepúcio e estabelecidos os coeficientes de correlação entre comprimento da concha e comprimento do prepúcio. Cortes longitudiais do complexo peniano foram também objeto de estudo. Em relação a rádula foram determinados o número de fileiras transversais e o número de dentes por fileira, e estabelecida uma fórmula radular aproximada para os diversos criadouros.Soft parts of Lymnaea columella from ten populations from the State of São Paulo were studied in order to determine morphometric variations. These morphometric cornparisons were made upon reproductive system, kidney and radula of snail samples collected in different municipalities: Campinas, Americana, Atibaia, Pirassununga, Caçapava and Taubaté. Length measurementes of uterus, duct of spermatheca, prepuce and penis sheath were taken; the ratio penis sheath/prepuce and correlation coefficients between length of shell and length of prepuce were established. Longitudinal sections of penial complex were also studied. The number of trans verse rows, number of teeth per rows and the length of shell were determined. For each sample, the radular formula was indicated.

  3. Cytogenetics of the land snails Cantareus aspersus and C. mazzullii (Mollusca: Gastropoda: Pulmonata).

    Science.gov (United States)

    Vitturi, Roberto; Libertini, Angelo; Sineo, Luca; Sparacio, Ignazio; Lannino, Antonella; Gregorini, Armando; Colomba, Mariastella

    2005-01-01

    A cytogenetic study was carried out on the chromosomes and nuclear DNA contents of the land snails Cantareus aspersus and C. mazzullii (Gastropoda: Pulmonata). Chromosomes were studied using Giemsa staining, banding methods and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [18S rDNA, (GATA)(n) and (TTAGGG)(n)]. Results were very similar in the two species both showing (1) 54 bi-armed chromosomes [submetacentrics (SM) + metacentrics (M) + subtelocentrics (ST)]; (2) 10 terminal NORs after sequential application of rDNA FISH and silver staining; (3) uniform DNA fluorescence with CMA(3) and DAPI staining and (4) genomic composition considerably enriched both in highly- and moderately-repeated DNAs. The telomeric (TTAGGG)(n) sequence hybridized with the termini of all of the chromosomes in the two species. In spite of their apparent karyological uniformity, flow cytometry DNA assays showed that C. aspersus and C. mazzullii are characterized by different nuclear DNA content (C values are 3.58 and 3.08 pg, respectively) and slightly different base composition in their genomes. Present data on GS and AT% in C. mazzullii and C. aspersus confirm the trend toward high GS values and GC percentages among land snails.

  4. Synthesis, distribution, and levels of an egg lipoprotein from the apple snail Pomacea canaliculata (Mollusca: Gastropoda).

    Science.gov (United States)

    Dreon, M; Lavarias, S; Garin, C F; Heras, H; Pollero, R J

    2002-02-15

    The site of synthesis of mollusc lipoproteins is hitherto unknown and was investigated for perivitellin 2 (PV2), an egg lipoprotein found in the freshwater snail Pomacea canaliculata. Tissues (albumen gland, gonad-digestive gland complex, and muscle) from vitellogenic females were incubated in vitro with 14C-leucine at 25 degrees C for 12 hr. At the end of incubation, soluble proteins from tissue homogenates and medium were analyzed for de novo protein synthesis by electrophoresis and HPLC, and radiolabeled proteins were quantified by liquid scintillation. Two albumen gland radiolabeled proteins (67 and 31 kDa) co-migrated with the subunits of PV2, and they represented 6.0% of the total labeled protein in that tissue. Western blot analysis confirmed the presence of PV2 only in the albumen gland. In vivo experiments where adult females were injected with 3H-leucine revealed that PV2 was not present in hemolymph. ELISA analysis in all tissues of the snail confirmed the PV2 presence only in the albumen gland and developing eggs with levels of 26 and 98 mg/g protein, respectively. Therefore, the albumen gland is the only site for PV2 synthesis, and no extra-gland synthesis, circulation, or accumulation could be found. PV2 subunits were further characterized analyzing N-terminal sequences which showed no homology with other proteins. Copyright 2002 Wiley‐Liss, Inc.

  5. The land Mollusca of Dominica (Lesser Antilles), with notes on some enigmatic or rare species

    NARCIS (Netherlands)

    Robinson, D.G.; Hovestadt, A.; Fields, A.; Breure, A.S.H.

    2009-01-01

    An overview of the land-snail fauna of the Lesser Antillean island of Dominica is given, based on data from literature and four recent surveys. There are 42 taxa listed, of which the following species are recorded for the first time from the island: Allopeas gracile (Hutt on, 1834), A. micra

  6. Estudo morfométrico da concha de Lymnaea columella say, 1817 (Mollusca, Gastropoda, Pulmonata

    Directory of Open Access Journals (Sweden)

    Marlene T. Ueta

    1980-12-01

    Full Text Available Foram estudadas variações morfométricas de conchas de L. columella, provenientes de dez criadouros localizados nos seguintes municípios do Estado de São Paulo: - Campinas, Americana, Atibaia, Pirassununga, Caçapava e Taubaté. Foram analisados os diferentes tipos de ambientes onde as limneas são encontradas com maior freqüência, estabelecendo-se a época do ano com maior abundância em espécimes, que correspondeu aos meses de julho a outubro. As medidas nas conhas dos diferentes criadouros referiram-se ao comprimento e largura da concha, comprimento e largura da abertura, comprimento da espira e número de voltas. Foram estabelecidos os coeficientes de correlação e de regressão e realizadas análises de variância entre as medidas tomadas e os índices obtidos da relação entre largura/comprimento da concha. Estas conchas foram comparadas com as de L. columella, L. viator, L. cubensis da coleção do Museu Nacional do Rio de Janeiro. Para a maioria das medidas as conchas mostraram proporções constantes, embora apresentassem diferenças em relação ao desenvolvimento. A maior variação foi observada em relação ao comprimento da espira. As variações morfométricas das conchas foram relacionadas com alguns fatores externos como pH, alcalinidade, dureza e teor da água. Aparentemente apenas a dureza total da água influiu na consistência das conchas.Shells of Lymnaea columella from ten populations from the State of São Paulo were studied to determine morphometric variation. Samples were collected in the following municipalities: Campinas, Americana, Atibaia, Pirassununga, Caçapava and Taubaté. Five measurements were taken from each shell: length and width of the shell, length and width of the aperture and lenght of the spire. Two ratios were also established: width/lenght of the shell and length of the aperture /length of the shell. The numbers of whorls and the length of the shell were also determined. Statistical tests (correlation coeficients, regression, and analysis of variance were used to compare the different samples. Also, com parisons of L. columella shells collected by us were made with those of L. columella, L. viator and L. cubensis from collections deposited in the Museu Nacional, Rio de Janeiro. The results of these studies revealed that in most of the cases the snail populations of different areas were similar, showing constant proportions, but they diverged in their absolute dimensions. Data on aquatic environmental conditions (pH, alkalinity, hardness, and calcium concentration were also obtained. These Chemical factors were examined with respect to shell morphology. Our results revealed that only hardness of water was associated with the robustness of the shells.

  7. The Continuing Debate on Deep Molluscan Phylogeny: Evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora

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    I. Stöger

    2013-01-01

    Full Text Available Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons, and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages.

  8. The classification of Columbella dormitor with description of a new genus Minipyrene (Mollusca, Gastropoda)

    NARCIS (Netherlands)

    Coomans, H.E.

    1967-01-01

    Columbella dormitor Sowerby, 1844, was placed by the malacologists in the genera Columbella, Pyrene, Parametaria (all Columbellidae), and in Mitromorpha (Turridae). It is a rare species, living in deeper water in the southern Caribbean. The species belongs to the Columbellidae; however, it is

  9. Redescription of Hiatella meridionalis d'Orbigny, 1846 (Mollusca, Bivalvia, Hiatellidae from Argentina

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    Luiz Ricardo L. Simone

    2008-01-01

    Full Text Available The redescription of Hiatella meridionalis (d’Orbigny, 1846 is provided as first attempt to improve the systematics of the genus in the regions of Atlantic and western Pacific. This reanalysis is based on specimens collected in the vicinity of the type localities and is based on detailed morphology of samples that some researches consider a single, wide ranging species. From the morphological characters, the more interesting are: a high quantity of papillae at incurrent siphon; the retractor muscles of siphon divided in two bundles; the small size of the palps; the muscular ring in the stomach; and the zigzag fashion of the short intestinal loops. These characters distinguish the species from the other hiatellids so far examined. Type material of the species was examined, by first time illustrated, and the lectotype is designated.A redescrição de Hiatella meridionalis (d’Orbigny, 1846 é realizada como primeiro passo na melhoria da sistemática do gênero das regiões atlântica e pacífica oeste. Esta re-análise é baseada em espécimes coletados nas vizinhanças da localidade tipo e em morfologia detalhada de amostras que alguns pesquisadores consideram pertencer a uma única espécie de ampla distribuição. Dos caracteres anatômicos, os mais interessantes são: uma grande quantidade de papilas no sifão inalante; o músculo retrator dos sifões dividido em duas porções; o tamanho pequeno dos palpos; um anel muscular transversal no estomago; e um padrão em zigzag no curto intestino. Estes caracteres distinguem a espécie dos demais hiatelídeos até então examinados. Os sintipos da espécie foram também examinados e pela primeira vez ilustrados; o lectótipo é designado.

  10. Unraveling the evolutionary history of the Chilostoma Fitzinger, 1833 (Mollusca, Gastropoda, Pulmonata) lineages in Greece.

    Science.gov (United States)

    Psonis, Nikolaos; Vardinoyannis, Katerina; Mylonas, Moisis; Poulakakis, Nikos

    2015-10-01

    The land snails of the genus Chilostoma Fitzinger, 1833 that includes, in Greece, the (sub)genera Cattania, Josephinella and Thiessea, are highly diversified and present high levels of endemism. However, their evolutionary history is unknown and their taxonomy is complex and continuously revised. The aim of this study is to investigate the phylogenetic relationships of the lineages of the genus Chilostoma distributed in Greece based on partial DNA sequences of two mitochondrial DNA (16S rRNA and COI) genes. Complete sequences of one nuclear gene (ITS1) representing the major mitochondrial lineages were also analyzed. The phylogenetic trees revealed three distinct major clades that correspond to the three (sub)genera. Several taxonomical incongruencies were made obvious, thus, raising questions about the "true" number of species in each clade, while rendering a taxonomic re-evaluation necessary. From a phylogeographic point of view, it seems that the three major phylogenetic clades were separated in the late Miocene. They started differentiating into distinct species during the Pliocene and Pleistocene through several vicariance and dispersal events. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Life history of the bathyal octopus Pteroctopus tetracirrhus (Mollusca, Cephalopoda) in the Mediterranean Sea

    Science.gov (United States)

    Quetglas, Antoni; Ordines, Francesc; González, María; Franco, Ignacio

    2009-08-01

    The life cycle of the deep-sea octopus Pteroctopus tetracirrhus was studied from monthly samples obtained throughout the year in different areas of the western Mediterranean (mainly around the Balearic Islands and along the coast of the Iberian Peninsula). A total of 373 individuals (205 females, 168 males) were analyzed; females ranged from 4.5 to 14.0 cm mantle length (ML) and males from 4.5 to 11.5 cm ML. There were few small-sized octopuses (osteichthyes, cephalopods and gastropods), were identified in the stomach contents. The diet of the octopus was based on crustaceans and teleosts, which accounted for 75% and 23% of the prey items, respectively. Cephalopods and gastropods were accessory prey as they only represented 1.6% and 0.7%, respectively, of the total. The octopus showed a marked preference for the benthic fish Symphurus nigrescens and the endobenthic crustacean Alpheus glaber. The bathymetric distribution of P. tetracirrhus coincides with those of these two main prey, which suggests that the distribution of the octopus might be strongly linked to its trophic resources.

  12. Caloric variability of Corbicula fluminea (Mollusca, Bivalvia in Rosana Reservoir, Brazil

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    Yara Moretto Bagatini

    2007-01-01

    Full Text Available The purpose of the present study was to investigate temporal and longitudinal variation of caloric density of Corbicula fluminea in Rosana Reservoir. Significant differences concerning the caloric density of C. fluminea were observed throughout the year at the three reservoir sites. The caloric density variation during the year was probably related to reproductive activity, which demanded higher allocation of energy in certain period. The food source used by this species might be an important factor in the caloric value temporal and spatial variation of C. fluminea in Rosana Reservoir.O objetivo deste estudo foi investigar a variação temporal e longitudinal da densidade calórica de C. fluminea no reservatório de Rosana. Diferenças significativas na densidade calórica de C. fluminea foram observadas ao longo do ano e nas três estações do reservatório. A variação na densidade calórica de C. fluminea, durante o ano, provavelmente foi relacionada à atividade reprodutiva, que exige uma maior alocação de energia em determinado período. O recurso alimentar utilizado por esta espécie pode ser um importante fator na variação temporal e espacial do valor calórico de C. fluminea no reservatório de Rosana.

  13. Ueber die formveraenderungen des golgiapparates waehrend der spermiogenese von Australorbis glabratus olivaceus: (Mollusca, Pulmonata, Planorbidae

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    Rudolf Barth

    1961-04-01

    Full Text Available Im ersten Teil der vorliegenden Arbeit werden die cytogenese und Histogenese der Spermien von australorbis glabratus olivaceus beschrieben, waehrend im zweiten Teil auf die Formveraenderungen des Golgiapparates des Naeheren eigegangen wird. Es wurden angewandt: Phasenkontrast, Halbdunkelfeld und Dunkelfeld; Vitalfaerbungen mit Janusgruen und Neutralrot; als histologische Faerbung nach Osmiumfixierung erwies sich Eisenhaematoxylin als guenstig, nach Sublimatfixierung zum histologischen Naschwei der chromophoben Substanz des Golgiapparates ergab die Azanfaerbung mit Nachfaerbung in Lichtgruen die besten Ergebnisse. Die Cytogenese zeigt bis zum Erreichen der Spermiden keine Besonderheiten im Vergleich mit anderen shon bearbeiteten Mollusken. Die Histogenese zeit jedoch einige bemerkenswerte Punkte, die von den bereits bekannten Befunden an anderen Mollusken erheblich abwichen. Die Kernmembran der Spermide bildet durch Schrumpfung in Folge Kondensierung des Chromatins eine Spiralfalte auf der Kernoberflaeche mit ueber 2 Um gaengen. Das proximale Centriol ist geteilt, ein Teil bildet eine Fusskappe des Kerns, von der ein Faden ausgeht, der das ganze Kerninnere durchzieht. Der andere Teil bildet den Axialfaden und dient beiden Spiralfilamenten als Lager. Das distale Centriol bildet eine umgekehrte Glocke, an deren Rand sich die Spiralfaeden und in deren Innerem sich der Axial faden anheften; es setzt sich distalwaerts in den nackten Schwanzfaden fort. Der Golgiapparat ist vom primordialen Spermiogonium bis zur reifenden Spermide durch alle Entwicklungs- und Teilungsstadien zu verfolgen. Er besteht in der Spermiocyte aus der chromophoben Masse und 12 Dictyosome, die sich dieser auflagern, sowie aus 4 Proacroblasten. Diese 16 Kondrete trennen sich vor der Diakinese und jedes wandert fuer sich zu einem der Spindelpole. Die Praespermide besitzt 6 Dictyosome und 2 Proacroblasten, die sich zu 3 Diatyosome und 1 Proacroblast auf die Spermide verteilen. Der leztere Koerper wandelt sich zum Acroblast um, der sich als Acrosom dem apikalen Kernpol auflegt.

  14. Anatomia e histologia do conduto genital feminino de Pomacea canaliculata (Lamarck, 1822 (Mollusca, Gastropoda, Pilidae

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    Eliana de Fátima Marques de Mesquita

    1990-01-01

    Full Text Available In this paper the authors give an anatomical and histological analysis of the genital duct in mature and immature females of Pomacea canaliculata (Lamarck, 1822. Anatomically, the vagina has an equal dimension in its extension, varying in form and volume, according to the maturation period. In the immaturity, it has a smaller diameter and volume. In the maturity, the vagina increases in volume, having the aspect of a tumescent organ, and in certain specimens shows an albuminous pink thread in its lumen. Histologically, the calcigenic activity of the gland is evidentiated by the presence of an amorphous and basophilic mass, without nuclear material. This material has a fragmented aspect in the vagina lumen that reacts positively in van Kossa's coloured preparations for calcareous salts.

  15. Isolation and characterization of a novel perivitellin from the eggs of Pomacea scalaris (Mollusca, Ampullariidae).

    Science.gov (United States)

    Ituarte, S; Dreon, M S; Ceolín, M; Heras, H

    2008-09-01

    Perivitellins are important components of the perivitelline fluid (PVF) that surrounds gastropod embryos. The glyco-lipo-carotenoprotein ovorubin (OR) from eggs of the snail Pomacea canaliculata has been the most studied to date. Here we report the characterization of scalarin (SC), a glyco-lipo-carotenoprotein from the PVF of P. scalaris. SC was purified by ultracentrifugation and exclusion chromatography. It is the major egg protein, representing 64% of the total soluble protein. The particle has a hydration density of 1.26 g/ml, an apparent molecular mass of 380 kDa and it is an elongated compact protein as estimated by small angle X-ray scattering (SAXS). It is composed of three subunits of ca. 35, 28, and 24 kDa noncovalently bonded. SC is highly glycosylated (carbohydrate content 20.1%, by wt.), with a low lipid content (0.7%), being esterified sterols, pigments and polar lipids the most abundant lipid classes. HPTLC and spectrophotometric analysis of the carotenoid fraction revealed the presence of free astaxanthin (ASX; 62.0%), and an unidentified carotenoid (38.0%). The carotenoid-apoprotein interaction was studied by spectrophotometry. Carotenoids do not seem to affect the structural characteristics of the oligomer. However, the carotenoid-protein association protected ASX against oxidation. The cross-reactivity between SC and perivitellins of P. canaliculata was tested using polyclonal antibodies (PAb) against SC, OR, and perivitellin PV2. The PAbs failed to cross-react with any egg proteins of either the same or other species. SC, among other functional similarities with OR, would be an antioxidant carrier, protecting at the same time carotenoids from oxidation in the perivitellin fluid of the egg.

  16. Fine structure of the mineralized teeth of the chiton Acanthopleura echinata (Mollusca: Polyplacophora).

    Science.gov (United States)

    Wealthall, Rosamund J; Brooker, Lesley R; Macey, David J; Griffin, Brendan J

    2005-08-01

    The major lateral teeth of the chiton Acanthopleura echinata are composite structures composed of three distinct mineral zones: a posterior layer of magnetite; a thin band of lepidocrocite just anterior to this; and apatite throughout the core and anterior regions of the cusp. Biomineralization in these teeth is a matrix-mediated process, in which the minerals are deposited around fibers, with the different biominerals described as occupying architecturally discrete compartments. In this study, a range of scanning electron microscopes was utilized to undertake a detailed in situ investigation of the fine structure of the major lateral teeth. The arrangement of the organic and biomineral components of the tooth is similar throughout the three zones, having no discrete borders between them, and with crystallites of each mineral phase extending into the adjacent mineral zone. Along the posterior surface of the tooth, the organic fibers are arranged in a series of fine parallel lines, but just within the periphery their appearance takes on a "fish scale"-like pattern, reflective of the cross section of a series of units that are overlaid, and offset from each other, in adjacent rows. The units are approximately 2 microm wide and 0.6 microm thick and comprise biomineral plates separated by organic fibers. Two types of subunits make up each "fish scale": one is elongate and curved and forms a trough, in which the other, rod-like unit, is nestled. Adjacent rod and trough units are aligned into large sheets that define the fracture plane of the tooth. The alignment of the plates of rod-trough units is complex and exhibits extreme spatial variation within the tooth cusp. Close to the posterior surface the plates are essentially horizontal and lie in a lateromedial plane, while anteriorly they are almost vertical and lie in the posteroanterior plane. An understanding of the fine structure of the mineralized teeth of chitons, and of the relationship between the organic and mineral components, provides a new insight into biomineralization mechanisms and controls. Copyright 2005 Wiley-Liss, Inc.

  17. New records and new species of cones from deeper water off Fiji (Mollusca, Gastropoda, Conidae)

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Röckel, D.; Bouchet, P.

    2008-01-01

    A little less than 100 species of cones are known in the literature from waters around the Fiji islands, all intertidal to subtidal. We report here on the species taken by recent offshore and deep-water benthic sampling expeditions. Samples were taken to depths of 1300 m, although cones were taken

  18. Evolutionary position of Peruvian land snails (Orthalicidae among Stylommatophora (Mollusca: Gastropoda

    Directory of Open Access Journals (Sweden)

    Jorge Ramirez

    2011-07-01

    Full Text Available The genera Bostryx and Scutalus (Orthalicidae: Bulimulinae are endemics from South America. They are mainly distributed on the western slopes of the Peruvian Andes. The goal of the present work was to assess their evolutionary position among the stylommatophoran gastropods based on the 16S rRNA mitochondrial marker. Four sequences were obtained, and along with 28 sequences of other Stylommatophora retrieved from the GenBank, were aligned with ClustalX. The phylogenetic reconstruction was carried out using the methods of Neighbor-Joining, Maximum Parsimony, Maximum Likelihood and Bayesian inference. The multiple sequence alignment had 371 sites, with indels. The two genera of the family Orthalicidae for the first time included in a molecular phylogeny (Bostryx and Scutalus, formed a monophyletic group along with another member of the superfamily Orthalicoidea (Placostylus, result that is comparable with that obtained with nuclear markers. Their evolutionary relationship with other land snails is also discussed.

  19. Biomphalaria occidentalis sp.n. from South America (Mollusca basommatophora pulmonata

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    W. Lobato Paraense

    1981-06-01

    Full Text Available A new species of South American planorbid snail, Biomphalaria occidentalis, is described. It is indistinguishable from B. tenagophila (Orbigny, 1835, by the characteristics of the shell and of most organs of the genital system. In B. tenagophila there is a pouch on the ventral wall of the vagina (Fig. 4A, vp, absent in B. occidentalis (Fig. 3A, and on the ventral wall of the vagina (Fig. 4A, vp, absent in B. occidentalis (Fig. 3A, and the prepuce is much wider than the penial sheath, its width increasing distalward (Fig. 4, ps,pp, whereas in B. occidentalis the prepuce is wider than the penial sheath but keeps about the same width all along (Fig.3, ps, pp. The two species are biologically separate by absolute reproductive isolation. The geographical distribution of B. occidentalis is shown in Fig. 14. So far it has been found in the Brazilian states of Acre, Amazonas (?, Mato Grosso, Mato Grosso do Sul and Paraná, and in Paraguay. Its type-locality is Campo Grande, state of Mato Grosso do sul, where it was collected from several biotopes related to affluents of the Aquiduana river, chiefly Córrego Prosa and Córrego Ceroula. Specimens were deposited in the following malacological collections: Instituto Oswaldo Cruz, Rio de Janeiro; Academy of Natural Sciences, Philadelphia; Museum of Zoology, University of Michigan; and British Museum (Natural History.É descrita uma nova espécie de molusco planorbídeo sul-americano, Biomphalaria occidentalis, indistinguível da b. tenagophila (Orbigny, 1835 pelos caracteres da concha e da maioria dos órgãos do sistema genital. Na B. tenagophila existe uma bolsa na parede ventral da vagina (Fig. 4A, vp, ausente na B. occidentalis (Fig. 3A, e o prepúcio é muito mais grosso que a bainha do pênis, aumentando de largura na direção distal (Fig.4, ps, pp, ao passo que na B. occidentalis o prepúcio é mais grosso que a bainha do pênis porém seu diâmetro pouco se altera em toda sua extensão (Fig.3, ps, pp. As duas espécies são biologicamente separadas por isolamento reprodutivo absoluto. A Fig. 14 mostra a distribuição geográfica da B. occidentalis, que até agora foi encontrada nos Estados brasileiros do Acre, Amazonas (?, Mato Grosso, Mato Grosso do Sul e Paraná, e no Paraguai. Sua localidade-tipo é Campo Grande, Estado de Mato Grosso do Sul, onde foi coletada em vários biótopos relacionados e afluentes do rio Aquidauana, principalemente nos córregos Prosa e Ceroula. Foram depositados exemplares nas seguintes coleç~eos malacológicas: Instituto Oswaldo Cruz, Rio de Janeiro; Academy of Natural Sciences, Philadelphia; Museum of Zoology, University of Michigan; British Museum (Natural History.

  20. Ten new complete mitochondrial genomes of pulmonates (Mollusca: Gastropoda and their impact on phylogenetic relationships

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    de Frias Martins António

    2011-10-01

    Full Text Available Abstract Background Reconstructing the higher relationships of pulmonate gastropods has been difficult. The use of morphology is problematic due to high homoplasy. Molecular studies have suffered from low taxon sampling. Forty-eight complete mitochondrial genomes are available for gastropods, ten of which are pulmonates. Here are presented the new complete mitochondrial genomes of the ten following species of pulmonates: Salinator rhamphidia (Amphiboloidea; Auriculinella bidentata, Myosotella myosotis, Ovatella vulcani, and Pedipes pedipes (Ellobiidae; Peronia peronii (Onchidiidae; Siphonaria gigas (Siphonariidae; Succinea putris (Stylommatophora; Trimusculus reticulatus (Trimusculidae; and Rhopalocaulis grandidieri (Veronicellidae. Also, 94 new pulmonate-specific primers across the entire mitochondrial genome are provided, which were designed for amplifying entire mitochondrial genomes through short reactions and closing gaps after shotgun sequencing. Results The structural features of the 10 new mitochondrial genomes are provided. All genomes share similar gene orders. Phylogenetic analyses were performed including the 10 new genomes and 17 genomes from Genbank (outgroups, opisthobranchs, and other pulmonates. Bayesian Inference and Maximum Likelihood analyses, based on the concatenated amino-acid sequences of the 13 protein-coding genes, produced the same topology. The pulmonates are paraphyletic and basal to the opisthobranchs that are monophyletic at the tip of the tree. Siphonaria, traditionally regarded as a basal pulmonate, is nested within opisthobranchs. Pyramidella, traditionally regarded as a basal (non-euthyneuran heterobranch, is nested within pulmonates. Several hypotheses are rejected, such as the Systellommatophora, Geophila, and Eupulmonata. The Ellobiidae is polyphyletic, but the false limpet Trimusculus reticulatus is closely related to some ellobiids. Conclusions Despite recent efforts for increasing the taxon sampling in euthyneuran (opisthobranchs and pulmonates molecular phylogenies, several of the deeper nodes are still uncertain, because of low support values as well as some incongruence between analyses based on complete mitochondrial genomes and those based on individual genes (18S, 28S, 16S, CO1. Additional complete genomes are needed for pulmonates (especially for Williamia, Otina, and Smeagol, as well as basal heterobranchs closely related to euthyneurans. Increasing the number of markers for gastropod (and more broadly mollusk phylogenetics also is necessary in order to resolve some of the deeper nodes -although clearly not an easy task. Step by step, however, new relationships are being unveiled, such as the close relationships between the false limpet Trimusculus and ellobiids, the nesting of pyramidelloids within pulmonates, and the close relationships of Siphonaria to sacoglossan opisthobranchs. The additional genomes presented here show that some species share an identical mitochondrial gene order due to convergence.

  1. Cellular biomarker responses of limpets (Mollusca as measure of sensitivity to cadmiumcontamination

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    Koot Reinecke

    2008-09-01

    Full Text Available Due to the availability and chemical nature of some heavy metals, sub-lethal toxicant levels may persist in the ocean waters and may cause physiological problems and toxicity in invertebrates and other marine organisms. Although studies of metal concentrations in False Bay showed relatively low mean concentrations of Cd, invertebrates such as molluscs, crustaceans and many other groups are able to accumulate high levels of heavy metals in their tissues and still survive in the heaviest polluted areas. They can accumulate numerous pollutants from natural waters in quantities that are many orders of magnitude higher than background levels. Bioaccumulation ofcadmium in intertidal species could cause stress which may be measurable at the cellular level. A variety of limpet species that may serve as suitable ecotoxicological monitoring species occur in abundance on rocky shores along the South African coastline. The aim of this study was to obtain sensitivity data which could contribute to the selection of a suitable monitoring species and the eventual establishment of a species sensitivity distribution model (SSD with a biomarker responseas endpoint. The limpets Cymbula oculus, Scutellastra longicosta, Cymbula granatina and Scutellastragranularis as well as water samples were collected at two localities in False Bay, South Africa. Analysis of water and biological samples were done by atomic absorption spectrometry. Exposures were done to three different sublethal concentrations of cadmium in the laboratory in static flow tanks over three days. There was a moderate increase in cadmium body concentrations over time. Results obtained at three exposure concentrations showed no significant differences in metal concentrations between the different C. oculus samples. Significant differences were obtained between the control and the exposure groups for each exposure time except between the control and the 1mg/L CdCl2 exposure group after 24 and 72 hours of exposure. Cd body concentrations(soft tissue varied between 4.56 and 21.41µg/g (wet mass.Mean Cd concentrations in soft tissue of S. longicosta was considerably lower (varying between 1.18 and 19.58 µg/g Cd than in the tissues of C. oculus. The control group differed significantly from the 0.8 and 1 mg/L CdCl2 exposures after 48 and 72 hours. Mean Cd body concentrations in S. granular is were the highest of all exposed species, reaching a level of 148 µg/g Cd at the highest exposure concentration and differed significantly from the means of the other samples of the 0.8 mg/L CdCl2 exposure group after 72 hours and from the 1 mg/L CdCl2 group after 24 hours. Significant differences were also obtained between theCd body concentrations of C. granatina for the three exposure concentrations and three exposure times. Lysosomal membrane integrity was determined for both exposed and control animals, using the neutral red retention assay. Three of the four species showed a significant decrease in retention times with an increase in Cd concentration. Inter-species differences in sensitivity to environmentally relevant cadmium concentrations were reflected in the biomarker responses. Based on reduction of NRR times, the order of relative sensitivity to cadmium was S. granularis >C. oculus> S. longicosta.> C.granatina. 

  2. A biomechanical model of rock drilling in the piddock Barnea candida (Bivalvia; Mollusca)

    NARCIS (Netherlands)

    Nederlof, R.; Muller, M.

    2012-01-01

    The bivalve Barnea candida (Pholadacea) makes its burrow in clay, soft rock and peat. Barnea has developed a number of adaptations to accommodate this lifestyle. Four muscles enable burrowing. These are situated around a dorsal pivot in such a way that the piddock is able to rotate the shells around

  3. A new record of marine wood-borer (Mollusca: Teredinidae) from waters off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Wagh, A.B.

    The occurrence of Teredona princesae (Sivickis) has been reported for the first time from the Exclusive Economic Zone (EEZ) off Bombay. A brief description of the pallet and distribution of this species is presented...

  4. Anatomia e histologia do aparelho reprodutor masculino de Pomacea canaliculata (Lamarck, 1822 (Mollusca, Gastropoda, Pilidae

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    Eliana de Fátima Marques de Mesquita

    1990-01-01

    Full Text Available In this paper the authors give an anatomical and histological analysis of the male reproductive system of Pomacea canaliculata (Lamarck, 1822. Anatomically, the testis is better evidentiated than the ovary. In the structure of the testis a great number of very small channels converges to a single one. The male copulatory organs result of transformations that take place in the inner surface on the palial membrane. Histologically, the testis of immature males shows seminiferous ducts with round egg-shaped forms. In their lumens we could notice masses of cells that will originate spermatozoids. The penis has a conjunctive muscular sheath that can be seen in van Gieson's coloured preparations.

  5. Changes in energetic metabolism of Biomphalaria glabrata (Mollusca, Planorbidae in response to exogenous calcium

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    L. D. Silva

    Full Text Available Abstract Calcium is considered an essential element for the metabolism of aquatic snail Biomphalaria glabrata (Say, 1818, intermediate host of Schistosoma mansoni Sambon, 1907 in Brazil, and represents a limiting factor to its distribution and adaptation to the environment. This study investigated the effect of different concentrations of exogenous CaCO3 on the energetic metabolism of B. glabrata for better understanding the physiological interference of chemical elements dissolved in the environment with the physiology of this species. Sixty-day-old snails were distributed into six groups, five exposed to different concentrations of CaCO3 (20, 40, 60, 80 and 100 mg/L and a control group. The exposure to CaCO3 was assessed over time, with analysis of 15 snails of each group in the following intervals: 1, 14, 21 or 30 days for hemolymph extraction. Concentrations of calcium and glucose in the hemolymph were determined by commercial kits, and organic acids were extracted using an ion exchange column and analyzed by high-performance liquid chromatography. Concentration of calcium in the hemolymph showed no significant difference (p>0.05 from the control group and between the concentrations tested. Concentration of glucose decreased (p<0.05 in the treatments of exposure to 20 and 40 mg/L and increased when exposed to 80 and 100 mg/L CaCO3 compared to control and to other concentrations tested over 30 days. The organic acids pyruvate, oxaloacetate, citrate, succinate, fumarate, beta-hydroxybutyrate and lactate presented increased concentrations, while propionate and acetoacetate, decreased concentrations, when exposed to CaCO3 compared to control. Considering the influence of different periods of exposure to CaCO3, on the 14th day, there were stronger alterations in the metabolism of B. glabrata. In conclusion, exposure to CaCO3 reduced the concentration of glucose, which is metabolized into pyruvate, the final product of glycolysis, and also influenced the energetic metabolism pathways, indicating an aerobic or partially anaerobic functioning.

  6. Wood-Boring Bivalves (Mollusca: Teredinidae, Pholadidae) of Pacific coast of Colombia

    International Nuclear Information System (INIS)

    Cantera K, Jaime R

    2010-01-01

    Twelve species of wood-boring bivalves, ten of the family Teredinidae and two of family Pholadidae were collected in mangroves at 6 locations of the Pacific coast of Colombia. This paper presents a brief escription of these species, including size, ecological notes and geographical distribution.

  7. Study on the reproductive biology of Pinctada fucata (Gould) (Mollusca: Pteriidae)

    OpenAIRE

    Behzadi, Safieh

    1997-01-01

    Annual cycle of gonad development and spawning in pearl oyster, Pinctada ficata (Gould) in Nakhiloo, Northeast Persian Gulf, was investigated over two years from August 1994 to June 1996. Gonadal condition was assessed by staging criteria to describe gametogenic development from histological preparations of randomly collected individuals of all sizes. A bimodal gametogenic pattern with summer and autumn spawning periods was evident throughout the study. Gametogensis commenced in November-Dece...

  8. The Transcriptomes of Xiphinema index and Longidorus elongatus Suggest Independent Acquisition of Some Plant Parasitism Genes by Horizontal Gene Transfer in Early-Branching Nematodes

    NARCIS (Netherlands)

    Danchin, Etienne G.J.; Perfus-Barbeoch, Laetitia; Rancurel, Corinne; Thorpe, Peter; Rocha, Da Martine; Bajew, Simon; Neilson, Roy; Sokolova, Elena; Silva, Da Corinne; Guy, Julie; Labadie, Karine; Esmenjaud, Daniel; Helder, Hans; Jones, John T.; Eves-van den Akker, Sebastian

    2017-01-01

    Nematodes have evolved the ability to parasitize plants on at least four independent occasions, with plant parasites present in Clades 1, 2, 10 and 12 of the phylum. In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been

  9. A study of the length – weight relationship and condition factor of ...

    African Journals Online (AJOL)

    1.1145 (March). Pseudotolithus elongatus exhibited an allometric growth. There was a positive correlation between length and weight of both sexes. P. elongatus was also in a good condition. Keywords: Fish, length–weight relationship, condition ...

  10. Melanoides tuberculata (Mollusca: Thiaridae as an intermediate host of Centrocestus formosanus (Trematoda: Heterophyidae in Brazil Melanoides tuberculata (Mollusca: Thiaridae como hospedeiro intermediário de Centrocestus formosanus (Trematoda: Heterophyidae no Brasil

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    Hudson Alves Pinto

    2010-08-01

    Full Text Available Pleurolophocercous cercariae emerged from naturally infected Melanoides tuberculata from Minas Gerais State, Brazil, were used to perform experimental infection of laboratory-reared Poecilia reticulata. Mature metacercariae were obtained from the gills of fishes and force-fed to Mus musculus. The adult parasites which recovered from small intestines of mice were identified as Centrocestus formosanus. This is the first report of M. tuberculata as intermediate host of this heterophyid in Brazil.Cercárias do tipo pleurolofocerca emergidas de Melanoides tuberculata naturalmente infectados coletados na represa da Pampulha, Belo Horizonte, Minas Gerais, Brasil, foram utilizadas para a infecção experimental de Poecilia reticulata criados em laboratório. Metacercárias maduras foram obtidas nas brânquias dos peixes e administradas por via oral a Mus musculus. Parasitos adultos recuperados no intestino delgado dos camundongos foram identificados como Centrocestus formosanus. Este é o primeiro relato de M. tuberculata como hospedeiro intermediário deste parasito no Brasil.

  11. Moluscos de importância econômica no Brasil: III. Subulinidae, Leptinaria unilamellata (Orbigny (Mollusca, Gastropoda, Pulmonata, Stylommatophora Molluscs of economic importance in Brasil: III. Subulinidae, Leptinaria unilamellata (Orbigny (Mollusca, Gastropoda, Pulmonata, Stylommatophora

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    José Luiz de B. Araújo

    1993-01-01

    Full Text Available An anatomic study of Leptinaria unilamellata (Orbigny, 1835 was made emphasizing the genital system, the pallial chamber the radulae and the mandible. The details of these parts characterize better the species and allow more systematic clarity to the group. The importance of the evolutive cycle of the two trematodes, Postharmostomum gallinum (Witenberg, 1923 and Paratanaisia bragai (Santos, 1934 both parasites of domestic birds in Brazil is accentuated.

  12. Desarrollo morfológico e histológico del sistema reproductor de Pomacea patula catemacensis (Baker 1922 (Mollusca, Caenogastropoda: Ampullariidae Morphological and histological development of the reproductive system of Pomacea patula catemacensis (Baker 1922 (Mollusca, Caenogastropoda: Ampullariidae

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    AURA CARREÓN-PALAU

    2003-12-01

    Full Text Available El "tegogolo" Pomacea patula catemacensis es un gasterópodo dulceacuícola comestible, endémico del Lago de Catemaco en Veracruz, México. En los últimos años las poblaciones naturales se han visto diezmadas debido a que su captura se realiza sin control, a lo que se suma el alto grado de deterioro ambiental que presenta el lago, producto del "azolvamiento", así como por la contaminación por plaguicidas y detergentes. El objetivo del presente estudio fue caracterizar histológica y morfológicamente el sistema reproductor de P. patula catemacensis y determinar las etapas de madurez gonádica en condiciones de laboratorio. Se determinó que la maduración depende de la talla y no de la edad de los organismos, y se identificaron cuatro etapas principales en el desarrollo de machos y hembras: Los estadios y sus longitudes promedio ± intervalo de confianza del 95 % son (1 inmadura o indiferenciada (talla de 0,72 a 7 mm, (2 maduración temprana (18,95 ± 1,96 mm, (3 maduración intermedia (29,29 ± 4,9 mm y (4 madurez total (35,89 ± 3,92 mm. En este molusco los sexos están separados, la fertilización es interna y el desarrollo es ovovivíparo. En las hembras la secreción de albúmina y de carbonato de calcio se realiza en la glándula de la albúmina, característica en la que difiere de otras especies como P. paludosa y P. canaliculata, las cuales poseen además glándula de la cápsula. Es posible identificar el grado de madurez de los caracoles utilizando criterios anatómicos visuales, como la glándula de la albúmina, en el caso de la hembra, y el órgano copulador en el machoThe "apple snail" Pomacea patula catemacensis is an edible freshwater mollusc, endemic to the Catemaco Lake in Veracruz, Mexico. During the past few years, the natural populations of this species have been depleted mainly by uncontrolled fishery, and because of environmental degradation and pollution by pesticides and detergents. In the present study, we carried out the histological and morphological characterization of the reproductive system of P. patula catemacensis under laboratory conditions. We found that the reproductive development of this snail depended more on the size than on the age the animals, and identified four development main stages, both for males and females. The main stages and their mean lengths ± confidence interval at P < 0.05 were (1 immature or not differenced (from 0.72 to 7 mm, (2 early maturation (from 18.95 ± 1.96 mm, (3 intermediate maturation (from 29.29 ± 4.9 mm, and (4 full maturity (from 35.89 ± 3.92 mm. This species is ovoviviparous, both sexes are separated, and fertilization is internal. Albumin and calcium carbonate secretion in females are performed through the albumin gland, a trait that distinguishes this species from others, such as P. paludosa and P. canaliculata. The stage of development can be identified by means of using anatomical traits, such as the albumin gland (in the case of females, or the intromittent organ (in males

  13. Estrutura fina do espermatozóide de Tagelus plebeius (Lightfoot (Mollusca, Bivalvia do litoral norte do Brasil Fine structure of the spermatozoon of Tagelus plebeius (Lightfoot (Mollusca, Bivalvia of the North littoral of Brazil

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    Edilson Matos

    1997-09-01

    Full Text Available It is described the sperm ultraestructure differentiation during spermiogenesis of Tagelus plebeius (Lightfoot, 1786. The spermatozoon is an uniflagellated cell of the primitive type. The head region contains a rounded or conical nucleus surrounded by acrosome. The middle piece contains four mitochondria which are arranged around the axoneme. The flagellum contains the usual microtubular axoneme.

  14. Ultraestrutura do espermatozóide de Protothaca pectorina (Lamarck (Mollusca, Bivalvia do litoral norte do Brasil Ultrastructure of the spermatozoon of Protothaca pectorina Lamarck (Mollusca, Bivalvia of the north litoral of the Brazil

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    Edilson Matos

    1997-12-01

    Full Text Available The ultrastructure of spermatozoa of the Protothaca pectorina (Lamarck, 1818 is described. The most significam differences were found in the structure and arreangement of the acrosomes, with contains two types of material, one fibrilar, the other electrondense granular. It is concluded that sperm ultrastructure is of the primitive type.

  15. Aspectos ultraestruturais do espermatozóide de Natica marochiensish (Gmelin (MOllusca, Gastropoda do litoral norte do Brasil Ultrastructural aspects of the spermatozoon of Natica marochiensish (Gmelin (Mollusca, Gastropoda of the North littoral of Brazil

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    Edilson Matos

    1997-09-01

    Full Text Available Spermatozoa of Natica marochienssish (Gmelin, 1791 is described by light and electron microscopy. The spermatozoon is of the primitive type with head contains a conical acrosomal complex with an acrosomal vesicle of dense matrix having a basis occupied by the subacrosomal space. The middle piece shows the centriolar complex surrounded by mitochondria and the tail contains the axoneme with a 9+2.

  16. Os gêneros Fasciolaria Lamarck, 1799 e Leucozonia Gray, 1847 no nordeste brasileiro (Mollusca: Gastropoda: Fasciolariidae The genera Fasciolaria Lamarck, 1799 and Leucozonia Gray, 1847 in the northeastern Brazil (Mollusca: Gastropoda: Fasciolariidae

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    Helena Matthews-Cascon

    1989-01-01

    Full Text Available The genera Fasciolaria Lamarck, 1799 and Leucozonia Gray, 1847 are represented in Northeastern Brazil by three species. Fasciolaria aurantiaca Lamarck, 1816; Leucozonia ocellata (Gmelin, 1791 and Leucozonia nassa (Gmelin, 1791. The three species are described and illustrated. An identification key for all the above mentioned taxa is included, together with some ecological data. The anatomy and radula of Fasciolaria aurantiaca and Leucozonia nassa are described and illustrated. Polimorfism in Fasciolaria aurantiaca and Leucozonia nassa is discussed.

  17. La Familia Trochidae (Mollusca: Gastropoda en el norte de Chile: consideraciones ecológicas y taxonómicas The trochidae family (Mollusca : Gastropoda in northern Chile: taxonomic and ecological considerations

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    DAVID VELIZ

    2000-12-01

    Full Text Available Este estudio describe la diversidad, y la distribución latitudinal y batimétrica de los caracoles de la Familia Trochidae en el norte de Chile, mediante muestreos intermareales y submareales someros, realizados entre 1996 y 1999 entre Arica (18º S y Los Vilos (31º S, y de muestras de profundidad provenientes de la pesca de arrastre del camarón nylon, Heterocarpus reedi. En el norte de Chile, la Familia Trochidae está representada por cuatro géneros: Tegula y Diloma de distribución intermareal y submareal somero hasta los 20 m de profundidad, y Bathybembix y Calliostoma presentes en profundidades superiores a los 200 m. El género Tegula tiene seis especies (T. quadricostata, T. luctuosa, T. ignota, T. atra, T. tridentata y T. euryomphala distribuídas en sustratos rocosos intermareales y submarales someros. El género Diloma está representado por una especie, D. nigerrima, de distribución intermareal hasta pocos metros de profundidad. El género Calliostoma tiene dos especies C. chilena y C. delli, las que se distribuyen entre 200 y 750 m de profundidad. Finalmente, el género Bathybembix está representado por B. humboldti y B. macdonaldi distribuídas entre 200 y 1480 m de profundidad. Esta segregación batimétrica parece estar relacionada a las estrategias alimentarias de cada uno de los géneros de la familia Trochidae. Diloma y Tegula son herbívoros, las especies del género Bathybembix son alimentadoras de depósito y las de Calliostoma son carnívorasThis study reveals the diversity, and the bathimetric and latitudinal distribution of the snails of the Trochidae family members in northern Chile, throughout the analysis of all Trochidae gastropods entailed in intertidal and subtidal (from the `camarón naylon' fishery samples collected during 1996 and 1999 between Arica (ca 18º S and Los Vilos (ca 31º S. The Trochidae family in northern Chile have four genus: Tegula and Diloma that are distributed on intertidal and shallow subtidal habitats, and Calliostoma and Bathybembix which occurr at dephts greather than 200 m. Tegula have 6 species: T. quadricostata, T. luctuosa, T. ignota, T. atra, T. tridentata, and T. euryomphala are distributed on intertidal and shallow subtidal habitats. Diloma is a monospecific genus, whereas D. nigerrima is an intertidal species. The genus Calliostoma have two species C. chilena and C. delli occurring between 200 and 750 m depth and the Bathybembix with two species, B. Humboldti and B. macdonaldi, distributed between 200 and 1480 m depth. The bathimetric distribution of Trochidae shows a strong correlation with food strategy: Diloma and Tegula are herbivores, while Bathybembix species are deposit feeders and Calliostoma are carnivores

  18. Algumas observações de campo sobre biologia e ecologia de Pomacea haustrum (Reeve, 1856 (Mollusca, Pilidae Some field observation on biology and ecology of Pomacea haustrum (Reeve, 1856 (Mollusca, Pilidae

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    Carlos Tito Guimarães

    1981-12-01

    Full Text Available Algumas observações de campo sobre o pilídeo Pomacea haustrum (Reeve, 1856, predador-competidor de planorbíneos hospedeiros intermediários da esquistossomose mansoni mostraram que: Cópula e oviposição são realizadas, preferencialmente, à noite e de madrugada. As desovas - cujas dimensões e formas dependem do número de ovos e tipos dos suportes - sao ovipostas, na maioria das vezes, de 6 a 10 cm acima do nível da água eclodindo após 9 a 30 dias de incubação; o número médio de ovos por desova foi de 236. A alimentação habitual deste molusco consiste de algas confervóides, além de vegetais aquáticos natantes e submersos; entretanto, e comum a utilização de outros materiais como alimento.Tem como habitat a zona marginal mais rasa das coleções hídricas onde e encontrado, predominando, aparentemente, nos ambientes lênticos. A distribuição espacial esta condicionada por determinadas características dos biótopos. Algumas aves aquáticas - anatídeos, ralídeos, etc.- revelaram-se importantes inimigos naturais, atacando além das desovas exemplares jovens e adultos; em determinadas condições podem constituir fator impeditivo da implantação e colonização de novos biótopos.Some field observations on the pilid Pomacea haustrum (Reeve, 1856, predator-competitor of schistosomiasis mansoni planorbid intermediate hosts have shown that: Copula and oviposition are preferably carried out at night or at dawn. Eggmasses - whose dimension and shape depend on the number of eggs and types of supports - are often laid from 6 to 10 com above the water level and hatched 9 to 30 days after incubation; the average number of eggs/egg-mass was 236. Habitual food consist of confervoid algae, besides natant and submerged aquatic vegetation; it is common, however, the utilization of the other material as food. Its habitat is the shallower marginal zone of hidric collections, predominatly in lentic surrounding. Its spacial distribution is conditioned to the biotipe special characteristics. Some aquatic birds - anatid, ralid, etc. - reveal important natural enemies, attacking both young and adult specimens, besides the egg-masses; under certain conditions they may be an impedictive factor to the establishment and colonization of this pilid in new biotopes.

  19. Shell morphometrics in four species of Gadilidae (Mollusca, Scaphopoda in Southwestern Atlantic Ocean, Brazil Morfometria da concha de quatro espécies de Gadilidae (Mollusca, Scaphopoda no Brasil, sudoeste do Oceano Atlântico

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    Ricardo Silva Absalão

    2005-03-01

    Full Text Available Six morphometric shell direct measurements of the Gadilidae species Gadila acus (Dall, 1889, Cadulus braziliensis Henderson, 1920, Cadulus parvus Henderson, 1920 and Polyschides tetraschistus (Watson, 1879 were carried out and used to build three morphometric indices in according to the proposition of SHIMEK (1989: LI, relating total shell length to length from the dorsal aperture to the maximum width; WI, relating maximum shell diameter to apertural diameter; and Ws, whorl expansion rate (sensu RAUP 1966. Direct measurements and morphometric indices were tested as discriminating tools among the four species. None of the morphometric indices, alone, were able to discriminate among all species. Among then, Ws is not an effective discriminating morphometric index because it fails in all pairwise comparisons, LI and WI are fairly efficient ones, since they have got effective discriminations in three out six pairwise comparisons. The combined use of direct measurements ones was more efficient than the indices ones when dealing with relatively small samples, as ours. Although both descriptors can be combiningly used; since the direct measurements descriptors are easier to obtain and understand than the more complex indices, they should be recommended as main tools.Seis medidas morfométricas tomadas diretamente da concha dos seguintes gadilideos: Gadila acus (Dall, 1889, Cadulus braziliensis Henderson, 1920, Cadulus parvus Henderson, 1920 e Polyschides tetraschistus (Watson, 1879 foram realizadas e utilizadas na construção de índices morfométricos em concordância com Shimek (1989: LI, razão entre o comprimento total da concha e o comprimento entre a abertura dorsal até o ponto de máximo diâmetro; WI, razão entre o diâmetro máximo da concha e o diâmetro da abertura; e Ws, taxa de expansão dos anfractos (sensu Raup 1966. Tanto as medidas tomadas diretamente das conchas como os índices morfométricos foram testados como instrumentos de discriminação entre as quatro espécies. Nenhum índice morfométrico, quando considerado isoladamente, foi capaz de discriminar entre todas as espécies. Ws teve o pior desempenho, falhando na discriminação de todas as comparações par-a-par, LI e WI se saíram melhor, desde que discriminaram, corretamente, três das seis comparações par-a-par. A utilização combinada das medidas diretas da concha foi mais eficiente que os índices morfométricos, ao menos ao se tratar de amostras pequenas como as nossas. Embora ambos tipos de descritores possam ser utilizados, a maior simplicidade e facilidade de obtenção das medidas diretas as habilitam como os principais instrumentos de discriminação conquiliológica.

  20. A new species of Temnocephala (Platyhelminthes, Temnocephalida commensal of Pomella megastoma (Mollusca, Ampullariidae from Misiones, Argentina Una especie nueva de Temnocephala (Platyhelminthes, Temnocephalida comensal de Pomella megastoma (Mollusca, Ampullariidae de Misiones, Argentina

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    Cristina Damborenea

    2008-08-01

    Full Text Available Temnocephala lamothei n. sp., a commensal of Pomella megastoma (Sowerby, 1825, is described herein from specimens collected at Arroyo Yabotí-Miní (Misiones province, Argentina. Juveniles and adults were removed from the mantle cavity by host relaxation. Distinctive characters of the new species are: non-partitioned intestine; conical cirrus with 1 face flat and another concave; distal area with spines, as evidenced by a strong, oblique sclerotized ring, and 2 rows of long spines, an internal one with long spines arising from base of introvert and an external one arising from distal end of the introvert. The closest species are T. iheringi, T. rochensis and T. haswelli, which are also commensals of mollusc species. The presence of this new species of Temnocephala, and its similarity to the other species that are commensals of molluscan species, suggest the existence of a morphologically homogeneous group.Temnocephala lamothei n. sp., comensal de Pomella megastoma (Sowerby, 1825, se describe para el arroyo Yabotí-Miní, provincia de Misiones, Argentina. Se extrajeron ejemplares juveniles y adultos de la cavidad paleal, por relajación de los hospederos. Las características distintivas de la nueva especie son: intestino no septado, cirro de forma cónica, con una cara plana y otra cóncava, zona distal con espinas evidente por un fuerte anillo oblicuo esclerosado. Dos hileras de espinas se reconocen en el extremo distal, 1 interna de espinas largas, que surge desde la base del introverso, y 1 externa, que surge del extremo distal del mismo. Las especies más semejantes son T. iheringi, T. rochensis y T. haswelli, especies comensales de moluscos con las que es comparada. El hallazgo de esta nueva especie de Temnocephala y sus características semejantes a las restantes especies del género comensales de moluscos, sugieren que las especies conocidas hasta la fecha formen un grupo morfológicamente homogéneo.

  1. Registro de Achatina fulica Bowdich, 1822 (Mollusca, Gastropoda no Brasil: caramujo hospedeiro intermediário da angiostrongilíase Occurrence of Achatina fulica Bowdich, 1822 (Mollusca, Gastropoda in Brazil: intermediate snail host of angiostrongyliasis

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    Horácio Manuel Santana Teles

    1997-06-01

    Full Text Available A introdução de Achatina fulica é assinalada em Itariri, SP, Brasil. Essa espécie de caramujo terrestre foi importada para cultivo, visando à comercialização para consumo humano como "escargot". O encontro de exemplares em vida livre mostra a dispersão de A. fulica e, conseqüentemente, o risco de transmissão de Angiostrongylus cantonensis, nematóide parasita do homem e de outros vertebrados. Além disso, o caramujo é uma praga importante da agricultura.Achatina fulica, the intermediate snail host of angiostrongyliasis and also an agricultural pest, is being bred in Brazil for human consumption as "escargot". The snail has escaped from its artificial breeding sites and its dispersal in Itariri county, State of S. Paulo, is reported here for the first time. A. fulica is a transmitter of the rat lungworm Angiostrongylus cantonensis, nematode which causes meningoencephalic angiostrongyliasis; the risks of human contamination are commented on.

  2. Prosobrânquios terrestres do Brasil: Cyclophoridae: Neocyclotus (N. agassizi (Bartsch & Morrison, 1942 (Mollusca, Gastropoda, Mesogastropoda Land prosobranchs of Brazil: Cyclophoridae: Neocyclotus (N. agassizi (Bartsch & Morrison, 1942 (Mollusca, Gastropoda, Mesogastropoda

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    Arnaldo C. dos Santos Coelho

    1989-01-01

    Full Text Available Studies on specimens from Brazil (States of Pernambuco and Alagoas were carried out in order to relate data about morphology of hard and soft parts o Nocyclotus (N. agassizi (Bartsh & Morrison, 1942.

  3. Histomorfologia do órgão acessório de perfuração de Thais haemastoma (Mollusca, Gastropoda Histology of the accessory boring organ in Thais haemastoma (Mollusca, Gastropoda

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    Ana Valêsca P. Lima

    2009-06-01

    Full Text Available Os representantes da família Thaididae são organismos predadores de outros moluscos, perfurando suas conchas pela ação alternada de secreção oriunda do "Accessory Boring Organ" (ABO e por raspagem através da rádula. Nesta família, o ABO está localizado na porção ventral mediano-anterior do pé. Os animais examinados neste estudo foram coletados na praia do Futuro, Fortaleza, em seguida levados ao laboratório para fixação e posterior tratamento histológico rotineiro. A porção glandular do ABO de Thais haemastoma (Linnaeus, 1758 se encontra alojada em uma cavidade circundada pela musculatura do pé e apresentando um ducto excretório que a comunica com o meio externo. Esta cavidade é revestida por um epitélio cilíndrico simples separando a porção glandular deste órgão do músculo pedioso, sendo contínuo com o epitélio de revestimento do ducto excretório. Subjacente a este tecido foi visualizado um tecido conjuntivo frouxo. A região glandular do ABO da espécie apresenta um formato discoidal com superfície irregular devido à presença de reentrâncias em direção à porção central da glândula. O epitélio glandular pseudoestratificado com células cilíndricas e ciliadas reagiu negativamente aos testes histoquímicos. Abaixo do epitélio, foi observado um tecido conjuntivo frouxo de sustentação.The mollusks of the family Thaididae are predators of others mollusks drilling their shell using alternately secretions from the accessory boring organ (ABO and scraping movements of the radula. In this family the ABO is located in the median-anterior ventral part of the foot. The animals examined in the study were collected in the "Praia do Futuro", Fortaleza, Ceará, Brazil. The glandular part of ABO in Thais haemastoma (Linnaeus, 1758 is located in a cavity inside the foot, surrounded by foot muscle, and shows an excretory duct connecting that glandular portion to the outside. The analysis of microscopic sections stained by eosin-hematoxylin showed an epithelial tissue lining the cavity, and separating the glandular portion of ABO from the foot muscle. This ephitelial tissue is continuous with the excretory duct ephitelium. Under this tissue was observed a loose connective tissue. The ABO gland of T. haemastoma has a discoidal format and an irregular surface due to the presence of reentrances heading to the central part of the gland. The pseudoestratificated glandular epithelium with cylindrical and ciliated cells reacted negatively to the histochemical tests. Under the epithelium a connective loose tissue of support was observed.

  4. Development and validation of an OECD reproductive toxicity test guideline with the mudsnail Potamopyrgus antipodarum (Mollusca, Gastropoda)

    DEFF Research Database (Denmark)

    Ruppert, Katharina; Geiß, Cornelia; Askem, Clare

    2017-01-01

    Mollusks are known to be uniquely sensitive to a number of reproductive toxicants including some vertebrate endocrine disrupting chemicals. However, they have widely been ignored in environmental risk assessment procedures for chemicals. This study describes the validation of the Potamopyrgus...... antipodarum reproduction test within the OECD Conceptual Framework for Endocrine Disrupters Testing and Assessment. The number of embryos in the brood pouch and adult mortality serve as main endpoints. The experiments are conducted as static systems in beakers filled with artificial medium, which is aerated...... trough glass pipettes. The test chemical is dispersed into the medium, and adult snails are subsequently introduced into the beakers. After 28 days the reproductive success is determined by opening the brood pouch and embryo counting. This study presents the results of two validation studies...

  5. Development and validation of an OECD reproductive toxicity test guideline with the mudsnail Potamopyrgus antipodarum (Mollusca, Gastropoda).

    Science.gov (United States)

    Ruppert, Katharina; Geiß, Cornelia; Askem, Clare; Benstead, Rachel; Brown, Rebecca; Coke, Maira; Ducrot, Virginie; Egeler, Philipp; Holbech, Henrik; Hutchinson, Thomas H; Kinnberg, Karin L; Lagadic, Laurent; Le Page, Gareth; Macken, Ailbhe; Matthiessen, Peter; Ostermann, Sina; Schimera, Agnes; Schmitt, Claudia; Seeland-Fremer, Anne; Smith, Andy J; Weltje, Lennart; Oehlmann, Jörg

    2017-08-01

    Mollusks are known to be uniquely sensitive to a number of reproductive toxicants including some vertebrate endocrine disrupting chemicals. However, they have widely been ignored in environmental risk assessment procedures for chemicals. This study describes the validation of the Potamopyrgus antipodarum reproduction test within the OECD Conceptual Framework for Endocrine Disrupters Testing and Assessment. The number of embryos in the brood pouch and adult mortality serve as main endpoints. The experiments are conducted as static systems in beakers filled with artificial medium, which is aerated trough glass pipettes. The test chemical is dispersed into the medium, and adult snails are subsequently introduced into the beakers. After 28 days the reproductive success is determined by opening the brood pouch and embryo counting. This study presents the results of two validation studies of the reproduction test with eleven laboratories and the chemicals tributyltin (TBT) with nominal concentrations ranging from 10 to 1000 ng TBT-Sn/L and cadmium with concentrations from 1.56 to 25 μg/L. The test design could be implemented by all laboratories resulting in comparable effect concentrations for the endpoint number of embryos in the brood pouch. After TBT exposure mean EC 10 , EC 50 , NOEC and LOEC were 35.6, 127, 39.2 and 75.7 ng Sn/L, respectively. Mean effect concentrations in cadmium exposed snails were, respectively, 6.53, 14.2, 6.45 and 12.6 μg/L. The effect concentrations are in good accordance with already published data. Both validation studies show that the reproduction test with P. antipodarum is a well-suited tool to assess reproductive effects of chemicals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Effect of temperature on growth, mortality, reproduction, and production of adult Lymnaea obrussa Say (Mollusca:Gastropoda)

    International Nuclear Information System (INIS)

    Mattice, J.S.

    1975-01-01

    Shell lengths and egg production were measured weekly under constant (K; 10, 15, 20, 25 0 C) and varying temperature regimes during the reproductive period. Varying regimes included natural field temperature in a pond (F; diurnal and seasonal), mean daily field temperature (anti F; seasonal) and 5 and 10 0 C above anti F. Growth rate of large snails (>10 mm) was unaffected by temperature, but small snails (6 to 10 mm) grew fastest at 15 0 C(K). Growth and reproductive periods were longest, production was highest, and mortality rate was lowest at 15 0 C(K). Rate (per snail) of egg production increased with temperature. At equal mean temperature, regime affected growth rate only at anti F. Regime affected the following values as shown: mortality rate,F > anti F = K; rate of reproduction, F > K > anti F; and total production, K > anti F = F. The validity of extrapolation of energetic data from laboratory to field is discussed. Data relating production and temperature are valuable in thermal impact analysis. (U.S.)

  7. Microsatellite loci for dreissenid mussels (Mollusca: Bivalvia: Dreissenidae) and relatives: markers for assessing exotic and native populations.

    Science.gov (United States)

    Feldheim, Kevin A; Brown, Joshua E; Murphy, Douglas J; Stepien, Carol A

    2011-07-01

    We developed and tested 14 new polymorphic microsatellite loci for dreissenid mussels, including the two species that have invaded many freshwater habitats in Eurasia and North America, where they cause serious industrial fouling damage and ecological alterations. These new loci will aid our understanding of their genetic patterns in invasive populations as well as throughout their native Ponto-Caspian distributions. Eight new loci for the zebra mussel Dreissena polymorpha polymorpha and six for the quagga mussel D. rostriformis bugensis were compared with new results from six previously published loci to generate a robust molecular toolkit for dreissenid mussels and their relatives. Taxa tested include D. p. polymorpha, D. r. bugensis, D. r. grimmi, D. presbensis, the 'living fossil'Congeria kusceri, and the dark false mussel Mytilopsis leucophaeata (the latter also is invasive). Overall, most of the 24 zebra mussel (N = 583) and 13 quagga mussel (N = 269) population samples conformed to Hardy-Weinberg equilibrium expectations for the new loci following sequential Bonferroni correction. The 11 loci (eight new, three previously published) evaluated for D. p. polymorpha averaged 35.1 alleles and 0.72 mean observed heterozygosity per locus, and 25.3 and 0.75 for the nine loci (six new, three previously published) developed for D. r. bugensis. All but three of these loci successfully amplified the other species of Dreissena, and all but one also amplified Congeria and Mytilopsis. All species and populations tested were significantly divergent using the microsatellite data, with neighbour-joining trees reflecting their evolutionary relationships; our results reveal broad utility for resolving their biogeographic, evolutionary, population and ecological patterns. © 2011 Blackwell Publishing Ltd.

  8. [The influence of the trematode invasion on the average daily rations and electoral nourishment of Planorbarius corneus (Mollusca: Pulmonata: Bulinidae)].

    Science.gov (United States)

    Stadnichenko, A P; Girin, V K

    2005-01-01

    The influence of the Trematode invasion on the average daily rations and electoral nourishment of the two size groups in the great ramshorn snail Planorbarius corneus, "young" (12-24 mm in diameter) and "old" (24-36.5 mm in diameter), have been investigated.

  9. Biomonitoring study of an estuarine coastal ecosystem, the Sacca di Goro lagoon, using Ruditapes philippinarum (Mollusca: Bivalvia)

    International Nuclear Information System (INIS)

    Sacchi, Angela; Mouneyrac, Catherine; Bolognesi, Claudia; Sciutto, Andrea; Roggieri, Paola; Fusi, Marco; Beone, Gian Maria; Capri, Ettore

    2013-01-01

    Coastal lagoons are constantly subjected to releases of chemical pollutants, and so organisms may be exposed to such toxicants. This study investigated through a multivariate approach the physiological status of bivalve Ruditapes philippinarum, farmed in Sacca di Goro lagoon. Biomarkers at different levels of biological organization (catalase, superoxide dismutase, genotoxicity, reburrowing behavior) were evaluated at three sites exposed to different environmental conditions. A seasonal trend was observed, and micronucleus frequency was significantly lowest at the relatively pristine reference site. Enzymatic activity toward oxyradicals be quite efficient since variations in responsiveness were not consistent. However, behavioral impairment was observed in reburrowing rates. Sediment concentrations showed low PAH levels and high natural levels of trace metals Cr and Ni. DistLM statistical analysis revealed a non-significant relationship between selected biomarkers and xenobiotics. Therefore other potentially toxic compounds in admixture at low doses may be involved in driving differing spatial distribution of physiological impairment. -- Highlights: ► Health status assessment of bivalve Ruditapes philippinarum, from lagoon of Sacca di Goro. ► Multiparametric approach (chemical analysis, biochemical and behavioral biomarkers). ► Impairments of burrowing kinetics in the contaminated site. ► Micronucleus genotoxicity test to detect effects of contaminants complex mixture. ► Multiple stress of chemicals in estuarine costal ecosystem. -- The bivalve Ruditapes philippinarum as a bioindicator in monitoring pollution of estuaries

  10. Dominant character of the molecular marker of a Biomphalaria tenagophila strain (Mollusca: Planorbidae resistant to Schistosoma mansoni

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    Rosa Florence Mara

    2004-01-01

    Full Text Available Biomphalaria tenagophila population from Taim (state of Rio Grande do Sul, Brazil is totally resistant toSchistosoma mansoni, and presents a molecular marker of 350 bp by polymerase chain reaction and restriction fragment length polymorphism of the entire rDNA internal transcriber spacer. The scope of this work was to determine the heritage pattern of this marker. A series of cross-breedings between B. tenagophila from Taim (resistant and B. tenagophila from Joinville, state of Santa Catarina (susceptible was carried out, and their descendants F1 and F2 were submitted to this technique. It was possible to demonstrate that the specific fragment from Taim is endowed with dominant character, since the obtained segregation was typically mendelian.

  11. Dominant character of the molecular marker of a Biomphalaria tenagophila strain (Mollusca: Planorbidae) resistant to Schistosoma mansoni

    OpenAIRE

    Rosa, Florence Mara; Caldeira, Roberta Lima; Carvalho, Omar dos Santos; Godard, Ana Lúcia Brunialti; Coelho, Paulo Marcos Zech

    2004-01-01

    Biomphalaria tenagophila population from Taim (state of Rio Grande do Sul, Brazil) is totally resistant toSchistosoma mansoni, and presents a molecular marker of 350 bp by polymerase chain reaction and restriction fragment length polymorphism of the entire rDNA internal transcriber spacer. The scope of this work was to determine the heritage pattern of this marker. A series of cross-breedings between B. tenagophila from Taim (resistant) and B. tenagophila from Joinville, state of Santa Catari...

  12. Dominant character of the molecular marker of a Biomphalaria tenagophila strain (Mollusca: Planorbidae) resistant to Schistosoma mansoni.

    Science.gov (United States)

    Rosa, Florence Mara; Caldeira, Roberta Lima; Carvalho, Omar dos Santos; Godard, Ana Lúcia Brunialti; Coelho, Paulo Marcos Zech

    2004-02-01

    Biomphalaria tenagophila population from Taim (state of Rio Grande do Sul, Brazil) is totally resistant to Schistosoma mansoni, and presents a molecular marker of 350 bp by polymerase chain reaction and restriction fragment length polymorphism of the entire rDNA internal transcriber spacer. The scope of this work was to determine the heritage pattern of this marker. A series of cross-breedings between B. tenagophila from Taim (resistant) and B. tenagophila from Joinville, state of Santa Catarina (susceptible) was carried out, and their descendants F1 and F2 were submitted to this technique. It was possible to demonstrate that the specific fragment from Taim is endowed with dominant character, since the obtained segregation was typically mendelian.

  13. Imposex in Thais rustica (Mollusca: Neogastropoda (Lamark, 1822 as an indicator of organotin compounds pollution at Maceio coast (Northeastern Brazil

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    Edmundo Camillo

    2004-06-01

    Full Text Available The use of OTC (organotin compounds as biocides in naval antifouling paints causes impacts on non-target organisms. One of these impacts is a syndrome called imposex in gastropod molluscs. Imposex is the imposition of male secondary sexual characteristics in female gastropods as result of endocrine disruption. In this preliminary study, imposex was observed in four out of ten sampled stations in Maceió: the city Port (100% females exhibited imposex, the Marine Emissary (23% females exhibited imposex, the Marine Terminal (35% females exhibited imposex and Saco da Pedra beach (12% females exhibited imposex. These stations were distributed in a NE-SW orientation from the Port southwards along the coastline, following the general circulation pattern of the area. The low values of VDSI, RPSI and RPLI indicate that Maceió Coast is a less contaminated area, probably because of low shipping activities together with the fact that the sampling zone is an open coastal system and not an enclosed bay. These results suggest that the imposex development in Thais rustica may be used as a biological indicator of OTC pollution.O uso de COE (compostos orgânicos de estanho como biocida em tintas antiincrustantes para embarcações causa impactos em organismos não-alvos. Um destes impactos é a síndrome chamada imposex, em moluscos gastrópodos. Imposex é a imposição de caracteres sexuais secundários masculinos em fêmeas de gastrópodos como resultado de desregulação endócrina. Neste estudo preliminar, o imposex foi observado em quatro de dez estações de amostragem em Maceió: o Porto de Maceió (100% de fêmeas imposexadas, o Emissário Submarino (23% de fêmeas imposexadas, o Terminal Marítimo (35% de fêmeas imposexadas e a praia do Saco da Pedra (12% de fêmeas imposexadas. Estas estações estão distribuídas no litoral no sentido NE/SW a partir do Porto, seguindo o padrão de circulação local. Os valores relativamente baixos dos índices VDSI, RPSI e RPLI indicam que a costa de Maceió é uma área moderadamente impactada. Isto poderia ser explicado pelo fato da costa não ser um sistema abrigado e pelo pequeno movimento de sua zona portuária. Estes resultados sugerem que o desenvolvimento do imposex em Thais rustica pode ser usado como indicador da poluição por COEs.

  14. Thais (Stramonita rustica (Lamarck, 1822 (Mollusca: Gastropoda: Thaididae, a potential bioindicator of contamination by organotin northeast Brazil

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    Ítalo Braga de Castro

    2004-06-01

    Full Text Available The use of antifouling paints containing the biocide compound tributyltin (TBT has been shown as an inductor of imposex in neogastropods mollusks. Imposex is characterized by the development of male features in females, mainly the appearance of a no functional vas deferens and penis. Samples of Thais rustica were collected in eight sites in the metropolitan area of Natal city, Rio Grande do Norte state, northeast Brazil, and examined for occurrence of imposex, which was found in many females. The higher imposex levels were presented by samples from sites near city harbor.A utilização de tintas antiincrustrantes contendo o composto biocida tributilestanho (TBT tem induzido moluscos neogastrópodes ao imposex. O imposex é caracterizado pelo surgimento de caracteres sexuais masculinos, sobretudo, pênis e vaso deferente não funcionais em fêmeas desses moluscos. Foram coletadas amostras de Thais rústica em oito estações ao longo da costa da cidade de Natal no Rio Grande do Norte. Esses animais foram analisados quanto a presença e o grau de imposex que apresentavam. Os níveis mais elevados de imposex foram observados na estação mais próxima ao porto.

  15. A natural history of the deep-sea aplacophoran Prochaetoderma yongei and its relationship to confamilials (Mollusca, Prochaetodermatidae)

    Science.gov (United States)

    Scheltema, Amélie H.; Ivanov, Dmitry L.

    2009-09-01

    Previously published studies are woven together into a natural history of a deep-sea aplacophoran mollusc species, Prochaetoderma yongei Scheltema, 1985, and its confamilial species in the Prochaetodermatidae. This amphi-Atlantic species occurs sometimes in great numbers at upper bathyal depths, rivaling polychaetes in numerical dominance. It appears to be an opportunist, with wide geographic and depth distribution, rapid development from lecithotrophic larva to settlement and maturity, and omnivory. A short illustrated morphological description using characters useful for identifying all prochaetodermatid species should prove useful to nontaxonomists whose business is the deep-sea benthic fauna.

  16. Population dynamics and secondary production of Donax trunculus (Mollusca, Bivalvia in the Gulf of Annaba (Northeast Algeria

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    I. HAFSAOUI

    2016-11-01

    Full Text Available The population dynamics and secondary production of the wedge clam Donax trunculus were studied in the Gulf of Annaba (Northeast Algeria monthly for one year at a site close to the Annaba port and the Seybouse river, affected by industrial and agricultural pollution (Sidi Salem, and at a site more distant from major pollution sources, but exploited by fishery (Echatt. The number of individuals (N was lower at Sidi Salem (36–148 ind m-2 than at Echatt (63–272 ind m-2 in most sampling dates, while the biomass was more variable from one date to another, with no consistent pattern of differences between sites. The condition index (CI, although slightly higher at Sidi Salem than at Echatt, showed at both sites a major increase in March/April, June/July and October, reflecting two main periods of gonads development and increase in the level of stored reserves at the end of the reproductive period. Consistently, the recruitment of D. trunculus ran from April to October with a major peak of abundance in spring and a minor one in early fall. The maximum age of D. trunculus was 3 years and the growth rate was highest in the first year. Annual somatic production (P was lower at Sidi Salem (0.773 g AFDM m-2 yr-1 than at Echatt (1.262 g AFDM m-2 yr-1, possibly reflecting a lower mean annual biomass at Sidi Salem (1.642 AFDM m-2 than at Echatt (3.046 AFDM m-2, while the annual P/B ratio was similar between the two sites (i.e. 0.471 and 0.414 yr-1, respectively. Lower N and P at Sidi Salem compared to Echatt are consistent with the proximity of Sidi Salem to the industrial port of Annaba and low hydrodynamic conditions which may favor the accumulation of pollutants, such as hydrocarbons. On the other hand, moderate secondary production of D. trunculus at Echatt compared to other Mediterranean sites may be due to excessive harvesting. We suggest that the low secondary production described in this study should be taken into account for the development of sustainable strategies of clam exploitation in the Gulf of Annaba. In particular, effort should be made to reduce land-based pollution and to regulate the collection of D. trunculus according to the life cycle and production potential of this species.

  17. Ultrastructure of the mature spermatozoon of the bivalve Estellarca olivacea (Mollusca: Bivalvia: Arcidae) and its phylogenetic implications.

    Science.gov (United States)

    Zhu, Jun-Quan; Yang, Wan-Xi

    2009-03-01

    Ultrastructure of mature spermatozoa of Estellarca olivacea was studied by transmission electron microscopy and its phylogenetic implications are discussed for the first time in this paper. The mature spermatozoon is composed of a head which contains a cone-shaped acrosome, a round nucleus and a tail region. The subacrosomal space is less electron dense which contains a homogeneous material. No axial rod and a basal plate were observed in subacrosomal space. No anterior invagination exists in the nucleus, but an inverted shallow V-shaped posterior invagination is visible. Nuclear lacunae could be seen clearly although the nucleus is highly condensed. Within the mid-piece of the spermatozoon there exist five spherical mitochondria while the long whip-like end portion is composed of an axoneme with the typical 9+2 structure. The spermatozoon of Estellarca olivacea is a product of the evolution of the reproductive system of the family Arcidae. Whether the particular acrosome, subacrosomal space, or the highly condensed nucleus might be adaptations of high fertilization rate in the particular environment of this species is discussed.

  18. Bioindicator Thais carinifera (mollusca, gastropoda: imposex response and consequences along the Pakistan coast during the period from 1993 to 2012

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    Nuzhat Afsar

    2015-06-01

    Full Text Available Abstract Endocrine mediated "imposex" phenomenon was investigated and recorded in the muricoid gastropod species Thais carinifera during the two decades from 1993 to 2012 at three (3 sites out of six (6 localities investigated along the Sindh and Balochistan coast, Pakistan. The VDS stages 1 to 4 were apparent in Thais carinifera. The intensity of imposex has remained comparatively low in the populations of harbours in close proximity to port Mohammad Bin-Qasim, namely; Old Korangi Fish Harbour (OKFH and New Korangi Fish Harbour (NKFH where shipping activities are sporadic as compared to those in Manora Channel and the adjoining Karachi Port area where intensive shipping activity is rather frequent. Target species found to be good bioindicators have shown a marked decrease over the prolonged study period. Investigations show that this decrease is solely due to globally imposed effective bans on tributyltin (TBT based antifouling paints over the past decade.

  19. Assessment of tributyltin contamination based on imposex in Stramonita rustica (Mollusca: Gastropoda along southern Bahia coast, northeastern Brazil

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    G. C. Zeidan

    Full Text Available Abstract This study investigated the effects of tributyltin (TBT on the morphology of the genital system of the gastropod Stramonita rustica in southern Bahia, Brazil. For this, 330 specimens were collected during the summer of 2014 at eight sampling points to ascertain whether male sex organs had developed in addition to the complete female genital tract in females (= imposex. The analyses were made under a stereoscopic microscope. Imposex and their associated indexes, and the sterile females, exhibited the highest rates in harbors and shipyards areas. Despite the total ban of TBT in anti-fouling paints on a global scale since 2003, the results of this and other studies indicate the continued use of those paints on the Brazilian coast. This shows the inefficiency of existing legislation and the need to strengthen enforcement of the ban.

  20. Imposex induction in Stramonita haemastoma floridana (Conrad, 1837 (Mollusca: Gastropoda: Muricidae submitted to an organotin-contaminated diet

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    Aline Fernandes Alves de Lima

    2006-03-01

    Full Text Available Marine organisms are affected by organotin compounds due to the cumulative, deleterious effects of these latter. The most evident and well known consequence of organotin contamination is imposex, a hormonal disruption that causes a superimposition of sexual male features in females of prosobranchia neogastropod molluscs such as Stramonita haemastoma floridana. Molluscs accumulate organotins mainly because of their poor ability to eliminate TBT and DBT from their tissues. The aim of this study was to analyze organotin uptake by ingestion experimentally, using uncontaminated subjects (S. haemastoma floridana fed with organotin-contaminated oysters (Crassostrea rhizophorae. A total of 248 gastropods, distributed in 7 tanks with uncontaminated water and contaminated food, were used in this study, a control group being fed uncontaminated oysters. Every 15 days, the individuals of one of the tanks were examined for the presence of imposex. Development of imposex was measured using the VDSI, RPSI and RPLI indexes. The animals had already developed imposex within the first 15 days, all the indexes measured (RPLI, RPSI and VDSI having increased significantly with duration of exposure, indicating that the animals were probablycontaminated by the food and had accumulated the pollutant. New paths of imposex development were also observed.Organismos marinhos são afetados por compostos organoestânicos que causam uma série de efeitos deletérios aos mesmos. O mais conhecido efeito da contaminação por organoestânicos é o imposex. Esse fenômeno consiste na masculinização de fêmeas de moluscos neogastrópodes tais como Stramonita haemastoma floridana. Esses compostos tendem a se acumular em moluscos devido a sua baixa capacidade de eliminá-los. Um total de 248 indivíduos de S. haemastoma floridana foram coletados de uma população livre qualquer indício de imposex. Esses animais foram mantidos em 7 aquários, com aproximadamente 30 indivíduos cada, 1 desses aquários foi considerado como controle e os animas do mesmo alimentados com ostras obtidas de locais onde não se verificou a ocorrência de imposex em neogastrópodes nativos. Os animais nos outros 6 aquários foram alimentados com ostras obtidas em local onde a incidência de imposex entre os gastrópodes nativos revelou-se muito alta. A cada 15 dias, por um período total de 90 dias, os animais de um dos tanques eram retirados e analisados quanto à presença de imposex. Os níveis de imposex foram quantificados através da % de imposex e dos índices: RPLI, RPSI e VDSI. Observou-se a indução de imposex em S. haemastoma floridana através da dieta a partir de Crassostrea rhizophora e um aumento significativo dos índices com o decorrer do tempo de exposição. Os animais do aquário controle foram analisados ao fim do experimento não revelando qualquer indício de imposex.

  1. Diversidade e distribuição do gênero Alvania (Mollusca, Gastropoda: Rissoidae) no litoral brasileiro

    OpenAIRE

    SILVA, Luciana Soares da

    2012-01-01

    Os Rissoidae Gray, 1847 são compostos por conchas pequenas ou micro-conchas, abundantes nos mares de todo mundo. Uma grande diversidade das espécies desse grupo é encontrada nas zonas de maré baixa e ao longo do litoral, onde há a maior ocorrência de algas, rochas, corais e outros locais que fornecem abrigo, todavia muitos ocorrem também em zonas de mar profundo. Em Rissoidae, Alvania é um dos mais diversos quanto ao número de espécies, sendo frequentes as descrições ou re-descrições de...

  2. Standardization of a Patella spp. (Mollusca, Gastropoda) embryo-larval bioassay and advantages of its use in marine ecotoxicology.

    Science.gov (United States)

    Pérez, Sara; Fernández, Nuria; Ribeiro, Pedro A

    2016-05-01

    The use of three limpet species, Patella vulgata Linnaeus, 1758, Patella depressa Pennant, 1777 and Patella ulyssiponensis Gmelin, 1791 as model organisms in marine ecotoxicology has been evaluated. Initial laboratory experiments were aimed to standardize a biological test with embryos and larvae of Patella spp, establishing the percentage of normal trochophore larvae as endpoint. Before conducting in vitro fertilization, oocytes must be maturated artificially by incubation in an alkaline solution; therefore, alkalinizing agent, pH and time of eggs alkalinization were evaluated. Moreover, time of sperm activation, optimum sperm and oocytes concentration during fertilization, gamete contact time, use of stirring during the fertilization, egg concentration and incubation temperature were examined. Minimum sample size per treatment was also estimated. Exposure of oocytes for 10min to FSW alkalinized with NH4OH at pH 9.0, the use of undiluted sperm pre-activated during 45min and a concentration of 200 oocytesmL(-1), a gamete-contact time of 180min and egg incubation at 18°C during 24h at a concentration of 80 eggsmL(-1) were the conditions allowing maximal embryo-larval development success. With an error of 0.05, a sampling size ≥320 allows a 95% confidence in the estimate. This Patella spp. acute bioassay fulfills a number of important a priori requirements to be used in ecotoxicological studies. Nevertheless, in vitro fertilization requires considerable handling, which may lead to failure in fecundation. Such difficulties are also addressed, in order to facilitate the routine use of this protocol by other laboratories. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. A Carboniferous chiton (Mollusca, Polyplacophora) at the end of its trail: a unique find from the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Mikuláš, Radek; Rindsberg, A. K.; Santos, A.; Pavela, M.

    2017-01-01

    Roč. 56, č. 2 (2017), s. 171-179 ISSN 0375-7633 Institutional support: RVO:67985831 Keywords : Viséan * Recent * locomotion traces * tracemakers * Proleptochiton Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Paleontology Impact factor: 0.903, year: 2016

  4. New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae

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    John Taylor

    2013-08-01

    Full Text Available Four new species and a new genus of lucinid bivalves are described from shallow and deeper waters in the Indian and West Pacific Oceans. The new genus Scabrilucina (subfamily Lucininae includes the little-known S. victorialis (Melvill, 1899 from the Arabian Sea and S. vitrea (Deshayes, 1844 from the Andaman Sea as well as a new species S. melvilli from the Torres Strait off northeastern Australia. Ferrocina brunei new species (Lucininae was recovered from 60 m near oil drilling activities off Borneo; its anatomy confirmed the presence of symbiotic bacteria. Two unusual deeper water species of Leucosphaerinae are described, both species included in on-going molecular analyses; Gonimyrtea ferruginea from 400–650 m in the southwest Pacific and Myrtina reflexa from 200–825 m off Zanzibar and Madagascar.

  5. Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca, Gastropoda

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    Nathalie Yonow

    2012-05-01

    Full Text Available Seventy species of opisthobranchs are described in this work based on collections from the Persian Gulf, Socotra, Kenya, Zanzibar, Madagascar, La Réunion, Mauritius, the Seychelles, the Maldives, and Sri Lanka. Ten species are newly recorded from the western Indian Ocean and four species are recorded in the scientific literature for the first time since their original descriptions. Two species are described as new: Cyerce bourbonica sp. n. from La Réand Doriopsilla nigrocera sp. n. from the Persian Gulf coast of Saudi Arabia. Chromodoris cavae is removed from its synonymy with C. tennentana and redescribed from specimens from La Réunion, while several new synonyms are proposed for some commonly occurring species. Risbecia bullockii is recorded for the second time from the Indian Ocean and assigned to its correct genus.

  6. Recrutamento larval e crescimento de teredinidae (mollusca-bivalvia em região entremarés de manguezais

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    Sônia Godoy Bueno Carvalho Lopes

    1997-01-01

    Full Text Available O recrutamento larval e o crescimento de Teredinidae na região entremarés do manguezal da Praia Dura, Ubatuba, SP, foi acompanhado durante doze meses (08/84 a 08/85 utilizando coletores construídos com madeira de mangue. O tempo decorrido para se detectar a presença dos primeiros Teredinidae foi de aproximadamente sete meses após o início do experimento e o número de indivíduos por coletor foi muito reduzido no período de amostragem. Esses resultados contrastam com os obtidos por outros autores que instalaram coletores em ambiente marinho, mas são semelhantes aos obtidos por autores que instalaram coletores em regiões estuarinas do litoral brasileiro. Essas diferenças nos resultados talvez possam ser explicadas pelo fato da salinidade ser mais baixa e mais variável nos estuários que no ambiente marinho. A análise dos dados sobre o recrutamento larval, permite concluir que a espécie mais abundante foi Nausitora fustieula (Jeffreys, 1860, com principal época de instalação em março e taxa inicial de crescimento de 1,86 mm/day. As outras espécies de Teredinidae, Bankiaflmbriatula Moll & Roch, 1931, Bankia roehi Moll, 1931 e Neoteredo reynei (Bartsch, 1920, apresentaram pequeno número de indivíduos e em função disso, não foi possível determinar suas épocas de instalação e respectivas taxas de crescimento.The larval settlement and growth of Teredinidae in the intertidal region of the Praia Dura mangrove, Ubatuba, SP, were undertaken during one year (08/84 to 08/85 using colectors made from mangrove wood. The presence of the first Teredinidae was detected approximately seven month after the inicial experiment and the number of specimens per coletor was small during the sampling period. These results contrast with those obtained by other authors working in a marine environment, but are similar to those obtained in experiments developed in Brazilian estuaries. The differences between data obtained in marine and estuarine environments, might be explained by the lower and more variable salinity gradient in estuaries. Larval settlement data revealed that the most abundant species was Nausitora fustieula (Jeffreys,1860, which settles on wood prefrerably in March, and has an initial growth rate of 1.86 mm/day. The other Teredinidae species Banida fimbriatula Moll & Roch, 1931, Bankia rochi Moll, 1931 and Neoteredo reynei (Bartsch, 1920, occurred in a very small number of specimens and therefore, their time of settlement and growth rates could not be determined.

  7. Growth estimation of mangrove cockle Anadara tuberculosa (Mollusca: Bivalvia: application and evaluation of length-based methods

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    Luis A Flores

    2011-03-01

    Full Text Available Growth is one of the key processes in the dynamic of exploited resources, since it provides part of the information required for structured population models. Growth of mangrove cockle, Anadara tuberculosa was estimated through length-based methods (ELEFAN I y NSLCA and using diverse shell length intervals (SLI. The variability of L∞, k and phi prime (Φ` estimates and the effect of each sample were quantified by jackknife techniques. Results showed the same L∞ estimates from ELEFAN I and NSLCA across each SLI used, and all L∞ were within the expected range. On the contrary, k estimates differed between methods. Jackknife estimations uncovered the tendency of ELEFAN I to overestimate k with increases in SLI, and allowed the identification of differences in uncertainty (PE and CV between both methods. The average values of Φ`derived from NSCLA1.5 and length-age sources were similar and corresponded to ranges reported by other authors. Estimates of L∞, k and Φ` from NSCLA1.5 were 85.97mm, 0.124/year and 2.953 with jackknife and 86.36mm de L∞, 0.110/year de k and 2.914 de Φ` without jackknife, respectively. Based on the observed evidence and according to the biology of the species, NSCLA is suggested to be used with jackknife and a SLI of 1.5mm as an ad hoc approach to estimate the growth parameters of mangrove cockle. Rev. Biol. Trop. 59 (1: 159-170. Epub 2011 March 01.El crecimiento es uno de los procesos clave en la dinámica de los recursos explotados. En este estudio se estimó el crecimiento de la concha prieta Anadara tuberculosa por medio de métodos basados en tallas (ELEFAN I y NSLCA y usando distintos intervalos de clase de talla (ICT. La variabilidad de los estimadores para L∞y k, y el efecto de cada muestra e ICT fueron cuantificados por la técnica de jackknife. ELEFAN I y NSLCA producen una misma estimación de L∞para cada uno de los ICT. Por el contrario, para k ambos métodos estiman diferentes valores. Las estimaciones con jackknife permitieron detectar que ELEFAN I sobreestima k a medida que se aumenta el ICT, y a definir diferencias en el grado de incertidumbre (EP y CV entre ambos métodos. Los valores promedio de Φ` derivados de NSCLA1.5 son similares a los de tallaedad y están dentro del rango reportado por otros autores. Las estimaciones de NSCLA1.5 fueron 85.97mm de L∞, 0.124/año de k y 2.953 de Φ` con jackknife y 86.36mm de L∞, 0.110/año de k y 2.914 de Φ` sin jackknife. Basado en las evidencias mostradas y acorde a la biología de la especie se sugiere utilizar el NSCLA conjuntamente con jackknife y un ICT de 1.5mm para estimar los parámetros de crecimiento de la concha prieta.

  8. Myogenesis in Aplysia californica (Cooper, 1863) (Mollusca, Gastropoda, Opisthobranchia) with special focus on muscular remodeling during metamorphosis

    DEFF Research Database (Denmark)

    Wollesen, Tim; Wanninger, Andreas; Klussmann-Kolb, Annette

    2008-01-01

    To date only few comparative approaches tried to reconstruct the ontogeny of the musculature in invertebrates. This may be due to the difficulties involved in reconstructing three dimensionally arranged muscle systems by means of classical histological techniques combined with light or transmissi...

  9. SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA), INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA) IN BRAZIL

    Science.gov (United States)

    Medeiros, Camilla; Scholte, Ronaldo Guilherme Carvalho; D'ávila, Sthefane; Caldeira, Roberta Lima; Carvalho, Omar dos Santos

    2014-01-01

    Snails of the family Lymnaeidae act as intermediate hosts in the biological cycle of Fasciola hepatica, which is a biological agent of fasciolosis, a parasitic disease of medical importance for humans and animals. The present work aimed to update and map the spatial distribution of the intermediate host snails of F. hepatica in Brazil. Data on the distribution of lymnaeids species were compiled from the Collection of Medical Malacology (Fiocruz-CMM, CPqRR), Collection of Malacology (MZUSP), “SpeciesLink” (CRIA) network and through systematic surveys in the literature. Our maps of the distribution of lymnaeids show that Pseudosuccinea columella is the most common species and it is widespread in the South and Southeast with few records in the Midwest, North and Northeast regions. The distribution of the Galba viatrix, G. cubensis and G. truncatula showed a few records in the South and Southeast regions, they were not reported for the Midwest, North and Northeast. In addition, in the South region there are a few records for G. viatrix and one occurrence of Lymnaea rupestris. Our findings resulted in the first map of the spatial distribution of Lymnaeidae species in Brazil which might be useful to better understand the fasciolosis distribution and delineate priority areas for control interventions. PMID:24879003

  10. New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Belgium and Luxembourg

    Science.gov (United States)

    2014-01-01

    Background The present study aims to assess the epidemiological role of different lymnaeid snails as intermediate hosts of the liver fluke Fasciola hepatica in Belgium and Luxembourg. Methods During summer 2008, 7103 lymnaeid snails were collected from 125 ponds distributed in 5 clusters each including 25 ponds. Each cluster was located in a different biogeographic area of Belgium and Luxembourg. In addition, snails were also collected in sixteen other biotopes considered as temporary wet areas. These snails were identified as Galba truncatula (n = 2474) (the main intermediate host of F. hepatica in Europe) and Radix sp. (n = 4629). Moreover, several biological and non-biological variables were also recorded from the different biotopes. DNA was extracted from each snail collected using Chelex® technique. DNA samples were screened through a multiplex PCR that amplifies lymnaeid internal transcribed spacer 2 gene sequences (500–600 bp) (acting as an internal control) and a 124 bp fragment of repetitive DNA from Fasciola sp. Results Lymnaeid snails were found in 75 biotopes (53.2%). Thirty individuals of G. truncatula (1.31%) and 7 of Radix sp. (0.16%) were found to be positive for Fasciola sp. The seven positive Radix sp. snails all belonged to the species R. balthica (Linnaeus, 1758). Classification and regression tree analysis were performed in order to better understand links and relative importance of the different recorded factors. One of the best explanatory variables for the presence/absence of the different snail species seems to be the geographic location, whereas for the infection status of the snails no obvious relationship was linked to the presence of cattle. Conclusions Epidemiological implications of these findings and particularly the role of R. balthica as an alternative intermediate host in Belgium and Luxembourg were discussed. PMID:24524623

  11. Experimental and molecular study of cercariae of Clinostomum sp. (Trematoda: Clinostomidae) from Biomphalaria spp. (Mollusca: Planorbidae) in Brazil.

    Science.gov (United States)

    Pinto, H A; Caffara, M; Fioravanti, M L; Melo, A L

    2015-02-01

    Despite the large number of reports of species of Clinostomum from vertebrate hosts in South America, studies evaluating the molluscan transmitters of these parasites are scarce. In the present study, clinostomatoid cercariae shed from 0.02% (4/17,485) specimens of Biomphalaria spp., collected at the Pampulha reservoir, Belo Horizonte, Minas Gerais, Brazil, were used for experimental infection of Poecilia reticulata . Samples of cercariae from molluscs and metacercariae experimentally obtained from fish were subjected to morphological and molecular analyses and compared with species of Clinostomum reported in the Americas. The cercariae and metacercariae, here identified as Clinostomum sp., present general morphology similar to that reported for Clinostomum marginatum , however, from molecular point of view, differ significantly from North American C. marginatum and other species of Clinostomum reported in South America. These results suggest that the diversity of Clinostomum found in Brazil may be underestimated. Additional studies aimed at molecular characterization of South American species of Clinostomum, including the finding of specimens with sequences similar to that reported for C. marginatum in North America are required.

  12. Putative midkine family protein up-regulation in Patella caerulea (Mollusca, Gastropoda) exposed to sublethal concentrations of cadmium

    International Nuclear Information System (INIS)

    Vanucci, Silvana; Minerdi, Daniela; Kadomatsu, Kenji; Mengoni, Alessio; Bazzicalupo, Marco

    2005-01-01

    A cDNA sequence of a putative midkine (MK) family protein was identified and characterised in the mollusc Patella caerulea. The midkine family consists of two members, midkine and pleiotrophin (PTN), and it is one of the recently discovered cytokines. Our results show that this putative midkine protein is up-regulated in specimens of P. caerulea exposed to sublethal cadmium concentrations (i.e. 0.5 and 1 mg l -1 Cd) over a 10-day exposure period. Semiquantitative RT-PCR and quantitative Real time RT-PCR estimations indicate elevated expression of midkine mRNA in exposed specimens compared to controls. Moreover, RT-PCR Real time values were higher in the viscera (here defined as the part of the soft tissue including digestive gland plus gills) than in the foot (i.e. foot plus head plus heart) of the limpets. At present, information on the functional signalling significance of the midkine family proteins suggests that the up-regulation of P. caerulea putative midkine family protein is a distress signal likely with informative value on health status of the organism and with potential prognostic capability

  13. Phytochemical and molluscicidal activity of Mikania glomerata Sprengel (Asteraceae in different lifestages of Subulina octona (Mollusca, Subulinidade

    Directory of Open Access Journals (Sweden)

    Bruna Aparecida de Souza

    2014-04-01

    Full Text Available The objective of this work was to study the molluscicidal activity of aqueous extract of Mikania glomerata on the land snail Subulina octona and to assess the changes caused on the snail's fecundity, growth, hatchability and the offspring produced after exposure. Eggs, newly hatched and 30 day old snails were exposed to the sublethal concentration of M. glomerata extract for 24 and 48 h and the observations were made for 120 days. The presence of tannins, flavonoids and saponins were shown by phytochemical tests. The extract reduced significantly the hatchability and the survival of the offspring hatched from the exposed eggs. The eggs exposed for 48 h presented lower hatchability rates. There was a reduction on survival and growth of newly hatched and 30-days old snails exposed to the extract. These results indicated that the aqueous extract of M. glomerata could be applied as an alternative molluscicide for the control of this snail species efficiently.

  14. Reproductive cycle of Anomalocardia brasiliana (Mollusca: Bivalvia: Veneridae) in the estuary of the Cachoeira River, Ilhéus, Bahia.

    Science.gov (United States)

    Luz, J R; Boehs, G

    2011-08-01

    The aim of this study was to characterize the reproductive cycle of Anomalocardia brasiliana, typical of the estuarine region of the Cachoeira River, Ilhéus, Bahia, Brazil. For this purpose, 20 specimens were collected biweekly between August 2005 and August 2006 on an intertidal bank (14º 48' 23" S and 39º 02' 47" W). The animals were measured on the anteroposterior axis (length), examined macroscopically and removed from the shell and fixed in Davidson's solution. Subsequently, the tissues were impregnated in paraffin, cut into 7 mm sections and stained with Harris hematoxylin and eosin (HE). The slides were examined under a light microscope. The water temperature at the site ranged from 24 to 30.5 ºC (mean: 27.4 ºC; SD ± 1.9), salinity from zero to 23 (mean: 13.7; SD ± 7.5) and rainfall from 28.3 mm to 248.8 mm monthly (yearly mean: 130 mm). The sample (n = 478) showed a sex ratio (M: F) of 1: 1.2 (p < 0.05) and no cases of hermaphroditism. There was no sexual dimorphism. Males and females showed reproductive synchrony. The reproductive cycle was continuous, with releases of gametes mainly in spring, summer and autumn. These results are similar to those found in other regions, but there was no reproductive rest period as reported for populations in higher latitudes.

  15. Reproductive cycle of Tagelus plebeius (Mollusca: Bivalvia in the estuary of the Cachoeira River, Ilhéus, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    LO. Ceuta

    Full Text Available This study characterized the reproductive cycle of the stout razor clam Tagelus plebeius in the estuary of the Cachoeira River, Ilhéus, Bahia, northeastern Brazil. Samples of 20 animals per collection were taken biweekly from August 2005 to August 2006. The 480 specimens were measured on the antero-posterior axis (length and then removed from the shell. After macroscopic analysis, the gonads were fixed in Davidson's solution, processed by routine histology and stained by Harris hematoxylin and eosin. The gonads of both males and females appeared milky white, without sexual dimorphism. Microscopic analyses indicated a M: F ratio of 1.06: 1 and continuous reproduction of T. plebeius in the region. The period from August to October showed the most intense spawning. This study provides another example of continuous reproduction of bivalves in tropical waters, and because this species is a heavily exploited fishery resource in the region, it draws attention to the need for a management plan aimed at reducing harvests.

  16. Reproductive cycle of Tagelus plebeius (Mollusca: Bivalvia) in the estuary of the Cachoeira River, Ilhéus, Bahia, Brazil.

    Science.gov (United States)

    Ceuta, L O; Boehs, G

    2012-08-01

    This study characterized the reproductive cycle of the stout razor clam Tagelus plebeius in the estuary of the Cachoeira River, Ilhéus, Bahia, northeastern Brazil. Samples of 20 animals per collection were taken biweekly from August 2005 to August 2006. The 480 specimens were measured on the antero-posterior axis (length) and then removed from the shell. After macroscopic analysis, the gonads were fixed in Davidson's solution, processed by routine histology and stained by Harris hematoxylin and eosin. The gonads of both males and females appeared milky white, without sexual dimorphism. Microscopic analyses indicated a M: F ratio of 1.06: 1 and continuous reproduction of T. plebeius in the region. The period from August to October showed the most intense spawning. This study provides another example of continuous reproduction of bivalves in tropical waters, and because this species is a heavily exploited fishery resource in the region, it draws attention to the need for a management plan aimed at reducing harvests.

  17. A new species of the zephyrinid nudibranch genus Janolus (Mollusca: Nudibranchia from North America and Costa Rica

    Directory of Open Access Journals (Sweden)

    Yolanda E Camacho-García

    2006-12-01

    Full Text Available A new species of zephyrinid nudibranch of the genus Janolus Bergh 1884 is described from the Pacific Coast of North America and Costa Rica. J. anulatus sp. nov. differs from other species of Janolus by its external and internal morphology. J. anulatus has a brown or white body with pink, white, and brown spots, smooth papillae epithelium at the base and papillated in the distal part, unbranched digestive gland ducts, smooth jaws, and smooth rachidian and lateral teeth. The species is compared with other species from the Panamic Province and the Western Atlantic. A new extension range of J. barbarensis is documented. Rev. Biol. Trop. 54(4: 1295-1305. Epub 2006 Dec. 15Una nueva especie de nudibranquio zefirínido del género Janolus Bergh 1884 es descrita de la costa pacífica de Norte América y Costa Rica. J. anulatus sp. nov. difiere de otras especies de Janolus por su morfología externa e interna. J. anulatus tiene un cuerpo café o blanco con manchas rosadas, blancas o cafés, papila del epitelio lisa en la base y con papilas en la parte distal, ductos de la glándula digestiva no ramificados, mandíbulas lisas y dientes laterales y raquidios lisos. La especie es comparada con otras especies de la Provincia Panámica y el Atlántico Oeste. Una nueva extensión de ámbito de J. barbarensis es documentada

  18. A new species of the zephyrinid nudibranch genus Janolus (Mollusca: Nudibranchia) from North America and Costa Rica

    OpenAIRE

    Yolanda E Camacho-García; Terrence M. Gosliner

    2006-01-01

    A new species of zephyrinid nudibranch of the genus Janolus Bergh 1884 is described from the Pacific Coast of North America and Costa Rica. J. anulatus sp. nov. differs from other species of Janolus by its external and internal morphology. J. anulatus has a brown or white body with pink, white, and brown spots, smooth papillae epithelium at the base and papillated in the distal part, unbranched digestive gland ducts, smooth jaws, and smooth rachidian and lateral teeth. The species is compared...

  19. Growth estimation of mangrove cockle Anadara tuberculosa (Mollusca: Bivalvia: application and evaluation of length-based methods

    Directory of Open Access Journals (Sweden)

    Luis A Flores

    2011-03-01

    Full Text Available Growth is one of the key processes in the dynamic of exploited resources, since it provides part of the information required for structured population models. Growth of mangrove cockle, Anadara tuberculosa was estimated through length-based methods (ELEFAN I y NSLCA and using diverse shell length intervals (SLI. The variability of L∞, k and phi prime (Φ` estimates and the effect of each sample were quantified by jackknife techniques. Results showed the same L∞ estimates from ELEFAN I and NSLCA across each SLI used, and all L∞ were within the expected range. On the contrary, k estimates differed between methods. Jackknife estimations uncovered the tendency of ELEFAN I to overestimate k with increases in SLI, and allowed the identification of differences in uncertainty (PE and CV between both methods. The average values of Φ`derived from NSCLA1.5 and length-age sources were similar and corresponded to ranges reported by other authors. Estimates of L∞, k and Φ` from NSCLA1.5 were 85.97mm, 0.124/year and 2.953 with jackknife and 86.36mm de L∞, 0.110/year de k and 2.914 de Φ` without jackknife, respectively. Based on the observed evidence and according to the biology of the species, NSCLA is suggested to be used with jackknife and a SLI of 1.5mm as an ad hoc approach to estimate the growth parameters of mangrove cockle. Rev. Biol. Trop. 59 (1: 159-170. Epub 2011 March 01.

  20. Un gigante olvidado. Un llamado a la conservación del caracol nativo, Megalobulimus oblongus (Mollusca, Strophocheilidae), en Colombia.

    OpenAIRE

    Páez, Adriana Paola; Calderon, Andrea Carolina; Pineda, Ivan Andres; Velásquez Trujillo, Luz Helena; Ruiz Sáenz, Julian

    2014-01-01

    El caracol nativo Megalobulimus oblongus, también conocido como guácara, caracol criollo o caracol de boca rosada es una especie de caracol terrestre suramericana, que se encuentra en Colombia, Bolivia, Brasil y Venezuela; alcanza cerca de 100mm de alto y 60 mm de ancho, con una apertura de borde grueso y rosado, posee 4 tentáculos en la cabeza y dos grandes barbelos alrededor de la región oral, es de hábitos nocturnos, detritívora y puede vivir hasta 14 años. Desde el punto de vista alimenta...

  1. Inhibition of dye-coupling in Patella (mollusca) embryos by microinjection of antiserum against Nephrops (arthropoda) gap junctions

    NARCIS (Netherlands)

    Serras, F.; Buultjens, T.E.J.; Finbow, M.E.

    1988-01-01

    Antiserum raised against Nephrops gap junctions was injected into single cells of the 2-, 4-, 8-, 16-, and 32-cell stage of the Patella vulgata embryos. The pattern of junctional communication by iontophoresis of Lucifer Yellow CH was tested at the 32-cell stage. The results show that the normal

  2. Histological study of the gonadal development of Ruditapes decussates (L. (Mollusca: Bivalvia and its relationship with available food

    Directory of Open Access Journals (Sweden)

    Marina Delgado

    2005-03-01

    Full Text Available This article describes the effects of food availability on the sexual maturation of Ruditapes decussates through histological examination of the gonadal tissue. Three food rations were tested: High (H: 1 mg. organic matter. g live weight–1.day-1 of the microalgae Isochrysis galbana clone T-ISO, intermediate (I: 0.5 mg OM g live weight-1 day-1 and nutritionally restricted (R: 0.25 mg OM g live weight-1 day-1. The tests were carried out at a constant temperature of 18°C for a period of 70 days for diets H and I, and 120 days for diet R. The results showed that in R. decussatus the energy from ingestion was mainly channelled to reproductive processes, especially when food was restricted. The clams matured sexually under all the conditions tested, both with a somatic growth and with a loss of body mass. The available food was directly related to the rate of the gonadal development and with the total quantity of gonad generated. Equally, food restrictions limited gonadal recovery after spawning episodes. Food quantity also affected the dry weight of soft tissues (DW, which increased with the highest ration (H and decreased notably with the lowest ration (R. Decreases in DW when food was scarce appeared to be more related to loss of reserve tissue rather than to variations in the quantity of reproductive tissue.

  3. Symbiotic relationship between the carapid fish Onuxodon fowleri (Ophidiiformes: Carapidae and the pearl oyster Pinctada margaritifera (Mollusca: Bivalvia: Pteriidae

    Directory of Open Access Journals (Sweden)

    Orphal Colleye

    2018-03-01

    Full Text Available At Makemo Atoll (French Polynesia, the carapid fish Onuxodon fowleri lives in symbiosis with the black-lip pearl oyster Pinctada margaritifera. Although the symbiont seems to live inside its host bivalve by using it as a shelter, additional data are still needed to better understand the exact nature of this association. For this purpose, we implemented an approach using stable isotope ratios of carbon (13C/12C and nitrogen (15N/14N. The δ13C and δ15N values were measured in tissues of the pearl oyster (gonads, gills, mantle and muscles, white muscle tissue from the fish and other food sources. This stable isotope approach was also complemented by the analysis of stomach contents in the carapid fish. Overall, the isotopic compositions measured in the present study support a commensal relationship between O. fowleri and P. margaritifera. In addition, our isotopic data bring new information about another guest living inside P. margaritifera, namely the palaemonid shrimp Conchodytes meleagrinae. Based on the δ13C and δ15N values, it appears that the shrimp might feed on the bivalve gonads.

  4. THE BEHAVIOR OF LOLIGO OPALESCENS (MOLLUSCA: CEPHALOPODA) AS OBSERVED BY A REMOTELY OPERATED VEHICLE (ROV). (R825381)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  5. Genetics and shell morphometrics of assimineids (Mollusca, Caenogastropoda, Truncatelloidea in the St Lucia Estuary, South Africa

    Directory of Open Access Journals (Sweden)

    Nelson Miranda

    2014-06-01

    Full Text Available The Assimineidae are a family of amphibious microgastropods that can be mostly found in estuaries and mangroves in South Africa. These snails often occur in great numbers and are ecologically important to the St Lucia Estuary, which forms a crucial part of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Genetic and shell morphometric analyses were conducted on individuals collected from nine localities distributed from the northern lake regions to the southern lake and the mouth of the St Lucia estuarine lake. Mitochondrial (COI and nuclear (28S DNA was used to construct Bayesian Inference, Neighbour-joining, Maximum Parsimony and Maximum Likelihood trees. Principal Component Analysis and Cluster Analysis were performed on standard shell parameter data. Results indicate that two different taxa are present in St Lucia. The taxon comprising individuals from the South Lake and St Lucia Estuary Mouth is identified as Assiminea cf. capensis Bartsch, in accordance with the latest taxonomic consensus. The taxon comprising assimineid individuals from False Bay, North Lake and South Lake, is here tentatively named “A.” aff. capensis (Sowerby. These two taxa exhibit patterns of spatial overlap that appear to vary depending on environmental parameters, particularly salinity. The need to resolve the complex taxonomy of assimineids is highlighted.

  6. Detection of Bioactive Compounds in the Mucus Nets of Dendropoma maxima, Sowerby 1825 (Prosobranch Gastropod Vermetidae, Mollusca

    Directory of Open Access Journals (Sweden)

    Anne Klöppel

    2013-01-01

    Full Text Available The sessile suspension-feeding wormsnail Dendropoma maxima, Sowerby 1825 (Vermetidae secretes a mucus net to capture planktonic prey. The nets are spread out over the corals and often have remarkable deleterious effects on them like changes in growth form and pigmentation shifts not uncommonly resulting in tissue necrosis. Until now, there is no explanation for this phenomenon although the indication as well as theories about its genesis is mentioned in several publications. Vermetids are well studied concerning the intraspecific competition with neighboring individuals but not in their interaction with other taxa like corals or fish. We did extensive in situ video recording and observed that fish avoided the plankton-load nets although several specialized taxa are known to be molluscivores, mucivores, and/or feed on plankton. As many molluscs use chemical weapons to combat feeding pressure and to defend themselves against predators, we screened empty and plankton-load mucus nets for potential bioactive metabolites. Bioactivity testing was performed with a recently developed system based on a chromatographic separation (high-performance thin-layer chromatography (HPTLC and a bioassay with luminescent bacteria Vibrio fischeri. Thus, we found at least two active compounds exclusively accumulated by the wormsnails themselves. This is the first record of bioactive properties in the whole family of Vermetidae.

  7. The Influence of Biotic Stresses on the Heart Rate of Duck Mussels (Mollusca, Bivalvia, Unionidae, Anоdontinae

    Directory of Open Access Journals (Sweden)

    E.D. Shimkovich

    2016-06-01

    Full Text Available The paper deals with the influence of “gill pregnancy”, the presence of epioiks (larvae of the European bitterling Rhodeus sericeus amarus (Bloch, 1782 and endoparasites (sporocysts and cercariae of the trematode Rhipidocotyle companula Dujardin, 1845, on the heart rate of the duck mussel Anodonta anatina (Linnaeus, 1758. The results of investigations show that biotic stresses, depending on the level of their expressiveness, put a pressure on the organism of A. anatina, thereby influencing its status, especially in what concerns the heart rate. Intensive “gill pregnancy”, high infestation level of the gills by epioiks, and total colonization of the gonads by parasites result in the development of bradycardia. The moderate influence of these factors on the mollusks is accompanied by tachycardia, which is a defense response aimed to support the viability of these animals at the optimal level.

  8. Limitations of cytochrome oxidase I for the barcoding of Neritidae (Mollusca: Gastropoda) as revealed by Bayesian analysis.

    Science.gov (United States)

    Chee, S Y

    2015-05-25

    The mitochondrial DNA (mtDNA) cytochrome oxidase I (COI) gene has been universally and successfully utilized as a barcoding gene, mainly because it can be amplified easily, applied across a wide range of taxa, and results can be obtained cheaply and quickly. However, in rare cases, the gene can fail to distinguish between species, particularly when exposed to highly sensitive methods of data analysis, such as the Bayesian method, or when taxa have undergone introgressive hybridization, over-splitting, or incomplete lineage sorting. Such cases require the use of alternative markers, and nuclear DNA markers are commonly used. In this study, a dendrogram produced by Bayesian analysis of an mtDNA COI dataset was compared with that of a nuclear DNA ATPS-α dataset, in order to evaluate the efficiency of COI in barcoding Malaysian nerites (Neritidae). In the COI dendrogram, most of the species were in individual clusters, except for two species: Nerita chamaeleon and N. histrio. These two species were placed in the same subcluster, whereas in the ATPS-α dendrogram they were in their own subclusters. Analysis of the ATPS-α gene also placed the two genera of nerites (Nerita and Neritina) in separate clusters, whereas COI gene analysis placed both genera in the same cluster. Therefore, in the case of the Neritidae, the ATPS-α gene is a better barcoding gene than the COI gene.

  9. Biochemical Change at the Setting-up of the Crossed-Lamellar Layer in Nerita undata Shell (Mollusca, Gastropoda

    Directory of Open Access Journals (Sweden)

    Julius Nouet

    2012-03-01

    Full Text Available Nerita undata is a marine gastropod, the shell of which consists of an external layer composed of very fine, long and undulating calcite prisms, and of an internal aragonite crossed-lamellar layer. As for any Ca-carbonate shell, both layers are composite materials, resulting from the  sub-micrometric association of organic macromolecules with the mineral phase. But at the transition between the two layers, in situ synchrotron-based mapping using μ-XANES spectroscopy performed at the S K-edge and SR-FTIR spectroscopy reveals that biochemical compositions change correlatively with the mineral phase, such as displayed by the distribution of sulfur-containing organic compounds (S-polysaccharides or S-amino acids and organic molecular groups (amide I and II bands. These results highlight the complex change of secretory activity operated by the mineralizing tissue (the mollusk mantle between these two parts of the shell, which is suspected to minutely control the setting-up of the crossed-lamellar microstructural pattern over the calcite prisms—A not so straightforward feature.

  10. Ecotoxicological studies with newly hatched larvae of Concholepas concholepas (Mollusca, Gastropoda): bioassay with secondary-treated kraft pulp mill effluents.

    Science.gov (United States)

    Manríquez, Patricio H; Llanos-Rivera, Alejandra; Galaz, Sylvana; Camaño, Andrés

    2013-12-01

    The Chilean abalone or "loco" (Concholepas concholepas, Bruguière 1789) represent the most economically important marine recourse exploited from inner inshore Management and Exploitation Areas for Benthic Resources along the Chilean coast. In this study, newly-hatched larvae of C. concholepas were investigated as a potential model species for marine ecotoxicological studies. The study developed a behavioral standard protocol for assessing the impact that kraft pulp mill effluents after secondary treatment have on C. concholepas larvae. Under controlled laboratory conditions, newly-hatched larvae were exposed to a series of different concentrations of kraft pulp mill effluents with secondary treatment (Pinus spp. and Eucalyptus spp.), potassium dichromate as standard reference toxicant and effluent-free control conditions. Regardless of the type of effluent the results indicated that diluted kraft pulp effluent with secondary treatment had reduced effect on larval survival. Low larval survivals were only recorded when they were exposed to high concentrations of the reference toxicant. This suggests that C. concholepas larval bioassay is a simple method for monitoring the effects of kraft pulp mill effluents with secondary treatment discharged into the sea. The results indicated that dilution of ca. 1% of the effluent with an elemental chlorine free (ECF) secondary treatment is appropriate for achieving low larval mortalities, such as those obtained under control conditions with filtered seawater, and to minimize their impact on early ontogenetic stages of marine invertebrates such as newly-hatched larvae of C. concholepas. The methodological aspects of toxicological testing and behavioral responses described here with newly-hatched larvae of C. concholepas can be used to evaluate in the future the potential effects of other stressful conditions as other pollutants or changes in seawater pH associated with ocean acidification. © 2013 Elsevier Inc. All rights reserved.

  11. A high molecular weight proteoglycan is differentially expressed during development of the mollusc Concholepas concholepas (Mollusca; Gastropoda; Muricidae).

    Science.gov (United States)

    Brandan, E; González, M; Inestrosa, N C; Tremblay, C; Urrea, R

    1992-12-15

    Incorporation of radioactive sulfate to hatched veliger larvae of the gastropod muricid Concholepas concholepas indicated that over 87% of the sulfated macromolecules were found in the detergent insoluble fraction, rich in extracellular matrix (ECM) components. The sulfated material was solubilized with guanidine salt followed by urea dialysis and fractionated by DEAE-Sephacel chromatography. Three sulfated compounds eluting at 0.7, 1.1, and 3.0 M NaCl, called peaks I, II, and III, respectively, were obtained. The sulfated compound present in peak I was degraded by pronase or sodium alkaline treatment to a small sulfated resistant material, suggesting the presence of a proteoglycan (PG). Filtration analysis on Sephacryl S-500 and SDS-PAGE of the intact PG indicates that it has a high molecular weight (360,000 to over 1 x 10(6)). Monoclonal antibodies (mAb) against this PG were produced. The specificity of one mAb, the 6H2, was demonstrated by size chromatography and ELISA analysis. The epitope recognized by this mAb seems to be present in the core protein of the PG. Both the extent of sulfation and the presence of different sulfated species of PGs were evaluated during the development of this mollusc. A twelvefold increase in the incorporation of sulfate to PGs per milligram of protein was found in veliger larvae compared to blastula-glastula stages. This change correlated well with the differential expression of the sulfated PG present in peak I. Biochemical and immunological analysis indicate that high levels of this PG are found in veliger and trocophore larvae in comparison with blastula-gastrula and early juveniles.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Genetic differentiation of Octopus minor (Mollusca, Cephalopoda) off the northern coast of China as revealed by amplified fragment length polymorphisms.

    Science.gov (United States)

    Yang, J M; Sun, G H; Zheng, X D; Ren, L H; Wang, W J; Li, G R; Sun, B C

    2015-12-02

    Octopus minor (Sasaki, 1920) is an economically important cephalopod that is found in the northern coastal waters of China. In this study, we investigated genetic differentiation in fishery populations using amplified fragment length polymorphisms (AFLPs). A total of 150 individuals were collected from five locations: Dalian (DL), Yan-tai (YT), Qingdao (QD), Lianyungang (LY), and Zhoushan (ZS), and 243 reproducible bands were amplified using five AFLP primer combinations. The percentage of polymorphic bands ranged from 53.33 to 76.08%. Nei's genetic identity ranged from 0.9139 to 0.9713, and the genetic distance ranged from 0.0291 to 0.0900. A phylogenetic tree was constructed using the unweighted pair group method with arithmetic mean, based on the genetic distance. The DL and YT populations originated from one clade, while the QD, LY, and ZS populations originated from another. The results indicate that the O. minor stock consisted of two genetic populations with an overall significantly analogous FST value (0.1088, P octopus fisheries, so that this marine resource can be conserved for its long-term utilization.

  13. Seasonal variation in the abundance and distribution of Anomalocardia flexuosa (Mollusca, Bivalvia, Veneridae in an estuarine intertidal plain

    Directory of Open Access Journals (Sweden)

    Jacqueline S. Silva-Cavalcanti

    2018-02-01

    Full Text Available Spatial and temporal density and biomass of the infaunal mollusk Anomalocardia flexuosa (Linnaeus, 1767 evaluated a tidal plain at Goiana estuary (Northeast Brazil. Three hundred and sixty core samples were taken during an annual cycle from three intertidal habitats (A, B and C. Shell ranged from 2.20 to 28.48 mm (15.08 ± 4.08 mm. Recruitment occurred more intensely from January to March. Total (0–1,129 g m−2 differed seasons (rainy and dry, with highest values in the early rainy season (221.0 ± 231.44 g m−2; and lowest values in the late dry season (57.34 ± 97 g m−2. The lowest occurred during the late rainy (319 ± 259 ind m−2 and early dry (496 ± 607 ind m−2 seasons. Extreme environmental situations (e.g., river flow, salinity and water temperature at the end of each season also affected density ranges (late dry: 0–5,798 ind m−2; late rainy: 0–1,170 ind m−2. A. flexuosa in the Goiana estuary presented a dominance of juvenile individuals (shell length < 20 mm, with high biomass main the recruitment period. Average shell length, density and biomass values suggest overfishing of the stock unit. A. flexuosa is an important food and income resource along its whole distribution range. The species was previously also known as Anomalocardia brasiliana (Gmelin, 1791.

  14. Anisospira velascorum, a new land snail from Mexico, with notes on the anatomy and histology (Mollusca, Gastropoda, Urocoptidae)

    NARCIS (Netherlands)

    Breure, A.S.H.

    1977-01-01

    During a collecting trip through southern and central Mexico (Breure, 1974) special attention has been paid to Bulimulidae and Urocoptidae. Among the material of urocoptids a new species has been found. Anisospira velascorum sp. n. (figs. 1-10, pl. 1) Description. — Shell up to 30.5 mm, 2.39 times

  15. Aspects of the biology of Mya arenaria and Ensis spp. (Mollusca; Bivalvia) in the Irish Sea and adjacent areas

    OpenAIRE

    Cross, Maud E.

    2014-01-01

    This study was undertaken to investigate the general biology, including the reproductive cycle and health status, of two clam taxa in Irish waters, with particular reference to the Irish Sea area. Monthly samples of the soft shell clam, Mya arenaria, were collected from Bannow Bay, Co. Wexford, Ireland, for sixteen months, and of the razor clam, Ensis spp. from the Skerries region (Irish Sea) between June 2010 and September 2011. In 2010, M. arenaria in Bannow Bay matured over the summer mont...

  16. SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA, INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA IN BRAZIL

    Directory of Open Access Journals (Sweden)

    Camilla Medeiros

    2014-06-01

    Full Text Available Snails of the family Lymnaeidae act as intermediate hosts in the biological cycle of Fasciola hepatica, which is a biological agent of fasciolosis, a parasitic disease of medical importance for humans and animals. The present work aimed to update and map the spatial distribution of the intermediate host snails of F. hepatica in Brazil. Data on the distribution of lymnaeids species were compiled from the Collection of Medical Malacology (Fiocruz-CMM, CPqRR, Collection of Malacology (MZUSP, “SpeciesLink” (CRIA network and through systematic surveys in the literature. Our maps of the distribution of lymnaeids show that Pseudosuccinea columella is the most common species and it is widespread in the South and Southeast with few records in the Midwest, North and Northeast regions. The distribution of the Galba viatrix, G. cubensis and G. truncatula showed a few records in the South and Southeast regions, they were not reported for the Midwest, North and Northeast. In addition, in the South region there are a few records for G. viatrix and one occurrence of Lymnaea rupestris. Our findings resulted in the first map of the spatial distribution of Lymnaeidae species in Brazil which might be useful to better understand the fasciolosis distribution and delineate priority areas for control interventions.

  17. Effect of zinc and benzene on respiration and excretion of mussel larvae (Perna perna (Linnaeus, 1758 (Mollusca; Bivalvia

    Directory of Open Access Journals (Sweden)

    RADLVC. Jorge

    Full Text Available The presence of pollutants in the ocean may affect different physiological parameters of animals. Oxygen consumption and ammonia excretion were evaluated in D-shaped larvae of mussels (Perna perna exposed to zinc sulphate (ZnSO4 and benzene (C6H6. When compared to the control group, both pollutants presented a significant reduction in oxygen consumption. A reduction in the ammonia excretion was also observed, both for ZnSO4 and C6H6 and also in the oxygen consumption. The results indicate that anaerobic metabolism may occur at the beginning of P. perna mussels development, as observed in veliger larvae. The O:N ratio under experimental conditions showed low values indicating that catabolism in veliger larvae was predominantly proteic.

  18. Metal concentrations in Unio pictorum mancus (Mollusca, Lamellibranchia from of 12 Northern Italian lakes in relation to their trophic level

    Directory of Open Access Journals (Sweden)

    Paolo LODIGIANI

    2003-08-01

    Full Text Available This research aims to test the reliability of environmental monitoring by bioaccumulators of pollutants; that is to establish a positive relationship between the pollutant concentrations in the bioaccumulator and those in the water in which it lives. To this end we analysed the contents of Al, Cu, Zn, Fe, Mn and Ca in the soft tissues and shell of Unio pictorum mancus. The filtered water samples from the mussel habitat were analysed for the same metals. The mussels were collected from 15 stations settled in 12 Northern Italian lakes during the first two weeks of July 2001. These results were obtained: a metal concentrations varied widely with mussel size and among stations; b a significant positive correlation between the concentration of calcium in the water and in the mussel tissues, but no relationship emerged for the other metals; c no relationship between the metal concentrations in the tissues and those in the shell was found; d there was a certain tendency for Mn, Fe and Zn concentrations in the soft tissues to increase with shell size; e the sequence of the decreasing metal concentrations arranged for the tissues was similar to that of the shell, but rather different from that in the water; and f the concentration factor values of the trace metals were high for the shell and soft tissues. In highly productive lakes large size mussels dominated, whereas small mussels were more abundant in low productive lakes. Although the metal concentrations in the water of productive lakes were greater than in low productive ones, the metal concentrations in the tissues of the mussels from the latter were generally higher than those in the mussels from the former. We propose some hypotheses to explain this paradox. Finally, our results show that the metal concentrations in the mussels do not reflect the metal concentrations in the water in which they live. It follows that this commonly used but oversimplified monitoring system cannot be recommended. On the other hand mussels may be very useful for other purposes, such as identifying new pollutants or pollutants present in such low concentrations that they cannot be measured with the commonly used methods. The pollutant content of mussels may enable the variations in time of the pollutant level of an environment to be monitored. In addition, the transplantation of mussels from a clean site to a polluted one may be a useful tool for identify the pollutants of the receiving environment.

  19. Isolation and Characterization of the First Microsatellite Markers for the Endangered Relict Mussel Hypanis colorata (Mollusca: Bivalvia: Cardiidae

    Directory of Open Access Journals (Sweden)

    Luis Ovidiu Popa

    2011-01-01

    Full Text Available Hypanis colorata (Eichwald, 1829 (Cardiidae: Lymnocardiinae is a bivalve relict species with a Ponto-Caspian distribution and is under strict protection in Romania, according to national regulations. While the species is depressed in the western Black Sea lagoons from Romania and Ukraine, it is also a successful invader in the middle Dniepr and Volga regions. Establishing a conservation strategy for this species or studying its invasion process requires knowledge about the genetic structure of the species populations. We have isolated and characterized nine polymorphic microsatellite markers in H. colorata. The number of alleles per locus ranged from 4 to 28 and the observed heterozygosity ranged from 0.613 to 1.000. The microsatellites developed in the present study are highly polymorphic and they should be useful for the assessment of genetic variation within this species.

  20. Abyssal Solenogastres (Mollusca, Aplacophora from the Northwest Pacific: Scratching the Surface of Deep-Sea Diversity Using Integrative Taxonomy

    Directory of Open Access Journals (Sweden)

    Franziska S. Bergmeier

    2017-12-01

    Full Text Available Solenogastres (Aplacophora is a small clade of marine, shell-less worm-molluscs with close to 300 valid species. Their distribution ranges across all oceans, and whereas the vast majority of species has been collected and described from the continental shelf and slope, only few species are known from depths below 4,000 m. Following traditional taxonomy, identification of specimens to species level is complex and time-consuming and requires detailed investigations of morphology and anatomy—often resulting in the exclusion of the clade in biodiversity or biogeographic studies. During the KuramBio expedition (Kuril-Kamchatka Biodiversity Studies to the abyssal plain of the Northwest Pacific and the Kuril-Kamchatka Trench, 33 solenogaster specimens were sampled from 4,830 m to 5,397 m. Within this study we present an efficient workflow to address solenogaster diversity, even when confronted with a high degree of singletons and minute body sizes, hampering the use of single individuals for multiple morphological and molecular approaches. We combine analyses of external characters and scleritome with molecular barcoding based on a self-designed solenogaster specific set of mitochondrial primers. Overall we were able to delineate at least 19 solenogaster lineages and identify 15 species to family level and beyond. Based on our approach we identified three key lineages from the two regionally most species-rich families (Acanthomeniidae and Pruvotinidae for deeper taxonomic investigations and describe the novel abyssal species Amboherpia abyssokurilensis sp. nov. (Cavibelonia, Acanthomeniidae using microanatomical 3D-reconstructions. Our study more than doubles the previous records of solenogaster species from the Northwest Pacific and its marginal seas. Almost all lineages are reported for the first time from the region of the (Northwest Pacific, vastly expanding distribution ranges of the respective clades. Moreover it doubles the number of Solenogastres collected from abyssal depths on a global scale and underlines the lack of exploratory α-diversity work in the abyssal zone for reliable species estimates in marine biodiversity.

  1. Phylogeography of the Rock Shell Thais clavigera (Mollusca): Evidence for Long-Distance Dispersal in the Northwestern Pacific

    Science.gov (United States)

    Jung, Daewui; Li, Qi; Kong, Ling-Feng; Ni, Gang; Nakano, Tomoyuki; Matsukuma, Akihiko; Kim, Sanghee; Park, Chungoo; Lee, Hyuk Je; Park, Joong-Ki

    2015-01-01

    The present-day genetic structure of a species reflects both historical demography and patterns of contemporary gene flow among populations. To precisely understand how these factors shape current population structure of the northwestern (NW) Pacific marine gastropod, Thais clavigera, we determined the partial nucleotide sequences of the mitochondrial COI gene for 602 individuals sampled from 29 localities spanning almost the whole distribution of T. clavigera in the NW Pacific Ocean (~3,700 km). Results from population genetic and demographic analyses (AMOVA, ΦST-statistics, haplotype networks, Tajima’s D, Fu’s FS, mismatch distribution, and Bayesian skyline plots) revealed a lack of genealogical branches or geographical clusters, and a high level of genetic (haplotype) diversity within each of studied population. Nevertheless, low but significant genetic structuring was detected among some geographical populations separated by the Changjiang River, suggesting the presence of geographical barriers to larval dispersal around this region. Several lines of evidence including significant negative Tajima’s D and Fu’s FS statistics values, the unimodally shaped mismatch distribution, and Bayesian skyline plots suggest a population expansion at marine isotope stage 11 (MIS 11; 400 ka), the longest and warmest interglacial interval during the Pleistocene epoch. The lack of genetic structure among the great majority of the NW Pacific T. clavigera populations may be attributable to high gene flow by current-driven long-distance dispersal of prolonged planktonic larval phase of this species. PMID:26171966

  2. The effect of stocking density on the growth of apple snails native Pomacea bridgesii and exotic Pomacea lineata (Mollusca, Gastropoda).

    Science.gov (United States)

    Souza Júnior, Esmar; De Barros, José Carlos N; Paresque, Karla; De Freitas, Rodrigo R

    2013-01-01

    The demand for alternative food sources is currently in evidence in the world and, therefore, the culture of animal species considered not conventional makes this theme relevant and appropriate. In the present study, the species Pomacea lineata and Pomacea bridgesii, each with three stowage densities (0.5 [T1], 1 [T2], and 1.5 [T3] animal/L), were tested. They were analyzed regarding growth rate, weight gain, final biomass, feed conversion and percentage of survival. There was not any statistically significant difference between the different densities for both species. The final average weight in the three waterworks did not differ significantly in P. bridgesii. In P. lineata, T1 (22.3 ± 1.80g) was significantly higher than T2 and T3. On the other hand, the absolute gain of weight in P. lineata and P. bridgesii was significantly higher in T1 (21.9 ± 1.80g and 37.2 ± 6.34g) than in T2 and T3 respectively. In contrast, the gain of biomass of P. lineata and P. bridgesii was significantly higher in T3 (276.3 ± 33.16g and 431.4 ± 37.20g) than in T1 and T2, respectively. Based on the results obtained, all species studied presented potential for aquaculture, mainly P. bridgesii, distinguished for showing a better development even in waterworks with higher densities.

  3. Histologia da glândula de albúmen de Pomacea canaliculata (Lamarck, 1822 (Mollusca, Gastropoda, Pilidae

    Directory of Open Access Journals (Sweden)

    Eliane de Fátima Marques de Mesquita

    1990-01-01

    Full Text Available In this paper the authors give a histological analysis of the albumen gland of mature and immature females of Pomacea canaliculata (Lamarck, 1822. In the immaturity, tthe gland doesn't show any secretory activity, although in the maturity this activity is indicated by the presence of a homogeneous and eosinophilic material in its lumen. We could notice in the capsule gland of matures females a calcareous element is present as a granular and basophilic deposit. The albumen gland is envolved by a thin conjunctive layer that can be seen in van Gieson's coloured preparations.

  4. On growth and form of irregular coiled-shell of a terrestrial snail: Plectostoma concinnum (Fulton, 1901 (Mollusca: Caenogastropoda: Diplommatinidae

    Directory of Open Access Journals (Sweden)

    Thor-Seng Liew

    2014-05-01

    Full Text Available The molluscan shell can be viewed as a petrified representation of the organism’s ontogeny and thus can be used as a record of changes in form during growth. However, little empirical data is available on the actual growth and form of shells, as these are hard to quantify and examine simultaneously. To address these issues, we studied the growth and form of a land snail that has an irregularly coiled and heavily ornamented shell–Plectostoma concinnum. The growth data were collected in a natural growth experiment and the actual form changes of the aperture during shell ontogeny were quantified. We used an ontogeny axis that allows data of growth and form to be analysed simultaneously. Then, we examined the association between the growth and the form during three different whorl growing phases, namely, the regular coiled spire phase, the transitional constriction phase, and the distortedly-coiled tuba phase. In addition, we also explored the association between growth rate and the switching between whorl growing mode and rib growing mode. As a result, we show how the changes in the aperture ontogeny profiles in terms of aperture shape, size and growth trajectory, and the changes in growth rates, are associated with the different shell forms at different parts of the shell ontogeny. These associations suggest plausible constraints that underlie the three different shell ontogeny phases and the two different growth modes. We found that the mechanism behind the irregularly coiled-shell is the rotational changes of the animal’s body and mantle edge with respect to the previously secreted shell. Overall, we propose that future study should focus on the role of the mantle and the columellar muscular system in the determination of shell form.

  5. Reproductive ecology of the common rock chiton Acanthopleura gemmata (mollusca: polyplacophora) in the Northwestern coast of the red sea

    OpenAIRE

    El Soliman, F. [فتحي السيد سليمان محفوظ; Hussein, M. A.; Elmaraghi, A. H.; Yousif, T. N.

    1996-01-01

    The reproductive cycle of the chiton, Acanthopleura gemmata was studied by observing the gonad indices at two localities in the North-western coast of the Red Sea, from January 1988 to December, 1989. The interrelationships between gonad, general viscera and body wall indices were evaluated. The gonad indices showed an inverse relationship with both the general viscera and the body wall indices. Spawning occurred once a year during the autumn. The annual and local changes in the reproductive ...

  6. Cytogenetic characterisation of the razor shells Ensis directus (Conrad, 1843) and E. minor (Chenu, 1843) (Mollusca: Bivalvia)

    Science.gov (United States)

    González-Tizón, Ana M.; Rojo, Verónica; Vierna, Joaquín; Jensen, K. Thomas; Egea, Emilie; Martínez-Lage, Andrés

    2013-03-01

    The European razor shell Ensis minor (Chenu 1843) and the American E. directus (Conrad 1843) have a diploid chromosome number of 38 and remarkable differences in their karyotypes: E. minor has four metacentric, one metacentric-submetacentric, five submetacentric, one subtelocentric and eight telocentric chromosome pairs, whereas E. directus has three metacentric, two metacentric-submetacentric, six submetacentric, six subtelocentric and two telocentric pairs. Fluorescent in situ hybridisation (FISH) using a major ribosomal DNA probe located the major ribosomal genes on one submetacentric chromosome pair in both species; FISH with a 5S ribosomal DNA (5S rDNA) probe rendered one chromosomal (weak) signal for E. minor and no signal for E. directus, supporting a more dispersed organisation of 5S rDNA compared to the major ribosomal genes. The vertebrate telomeric sequence (TTAGGG) n was located on both ends of each chromosome, and no interstitial signals were detected. In this work, a comparative karyological analysis was also performed between the four Ensis species analysed revealing that the three European species studied so far, namely E. minor, E. siliqua (Linné 1758) and E. magnus Schumacher 1817 show more similarities among them than compared to the American species E. directus. In addition, clear karyotype differences were found between the morphologically similar species E. minor and E. siliqua.

  7. The effects of mercury exposure on the surface morphology of gill filaments in Perna perna (Mollusca: Bivalvia)

    CSIR Research Space (South Africa)

    Gregory, MA

    1999-01-01

    Full Text Available the lateral- frontal cirri appeared to be separating. Further, although only a subjective observation, unlike those in controls, the cirri did not curl over the frontal cilia, but hung in a `languid' fashion beyond them. The most obvious and perhaps signi.... edulis, where numerous studies describe the normal and abnormal appearance of gill ?laments and other soft tissues before and after expo- sure to heavy metals, little was known of these struc- tures in P. perna. While South Africa has never formally...

  8. Where’s Waldo? A new commensal species, Waldo arthuri (Mollusca, Bivalvia, Galeommatidae, from the Northeastern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Paul Valentich-Scott

    2013-07-01

    Full Text Available A galeommatid bivalve mollusk, representing a new species, is described from off the coasts of California and Vancouver Island, British Columbia. The new bivalve has a commensal relationship with the heart urchin, Brisaster latifrons. It has been observed crawling between the oral spines of this urchin, frequently near the peristome. The bivalve has been recorded from 80 (Vancouver Island to 444 (southern California meters depth, in muddy sediments.In common with other galeommatoideans, the new species broods its young; however it differs from the large majority of commensal members in lacking planktotrophic larval development.Waldo arthuri, new species, has multiple morphological, ecological and developmental similarities to other members of the genus Waldo Nicol, 1966, from the southern Atlantic and Antarctic Oceans. This is most pronounced for the Argentine species, Waldo paucitentaculatus Zelaya & Ituarte, 2013, W. arthuri’s sister species in nuclear and mitochondrial gene trees. Despite this close relationship, W. arthuri is phylogentically distinct and possesses several hinge, shell sculpture, foot, and mantle tentacle characteristics that merit its description as new.

  9. Physiological effects of temperature and a herbicide mixture on the soft-shell clam Mya arenaria (Mollusca, Bivalvia).

    Science.gov (United States)

    Greco, Luna; Pellerin, Jocelyne; Capri, Ettore; Garnerot, Florent; Louis, Séverine; Fournier, Michel; Sacchi, Angela; Fusi, Marco; Lapointe, Dominique; Couture, Patrice

    2011-01-01

    The aim of the current study was to investigate effects of temperature and a mixture of herbicides on the physiological status of the bivalve Mya arenaria. Bivalves acclimated to two temperatures (7 and 18°C) were exposed for 28 d to 0.01 mg/L of a pesticide formulation containing dichlorophenoxyacetic acid (2,4-D), 2-(2-methyl-4-chlorophenoxy) propionic acid (mecoprop), and 3,6-dichloro-2-methoxybenzoic acid (dicamba). At days 7, 14, and 28, mortality, immune parameters (hemocyte number, phagocytic activity, and efficiency), biomarkers of oxidative stress (catalase [CAT] and superoxide dismutase [SOD] activities and malondialdehyde [MDA] content), the metabolic enzyme cytochrome C oxidase (CCO), a biomarker of pesticide exposure (acetylcholinesterase [AChE]), and the activity of an enzyme related to gametogenesis (aspartate transcarbamylase [ATCase]) were monitored in clam tissues. Gonadosomatic index (GSI), condition factor (CF), and sex were also assessed. In clams acclimated to 7°C, exposure to pesticide enhanced CCO activity and CF and decreased MDA content, hemocyte number, CAT, and SOD activities. In clams kept at 18°C, pesticide effects appeared minor compared with samples kept at 7°C. In bivalves acclimated to 18°C, CCO, SOD, and ATCase activity and MDA content were enhanced, and hemocyte number, CAT, and AchE activities and phagocytosis were suppressed. In samples exposed to pesticides, increased temperature enhanced MDA content and CCO and SOD activity and suppressed hemocyte number and CAT and AchE activity. A gradual sexual maturation was observed in both sexes through experimental time, but females had a higher sensitivity to temperature and pesticides compared to males. Increased temperature altered the ability of the sentinel species Mya arenaria to respond to pesticide exposures. Further work is needed to understand the impacts of increasing temperature on the whole St. Lawrence estuary ecosystem. © 2010 SETAC.

  10. Colonization and distribution of nassarius reticulatus (mollusca: Prosobranchia) in the newly created saline lake grevelingen (SW Netherlands)

    Science.gov (United States)

    Lambeck, R. H. D.

    After the Grevelingen estuary had been cut off from the North Sea in 1971 and was turned into a 108 km 2 saline lake, Nassarius reticulatus gradually colonized the area. Estimated average numbers increased from near 5 m -2 in spring 1976 to over 200 m -2 in spring 1977 and (ADW) biomass correspondingly from 0.25 g·m -2 to 2.1 g·m -2. Numbers consolidated in the years thereafter, whereas biomass increased further to 3.3 g·m -2 in spring 1981. Causal factors are discussed. Nassarius in widespread in the lake. Presumably sediment characteristics and eelgrass presence are secondary importance in the distribution. Highest densities in 1981 occurred at 4 to 4.5 m depth, lowest in the deep channels. A similar pattern showed the total zoobenthic biomass. The distribution data suggests Nassarius to be mainly a secondary consumer, probably primarily a predator.

  11. Description of a new species of the genus Arganiella Giusti & Pezzoli, 1980 (Mollusca, Gastropoda, Hydrobiidae from the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Ramos, M.ª A.

    2007-06-01

    Full Text Available A new species of Arganiella Giusti & Pezzoli, 1980, up to now a monotypic genus, thought to be endemic to the Italian Central Apennines, is described from the Iberian Peninsula. This new species, named Arganiella tartessica, is located in southwestern Spain, provinces of Huelva and Badajoz. In this paper, a detailed description of its morphological characters is given and new data of nervous system and ciliated areas in the cephalic region are provided.Se describe una especie ibérica de Arganiella Giusti y Pezzoli, 1980, un género que hasta ahora se consideraba monotípico y endémico de los Apeninos centrales italianos. Esta nueva especie, denominada Arganiella tartessica, ha sido localizada en el sureste español, en las provincias de Huelva y Badajoz. En este artículo se describen en detalle sus caracteres morfológicos y se presentan datos, hasta la fecha desconocidos en el género Arganiella, del sistema nervioso y de áreas ciliadas en la región cefálica.

  12. 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.

  13. Cutaneous application of an accessory-gland secretion after sperm exchange in a terrestrial slug (Mollusca : Pulmonata)

    NARCIS (Netherlands)

    Benke, Mandy; Reise, Heike; Montagne-Wajer, Kora; Koene, Joris M

    Competition for fertilisation in hermaphroditic animals seems to have led to many odd behaviours and complex morphologies involved in the transfer of accessory-gland products to the partner. Terrestrial slugs of the genus Deroceras show remarkably elaborate and interspecifically diverse penis

  14. Molecular discrimination of Perna (Mollusca: Bivalvia) species using the polymerase chain reaction and species-specific mitochondrial primers

    DEFF Research Database (Denmark)

    Blair, D.; Waycott, M.; Byrne, L.

    2006-01-01

    This work was prompted by the need to be able to identify the invasive mussel species, Perna viridis, in tropical Australian seas using techniques that do not rely solely on morphology. DNA-based molecular methods utilizing a polymerase chain reaction (PCR) approach were developed to distinguish...... designed that can act as a forward primer in PCRs for any Perna species. Four reverse primers have also been designed, based on nad4 and intergenic spacer sequences, which yield species-specific products of different lengths when paired with the conserved forward primer. A further pair of primers has been...

  15. ORF Alignment: NC_006576 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available ccus ... elongatus PCC 6301] ... Length = 155 ... Query: 2 ... AKTASTMLALGTAAPDFALPDVVSGRTVQLADFSDR...AGLLVMFICQHCPFVKHVEEELAA 61 ... AKTASTMLALGTAAPDFALPDVVSGRTVQLADFSDRAGLLVM...FICQHCPFVKHVEEELAA Sbjct: 1 ... AKTASTMLALGTAAPDFALPDVVSGRTVQLADFSDRAGLLVMFICQHCPFVKHVEEELAA 60 ... Query: 122 DF

  16. ORF Alignment: NC_006576 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available ... [Synechococcus elongatus PCC 6301] ... Length = 288 ... Query: 24 ... LVYATYGELNRDRSNAILYPTSYGA...QHSTIDWLIGGDRILDPDRWFIVIVNQFGNGLSSS 83 ... LVYATYGELNRDRSNAILYPTSYGAQHSTID...WLIGGDRILDPDRWFIVIVNQFGNGLSSS Sbjct: 1 ... LVYATYGELNRDRSNAILYPTSYGAQHSTIDWLIGGDRILDPDRWFIVIVNQFGNGLSSS 60 ... Qu

  17. ORF Alignment: NC_004113 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available ... elongatus BP-1] ... Length = 101 ... Query: 1 ... MIPGELIPAEGTIELNAGRPTVTLTVANTGDRPIQVGSHYHFYEV...NPALQFEREQARGMR 60 ... MIPGELIPAEGTIELNAGRPTVTLTVANTGDRPIQVGSHYHFYEVNPALQF...EREQARGMR Sbjct: 1 ... MIPGELIPAEGTIELNAGRPTVTLTVANTGDRPIQVGSHYHFYEVNPALQFEREQARGMR 60 ...

  18. Genetic diversity and population genetic analysis of Donax vittatus (Mollusca: Bivalvia) and phylogeny of the genus with mitochondrial and nuclear markers

    Science.gov (United States)

    Fernández-Pérez, Jenyfer; Froufe, Elsa; Nantón, Ana; Gaspar, Miguel B.; Méndez, Josefina

    2017-10-01

    In this study, the genetic diversity of Donax vittatus across the Iberian Peninsula was investigated using four mitochondrial (COI, Cytb, 16S F and M types) and three nuclear (H3, 18S and 28S) genes. These same molecular markers were also sequenced in D. semistriatus and D variegatus to address the phylogenetic relationships of the species of the genus Donax common along the European coasts. Our results showed high haplotype diversity in combination with a low nucleotide diversity and a star-shaped network with a predominant haplotype, indicating a recent population expansion for the examined sampling sites of D. vittatus. Furthermore, analyses of population differentiation performed with COI mitochondrial marker, including global FST estimation and pairwise FST values, indicated the non-existence of significant genetic structure in D. vittatus of Northwest Iberian populations. Because these localities show a high genetic similarity, we suggest that D. vittatus could be a potentially alternative exploitable resource, as complement to the D. trunculus fisheries, whose natural stocks have decreased dramatically in some areas. Furthermore, we present for the first time, evidence of DUI in the clams D. vittatus and D. semistriatus.

  19. Genetic Population Structure and Demographic History of the Widespread Common Shipworm Teredo navalis Linnaeus 1758 (Mollusca: Bivalvia: Teredinidae in European Waters Inferred from Mitochondrial COI Sequence Data

    Directory of Open Access Journals (Sweden)

    Ronny Weigelt

    2017-06-01

    Full Text Available The first documented scientific reports of the common marine shipworm Teredo navalis (Bivalvia for Central European waters date back to the time between 1700 and 1730 in the Netherlands. During the following centuries there were several irregular mass occurrences reported for both the North Sea and the Baltic Sea. These events were accompanied by massive destruction of wooden ships and coastal protection structures. In this study, the first population analysis of T. navalis is presented with the aim to detect the genetic population structure in the waters of Central Europe. The mtDNA COI (cytochrome c oxidase subunit I locus was found as suitable molecular marker and hence a 675 bp gene fragment was studied. A total of 352 T. navalis specimens from 13 different sampling sites distributed across Central Europe were examined. Subsequently, various population genetic indices including FST values and an AMOVA analysis were applied for the description of the population structure. To visualize the distribution of haplotypes at the different sampling sites two median-joining networks were calculated. In addition, the past demographic structure of the T. navalis population was analyzed, among others by calculating Tajima's D, Fu's F and the mismatch distribution. Finally, all computations of the population genetic indices could not reveal differentiated populations or any kind of distinct population structure in T. navalis. The network analyses revealed “star-like” patterns without differentiated substructures or demes. Therefore, it can be assumed that a sudden expansion of this species took place without any indications of neither a bottleneck nor a founder effect for the study area. The results of this study support the concept of a regional panmictic population in the waters of Central Europe with unhindered migration of individuals (e.g., via pelagic larvae between the various sampling sites as reflected by a high gene flow.

  20. [Effect of excretion-secretion products of some fouling species on the biochemical parameters of blue mussel Mytilus edulis L. (Mollusca: Bivalvia) in the White Sea].

    Science.gov (United States)

    Skidchenko, V S; Vysotskaia, R U; Krupnova, M Iu; Khalaman, V V

    2011-01-01

    The effect of excretion-secretion products (ESP) of five abundant fouling invertebrate species (bivalve mollusks Hiatella arctica and Mytilus edulis, solitary ascidia Styela rustica, sponge Halichondria panicea, and sea starAsterias rubens, inhabiting the White Sea) on the biochemical status of blue mussel M. edulis was assessed by the dynamics of lysosomal enzymes activity (nucleases, glycoside hydrolases, and cathepsins). ESP of conspecific species had no effect on the metabolism of the mollusks of this species. ESP of A. rubens, S. rustica, and H. panicea activated the same enzymes. First, acid RNase and glycoside hydrolases activity increased, but in different ways. The metabolites of H. arctica affected the activity of proteometabolism enzymes.

  1. Bioaccumulation and elimination of 60 Co and 137 Cs by Anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilization of 60 Co, retained in marine sediment by microbial activity

    International Nuclear Information System (INIS)

    Mayr, L.M.

    1984-05-01

    It was studied the capacity of a bi valve mollusc Anomalocardia brasiliana, which lives in the local bottom sediment, to remobilize 60 Co previously sorbed in the sediment. Laboratory experiments demonstrated that the transference of 60 Co from the sediment to the animal was insignificant (bioaccumulation factor (BF) of the order of 10 -3 ). At the same time, the capacity of microorganisms, present in the bottom sediment, to remobilize 60 Co was studied. The results showed that this via of transference was important, considering the much greater microorganism biomass in relation to the biomass of bentonic organisms, as a whole. For 137 Cs the determined BF from water to the animal was 2.2. and, as in the case of 60 Co, the soft tissues concentrated more 137 Cs than shell. Remaining viscera showed the highest BFs. In another series of experiments, the loss of 60 Co or 137 Cs, previously accumulated by A. brasiliana, was followed in aquaria with or without sediment and the respective biological half-lives were calculated. Soft tissues retained 60 Co longer (biological half-life = 117 days) than shells, whereas for 137 Cs the opposite was observed and shells showed a biological half life of 38.5 days. The low values of 60 Co and 137 Cs BF S do not allow to classify A. brasiliana as good biological indicator for pollution by there radionuclides. However since A brasiliana is consumed by the local population and is commercialized to other areas, it was recommended that its contamination by 60 Co or 137 Cs should be monitored. (author)

  2. 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 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.

  3. Polar localization of plasma membrane Ca2+/Mg2+ ATPase correlates with the pattern of steady ionic currents in eggs of Lymnaea stagnalis and Bithynia tentaculata (Mollusca)

    NARCIS (Netherlands)

    D. Zivkovic (Dana); R. Créton (Robbert); G. Zwaan (Gideon); W.C. de Bruijn (Wim); M.R. Dohmen (M.René)

    1990-01-01

    textabstractDuring extrusion of the first polar body in eggs of Lymnaea stagnalis and Bithynia tentaculata a localized Ca2+ /Mg2+ ATPase activity was detected, using Ando's enzyme-cytochemical method for electron microscopy [Ando et al. (1981) Acta Histochem Cytochem 14:705-726]. The enzyme activity

  4. Chaetogaster limnaei (annelida: oligochaeta) as a parasite of the zebra mussel Dreissena polymorpha, and the quagga mussel Dreissena bugensis (mollusca: bivalvia).

    Science.gov (United States)

    Conn, D B; Ricciardi, A; Babapulle, M N; Klein, K A; Rosen, D A

    1996-01-01

    Dreissenid mussels, Dreissena polymorpha and D. bugensis, were found to be infected by the naidid oligochaete Chaetogaster limnaei at four sites in the St. Lawrence River. This is the first report of this species infecting dreissenids anywhere in the world. Most worms inhabited the mantle cavity, where they caused erosion of the mantle and gill epithelia as determined by histopathological examination. Others penetrated various tissues; one had invaded the ovary and was feeding on oocytes and ovarian tissues. Of 606 mussels examined, 166 (27.4%) harbored at least 1 C. limnaei. The prevalence varied between 1% and 80%, depending on the collection site and date. The worms were slightly but significantly more prevalent in D. bugensis than in D. polymorpha. The intensity ranged from 1 to 18 worms per infected host. Variations in prevalence and intensity were not related to the size or sex of the host, but the data did suggest some seasonality.

  5. The introduced snail Melanoides Tuberculatus (Muller, 1774 (Mollusca: Thiaridae in aquatic ecosystems of the Brazilian Semiarid Northeast (Piranhas-Assu River basin, State of Rio Grande do Norte

    Directory of Open Access Journals (Sweden)

    CM. Santos

    Full Text Available Records of the gastropod Melanoides tuberculatus (Müller, 1774, family Thiaridae, in the Piranhas-Assu River basin in Rio Grande do Norte reveal the dispersal of this native Southeast Asian and East African species into aquatic environments of the Brazilian semiarid region, including artificial environments (reservoirs and lotic systems. The eutrophic conditions of the local waterbodies appear to favor the present situation, where this invasive species reaches extremely high densities, sometimes over 10,000 ind.m-2 as in Armando Ribeiro Gonçalves Reservoir. These observations indicate the immediate need for new studies on the spatial distribution of the species and its potential impact on the biodiversity and water quality of the waterbodies of the semiarid region of the state. Implantation of regular and systematic monitoring of the aquatic resources of the region is urgently required.

  6. Preliminary report on the geographical distribution of the species of Carinariidae and Pterotracheidae (Heteropoda, Mollusca) from the International Indian Ocean Expedition

    Digital Repository Service at National Institute of Oceanography (India)

    Aravindakshan, P.N.

    during the IIOE The samples obtained by these vessels provide broad coverage of the Indian Ocean, including the Arabian Sea and Bay of Bengal and southward to 40 degrees S Beyond 40 degrees S there were only three collections and these contained...

  7. The influence of caffeine and thymol on the survival, growth and reproduction of Subulina octona (Brugüière, 1789) (Mollusca, Subulinidae)

    OpenAIRE

    Ferreira,Paula; Soares,Geraldo Luiz Gonçalves; D'ávila,Sthefane; Bessa,Elisabeth Cristina de Almeida

    2009-01-01

    Subulina octona is a terrestrial snail which serves as an intermediate host for the parasites. It is also an agricultural pest. The aim of this work was to assess, during 120 days, the effects of caffeine and thymol at 2.5 g/L and 5 g/L on the hatchability, survival after hatching, growth and reproduction of S. octona under the laboratory conditions. A total of 240 eggs, 240 juveniles aged 10-day-old, and 240 aged 30-day-old were tested. The results showed that thymol (at 2.5 g/L and 5 g/L) a...

  8. The influence of caffeine and thymol on the survival, growth and reproduction of Subulina octona (Brugüière, 1789 (Mollusca, Subulinidae

    Directory of Open Access Journals (Sweden)

    Paula Ferreira

    2009-08-01

    Full Text Available Subulina octona is a terrestrial snail which serves as an intermediate host for the parasites. It is also an agricultural pest. The aim of this work was to assess, during 120 days, the effects of caffeine and thymol at 2.5 g/L and 5 g/L on the hatchability, survival after hatching, growth and reproduction of S. octona under the laboratory conditions. A total of 240 eggs, 240 juveniles aged 10-day-old, and 240 aged 30-day-old were tested. The results showed that thymol (at 2.5 g/L and 5 g/L and caffeine (at 5 g/L acted as ovicides. In the 10-day-old juveniles, caffeine at 5 g/L caused 25% mortality and at 2.5 g/L it caused 30% mortality. Thymol at 2.5 and 5 g/L caused 20 and 22.5% mortality, respectively. In the 30-day-old juveniles, caffeine at 5 g/L caused 47.5% mortality.Subulina octona é um molusco terrestre que atua como hospedeiro intermediário de parasitos. Também atua como praga agrícola. O objetivo deste trabalho foi avaliar, durante 120 dias, o efeito da cafeína e do timol a 2,5g/L e a 5g/L, sobre a eclodibilidade, a sobrevivência após a eclosão, crescimento e a reprodução de S. octona em condições de laboratório. Foram testados 240 ovos, 240 jovens com 10 e 30 dias de vida. Os resultados dos testes mostraram que o timol (5g/L e 2,5g/L e a cafeína a 5g/L atuaram como ovicida. Nos jovens com 10 dias de vida a cafeína à 5g/L provocou uma mortalidade de 25% e a 2,5 g/L 30%. O timol a 2,5g/L e 5g/L provocou 20 e 22,5% de mortalidade, respectivamente. Nos jovens com 30 dias de vida a cafeína a 5g/L causou 47,5% de mortalidade. Esses resultados sugerem novos estudos no campo.

  9. Emergence, development, and maturity of the gonad of two species of chitons "sea cockroach" (Mollusca: Polyplacophora through the early life stages.

    Directory of Open Access Journals (Sweden)

    Omar Hernando Avila-Poveda

    Full Text Available This study describes and recognises, using histological and microscopical examinations on a morphometrical basis, several gonad traits through the early life stages of Chiton articulatus and C. albolineatus. Gonadal ontogenesis, gonad development stages, sexual differentiation, onset of the first sexual maturity, and growth sequences or "early life stages" were determined. In addition, allometry between lengths and body weight pooled for both sexes per each chiton were calculated using equation Y = aX(b . A total of 125 chitons (4≤TL≤40 mm, in total length "TL" were used. All allometric relations showed a strong positive correlation (r, close to 1, with b-values above three, indicating an isometric growth. Gonadal ontogenesis and gonad development stages were categorised into three periods ("Pw" without gonad, "Pe" gonad emergence, and "Pf" gonadal sac formed and four stages ("S0" gametocytogenesis, "S1" gametogenesis, "S2" mature, and "S3" spawning, respectively. Compound digital images were attained for each process. Periods and stages are overlapped among them and between species, with the following overall confidence intervals in TL: Pw 6.13-14.32 mm, Pe 10.32-16.93 mm, Pf 12.99-25.01 mm, S0 16.08-24.34 mm (females and 19.51-26.60 mm (males, S1 27.15-35.63 mm (females and 23.45-32.27 mm (males, S2 24.48-40.24 mm (females and 25.45-32.87 mm (males. Sexual differentiation (in S0 of both chitons occurs first as a female then as a male; although, males reach the onset of the first sexual maturity earlier than females, thus for C. articulatus males at 17 mm and females at 32 mm, and for C. albolineatus males at 23.5 mm and females at 28 mm, all in TL. Four early life stages (i.e., subjuvenile, juvenile, subadult, and adult are described and proposed to distinguish growth sequences. Our results may be useful to diverse disciplines, from developmental biology to fisheries management.

  10. Catalog of the recent taxa of the families Epitoniidae and Nystiellidae (Mollusca: Gastropoda) with a bibliography of the descriptive and systematic literature.

    Science.gov (United States)

    Brown, Leonard G; Neville, Bruce D

    2015-01-15

    This catalog includes 1,487 names recent genera, subgenera, species, subspecies, varieties, and forms that have been referred to the families Epitoniidae and Nystiellidae as well as a bibliography of the descriptive and systematic literature associated with these names. For the names covered herein, we make a determination of whether the name is an available name, as that term is defined in the International Code of Zoological Nomenclature ("ICZN") and, based on a review of the literature listed in the bibliography, indicate whether the taxon is a potentially valid name or a probable synonym. This catalog includes not only includes a list of names, but also includes information on type material, type localities and species' geographic, bathymetric and size ranges. We also suggest generic assignments for many of the species level taxa listed in this work. We herein designate Scalaria acuta J. Sowerby, 1812, to be the type species of Clathrus Agassiz, 1837, designate Scalaria raricostata G.B. Sowerby II, 1844b, to be the type species of Variciscala de Boury, 1909a, designate Turbiniscala sexcosta Jousseaume, 1912, to be the type species of Turbiniscala de Boury, 1909a, and designate Scala dubia 'G. B. Sowerby II' de Boury, 1912b to be the type species of Foliaceiscala de Boury, 1912b. 

  11. Six new subterranean freshwater gastropod species from northern Albania and some new records from Albania and Kosovo (Mollusca, Gastropoda, Moitessieriidae and Hydrobiidae

    Directory of Open Access Journals (Sweden)

    Jozef Grego

    2017-10-01

    Full Text Available During a field trip to the western part of the Balkan Peninsula in 2016, investigations of several caves and karstic springs revealed six new gastropod species living in subterranean waters and resulted in some noteworthy faunistic records. Five of the new species are assigned to the genus Paladilhiopsis Pavlović, 1913, namely P. prekalensis sp. n., P. lozeki sp. n., P. szekeresi sp. n., P. wohlberedti sp. n., P. falniowskii sp. n. and one to the genus Plagigeyeria Tomlin, 1930, namely P. steffeki sp. n. New Albania and Kosovo distribution records are given for Iglica illyrica Schütt, 1975, Plagigeyeria zetaprotogona Schütt, 1960, Vinodolia matjasici (Bole, 1961, and the first georeferenced record is given for Saxurinator schlickumi Schütt, 1960. The most important environmental factors influencing habitat selection of these subterranean freshwater gastropods are briefly discussed.

  12. Producción secundaria e índice de condición en Arca zebra (Mollusca: Bivalvia del Golfo de Cariaco, Venezuela

    Directory of Open Access Journals (Sweden)

    Antulio Prieto Arcas

    2001-06-01

    Full Text Available Se estudió la biomasa, producción secundaria e índice de condición del bivalvo Arca zebra, desde agosto, 1984 hasta agosto, 1985 en Pariche, localidad situada en la costa norte del Golfo de Cariaco, Venezuela. La densidad promedio fue de 37 ind.m-2, con una mayor abundancia a 3 m de profundidad (49.75 ind.m-2. La estructura poblacional es estable con reclutamientos en octubre, diciembre 1984 y junio 19885. Los valores bimensuales de biomasa oscilaron entre 189.86 g Ps m-2 (agosto-84 y 28.51 g Ps m-2 (octubre-84, con un promedio de 93.69 g Ps m-2, y no presentaron diferencias significativas (Fs, P 0.05. Utilizando un método para poblaciones con reproducción contínua y edades no separables, se obtuvo una producción secundaria de 131.61 g Ps. m-2.año-1, y la relación P/B de1.41 año-1. La mayor producción secundaria ocurrió entre febrero 1985 y agosto 1985 (65%, con el mayor aporte por el intervalo 60.00-79.95 mm (45.73%. Se observaron cambios significativos en la variación mensual del índice de condición (IC= (Ps/ Ph x100 en dos clases de tallas analizadas, presentando los valores más altos en julio de 1985 (26.84% y el mínimo en enero de 1985 (16.31%.Production and condition index of a turkeywing (Arca zebra population were studied from August 1984 to August 1985 in Pariche, Cariaco Gulf, Venezuela. Production was studied through bimonthly collections using a method designed for populations with continuous reproduction and indistinguishable age classes. The population distribution was stable with a mean density of 37 ind.m-2. A production of 131.61 g dry weight m-2.year-1 was calcuclated from data on density, biomass and weight increase along the year. Highest production was between February 1985 and August 1985 (65% and concentrated in individuals 60.00-79.95 mm long (45.73%. There was large seasonal variation in the mean monthly condition index (IC= (Ps/Ph x100 in the two size classes examined: it reached a maximum in July 1985 (26.84% and a minimum in January 1985 (16.31%.

  13. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda in the Royal Belgian Institute of Sciences, Brussels, with descriptions of two new species

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    Abraham Breure

    2011-05-01

    Full Text Available  The type status is described of 57 taxa from the superfamily Orthalicoidea in the collection of the Brussels museum. Two new species are described: Stenostylus perturbatus spec. nov., and Suniellus adriani spec. nov. A new lectotype is designated for Thaumastus alausiensis Cousin, 1887. New combinations are: Bostryx borellii (Ancey, 1897; Bostryx carandaitensis (Preston, 1907; Protoglyptus mazei (Crosse, 1874; Kuschelenia (Vermiculatus sanborni (Haas, 1947. New synonymies are established for the following nominal taxa: Orphnus thompsoni var. lutea Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845; Orphnus thompsoni var. nigricans Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845; Thaumastus nystianus var. nigricans Cousin, 1887 = Drymaeus (Drymaeus nystianus (Pfeiffer, 1853; Orphnus thompsoni var. olivacea Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845; Orphnus thompsoni var. zebra Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845.

  14. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Royal Belgian Institute of Sciences, Brussels, with descriptions of two new species

    Science.gov (United States)

    Breure, Abraham S.H.

    2011-01-01

    Abstract The type status is described of 57 taxa from the superfamily Orthalicoidea in the collection of the Brussels museum. Two new species are described: Stenostylus perturbatus sp. n., and Suniellus adriani sp. n. New lectotypes are designated for Bulimulus (Naesiotus) amastroides Ancey, 1887; Bulimulus blanfordianus Ancey, 1903; Bulimulus montivagus chacoensis Ancey, 1897; Bulimus coloratus Nyst, 1845; Plecochilus dalmasi Dautzenberg, 1900; Placostylus porphyrostomus elata Dautzenberg, 1923; Bulimulus ephippium Ancey, 1904; Bulimus fulminans Nyst, 1843; Bulimus funckii Nyst, 1843; Orphnus thompsoni lutea Cousin, 1887; Bulimus melanocheilus Nyst, 1845; Orphnus thompsoni nigricans Cousin, 1887; Orphnus thompsoni olivacea Cousin, 1887; Bulimulus pollonerae Ancey, 1897; Orphnus thompsoni zebra Cousin, 1887. New combinations are: Bostryx borellii (Ancey, 1897); Bostryx carandaitiensis (Preston, 1907); Protoglyptus mazei (Crosse, 1874); Kuschelenia (Vermiculatus) sanborni (Haas, 1947). New synonymies are established for the following nominal taxa: Orphnus thompsoni var. lutea Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845); Orphnus thompsoni var. nigricans Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845); Thaumastus nystianus var. nigricans Cousin, 1887 = Drymaeus (Drymaeus) nystianus (Pfeiffer, 1853); Orphnus thompsoni var. olivacea Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845); Orphnus thompsoni var. zebra Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845). PMID:21747669

  15. New species of Rissoidae (Mollusca, Gastropoda) from the Archipelago of the Azores (northeast Atlantic) with an updated regional checklist for the family

    OpenAIRE

    Cordeiro,Ricardo; Ávila,Sérgio

    2015-01-01

    Abstract Four new species of shallow-water marine gastropods belonging to the family Rissoidae are described from the Archipelago of the Azores: Setia alexandrae sp. n., Setia ermelindoi sp. n., Setia netoae sp. n., and Manzonia martinsi sp. n. These novelties increase the regional rissoid fauna to 39 species, of which 29 live in shallow-water habitats. A list of the species of Rissoidae from the Azores is presented based on data from the literature and new material examined.

  16. On the doubtful records of Alvania platycephala, Alvania pagodula and Alvania didyma, with the description of two new rissoid species (Mollusca; Gastropoda: Rissoidae)

    OpenAIRE

    Faber, M.J.; Moolenbeek, R.G.

    1987-01-01

    Two new species of Alvania are described from Bermuda. Both species have been wrongly identified in the past. The generic classification is discussed but a definitive statement based only on conchological characters seems impossible.

  17. New species of Rissoidae (Mollusca, Gastropoda) from the Archipelago of the Azores (northeast Atlantic) with an updated regional checklist for the family.

    Science.gov (United States)

    Cordeiro, Ricardo; Ávila, Sérgio P

    2015-01-01

    Four new species of shallow-water marine gastropods belonging to the family Rissoidae are described from the Archipelago of the Azores: Setiaalexandrae sp. n., Setiaermelindoi sp. n., Setianetoae sp. n., and Manzoniamartinsi sp. n. These novelties increase the regional rissoid fauna to 39 species, of which 29 live in shallow-water habitats. A list of the species of Rissoidae from the Azores is presented based on data from the literature and new material examined.

  18. Insights into the relationships of Palearctic and Nearctic lymnaeids (Mollusca : Gastropoda by rDNA ITS-2 sequencing and phylogeny of stagnicoline intermediate host species of Fasciola hepatica

    Directory of Open Access Journals (Sweden)

    Bargues M.D.

    2003-09-01

    Full Text Available Fascioliasis by Fasciola hepatica is the vector-borne disease presenting the widest latitudinal, longitudinal and altitudinal distribution known. F. hepatica shows a great adaptation power to new environmental conditions which is the consequence of its own capacities together with the adaptation and colonization abilities of its specific vector hosts, freshwater snails of the family Lymnaeidae. Several lymnaeid species only considered as secondary contributors to the liver fluke transmission have, however, played a very important role in the geographic expansion of this disease. Many of them belong to the so-called "stagnicoline" type group. Stagnicolines have, therefore, a very important applied interest in the Holarctic region, to which they are geographically restricted. The present knowledge on the genetics of stagnicolines and on their parasite-host interrelationships is, however, far from being sufficient. The present paper analyses the relationships between Palaearctic and Nearctic stagnicoline species on the base of the new light furnished by the results obtained in nuclear rDNA ITS-2 sequencing and corresponding phylogenetic studies of the lymnaeid taxa Lymnaea (Stagnicola occulta, L. (S. palustris palustris (topotype specimens and L.(S. p. turricula from Europe. Natural infections with F. hepatica have been reported in all of them. Surprisingly, ITS-2 length and G C content of L. occulta were similar and perfectly fitted within the respective ranges known in North American stagnicolines. Nucleotide differences and genetic distances were higher between L. occulta and the other European stagnicolines than between L. occulta and the North American ones. The ITS-2 sequence of L. p. turricula from Poland differed from the other genotypes known from turricula in Europe. The phylogenetic trees using the maximum-parsimony, distance and maximum-likelihood methods confirmed (i the inclusion of L. occulta in the branch of North American stagnicolines, (iii the link between the North American stagnicolines-L. occulta group with Galba truncatula, and (iii the location of the L. p. turricula genotype from Poland closer to L. p. palustris than to other European L. p. turricula genotypes. The Palaearctic species occulta is included in the genus Catascopia, together with the Nearctic species catascopium, emarginata and elodes. The results suggest a potential of transmission capacity for C. occulta higher than that of other European stagnicolines or Omphiscola glabra. The relatively low genetic distances between C. occulta and G. truncatula and the clustering of both species in the same clade suggest that C.occulta may be potentially considered as the second lymnaeid intermediate host species of F. hepatica in importance in eastern and northern Europe, and probably also western and central Asia, after G. truncatula. L. p. turricula may be considered as a potential secondary vector of F. hepatica, at a level similar tot that of L.p. palustris.

  19. The population density of Lymnaea columella (Say, 1817) (Mollusca, Lymnaeidae) an intermediate host of Fasciola hepatica (Linnaeus, 1758), in the Caparaó microregion, ES, Brazil.

    Science.gov (United States)

    D'Almeida, S C G; Freitas, D F; Carneiro, M B; Camargo, P F; Azevedo, J C; Martins, I V F

    2016-06-01

    The aim of this study was to monitor the population density of Lymnaea columella, an intermediate host of Fasciola hepatica, in various aquatic habitats and in drinking water in the area of the Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo, on Caparaó Microregion, municipality of Alegre, state of Espírito Santo, Brazil. Monthly samplings were performed at certain points between drainage areas and drinking water in cattle and goat production systems during the years 2010 to 2013. The mean temperature, precipitation and the frequency of samples of L. columella were analysed graphically according the monthly average during the study period. A total of 2,038 molluscs were collected, 1558 of which were L. columella, that predominated in all sampled points. The highest average of specimens observed for L. columella was in the years 2010 and 2013 (51.0), and occurred decreased in 2011 (19.8). The temperature and precipitation averaged is 23.7 °C and 141 mm/year, respectively. Rainfall peak occurred in March (2011, 2013) and November (2012), during these periods the population of L. columella growth. There was no significant difference in the relationship between the specimens observed with seasons (dry-wet), thus the population of L. columella remained stable and can be found throughout the year.

  20. On the identities of the molluscan names described in A Short Zoology of Tahiti in the Society Islands by Anthony Curtiss in 1938 (Mollusca: Cephalopoda, Gastropoda).

    Science.gov (United States)

    Low, Martyn E Y; Tan, Siong Kiat

    2014-02-11

    Anthony Curtiss described two species of cephalopod and nine species of gastropod molluscs from Tahiti. Herein, we discuss and determine the identities of these eleven names. Ten of these names are considered to be junior subjective synonyms of well-known taxa, and one an unavailable name.

  1. Intra-specific variability in life-history traits of Anadara tuberculosa (Mollusca: Bivalvia in the mangrove ecosystem of the Southern coast of Ecuador

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    Luis Flores

    2014-08-01

    Full Text Available Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, longlife span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these lifehistory traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB, Puerto Jeli (PJ and Puerto Hualtaco (PH]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L∞ and 0.22 to 0.80/year for k. The growth indices (Φ’ ranged from 3.17 to 3.85, while the overall growth performance (OGP ranged from 5.03 to 5.82. The mean of long-life span (t max, size and age at maturity (L50% and t50% were estimated in 7.71±2.53years, 39.13±2.24mm and 1.46±0.56years for PB; 9.51±2.85years, 37.78±1.95mm and 1.37±0.41years for PJ and 5.81±2.11years, 39.73±3.31mm and 0.94±0.41years for PH. Natural mortality (M ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in Φ’ and OGP indices as well as L50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery.

  2. Intra-specific variability in life-history traits of Anadara tuberculosa (Mollusca: Bivalvia) in the mangrove ecosystem of the Southern coast of Ecuador.

    Science.gov (United States)

    Flores, Luis; Licandeo, Roberto; Cubillos, Luis A; Mora, Elba

    2014-06-01

    Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, long-life span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these life-history traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB), Puerto Jeli (PJ) and Puerto Hualtaco (PH)]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L(infinity) and 0.22 to 0.80/year for k. The growth indices (PHI') ranged from 3.17 to 3.85, while the overall growth performance (OGP) ranged from 5.03 to 5.82. The mean of long-life span (t(max)), size and age at maturity (L50% and t50%) were estimated in 7.71 +/- 2.53 years, 39.13 +/- 2.24mm and 1.46 +/- 0.56 years for PB; 9.51 +/- 2.85 years, 37.78 +/- 1.95mm and 1.37 +/- 0.41 years for PJ and 5.81 +/- 2.11 years, 39.73 +/- 3.31mm and 0.94 +/- 0.41 years for PH. Natural mortality (M) ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in PHI' and OGP indices as well as L50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery.

  3. Length class and histological description of the gonads of Diplodon ellipticus (Wagner, 1827 (Mollusca, Bivalvia, Hyriidae at an artificial lake, Morretes, Paraná, Brazil

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    Ana Aparecida Nogueira Meyer

    2014-05-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2014v27n3p81 This study aimed to analyze the frequency by length classes and the histological organization of gonads of Diplodon ellipticus at an artificial lake located in the town of Morretes, Paraná, Brazil. Six bimonthly sampling campaigns were conducted within the period from July 2009 to May 2010, with capture of 150 specimens. The total length of shells was measured for determining the frequencies of length classes and an analysis of the presence of marsupials in branchiae was performed. Sex determination was performed through histological analysis of cross sections of the visceral mass. We registered 8 length classes, with an interval of 9 mm, and the modal class varied between 50 and 59 mm. The population is predominantly dioecious, with occurrence of hermaphrodite specimens at low frequency. Marsupials were registered among females (86% in all sampling campaigns and in 2 hermaphrodite specimens. Histological analyses showed that spermatogenesis and oogenesis occur over the year, indicating that D. ellipticus has a strategy that provides continuous reproduction, with peaks of glochidia release.

  4. Ocorrência de Limnoperna fortunei (Mollusca, Mytilidae, no rio Uruguai, município de Uruguaiana, Fronteira Oeste do Rio Grande do Sul, Pampa Brasileiro

    Directory of Open Access Journals (Sweden)

    Marcus Morini Querol

    2013-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n3p249 O presente trabalho registra a ocorrência do mexilhão dourado Limnoperna fortunei (Dunker, 1857 em ambiente natural no município de Uruguaiana, Fronteira Oeste do Rio Grande do Sul, Pampa Brasileiro. Os aglomerados da espécie foram detectados, fotografados e coletados na margem esquerda do rio Uruguai, em território brasileiro, em dois locais distintos, sendo o primeiro próximo a Ponte Internacional Getúlio Vargas - Agustín Justo, que faz divisa entre as cidades de Uruguaiana/Brasil e Paso de Los Libres/Argentina e o segundo próximo à foz do arroio Salso, afluente do rio Uruguai. Os animais foram capturados e levados para laboratório onde foram identificados e armazenados.

  5. Bait formulations of molluscicides and their effects on biochemical changes in the ovotestis of snail Lymnaea acuminata (Mollusca; Gastropoda:Lymnaeidae).

    Science.gov (United States)

    Kumar, Pradeep; Singh, Vinay Kumar; Singh, D K

    2011-01-01

    The effect of sub-lethal feeding of bait formulations containing molluscicidal component of Ferula asafoetida (ferulic acid, umbelliferone), Syzygium aromaticum (eugenol) and Carum carvi (limonene) on biochemical changes in the ovotestis of snail Lymnaea acuminata were studied. Bait formulations feeding to L. acuminata were studied in clear glass aquaria having diameter of 30 cm. Baits were prepared from different binary combinations of attractant amino acid (valine, aspartic acid, lysine and alanine 10 mM) in 100 mL of 2% agar solution + sub-lethal (20% and 60% of 24h LC50) doses of different molluscicides (ferulic acid, umbelliferone, eugenol and limonene). These baits caused maximum significant reduction in free amino acid, protein, DNA, RNA levels i.e. 41.37, 23.56, 48.36 and 14.29% of control in the ovotestis of the snail, respectively. Discontinuation of feeding after treatment of 60% of 96h LC50 of molluscicide containing bait for next 72h caused a significant recovery in free amino acid, protein, DNA and RNA levels in the ovotestis of L. acuminata.

  6. Biomphalaria straminea and Biomphalaria glabrata (Mollusca: Planorbidae) as new intermediate hosts of the fish eyefluke Austrodiplostomum compactum (Trematoda: Diplostomidae) in Brazil.

    Science.gov (United States)

    Pinto, H A; Melo, A L

    2013-08-01

    Austrodiplostomum compactum has been involved in cases of ocular diplostomiasis in several species of fish in Brazil, but the molluscan intermediate hosts of the parasite remain unknown. In the present study, malacological surveys were carried out at Pampulha Reservoir, Belo Horizonte, Minas Gerais, Brazil, between January 2009 and July 2012. A total of 16,119 specimens of Biomphalaria spp. were collected and examined, of which 68/14,948 specimens (0.45%) of Biomphalaria straminea and 6/541 (1.11%) of Biomphalaria glabrata were found harboring a strigeid cercariae. Groups of 5 specimens of Cyprinius carpio were experimentally infected with these cercariae (100 larvae/fish), and metacercariae were recovered from the eyes of the fish, 65 days after infection, with a mean intensity of infection of 10.4 (8-13) metacercariae/fish. Morphological study on cercariae and metacercariae identified them as A. compactum . This is the first record of cercariae of A. compactum in Brazil, and B. straminea and B. glabrata as new intermediate hosts for the parasite.

  7. Characterization of nine microsatellite markers and development of multiplex PCRs for the Chinese huge musel Anodonta (Sinanodonta) woodiana Lea, 1834 (Mollusca, Bivalvia)

    Czech Academy of Sciences Publication Activity Database

    Popa, O. P.; Bartáková, Veronika; Bryja, Josef; Reichard, Martin; Popa, L. O.

    2015-01-01

    Roč. 60, June (2015), s. 234-237 ISSN 0305-1978 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : Invasive species * SSRs * Population genetics * Unionidae Subject RIV: EG - Zoology Impact factor: 0.988, year: 2015

  8. Studies on the Streptaxidae (Mollusca: Gastropoda Pulmonata) of Malawi9. Description of Gulella streptostelopsis, a new Streptostele-like species of Gulella.

    NARCIS (Netherlands)

    Bruggen, van A.C.

    2007-01-01

    Gulella streptostelopsis spec. nov. is described from a series of localities of mainly between 1000 and 1500 m a.s.l. in Malawi south of about 11°S. The minute, almost smooth, shell (length 2.0-2.4 mm) resembles that of the genus Streptostele (hence the name), but is characterized by three-fold

  9. Is the Schwabe Organ a Retained Larval Eye? Anatomical and Behavioural Studies of a Novel Sense Organ in Adult Leptochiton asellus (Mollusca, Polyplacophora Indicate Links to Larval Photoreceptors.

    Directory of Open Access Journals (Sweden)

    Lauren H Sumner-Rooney

    Full Text Available The discovery of a sensory organ, the Schwabe organ, was recently reported as a unifying feature of chitons in the order Lepidopleurida. It is a patch of pigmented tissue located on the roof of the pallial cavity, beneath the velum on either side of the mouth. The epithelium is densely innervated and contains two types of potential sensory cells. As the function of the Schwabe organ remains unknown, we have taken a cross-disciplinary approach, using anatomical, histological and behavioural techniques to understand it. In general, the pigmentation that characterises this sensory structure gradually fades after death; however, one particular concentrated pigment dot persists. This dot is positionally homologous to the larval eye in chiton trochophores, found in the same neuroanatomical location, and furthermore the metamorphic migration of the larval eye is ventral in species known to possess Schwabe organs. Here we report the presence of a discrete subsurface epithelial structure in the region of the Schwabe organ in Leptochiton asellus that histologically resembles the chiton larval eye. Behavioural experiments demonstrate that Leptochiton asellus with intact Schwabe organs actively avoid an upwelling light source, while Leptochiton asellus with surgically ablated Schwabe organs and a control species lacking the organ (members of the other extant order, Chitonida do not (Kruskal-Wallis, H = 24.82, df = 3, p < 0.0001. We propose that the Schwabe organ represents the adult expression of the chiton larval eye, being retained and elaborated in adult lepidopleurans.

  10. The complete mitochondrial genome of the land snail Cornu aspersum (Helicidae: Mollusca: intra-specific divergence of protein-coding genes and phylogenetic considerations within Euthyneura.

    Directory of Open Access Journals (Sweden)

    Juan Diego Gaitán-Espitia

    Full Text Available The complete sequences of three mitochondrial genomes from the land snail Cornu aspersum were determined. The mitogenome has a length of 14050 bp, and it encodes 13 protein-coding genes, 22 transfer RNA genes and two ribosomal RNA genes. It also includes nine small intergene spacers, and a large AT-rich intergenic spacer. The intra-specific divergence analysis revealed that COX1 has the lower genetic differentiation, while the most divergent genes were NADH1, NADH3 and NADH4. With the exception of Euhadra herklotsi, the structural comparisons showed the same gene order within the family Helicidae, and nearly identical gene organization to that found in order Pulmonata. Phylogenetic reconstruction recovered Basommatophora as polyphyletic group, whereas Eupulmonata and Pulmonata as paraphyletic groups. Bayesian and Maximum Likelihood analyses showed that C. aspersum is a close relative of Cepaea nemoralis, and with the other Helicidae species form a sister group of Albinaria caerulea, supporting the monophyly of the Stylommatophora clade.

  11. Morphological analysis of the reproductive system and molecular identification by mitochondrial markers COI and 16S rRNA of Megalobulimus oblongus (Mollusca, Strophocheilidae) of Colombia

    OpenAIRE

    Jaramillo Roldán, Erika; 1 Grupo de Microbiología Ambiental, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia. 3 Programa de Estudio y Control de Enfermedades Tropicales – PECET, Sede de Investigación Universitaria – SIU, Medellín, Colombia.; López Martínez, Jessika; 1 Grupo de Microbiología Ambiental, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia. 3 Programa de Estudio y Control de Enfermedades Tropicales – PECET, Sede de Investigación Universitaria – SIU, Medellín, Colombia.; Ramírez, Rina; Laboratorio de Sistemática Molecular y Filogeografía, Facultad de Ciencias Biológicas; y Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Av. Arenales 1256, Lima-11, Perú.; Velásquez Trujillo, Luz Elena; 1 Grupo de Microbiología Ambiental, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia. 3 Programa de Estudio y Control de Enfermedades Tropicales – PECET, Sede de Investigación Universitaria – SIU, Medellín, Colombia.

    2014-01-01

    En este trabajo se hizo el análisis morfológico y molecular a 28 caracoles terrestres de Megalobulimus oblongus, colectados en diferentes departamentos de Colombia, depositados en una colección de referencia. Para la caracterización morfológica, los animales se disecaron al estéreomicroscopio. Se describieron el sistema reproductor y la concha. Del sistema reproductor se tomaron medidas a las estructuras que lo componen. De la concha se describió la forma, el color, el número de espiras y la ...

  12. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna Mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coast of Sao Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiki; Catharino, Marilia G.M.; Moreira, Edson G., E-mail: danyseo@uol.com.br, E-mail: mbvascon@ipen.br, E-mail: mitiko@ipen.br, E-mail: mgcatharino@uol.com.br, E-mail: emoreira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de, E-mail: edvinett@usp.br [Universidade de Sao Paulo (IO/USP), Sao Paulo, SP (Brazil). Instituto Oceanografico. Laboratorio de Ecotoxicologia Marinha e Microfitobentos

    2013-07-01

    In this study the content of Br, Cl, K, Mg, Mn and V was evaluated in samples of Perna perna mussels collected in coastal regions of Sao Paulo (Ponta de Itaipu and Palmas Island, in Santos) subjected to anthropogenic contamination, to compare these values with those of mussels from reference site of Cocanha Beach (in Caraguatatuba). The mussels were collected seasonally from September 2008 to July 2009. They were cleaned, ground, homogenized, lyophilized and then analyzed by Instrumental Neutron Activation Analysis (INAA). The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 8 and 10 s, under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} in the IEA-R1 nuclear research reactor. For quality control of analytical results, certified reference materials NIST 1566b Oyster Tissue and NIST 2876 Mussel Tissue were analyzed and their results indicated good accuracy. The ranges of concentrations (dry basis) of the elements obtained in mussels collected for the four seasons of the year were: 173.80 to 358.99 mg kg{sup -1} for Br; 45658 ± 1811 to 109166 ± 824 mg kg{sup -1} for Cl; 7043 ± 856 to 12506 ± 675 mg kg{sup -1} for K; 2774 ± 211 to 5691 ± 717 mg kg{sup -1} for Mg; 7.01 ± 0.30 to 29.74 ± 3.32 mg kg{sup -1} for Mn and 0.77 ± 0.02 to 3.43 ± 0.28 mg kg{sup -1} for V. The seasonal and spatial variations of these element concentrations were in this study. (author)

  13. Vanadium determination in Perna perna mussels (Linnaeus, 1758: Mollusca, Bivalvia) by instrumental neutron activation analysis using the passive biomonitoring in the Santos coast, Brazil

    International Nuclear Information System (INIS)

    Seo, D.; Vasconcellos, M.B.A.; Catharino, M.G.M.; Moreira, E.G.; Saiki, M.; Sousa de, E.C.P.M.

    2013-01-01

    Vanadium determination present in seawater is of great importance to evaluate marine contamination from industrial sources as well as to identify health hazards since mussels and other marine organisms are used as food. Besides, this evaluation in the Santos coast, SP, Brazil, is important, since this area is impacted by industrial and urban activities and discharges from ships and boats. In a previous study, V results obtained for transplanted mussel (active biomonitoring) were presented. This study aimed the V determination by passive biomonitoring by analyzing Perna perna mussels collected in natural environment, from three sites in Sao Paulo State coast: Cocanha Beach (reference site), Ponta de Itaipu and Palmas Island. Ninety individuals of mussels were collected in each site between September/08 and July/09 during the four seasons of the year. After shell removal and sample preparation, V was determined by instrumental neutron activation analysis. For analytical quality control, the NIST Standard Reference Material SRM 1566b Oyster Tissue was analyzed and the results presented good accuracy. The V concentrations in mussels on dry mass basis varied from 0.77 ± 0.02 to 3.56 ± 0.88 mg kg -1 . Statistical tests were applied to the results showing differences on V concentrations among the sampling sites and season of sample collection. (author)

  14. On a collection of Peruvian Neniinae (Mollusca: Gastropoda: Clausiliidae), with a check-list and a provisional key to all the Peruvian species known

    NARCIS (Netherlands)

    Loosjes, F.E.; Loosjes-van Bemmel, A.C.W.

    1984-01-01

    An annotated list is given of all Neniinae collected in 1975 by Dr. A. S. H. Breure in Peru. The localities that have been visited are also listed, together with the Neniinae collected there. Pseudogracilinenia gen. nov. is described for P. huallagana (Pilsbry, 1949) (type-species) and P.jolyi (O.

  15. Calyptraeotheres sp. nov. (Crustacea: Decapoda: Pinnotheridae), symbiont of the slipper shell Crepidula striolata Menke, 1851 (Mollusca: Gastropoda: Calyptraeidae) from the Gulf of California, Mexico.

    Science.gov (United States)

    Ayón-Parente, Manuel; Hendrickx, Michel E

    2014-10-07

    Calyptraeotheres camposi sp. nov. is described from the Gulf of California, Mexico. The new species is close to C. granti (Glassell, 1933) and C. pepeluisi Campos & Hernández-Ávila, 2010 from the Mexican Pacific and to C. hernandezi Hernández-Ávila & Campos 2006 from the Western Atlantic. These four species feature a third maxilliped with a 2-segmented endopod palp and the exopod with unsegmented flagellum. Calyptraeotheres camposi sp. nov. differs from C. granti and C. hernandezi by having the eyes visible in dorsal view, the carapace with arcuate anterolateral margins, the dorsal, longitudinal depressions connected with the transversal depression, and the propodus of pereiopod 2 equal or slightly longer than the carpus. From C. pepeluisi it is distinguished by the absence of a transversal depression on the carapace and the longitudinal depressions not connecting, the carpus and propodus of the third maxilliped being sub-trapezoidal and sub-conical, respectively, in lieu of subrectangular, and the inner surface of the fixed finger nude instead of bearing short setae near the cutting edge and ventral margin.

  16. “First” abyssal record of Stenosemus exaratus (G.O. Sars, 1878 (Mollusca, Polyplacophora in the North-Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Louise Allcock

    2013-04-01

    Full Text Available The first proven abyssal record of Stenosemus exaratus (G.O. Sars, 1878 is presented on the basis of an ROV study in the Irish Sea. For the first time in situ images of the species and data on the environmental parameters are provided.

  17. Detection of genotoxicity of water from an urbanized stream, in Corbicula fluminea (Mollusca) (in vivo) and CHO-K1 cells (in vitro) using comet assay.

    Science.gov (United States)

    Rigonato, Janaina; Mantovani, Mário Sérgio; Jordão, Berenice Quinzani

    2010-07-01

    The comet assay was utilized to investigate the quality of water from seven locations along the Cambé Stream, in vivo (Corbicula fluminea hemolymph), in vitro (CHO-K1 cells), in situ, and in laboratory studies. The Cambé Stream basin (Londrina, PR, Brazil) is almost completely urbanized and receives different forms of industrial and domestic runoff. The data indicated the occurrence of DNA damage in cells examined in vivo and in vitro, shown by the significant increase in frequencies of cells with DNA damage after exposure to water from all seven locations used in the study. Our results strongly suggest the presence of genotoxic agent(s) in water at all of the sampled locations, demonstrated by elevated numbers of cells with DNA damaged in field and laboratory tests. In all of the places sampled, domestic sewage influence appeared to be one important cause for the introduction of xenobiotics, environmental genotoxins, and pollutants into the water. Thus, the comet assay applied in these cell systems was able to detect adverse environmental conditions, proving to be a very adequate short-term test and should be included in batteries of tests utilized in the monitoring of aquatic environments.

  18. Food intake of Macoma balthica (mollusca) in relation to seasonal changes in its potential food on a tidal flat in the Dutch Wadden Sea

    Science.gov (United States)

    Hummel, H.

    Food intake, absorption and presumed origin of the food were studied simultaneously throughout the year for a tidal flat population of Macoma balthica in the westernmost part of the Dutch Wadden Sea. The rate of food intake was calculated from the amount of chlorophyll a in the stomach and the rate of stomach evacuation. Highest rates of intake by Macoma were found during the first 4 hours of submersion and during the months April, May and June. During the emersion period and in winter the feeding activity was low. The total intake per submersion period was positively correlated with the concentration of chlorophyll a in the water, but not with that in the top layer of the sediment. Moreover, the season with high rates of intake coincided with the short maxima in spring for the concentrations of organic carbon and chlorophyll a in the water, but not with the longer seasonal maxima (from April to October) for these concentrations in the sediment. In the sediment mainly pennate diatoms were found, in the water centric diatoms. The algal species composition of the stomach content showed a strong resemblance to the composition of the water samples. Observations on siphon movements in the laboratory showed that Macoma spent more time with the siphon near the bottom than with the siphon extended into the water column. It is concluded that Macoma, although it behaves most of the time as a deposit feeder, depends for its food intake for the greater part on food present in the water column.

  19. Pterópodos thecosomados en el Pacífico suroriental frente a Caldera, Chile (Mollusca, Opistobranchiata: Euthecostomata y Pseudothecostomata

    Directory of Open Access Journals (Sweden)

    Mónica Labrín

    2015-03-01

    Full Text Available Se analizaron los pterópodos thecosomados colectados en una transecta oceanógrafica efectuada entre Caldera, Chile (~27°S y los alrededores de Isla de Pascua e Isla Salas y Gómez, Pacífico suroriental. Se registró un total de 2021 individuos, agrupados en 18 especies, siendo Clio pyramidata y Styliola subula especies dominantes a lo largo del transecto, las más frecuentes y representadas en 18 de las 23 estaciones analizadas. Las especies más abundantes fueron S. subula (35%, C. pyramidata (28% y Cavolinia inflexa (13%. Las siguientes especies constituyen nuevos registros para el Pacífico suroriental: Cavolinia labiata, Cavolinia uncinata, Cavolinia gibosa, Cuvierina columnella, Clio cuspidata, Clio chaptali, Diacria trispinosa, D. quadridentata, D. major, Cymbulia sp. y Peracle reticulata. La clasificación permite reconocer tres conjuntos de estaciones caracterizadas por sus especies, abundancia total, riqueza de especies y diversidad, que incluyen un conjunto nerítico (71-79°W, un conjunto oceánico (82-105°W y un conjunto de estaciones talasoepipelágicas asociadas a las islas oceánicas.

  20. Morphological and morphometric variability of the squid Lolliguncula brevis (Mollusca: Cephalopoda in Brazilian waters: evidence for two species in the western atlantic?

    Directory of Open Access Journals (Sweden)

    Tânia Zaleski

    2012-12-01

    Full Text Available Morphological and morphometric variability of the small-sized coastal squid Lolliguncula brevis was assessed along the largest part of its latitudinal range in the southern hemisphere, off the Brazilian coast (8º S - 27º S. A general homogeneity in form was found throughout the entire latitudinal range. In terms of body proportions, no latitudinal gradients were evident, but a few local "morphotypes" could be distinguished. The distinctive egg mass morphology, and size and form features, including a hectocotylus 20-40% longer than the opposing ventral arm and the presence of suckers on the buccal membrane, indicated that Lolliguncula from northern and southern hemispheres might comprise two different taxa.A variabilidade morfológica e morfométrica do pequeno loliginídeo costeiro Lolliguncula brevis foi avaliada ao longo da maior parte de sua amplitude latitudinal no hemisfério sul, ao longo da costa brasileira (8º S - 27º S. Uma homogeneidade na forma foi observada em toda sua área de ocorrência. Em termos de proporções corporais, não foram observados gradientes latitudinais evidentes, mas alguns "morfotipos" locais puderam ser distinguidos. O tamanho e as formas características, incluindo a presença de ventosas na membrana bucal, hectocótilo cerca de 20-40% maior do que o braço oposto ventral e a distinta morfologia da massa dos ovos sugerem que Lolliguncula ocorrentes no hemisférios norte e sul devam pertencer a táxons diferentes.

  1. Biología reproductiva del pulpo Octupus mimus (Mollusca: Cephalopoda de la región de Matarani, Arequipa, Perú

    Directory of Open Access Journals (Sweden)

    Victor Ishiyama

    2014-06-01

    Full Text Available De mayo de 1995 a abril de 1996, se realizaron al azar muestreos mensuales de 25 ejemplares de Octopus mimus de los desembarques del puerto de Matarani, Arequipa (16° 59'40"S y 72° 06'13"W. Son animales gonocóricos, presentan dimorfismo sexual, y los machos tienen el brazo ectocotilizado o copulador. La proporción de sexos fue de 2,1:1,0 a favor de los machos; se determinaron ocho estadios de desarrollo de los ovocitos, durante la ovogénesis. De acuerdo a su comportamiento reproductivo, se estableció la siguiente escala de madurez gonadal: a indiferenciado, b inmaduro, c inicio de maduración, d en desarrollo, e maduros, fl cópula, g postcópula, autofecundación y evacuación, h postevacuación. Las hembras maduras se encontraron preferentemente, en la primavera y verano; los machos maduros a fines de la primavera y en el verano; la cópula se realizó preferentemente durante el verano; la autofecundación y evacuación de los huevos, se evidenciaron en agosto (50%, octubre 50%, noviembre (71,4%, diciembre (33% y enero (33%. La primera madurez en los machos se encontró a los 9,5 cm y en las hembras a los 12,5 cm de la longitud dorsal del cuerpo. Se observó algunas hembras con ovocitos maduros en lisis y con inicio de ovogénesis avanzada de un nuevo ciclo, que evidencia que no todas las hembras mueren después de cuidar los huevos hasta el final de la eclosión.

  2. Crecimiento del pulpo Octopus maya (Mollusca: Cephalopoda de la costa de Yucatán, México: un análisis de largo plazo

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    Marta Rocío Nepita Villanueva

    2001-03-01

    Full Text Available Los parámetros de crecimiento del pulpo (Octopus maya de las costas de Yucatán (México fueron estimados en siete años comprendidos entre 1983-1987, 1989 y 1992. A tales efectos se realizó un análisis de frecuencia de tallas de 19 251 pulpos muestreados de la captura comercial, con un intervalo de longitud de manto comprendido entre 50 y 240 mm. Se usaron los métodos indirectos ELEFAN, PROJMAT y SLCA. La incertidumbre de las estimaciones inherente a cada método y derivada del diseño de muestreo fue analizada con la técnica jackknife. Los parámetros de crecimiento L y K se unificaron a efectos comparativos mediante el índice phi prima (. El método ELEFAN resultó ser el más adecuado para estimar los parámetros de crecimiento de O. maya, brindando valores en el rango de aquellos previamente reportados en la literatura, mientras que PROJMAT y SLCA mostraron problemas en la convergencia de los parámetros, y tendieron a subestimarlos. Las estimaciones mediante jackknife detectaron poca variabilidad intermensual en pero gran variabilidad interanual. Los estimadores de precisión de la técnica jackknife, error porcentual y coeficiente de variación porcentual, no difirieron significativamente entre métodos. Las estimaciones de derivadas del ELEFAN variaron entre 4.19 y 5.23, coincidiendo con aquellas reportadas en la literatura (entre 4.25 y 4.91, mientras que PROJMAT y SLCA aportaron valores significativamente menores. Los resultados de dicho métodos condicen además con aspectos de la biología de la especie (e.g., corta longevidad. Sugerimos utilizar el ELEFAN conjuntamente con jackknife para estimar los parámetros de crecimiento de Octopus maya.Growth of the octopus (Octopus maya off Yucatan (Mexico was estimated from a long-term study (seven years by the length-based methods ELEFAN, PROJMAT and SLCA. Some 19 251 octopuses with a range of mantle length between 50 and 240 mm were sampled from commercial landings in 1983 - 1987, 1989 and 1992. The jackknife technique was applied to deal with uncertainty in growth estimates resulting from chance variations in sampling design. The growth index was used for comparative purposes. Results differed markedly among methods: ELEFAN produced parameter estimates within the range reported in the literature, whereas PROJMAT and SLCA showed problems to converge in an optimum combination of parameters, and tended to underestimate them. Jackknife analysis revealed very low intraannual variability in but high variability among years, especially when applying PROJMAT. No significant differences were found in precision parameters -percent error and coefficient of variation- among methods. Estimates of derived by ELEFAN varied between 4.19 and 5.23 and agreed with those reported in the literature (between 4.25 and 4.91, whereas PROJMAT and SLCA estimates were significantly lower. We suggest the use of ELEFAN, together with jackknife to estimate growth parameters of Octopus maya.

  3. First report of Temnocephala haswelli (Platyhelminthes: Temnocephalida in Pomacea canaliculata (Mollusca: Ampullariidae from Brazil: description update based on specimens from the state of Rio Grande do Sul, Brazil

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    Samantha A. Seixas

    2010-06-01

    Full Text Available The impact of the discovery of Temnocephala haswelli Ponce de Léon, 1989, described as ectosymbionts of ampullariid apple snails outside of Uruguay, motivated us to collect a large number of specimens of Pomacea canaliculata (Lamarck, 1822 from several localities in the southern portion of the state of Rio Grande do Sul. This species was recorded three times after its description: in a study of chromosomes, in a study about the ultrastructure of the collar receptor cells, and in a study of the Haswell glands, all conducted in Uruguay. A total of 301 specimens of P. canaliculata were collected from 1999 to 2007. Temnocephalans found in the pallial cavity were identified as T. haswelli, which occurred in single infestations or concurrently with Temnocephala iheringi Haswell, 1893. Helminths usually showed a light-orange body pigmentation and conspicuous, intense red-eye pigment. Many taxonomic characters evidenced by several techniques were documented photographically for the first time. The typical curved cirrus, approximately 90°, typical of the species, showed some variation in the width of the shaft base, whereas the first longitudinal row of spines of the introvert appeared with shorter spines. The vagina was found to be thick-walled, but not very muscular, and to have a single, large and slightly asymmetrical sphincter, with the posterior portion of slightly larger diameter. Eggs were observed in the umbilicus and along the suture, but predominantly in the body whorl of the shell. Egg peduncles were found to be very short or, most of the time, the eggs were sessile, always with a long apical filament. The rounded shape of the dorsolateral 'excretory' syncytial epidermal plates had external margins reaching the ventrolateral region of the body and eccentric nephridiopores. This is the first record of the species outside Uruguay and in Brazil.

  4. Lucinoma kazani n.sp. (Mollusca: Bivalvia): evidence of a living benthic community associated with a cold seep in the Eastern Mediterranean Sea

    NARCIS (Netherlands)

    Salas, C.; Woodside, J.M.

    2002-01-01

    Lucinoma kazani, a new deep-water species of Lucinidae from the Eastern Mediterranean Basin, is described and illustrated. The material was collected in the Anaximander Mountains, between Rhodes and Cyprus, Eastern Mediterranean. The first living specimens were collected during the Dutch ANAXIPROBE

  5. Lucinoma kazani n. sp. (Mollusca: Bivalvia): evidence of a living benthic community associated with a cold seep in the Eastern Mediterranean Sea

    Science.gov (United States)

    Salas, C.; Woodside, J.

    2002-06-01

    Lucinoma kazani, a new deep-water species of Lucinidae from the Eastern Mediterranean Basin, is described and illustrated. The material was collected in the Anaximander Mountains, between Rhodes and Cyprus, Eastern Mediterranean. The first living specimens were collected during the Dutch ANAXIPROBE project in the Kazan volcano, at a depth of 1709 m. Later, during the MEDINAUT programme, both living specimens and shells were collected from several mud volcanoes at different depths in the Anaximander Mountains. This bivalve holds symbionts in the ctenidia, as do all previously studied Lucinidae. The type of habitat of this new species is gas-saturated mud, with high levels of methane, which diffuses upwards into a low-oxygen deep-water. Therefore, we consider this as evidence of a living cold seep community in the Eastern Mediterranean Sea.

  6. Molecular identification of similar species of the genus Biomphalaria (Mollusca: Planorbidae determined by a polymerase chain reaction-restriction fragment length polymorphism

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    Roberta Lima Caldeira

    1998-01-01

    Full Text Available The freshwater snails Biomphalaria straminea, B. intermedia, B. kuhniana and B. peregrina, are morphologically similar; based on this similarity the first three species were therefore grouped in the complex B. straminea. The morphological identification of these species is based on characters such as vaginal wrinkling, relation between prepuce: penial sheath:deferens vas and number of muscle layers in the penis wall. In this study the polymerase chain reaction restriction fragment length polymorphism technique was used for molecular identification of these molluscs. This technique is based on the amplification of the internal transcribed spacer regions ITS1 e ITS2 of the ribosomal RNA gene and subsequent digestion of these fragments by restriction enzymes. Six enzymes were tested: Dde I, Mnl I, Hae III, Rsa I, Hpa II e Alu I. The restriction patterns obtained with DdeI presented the best profile for separation of the four species of Biomphalaria. The profiles obtained with all the enzymes were used to estimate the genetic distances among the species through analysis of common banding patterns.

  7. Taxonomic and population genetic re-interpretation of two color morphs of the decollate snail, Rumina decollata (Mollusca, Pulmonata) in southern France.

    Science.gov (United States)

    Prévot, Vanya; Jordaens, Kurt; Van Houtte, Natalie; Sonet, Gontran; Janssens, Kenny; Castilho, Rita; Backeljau, Thierry

    2013-09-01

    The hermaphroditic terrestrial snail Rumina decollata has a mixed breeding system with a high prevalence of self-fertilization. In the Montpellier area (France), the species is represented by a dark and a light color morph. Based on allozyme data, both morphs have been reported as single, homozygous multilocus genotypes (MLG), differing at 13 out of 26 loci, but still showing occasional hybridization. Recent DNA sequence data suggest that each morph is a different phylogenetic species. In order to further evaluate this new taxonomic interpretation, the present contribution explores to what extent populations or color morphs indeed consist of single or few MLG. As such it is shown that both morphs are not single, homozygous MLG, but instead reveal a considerable amount of allelic variation and substantial numbers of heterozygous microsatellite genotypes. This suggests that outcrossing may be more prevalent than previously reported. Nevertheless, both morphs maintain a diagnostic multimarker differentiation in the presence of outcrossing in sympatric conditions, implying that they may be interpreted as species under the biological species concept. Finally, our data challenge the idea that simultaneous hermaphrodites should be either strict selfers or strict outcrossers.

  8. Threatened freshwater and terrestrial molluscs (Mollusca, Gastropoda et Bivalvia of Santa Catarina State, Southern Brazil: check list and evaluation of regional threats

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    2011-06-01

    Full Text Available A total of nineteen continental native mollusc species are confirmed for the Santa Catarina State (SC(organized in ten Genera and seven Families, one aquatic Prosobranchia/Caenogastropoda (Ampullariidae,six Pulmonata terrestrial gastropods (one Ellobiidae, three Megalobulimidae and two micro-snails –Charopidae and Streptaxidae and twelve freshwater mussels (eight Mycetopodidae and four Hyriidae. Thesespecies are designated by the International Union for Conservation of the Nature – IUCN as follows: seven as"Vulnerable", six "In Danger" and six “Without Category Established”. The general regional threats that thesespecies are subjected to are briefly analyzed.

  9. Evaluation of magnesium and manganese in Perna perna mussels (Linnaeus, 1758: mollusca, bivalvia) collected in the cost of the state of Sao Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiko; Cathartino, Marilia G.M.; Moreira, Edson G., E-mail: mbvascon@ipen.b, E-mail: mitiko@ipen.b, E-mail: emoreira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de, E-mail: edvinett@usp.b [Universidade de Sao Paulo (IO/USP), SP (Brazil). Inst. Oceanografico. Lab. de Ecotoxicologia Marinha e Microfitobentos

    2011-07-01

    The objective of the present study was to evaluate magnesium and manganese concentrations in Perna perna mussels by applying instrumental neutron activation analysis (INAA). The mussels were collected seasonally from September 2008 to July 2009 at Cocanha Beach in the city of Caraguatatuba (clean region), and at two sites in Santos Bay (Ponta de Itaipu and Palmas Island). The mussel samples were cleaned, grinded, homogenized, lyophilized and then analyzed by INAA. The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 10 s, under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} in the nuclear research reactor of IPEN-CNEN/SP. The measurements of the gamma radioactivity of the samples and standards were carried out using a hyperpure semiconductor Ge detector, coupled to Digital Spectral Analyzer. The elemental concentrations were calculated by the comparative method. For quality control of analytical results, certified reference materials NIST SRM 1566b oyster tissue and NRC DORM-2 Dogfish Muscle were analyzed and their results indicated good accuracy. The element concentrations in mussels on dry mass basis varied from 2734 {+-} 205 to 5138 {+-} 507 mg kg{sup -1} for Mg and from 7.35{+-}0.57 to 29.06{+-}3.35 mg kg{sup -1} for Mn. The results obtained in mussel analysis indicated that the samples collected in Itaipu in the winter season presented higher accumulation of Mg than the other sites. For Mn, the highest concentrations were obtained for the mussels collected in Palmas in summer time. (author)

  10. Prevalence and distribution of Angiostrongylus cantonensis (Nematoda, Angiostrongylidae in Achatina fulica (Mollusca, Gastropoda in Baixada Santista, São Paulo, Brazil

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    Laura Rocha Guerino

    Full Text Available ABSTRACT INTRODUCTION Angiostrongylus cantonensis is causes eosinophilic meningoencephalitis in humans. Worldwide expansion of this nematode is linked to the dispersion of their hosts. This study aimed to determine the prevalence of A. cantonensis infection in Achatina fulica in the nine municipalities that make up Baixada Santista, São Paulo, Brazil. METHODS Angiostrongylus cantonensis larvae were analyzed using optical microscopy. We performed polymerase chain reaction and restriction fragment length polymorphism using restriction endonuclease ClaI, directed to the internal transcribed spacer region 2 of A. cantonensis larval DNA. RESULTS Of the 540 snails analyzed, 117 (21.7% were infected by A. cantonensis. For morphological and morphometric analyses, 60 larvae were used. Second-stage larvae were, on average, 358.2µm long and 26.4µm wide, while third-stage larvae were, on average, 450µm long and 21.12µm wide. The tails of the larvae ended in a fine tip. CONCLUSIONS All municipalities comprising Baixada Santista had A. fulica that were naturally infected with A. cantonensis. All of the observed characteristics were typical of the species.

  11. Type specimens of Mollusca described by Col. George Montagu in the Royal Albert Memorial Museum & Art Gallery, Exeter and The Natural History Museum, London

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    P. Graham Oliver

    2017-11-01

    Full Text Available A complete list of new molluscan taxa introduced by Col. George Montagu (1753–1815 is presented. The available type material of these taxa are itemised and illustrated. The majority are present in the Royal Albert Memorial Museum & Art Gallery, Exeter with a smaller number in the Natural History Museum, London. The historic background of both collections is reviewed with special reference to the many non-British species spuriously introduced into Testacea Britannica and its Supplement.

  12. Los moluscos terrestres (Mollusca: Gastropoda de Costa Rica: clasificación, distribución y conservación

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    Zaidett Barrientos Llosa

    2010-12-01

    Full Text Available Los moluscos terrestres son un grupo muy poco estudiado a nivel mundial. Hay 183 especies reportadas para Costa Rica, 30% son endémicas y 7% posiblemente están extintas. Se espera que en el país haya alrededor de 400 especies, de más del 95% se desconoce su biología, ecología, distribución, genética y otros campos de estudio. En Costa Rica las familias con mayor número de especies son Spiraxidae, Orthalicidae y Subulinidae. No obstante, es posible que Euconulidae sea aun más diversa, pues habitan las zonas altas del país que es en donde menos trabajo se ha hecho. El estudio de regiones altas aumentará el porcentaje de endemismo. Los futuros trabajos malacológicos taxonómicos, biológicos y ecológicos deben considerar la poca movilidad de este grupo, su tendencia a formar especies nuevas en simpatría, la especificidad de requerimientos de microhábitat, el hermafroditismo, la alta tasa de evolución (10% por millón de años y la divergencia entre especies (2-30%. Para proteger adecuadamente la biodiversidad de la malacofauna costarricense, se requiere de estudios que determinen la distribución y abundancia de las especies y el efecto del uso de la tierra y del climático.

  13. Biodiversidad de gasterópodos terrestres (Mollusca en el Parque Biológico Sierra de San Javier, Tucumán, Argentina

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    María José Miranda

    2010-09-01

    Full Text Available Se realizó un inventario y se analizaron parámetros de diversidad de la malacofauna terrestre del Parque Biológico Sierra de San Javier. Se llevaron a cabo muestreos cualitativos y cuantitativos en parcelas de 10x10m tomadas en transectas altitudinales, para un total de 22 169 especímenes recolectados. Las identificaciones taxonómicas se llevaron a cabo a nivel de especie. Se construyó una matriz de especies por parcela para analizar patrones de diversidad y se utilizaron estimadores no paramétricos (ICE, ACE, Chao 1 y Chao 2 para calcular la diversidad del Parque, el grado de completitud del muestreo y la agregación espacial de los datos. Se calcularon los índices de Shannon, Simpson, Whittaker y Jaccard. La riqueza del Parque fue estimada en 32 especies distribuidas en 21 géneros y 13 familias. Solo una especie pertenece a Caenogastropoda, el resto son Pulmonados Stylommatophora y Systellommatophora. La familia más representada fue Charopidae mientras que la especie con mayor abundancia relativa fue Adelopoma tucma. La riqueza y diversidad fue levemente mayor en chaco seco que en bosque húmedo de Yungas. Los valores de diversidad obtenidos fueron elevados en comparación con estudios previos realizados en el noroeste Argentino.

  14. Ocorrência e recrutamento larval de Teredinidae (Mollusca, Bivalvia na região do Sistema Costeiro Cananéia-Iguape, São Paulo, Brasil

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    Daniela T. de Moraes

    2015-03-01

    Full Text Available A ocorrência e o recrutamento larval de Teredinidae na região do Sistema Costeiro Cananéia-Iguape foram acompanhados por doze meses utilizando-se coletores laminados de pinho, instalados em três estações dentro do bosque de mangue (mediolitoral e em uma estação, localizada no infralitoral. No manguezal, a colonização por larvas de teredinídeos ocorreu após quatro meses de permanência dos coletores na estação mais frequentemente inundada pela maré e somente após oito meses nas duas estações com menor frequência de inundação. No infralitoral, após quatro meses, os coletores já estavam consideravelmente danificados. Ao longo do experimento, houve um decréscimo no número de teredinídeos, especialmente no infralitoral, ocasionado possivelmente pela competição por alimento e espaço entre teredinídeos e foladídeos. Foram encontrados 2.658 indivíduos, sendo 704 de Teredinidae e 1.954 de Pholadidae. Entre os teredinídeos, Bankia fimbriatula foi a espécie mais abundante tanto no infralitoral quanto no manguezal, seguida de Bankia gouldi e Lyrodus floridanus que ocorreram somente no infralitoral, e Nausitora fusticula encontrada somente no manguezal. Martesia striata, único foladídeo, ocorreu somente no infralitoral.

  15. Single cell gel electrophoresis as a tool to assess genetic damage in Heleobia cf. australis (Mollusca: Gastropoda as sentinel for industrial and domestic pollution in Montevideo bay (Uruguay

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    Silvia Villar

    2015-09-01

    Full Text Available AbstractThe knowledge of the extent of DNA damage in aquatic organisms in polluted areas is an important issue because contamination may alter their health at sublethal levels. Although molluscs have been widely used to monitor water pollution, there are no records of in vivo genotoxicity studies. Heleobia cf. australis, is distributed in almost all Uruguayan coastal ecosystems, including highly polluted sites. The comet assay is a damage genetic biomarker based on the migration of negatively charged DNA fragments produced by mutagenic agents in individual cells. Live individuals were collected in the Montevideo Bay (impacted area and Laguna Garzón (control to analyze the presence of mutagenic agents in the former site through comet assay. Cells from organisms of the impacted area showed significantly higher levels of genetic damage than those obtained in the control population, measured by percentage of DNA in the tail. Although preliminary, this approach supports the idea that H. cf. australis could be used as a sentinel to evaluate the presence of mutagenic agents in estuarine environments, alerting to the impact of contamination in its early stages.

  16. Diet and stable isotope analyses reveal the feeding ecology of the orangeback squid Sthenoteuthis pteropus (Steenstrup 1855) (Mollusca, Ommastrephidae) in the eastern tropical Atlantic

    Science.gov (United States)

    Christiansen, Bernd; Javidpour, Jamileh; Piatkowski, Uwe; Puebla, Oscar; Gasca, Rebeca; Hoving, Henk-Jan T.

    2017-01-01

    In the eastern tropical Atlantic, the orangeback flying squid Sthenoteuthis pteropus (Steenstrup 1855) (Cephalopoda, Ommastrephidae) is a dominant species of the epipelagic nekton community. This carnivore squid has a short lifespan and is one of the fastest-growing squids. In this study, we characterise the role of S. pteropus in the pelagic food web of the eastern tropical Atlantic by investigating its diet and the dynamics of its feeding habits throughout its ontogeny and migration. During three expeditions in the eastern tropical Atlantic in 2015, 129 specimens were caught by hand jigging. Stomach content analyses (via visual identification and DNA barcoding) were combined with stable isotope data (∂15N and ∂13C) of muscle tissue to describe diet, feeding habits and trophic ecology of S. pteropus. Additionally, stable isotope analyses of incremental samples along the squid’s gladius—the chitinous spiniform structure supporting the muscles and organs—were carried out to explore possible diet shifts through ontogeny and migration. Our results show that S. pteropus preys mainly on myctophid fishes (e.g. Myctophum asperum, Myctophum nitidulum, Vinciguerria spp.), but also on other teleost species, cephalopods (e.g. Enoploteuthidae, Bolitinidae, Ommastrephidae), crustaceans and possibly on gelatinous zooplankton as well. The squid shows a highly opportunistic feeding behaviour that includes cannibalism. Our study indicates that the trophic position of S. pteropus may increase by approximately one trophic level from a mantle length of 15 cm to 47 cm. The reconstructed isotope-based feeding chronologies of the gladii revealed high intra- and inter-individual variability in the squid’s trophic position and foraging area. These findings are not revealed by diet or muscle tissue stable isotope analysis. This suggests a variable and complex life history involving individual variation and migration. The role of S. pteropus in transferring energy and nutrients from lower to higher trophic levels may be underestimated and important for understanding how a changing ocean impacts food webs in the eastern Atlantic. PMID:29244845

  17. Taxonomy, distribution and population structure of invasive Corbiculidae (Mollusca, Bivalvia in the Suquía River basin, Córdoba, Argentina

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    Paola B. Reyna

    2013-06-01

    Full Text Available Invasive species are one of the most significant causes of biodiversity loss and changes in ecosystem services, which underlines the importance of their detection and their study. The Asian clams (Corbiculidae are invasive organisms that accidentally entered the La Plata River, Argentina, presumably in the 1960s. The objectives of the present study were to identify the corbiculid species and to determine their distribution at several locations along the Suquía River basin, an extended area in central Argentina. In addition, population structure was evaluated monthly during one year, at a site in the city of Córdoba that is characterized by high human influence. The presence of Corbicula fluminea (Müller, 1774 and Corbicula largillierti (Philippi, 1844 in the Suquía River basin is reported for the first time. The former species was found only in a lentic environment (San Roque reservoir, while the latter was also found along the tributary rivers and brooks of the basin. Corbicula largillierti showed variations in average density between the different sites and also in biomass and size classes throughout the study period at the site at Córdoba city. The relative composition of the sediments, flow fluctuation and human pollution may be responsible for the observed differences.

  18. Morphometric study of a Brazilian strain of Carchesium polypinum (Ciliophora: Peritrichia attached to Pomacea figulina (Mollusca: Gastropoda, with notes on a high infestation

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    Roberto Júnio P. Dias

    2010-06-01

    Full Text Available During an ecological study of the epibiotic relationship between ciliate protists and Pomacea figulina (Spix, 1827 (Gastropoda, Ampullariidae, originating from an urban stream in southeast Brazil, a high infestation by the peritrich ciliate Carchesium polypinum (Linnaeus, 1758 Ehrenberg, 1830 (Ciliophora, Peritrichia associated to the shell of one mollusc among 23 was observed. We provided a morphological and morphometric study of C. polypinum using observations of specimens in vivo, after protargol staining, and examined using scanning electron microscopy. The Brazilian-population of C. polypinum is characterized by: size of zooid in vivo 89 µm x 57 µm on average; colony regularly dichotomously branched with usually up to 40 zooids; macronucleus usually J-shaped; single contractile vacuole located in the upper third of body; myoneme not continuous throughout the colony; stalks contract despite the discontinuity of their individual myonemes; polykinety comprises three peniculi, each consisting of three kineties. The high infestation showed here could be related to the preference for eutrophic environments showed by C. polypinum and suggested that ciliate epibionts may be ecologically important in aquatic habitats.

  19. Effect of pollution on some freshwater species. I. histochemical and biochemical features of lead pollution on some organs of Viviparus viviparus L. (Mollusca Gastropoda)

    Energy Technology Data Exchange (ETDEWEB)

    Benedetti, I.; Benedetti, L.; Bolognani, L.; Bolognani Fantin, A.M.; Marini, M.; Ottaviani, E.

    1982-01-01

    Experimental lead pollution was studied in some organs (foot, mantle and digestive gland) of Viviparus viviparus L. The amount of lead contained after 48h, 96 h and one week of pollution were established using an atomic absorption spectrophotometer. On the basis of physicochemical determination, it turns out that lead is mainly concentrated in the mantle. The biochemical tests (cholesterol, sulpholipids and phospholipids) were aimed at evaluating the lipids involved in the membranes. The histochemical research was carried out chiefly to evaluate the modifications of polysaccharides and proteins. Some hydrolytic enzymes (Na+ and K+ dependent ATPase) and some ooreductive enzymes (NADH+ and NADPH+ dependent diaphorases, D-lactate dehydrogenase, succinate dehydrogenase and glucose-6-P-dehydrogenase) were also tested. The digestive gland is the most severely damaged organ as proved by histomorphological and biochemical analyses.

  20. Bait formulations of molluscicides and their effects on biochemical changes in the ovotestis of snail Lymnaea acuminata (Mollusca; Gastropoda:Lymnaeidae

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    Pradeep Kumar

    2011-10-01

    Full Text Available The effect of sub-lethal feeding of bait formulations containing molluscicidal component of Ferula asafoetida (ferulic acid, umbelliferone, Syzygium aromaticum (eugenol and Carum carvi (limonene on biochemical changes in the ovotestis of snail Lymnaea acuminata were studied. Bait formulations feeding to L. acuminata were studied in clear glass aquaria having diameter of 30 cm. Baits were prepared from different binary combinations of attractant amino acid (valine, aspartic acid, lysine and alanine 10 mM in 100 mL of 2% agar solution + sub-lethal (20% and 60% of 24h LC50 doses of different molluscicides (ferulic acid, umbelliferone, eugenol and limonene. These baits caused maximum significant reduction in free amino acid, protein, DNA, RNA levels i.e. 41.37, 23.56, 48.36 and 14.29% of control in the ovotestis of the snail, respectively. Discontinuation of feeding after treatment of 60% of 96h LC50 of molluscicide containing bait for next 72h caused a significant recovery in free amino acid, protein, DNA and RNA levels in the ovotestis of L. acuminata.

  1. First report of Temnocephala rochensis (Platyhelminthes: Temnocephalida from Pomacea canaliculata (Mollusca: Ampullariidae outside Uruguay: description update based on specimens from the state of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Samantha A. Seixas

    2010-10-01

    Full Text Available Temnocephala rochensis Ponce de Léon, 1979, was the second of four species of Temnocephala Blanchard, 1849 to be described as ectosymbiont of ampullariid apple snails, Pomacea canaliculata (Lamarck, 1822. There have been no records of this Uruguayan species after its initial description. As part of the present study, 111 specimens of P. canaliculata were collected between 2003 and 2009. Temnocephalans found in the pallial cavity were identified as T. rochensis, occurring in single infestations, or concurrently with Temnocephala haswelli Ponce de Léon, 1989. Specimens of T. rochensis showed a conspicuous red eye pigment which faded after ethanol fixation. Important taxonomic characters of the reproductive system were evidenced by several techniques, and documented photographically for the first time for this species: 1 the typical curved cirrus of the species showing very short and stout spines; 2 the vagina with the proximal portion dilated, forming a "vesicula intermedia"; and 3 the distal portion very muscular, as well as the large and symmetrical vaginal sphincter were documented in detail with Nomarski's DIC microscopy. Eggs were observed in the suture, in the spire, and in the umbilicus of the shell; they had a short peduncle or were sessile, always with short and curved, sometimes straight apical filaments. The rounded shape of the dorsolateral 'excretory' syncytial epidermal plates had central nephridiopores. This is the first record of this species outside of Uruguay and in the State of Rio Grande do Sul, Brazil. Even with extended sampling efforts in the eastern region of Rio Grande do Sul, T. rochensis has not been found, showing a geographical distribution restricted to the southern region, close to its type locality of Laguna Negra, Uruguay.

  2. Evaluation of magnesium and manganese in Perna perna mussels (Linnaeus, 1758: mollusca, bivalvia) collected in the cost of the state of Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiko; Cathartino, Marilia G.M.; Moreira, Edson G.; Sousa, Eduinetty C.P.M. de

    2011-01-01

    The objective of the present study was to evaluate magnesium and manganese concentrations in Perna perna mussels by applying instrumental neutron activation analysis (INAA). The mussels were collected seasonally from September 2008 to July 2009 at Cocanha Beach in the city of Caraguatatuba (clean region), and at two sites in Santos Bay (Ponta de Itaipu and Palmas Island). The mussel samples were cleaned, grinded, homogenized, lyophilized and then analyzed by INAA. The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 10 s, under a thermal neutron flux of 6.6 x 10 12 n cm -2 s -1 in the nuclear research reactor of IPEN-CNEN/SP. The measurements of the gamma radioactivity of the samples and standards were carried out using a hyperpure semiconductor Ge detector, coupled to Digital Spectral Analyzer. The elemental concentrations were calculated by the comparative method. For quality control of analytical results, certified reference materials NIST SRM 1566b oyster tissue and NRC DORM-2 Dogfish Muscle were analyzed and their results indicated good accuracy. The element concentrations in mussels on dry mass basis varied from 2734 ± 205 to 5138 ± 507 mg kg -1 for Mg and from 7.35±0.57 to 29.06±3.35 mg kg -1 for Mn. The results obtained in mussel analysis indicated that the samples collected in Itaipu in the winter season presented higher accumulation of Mg than the other sites. For Mn, the highest concentrations were obtained for the mussels collected in Palmas in summer time. (author)

  3. Emergence, development, and maturity of the gonad of two species of chitons "sea cockroach" (Mollusca: Polyplacophora) through the early life stages.

    Science.gov (United States)

    Avila-Poveda, Omar Hernando; Abadia-Chanona, Quetzalli Yasú

    2013-01-01

    This study describes and recognises, using histological and microscopical examinations on a morphometrical basis, several gonad traits through the early life stages of Chiton articulatus and C. albolineatus. Gonadal ontogenesis, gonad development stages, sexual differentiation, onset of the first sexual maturity, and growth sequences or "early life stages" were determined. In addition, allometry between lengths and body weight pooled for both sexes per each chiton were calculated using equation Y = aX(b) . A total of 125 chitons (4≤TL≤40 mm, in total length "TL") were used. All allometric relations showed a strong positive correlation (r), close to 1, with b-values above three, indicating an isometric growth. Gonadal ontogenesis and gonad development stages were categorised into three periods ("Pw" without gonad, "Pe" gonad emergence, and "Pf" gonadal sac formed) and four stages ("S0" gametocytogenesis, "S1" gametogenesis, "S2" mature, and "S3" spawning), respectively. Compound digital images were attained for each process. Periods and stages are overlapped among them and between species, with the following overall confidence intervals in TL: Pw 6.13-14.32 mm, Pe 10.32-16.93 mm, Pf 12.99-25.01 mm, S0 16.08-24.34 mm (females) and 19.51-26.60 mm (males), S1 27.15-35.63 mm (females) and 23.45-32.27 mm (males), S2 24.48-40.24 mm (females) and 25.45-32.87 mm (males). Sexual differentiation (in S0) of both chitons occurs first as a female then as a male; although, males reach the onset of the first sexual maturity earlier than females, thus for C. articulatus males at 17 mm and females at 32 mm, and for C. albolineatus males at 23.5 mm and females at 28 mm, all in TL. Four early life stages (i.e., subjuvenile, juvenile, subadult, and adult) are described and proposed to distinguish growth sequences. Our results may be useful to diverse disciplines, from developmental biology to fisheries management.

  4. New records of Omalonyx matheroni (Pontiez & Michaud, 1835 (Mollusca, Gastropoda, Succineidae for the São Paulo and Paraná States.

    Directory of Open Access Journals (Sweden)

    Maria Cristina Dreher Mansur

    2009-06-01

    Full Text Available Omalonyx matheroni is a succineid gastropod that lives on aquatic macrophytes and on emergent vegetation in the wetlands of inner deltas, lakes and dikes. Occurrences of this species were recorded in the municipalities of Ibitinga (SP and Paranaguá (PR, broadening its distribution southwards in South America. Until now this species had been recorded in Demerara (Guiana, Zanderij and Belwaarde (Suriname, Guiana Francesa, Peru, Limoncocha (Equador, Amazonas, Pará, Pernambuco, Rio de Janeiro and Minas Gerais (Brazil, as well as on the islands of Guadalupe and Trinidade.

  5. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna Mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coast of Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiki; Catharino, Marilia G.M.; Moreira, Edson G.; Sousa, Eduinetty C.P.M. de

    2013-01-01

    In this study the content of Br, Cl, K, Mg, Mn and V was evaluated in samples of Perna perna mussels collected in coastal regions of Sao Paulo (Ponta de Itaipu and Palmas Island, in Santos) subjected to anthropogenic contamination, to compare these values with those of mussels from reference site of Cocanha Beach (in Caraguatatuba). The mussels were collected seasonally from September 2008 to July 2009. They were cleaned, ground, homogenized, lyophilized and then analyzed by Instrumental Neutron Activation Analysis (INAA). The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 8 and 10 s, under a thermal neutron flux of 6.6 x 10 12 n cm -2 s -1 in the IEA-R1 nuclear research reactor. For quality control of analytical results, certified reference materials NIST 1566b Oyster Tissue and NIST 2876 Mussel Tissue were analyzed and their results indicated good accuracy. The ranges of concentrations (dry basis) of the elements obtained in mussels collected for the four seasons of the year were: 173.80 to 358.99 mg kg -1 for Br; 45658 ± 1811 to 109166 ± 824 mg kg -1 for Cl; 7043 ± 856 to 12506 ± 675 mg kg -1 for K; 2774 ± 211 to 5691 ± 717 mg kg -1 for Mg; 7.01 ± 0.30 to 29.74 ± 3.32 mg kg -1 for Mn and 0.77 ± 0.02 to 3.43 ± 0.28 mg kg -1 for V. The seasonal and spatial variations of these element concentrations were in this study. (author)

  6. Observations on the symbiosis between Colus gracilis (Da Costa, 1778) (Mollusca: Gastropoda) and Hormathia digitata (O.F. Müller, 1776) (Cnidaria: Actiniaria)

    NARCIS (Netherlands)

    Ates, R.M.L.

    1998-01-01

    Aquarium observations of the behaviour of the actinian Hormathia digitata when mounting live specimens of the gastropod Colus gracilis are fully described for the first time. C. gracilis actively initiates an association with H. digitata by approaching and remaining stationary near the actinian.

  7. Registro de Achatina fulica Bowdich, 1822 (Mollusca, Gastropoda no Brasil: caramujo hospedeiro intermediário da angiostrongilíase

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    Santana Teles Horácio Manuel

    1997-01-01

    Full Text Available A introdução de Achatina fulica é assinalada em Itariri, SP, Brasil. Essa espécie de caramujo terrestre foi importada para cultivo, visando à comercialização para consumo humano como "escargot". O encontro de exemplares em vida livre mostra a dispersão de A. fulica e, conseqüentemente, o risco de transmissão de Angiostrongylus cantonensis, nematóide parasita do homem e de outros vertebrados. Além disso, o caramujo é uma praga importante da agricultura.

  8. Registro de Achatina fulica Bowdich, 1822 (Mollusca, Gastropoda no Brasil: caramujo hospedeiro intermediário da angiostrongilíase

    Directory of Open Access Journals (Sweden)

    Horácio Manuel Santana Teles

    1997-06-01

    Full Text Available A introdução de Achatina fulica é assinalada em Itariri, SP, Brasil. Essa espécie de caramujo terrestre foi importada para cultivo, visando à comercialização para consumo humano como "escargot". O encontro de exemplares em vida livre mostra a dispersão de A. fulica e, conseqüentemente, o risco de transmissão de Angiostrongylus cantonensis, nematóide parasita do homem e de outros vertebrados. Além disso, o caramujo é uma praga importante da agricultura.

  9. Phylogeny of selected Sepiidae (Mollusca, Cephalopoda) based on 12S, 16S, and COI sequences, with comments on the taxonomic reliability of several morphological characters.

    Science.gov (United States)

    Yoshida, Masa-aki; Tsuneki, Kazuhiko; Furuya, Hidetaka

    2006-04-01

    Phylogenetic relationships among 11 species of sepiids from Japanese waters and Sepia officinalis from Mediterranean were studied using partial sequences of the mitochondrial 12S rRNA, 16S rRNA, and cytochrome c oxidase subunit I genes. These three genes had been analyzed in an Atlantic species S. elagans and was obtained from database. In the two-gene set analysis (16S+COI), sequence data of another 4 species were added from database. We also studied morphological characters of radulae, tentacular clubs, and cuttlebones. The molecular phylogeny was not congruent with relationships detected by the number of rows in radulae and the arrangement of suckers on the tentacular club. As to the cuttlebone shape, the molecular phylogeny suggests the separation of two groups, Doratosepion species with a lanceolate cuttlebone and the others with a broad cuttlebone. Our molecular phylogenetic study revealed these sepiids are separated into four clades. The first clade includes Sepia officinalis, S. hierrendda, S. bertheloti, S. pharaonis and Sepiella japonica. The second clade consists of S. latimanus and Metasepia tullbergi from sub-tropical waters. The third clade includes Sepia esculenta, S. madokai, S. aculeata and S. lycidas, which have a cuttlebone with a prominent spine. The fourth clade consists of Doratosepion species complex, S. kobiensis, S. lorigera, S. pardex, S. peterseni, and S. sp., which are characterized by a narrow cuttlebone with a distinct outer cone at the posterior end. The lack of membranous structures in the cuttlebone is a synapomorphy for this clade. S. elegans did not clearly belong to any of these clades and might represent the fifth clade.

  10. Pleurolucina from the western Atlantic and eastern Pacific Oceans: a new intertidal species from Curaçao with unusual shell microstructure (Mollusca, Bivalvia, Lucinidae

    Directory of Open Access Journals (Sweden)

    Emily A. Glover

    2016-09-01

    Full Text Available A new shallow water species of the lucinid bivalve Pleurolucina is described from Curaçao in the southern Caribbean Sea and compared with known species of the genus from the western Atlantic and eastern Pacific Oceans. Although confused with the Floridian species P. leucocyma, it is most similar to the eastern Pacific P. undata. As in all studied lucinids, the new species possesses symbiotic bacteria housed in the ctenidia. The shell microstructure is unusual with repeated and intercalated conchiolin layers that have sublayers of ‘tulip-shaped’ calcareous spherules. Predatory drillings by naticid gastropods frequently terminate at the conchiolin layers.

  11. Invertebrates Collected on and around Carroll Island, Maryland.

    Science.gov (United States)

    INVERTEBRATES, *MARYLAND, *WATER POLLUTION, TEST FACILITIES, TEST FACILITIES, ECOLOGY, CHESAPEAKE BAY, WATER POLLUTION, AIR POLLUTION, ANNELIDA, MOLLUSCA, PROTOZOA, ARTHROPODA , CRUSTACEA, ARACHNIDA, PLANKTON, WORMS.

  12. Heavy metals (cadmium and lead) in the estuarine croaker ...

    African Journals Online (AJOL)

    A study to determine the concentrations of cadmium (Cd) and lead (Pb) in the muscles of Pseudotolithus elongatus as well as estimating the condition and growth pattern of the fish was carried out in 2013. Ten samples of the croaker P. elongatus were purchased from the Mile One market, Port Harcourt, Nigeria and their ...

  13. The influence of diet and isolation on growth and survival in the land snail Bulimulus tenuissimus (Mollusca: Bulimulidae in laboratory Influência da dieta no crescimento e na sobrevivência de Bulimulus tenuissimus (Mollusca: Bulimulidae mantidos isolados e agrupados em condição de laboratório

    Directory of Open Access Journals (Sweden)

    Liliane M. O. Meireles

    2008-06-01

    Full Text Available Feed influences directly growth and survival in land snails. Here, we investigate the influence of diet and isolation on growth and survival in Bulimulus tenuissimus (d'Orbigny, 1835 in the laboratory. Animals were maintained individually and in groups and three different types of diets: lettuce, ration and both lettuce and ration (mixed diet for 210 days. Isolated animals, in all diet types, grew more rapidly than grouped animals. Also, snails fed with lettuce grew most slowly in isolated or grouped treatments. Within isolated or grouped treatments, growth rates were similar for the ration and the mixed diet. Mortality rate was higher in animals fed on lettuce only, in both density treatments. Thus, diet and density are important components of the population dynamics of B. tenuissimus.O conteúdo energético e a aglomeração intra-específica são fatores que influenciam diretamente aspectos da biologia de moluscos terrestres. Foi investigada a influência da dieta sobre o crescimento e a sobrevivência de Bulimulus tenuissimus (d'Orbigny, 1835 mantidos agrupados e isolados em terrários plásticos e submetidos a três tipos diferentes de dietas: alface, ração e ração e alface (RA, por um período de 210 dias. Foi verificado que os animais mantidos isolados, independentemente, do tipo de dieta oferecida apresentaram maior crescimento do que aqueles mantidos agrupados, evidenciando a influência da densidade populacional no crescimento. Moluscos alimentados com dieta alface apresentaram o menor crescimento, tanto mantidos agrupados quanto isolados. Não houve diferença significativa entre o crescimento dos animais mantidos agrupados e isolados alimentados com as dietas RA e ração. A taxa de mortalidade foi significativamente maior para os indivíduos alimentados com a dieta alface em ambas as densidades. Tais resultados evidenciam que a dieta oferecida exerceu grande influência na biologia de B. tenuissimus.

  14. Simbiontes associados com Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae na Ilha de Santa Catarina e região continental adjacente, Santa Catarina, Brasil Symbionts associated with Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae on Santa Catarina Island and adjacent continental region, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Guisla Boehs

    2004-12-01

    Full Text Available Berbigões, Anomalocardia brasiliana (Gmelin, 1791, de bancos naturais da Ilha de Santa Catarina e região continental adjacente (SC, Brasil, foram examinados quanto a presença de simbiontes. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia e poliquetos espionídeos (Polychaeta foram observados macroscopicamente. A análise das secções histológicas evidenciou esporocistos de trematódeos (Digenea, um metacestóide (Cestoda e dois ciliados (Ciliophora.Pointed venus, Anomalocardia brasiliana (Gmelin, 1791, from natural beds of Santa Catarina Island and adjacent continental region (SE Brazil were examined in respect of symbiotic associations. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia, and polychaete worms (Polychaeta were found by macroscopic diagnosis. By analysis of histological sections, it was noted trematode sporocysts (Digenea, a metacestode (Cestoda and two ciliates (Ciliophora.

  15. Long-term controlled field experiment on the competition between two species of Biomphalaria (Mollusca, Basommatophora, the snail vectors of Schistosoma mansoni in Northeastern Brazil Estudo experimental de campo sobre a competição entre duas espécies de Biomphalaria (Mollusca, Basommatophora, vetores do Schistosoma mansoni no Nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Constança S. Barbosa

    1993-06-01

    Full Text Available A long-term controlled field experiment on the interactions of the populations of Biomphalaria glabrata (target population and B. straminea (competitor was carried out in the county of Alhandra, state of Paraíba, Brazil, during the period 1980 through 1989. Results obtained in the current paper show that the snail B. straminea has strong competitive advantages over B. glabrata. In six out of nine streams the native population of B. glabrata were totally excluded and replaced by B. straminea. There is evidence showing that seasonal dryness has marked influence on the phenomenon studied in this paper. In all the streams were B. straminea already predominated, return of B. glabrata was never observed.Um estudo experimental de campo sobre a interação populacional entre Biomphalaria glabrata (população-alvo e Biomphalaria straminea (competidor foi realizado no município de Alhandra, PB, no período de 1980 a 1989. Os resultados deste experimento nos levam a considerar que é possível a indução de um processo competitivo entre B. glabrata e B. straminea, uma vez que em nove dos criadouros trabalhados até o final, seis deles tiveram as populações da espécie endêmica totalmente substituídas pelo caramujo competidor. O processo competitivo ocorreu mais eficazmente naqueles criadouros sujeitos à dessecação, o que parece ter favorecido a espécie competidora, que resiste bem mais aos períodos de seca. Não houve regressão do processo, ou seja, em todos os riachos onde B. straminea se estabeleceu, o caramujo alvo não voltou a proliferar.

  16. Distribución temporal de larvas de Mytilus chilensis (Hupé, 1954 (Mollusca: Mytilidae, en el mar interior de Chiloé, sur de Chile Temporal distribution of larvae of Mytilus chilensis (Hupé, 1854 (Mollusca: Mytilidae, in the interior sea of Chiloé, southern Chile

    Directory of Open Access Journals (Sweden)

    Miguel Avendaño

    2011-11-01

    Full Text Available Entre septiembre 2007 y marzo 2008, en Quillaipe, Metri, Sotomo, Canutillar y Pichicolo (mar interior de Chiloé, se determinó mensualmente la presencia larval de M. chilensis, mediante arrastres verticales de plancton, en una columna de 0-7,5 m y paralelamente se determinó histológicamente el estado reproductivo de ejemplares adultos. Se detectó permanentemente la presencia de larvas en los cinco sitios estudiados, con un significativo incremento entre octubre y diciembre, superando en Canutillar 49 mil larvas por m-3, sitio que junto a Sotomo registraron las mayores densidades. El análisis de cohortes mostró una similitud de los grupos larvales presentes en los diferentes sitios a partir de septiembre, acentuándose durante noviembre y diciembre, así como una permanente aparición de cohortes en estadios iniciales. En contraste con estos resultados, el proceso reproductivo de M. chilensis en estos sitios, se manifestó de enero a marzo. Se discute que los desoves registrados en estos sitios, no serían responsables de la presencia de las larvas, actuando en consecuencia como áreas receptoras, y de retención de larvas provenientes de otros sitios. Estos resultados sugieren la necesidad de profundizar conocimientos biológicos y ecológicos en áreas de distribución de la especie, así como de dinámica larval y post-larval para identificar áreas exportadoras y de retención, para contribuir a un manejo eficiente y optimizar la captación de semilla.The larval presence of M. chilensis was determined monthly from September 2007 to March 2008, in Quillaipe, Metri, Sotomo, Canutillar, and Pichicolo (interior sea of Chiloé using vertical plankton trawls through a water column from 0 to 7.5 m. At the same time, the reproductive stage of adult individuals was determined histologically. Larvae were detected continuously at the five study sites, with a significant increase from October to December, exceeding 49 thousand per m-3 at Canutillar where, along with Sotomo, the greatest densities were recorded during the study. Cohort analysis showed a similarity in the larval cohorts present at the different sites from September onwards; this was accentuated in November and December, as was the constant appearance of cohorts in the initial stages. In contrast with these results, the reproductive process of M. chilensis at these sites occurred from January to March. Whether or not the spawning recorded at these sites is responsible for the observed larvae is a matter of debate, as the sites may receive and retain larvae exported from other sites. These results suggest a need to compile further biological and ecological knowledge on the areas where this species is distributed and its larval and post-larval dynamics in order to identify exporting and retention areas and thereby contribute to efficient management and the optimization of spat collection.

  17. Influência do substrato sobre a reprodução de Subulina octona (Brugüière (Mollusca, Subulinidae, sob condições de laboratório Influence of substrate on reproduction of Subulina octona (Brugüière (Mollusca, Subulinidae, under laboratorial conditions

    Directory of Open Access Journals (Sweden)

    Sthefane D'ávila

    2005-03-01

    Full Text Available O objetivo deste trabalho foi determinar se o substrato influencia a reprodução de indivíduos da espécie Subulina octona (Brugüière, 1789, mantidos em três diferentes substratos: areia, argila e terra vegetal. Foram analisados os seguintes parâmetros: número de ovos produzidos a cada evento reprodutivo, tempo para o alcance da maturidade sexual, idade dos indivíduos a cada evento reprodutivo, intervalo entre eventos reprodutivos, número total de ovos por indivíduo, número total de eventos reprodutivos por indivíduo e aumento do número de ovos de um evento para o subseqüente. O substrato influenciou o tempo necessário para o alcance da maturidade sexual, bem como o tempo para a realização dos eventos reprodutivos subseqüentes ao primeiro, a produção de ovos, o número total de ovos produzidos e de eventos reprodutivos de S. octona. Indivíduos mantidos em caixa com terra vegetal levaram mais tempo para realizar o primeiro, segundo, terceiro e quarto evento reprodutivo, produziram menos ovos, no segundo, terceiro e quarto evento e apresentaram um intervalo maior entre o primeiro e segundo evento.The influence of substrate on reproduction of Subulina octona (Brugüière, 1789, reared in sand, clay and humus, was investigated under laboratorial conditions. There were significant differences in onset of sexual maturity, egg production, shell length and aging in each reproductive event, total number of eggs produced and total number of reproductive events. The individuals reared in humus spent more time to reach sexual maturity, as well as to accomplish the subsequent reproductive events. Moreover, produced fewer eggs in the second, third and fourth ovipositions and exhibited a longer interval between the first and second reproductive events. After 120 days of experiment such individuals had produced fewer eggs, and performed fewer reproductive events, when compared with those kept in sand and clay. There was a progressive decline in egg number increase with time. In this study was also observed that S. octona of different developmental stages fed on substrate and the molluscs reared in humus consumed less food. This is probably due to the fact that humus is more likely to be take as food resource. So that, the snails reared in humus tend to consume more substrate and less ration, obtaining less proteins, carbohydrates and calcium than those snails reared in sand and clay. This low intake of ration might have negative effects over reproduction of the snails.

  18. Caracterização morfológica e molecular de Corbicula (Mollusca, Bivalvia no reservatório de Rosana, Brasil - DOI: 10.4025/actascibiolsci.v27i4.1274 Morphological and molecular characterization of Corbicula (Mollusca, Bilvalvia at Rosana Resevoir, Brazil - DOI: 10.4025/actascibiolsci.v27i4.1274

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    Alberto José Prioli

    2005-03-01

    Full Text Available O objetivo do presente estudo foi verificar através de técnicas moleculares, RAPD e ISSR aliadas à caracterização morfológica da concha dos bivalves, se os indivíduos morfologicamente distintos de Corbicula fluminea amostrados no reservatório de Rosana pertencem a espécies diferentes. O tecido muscular do pé dos três grupos (G1, G2 e G3 de Corbicula foi removido e congelado em nitrogênio líquido para a análise do DNA. As variáveis morfométricas das conchas indicaram diferenças significativas entre os indivíduos de Corbicula. Por outro lado, as análises moleculares revelaram similaridade genética, evidenciando a não existência de polimorfismo molecular. Os resultados confirmam que os dois grupos diferentes morfologicamente também pertencem a espécie C. fluminea, demonstrando a ocorrência de plasticidade fenotípica, provavelmente causada por fatores bióticos ou ambientaisThe purpose of the present study was to verify, using RAPD and ISSR molecular techniques associated with the morphological characterization of bivalve shells, if the morphologically distinct specimens of Corbicula fluminea sampled at Rosana Reservoir belong to different species. The foot muscle tissue of the three groups (G1, G2, and G3 of Corbicula was removed and frozen in liquid nitrogen to the DNA analyze. Morphometric variables of the shell indicated significant differences among the specimens of Corbicula. On the other hand, molecular analyses revealed genetic similarity among the specimens, showing the nonexistence of molecular polymorphism. The data confirmed that the two morphologically different groups also belong to the species C. fluminea, showing the occurrence of phenotypic plasticity, probably caused by environmental or biotic factors

  19. Novos registros de Veronicellidae (Gastropoda, Mollusca para Itabuna, Bahia, Brasil e sua ocorrência no conteúdo estomacal de serpentes do gênero Dipsas Laurenti (Colubridae New record for Itabuna, Bahia, Brazil of Veronicellidae (Gastropoda, Mollusca and its occurrence in the stomach contents of snakes Dipsas Laurenti (Colubridae

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    José Willibaldo Thomé

    2001-03-01

    Full Text Available The predominant occurrence of the species Sarasinula marginata (Semper, 1885 in 31 lots, all proceeding from the stomach contents of the snakes Dipsas Laurenri, 1768 was determined. A species still not determined of Novovaginula Thiele, 1931 was represented in 10 lots and in a living collected lot (with only one specimen, not mature. One-third species, Potamojanuarius fuscus (Heynemann, 1885 is represented only in a lot of slugs collected alive (seven specimens and was confirmed in a lot of four specimens, this of the Museum of Zoology, University of São Paulo (USP, São Paulo. All the other lots were sent by F.Q. Alves, Department of Zoology, State University of São Paulo (UNESP, Botucatu, São Paulo.

  20. Occurrence of Aelurostrongylus abstrusus (Railliet, 1898 larvae (Nematoda: Metastrongylidae infecting Achatina (Lissachatina fulica Bowdich, 1822 (Mollusca: Gastropoda in the Amazon region Ocorrência de Aelurostrongylus abstrusus (Railliet, 1898 (Nematoda: Metastrongylidae infectando o Achatina (Lissachatina fulica Bowdich, 1822 (Mollusca: Gastropoda na região amazônica

    Directory of Open Access Journals (Sweden)

    Sanny Maria de Andrade-Porto

    2012-06-01

    Full Text Available Achatina fulica or "giant African snail" is an exotic species, considered to be one of the world's hundred most invasive species, causing serious environmental damages. In the present study we report, for the first time, the occurrence of Aelurostrongylus abstrusus infecting A.fulica in the Amazon region. This nematode is described parasitizing mainly the pulmonary system of felines, which causes "aelurostrongilose", also known as feline cardio-pulmonary strongyloidosis. New morphometric data of third stage larvae are presented herein. The present study demonstrated that 40% of all the snails were infected by A. abstrusus. Achatina fulica specimens were collected from three different areas in Manaus namely: rural; east and west areas. The east area presents the highest prevalence of 80%. The large number of A.fulica found in inhabited areas increases the chances of emergent zoonoses, which highlights the need of further studies so as to better control this disease.Achatina fulica ou "caramujo africano" é uma espécie exótica, considerada uma das cem piores espécies invasoras do mundo, causando sérios danos ambientais. No presente estudo foi registrado, pela primeira vez, a ocorrência do Aelurostrongylus abstrusus infectando o A.fulica na região amazônica. Esse nematóide é descrito parasitando principalmente o sistema pulmonar de felinos, causando a "aelurostrongilose", também conhecida como estrongiloidose cardio-pulmonar felina. Novos dados morfométricos de larvas de terceiro estágio são apresentados. Dos 45 caramujos coletados, 40% estavam infectados por larvas de A. abstrusus. Especimens de Achatina fulica foram coletados em três áreas da cidade de Manaus: rural, leste e oeste. A zona leste apresentou a maior prevalência de 80%. O grande número de A.fulica encontrado em áreas habitadas aumenta as chances de ocorrência de zoonoses emergentes e destaca a necessidade de mais estudos para o melhor controle da doença.

  1. Molluscan Evolutionary Development

    DEFF Research Database (Denmark)

    Wanninger, Andreas Wilhelm Georg; Koop, Damien; Moshel-Lynch, Sharon

    2008-01-01

    Brought together by Winston F. Ponder and David R. Lindberg, thirty-six experts on the evolution of the Mollusca provide an up-to-date review of its evolutionary history. The Mollusca are the second largest animal phylum and boast a fossil record of over 540 million years. They exhibit remarkable...

  2. Geologie van die Addo-Olifant Nasionale Park

    Directory of Open Access Journals (Sweden)

    D. K Toerien

    1972-12-01

    Full Text Available Geologiese aspekte van die Addo-olifant Nasionale Park word beskryf. Die topografie, fisiografie en geologic word behandel, asook 'n aanduiding van fossiele (hoofsaaklik Mollusca wat aangetref word. Geological aspects of the Addo Elephant National Park are described. The topography, physiography and geology is discussed, including a brief survey of fossils (mainly Mollusca encountered.

  3. Molluscs of the Krkonoše Mts. (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Juřičková, L.; Ložek, Vojen

    2008-01-01

    Roč. 7, 10. září (2008), s. 55-69 ISSN 1336-6939 Institutional research plan: CEZ:AV0Z30130516 Keywords : Mollusca * Krkonoše Mts. * faunistic Subject RIV: EG - Zoology http://mollusca.sav.sk/pdf/7/7.Jurickova.pdf

  4. Marine Ecological Index Survey of San Diego Bay

    Science.gov (United States)

    2013-03-01

    Seasonally Hypersaline, Estuarine Echinodermata Amphipholis squamata SP Seasonally Hypersaline, Thermal Arthropoda Ampithoe plumulosa SP Seasonally...Thermal Arthropoda Synalpheus lockingtoni 40 Region Type  Sample Phylum Species Estuarine Seine Echinodermata Amphipholis squamata Estuarine Seine Chordata...spinohirsutus Marine Sieve Echinodermata Amphipholis squamata Thermal Sieve Mollusca Notoucmea insessa Seasonally Hypersaline Sieve Mollusca

  5. ORF Alignment: NC_004113 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available occus ... elongatus BP-1] pdb|1S5L|UU Chain u, Architecture Of The ... Photosynthetic Oxygen E...volving Center pdb|1S5L|U Chain ... U, Architecture Of The Photosynthetic Oxygen Evolving ...

  6. ORF Alignment: NC_004369 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available occus ... elongatus BP-1] pdb|1S5L|UU Chain u, Architecture Of The ... Photosynthetic Oxygen E...volving Center pdb|1S5L|U Chain ... U, Architecture Of The Photosynthetic Oxygen Evolving ...

  7. Description d’un Gyrinide nouveau

    NARCIS (Netherlands)

    Régimbart, M.

    1887-01-01

    Oralis, sat elongatus, valde convexus, corpore subtus pedibusque pallide testaceis, supra subtilissime reticulatus, niger, anguste flavolimbatus, in capite et pronoto viridi-aenescens, elytris nigris vix metallicis, in regionibus punctatis brunneotomentosis, costa discoïdali sat lata, ante apicem

  8. Coléoptères nouveaux ou peu connus du Musée de Leyde

    NARCIS (Netherlands)

    Fairmaire, L.

    1887-01-01

    Long. 13 millim. — Elongatus, modice convexus, rufus, modice nitidus, capite infuscato, fulvo-pubescens, subtus cum pedibus dilute rufescens, tarsis obscuris; capite summo fortiter punctato, antice transversim late impresso et subtilius sed densius punctato, labro rufescente, late sinuato; antennis

  9. Species-specific differences of the spectroscopic properties of P700 - Analysis of the influence of non-conserved amino acid residues by site-directed mutagenesis of photosystem I from Chlamydomonas reinhardtii

    NARCIS (Netherlands)

    Witt, H.; Bordignon, E.; Carbonera, D.; Dekker, J.P.; Karapetyan, N.; Teutloff, C.; Webber, A.; Lubitz, W.; Schlodder, E.

    2003-01-01

    We applied optical spectroscopy, magnetic resonance techniques, and redox titrations to investigate the properties of the primary electron donor P700 in photosystem I (PS I) core complexes from cyanobacteria (Thermosynechococcus elongatus, Spirulina platensis, and Synechocystis sp. PCC 6803), algae

  10. Mobile acoustic telemetry data - Lingcod Stock Enhancement: ecological interactions, fishery contributions, and life history

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Lingcod (Ophiodon elongatus) populations along the West Coast of North America have recovered from overfishing, but the status of genetically distinct lingcod in...

  11. Tag effect data - Lingcod Stock Enhancement: ecological interactions, fishery contributions, and life history

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Lingcod (Ophiodon elongatus) populations along the West Coast of North America have recovered from overfishing, but the status of genetically distinct lingcod in...

  12. Description of a new genus and species of the Coleopterous family Colydidae

    NARCIS (Netherlands)

    Reitter, E.

    1882-01-01

    Corpus valde elongatum, convexum. Antennae 11-articulatae, sub frontis margine ante oculos insertae, apicem versus sensim incrassatae, articulo ultimo rotundato. Fronte tateribus elevata. Oculi antice emarginati. Prothorax elongatus, carinatus. Scutellum minutum. Elytra punctatostriata, interstitiis

  13. Freshwater Mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at Selected Sites Within the 9-Foot Navigation Channel Project for the St. Paul District, United States Army Corps of Engineers, 1977 - 1979. Volume II. Appendices.

    Science.gov (United States)

    1980-09-10

    as caz’nata A J T R H Ligwnia recta L. subrost rat a Carunculina parva Lampsilis terea L. higginsi L. radiata siliquoidea L. ovata ventricosa Plagio ...radiata siZiquc’idea 1 1 0.?2 X L. ovata ventricosa 2 2 0. 3 Plagio Za trique tra X Arcidens con fragosus 2 2 0.3 Lasmiqona camptlcnata L. cost ata L

  14. O enigma da "reação espermatofórica": breve síntese do conhecimento sobre a estrutura e o funcionamento dos espermatóforos dos cefalópodes (Mollusca: Cephalopoda

    Directory of Open Access Journals (Sweden)

    José Eduardo Amoroso Rodriguez Marian

    2011-01-01

    Full Text Available Cefalópodes coleóides (lulas, sépias e polvos produzem espermatóforos muito complexos que são transferidos à fêmea durante a cópula por meio do hectocótilo, um apêndice modificado nos machos. Durante a transferência à fêmea, ocorre a chamada "reação espermatofórica", complexo processo de evaginação do aparato ejaculatório do espermatóforo, que conduz à exteriorização da massa espermática e corpo cimentante. A presente revisão sintetiza o conhecimento acerca da morfologia e funcionamento desta estrutura exclusiva dos coleóides, identificando lacunas e definindo estratégias que possibilitem avanços na área. Poucos trabalhos abordam com detalhes a morfologia e anatomia funcional dos espermatóforos dos cefalópodes, grande parte do conhecimento acerca da estrutura do espermatóforo tendo sido gerada por trabalhos clássicos do século XIX e início do século XX. Investigações acerca do funcionamento dos espermatóforos são consideravelmente mais raras, estando o conhecimento básico sobre a reação espermatofórica restrito a apenas 19 espécies de coleóides. A revisão da literatura especializada permite sugerir que existem dois tipos básicos de fixação de espermatóforos em Decapodiformes (lulas e sepióides: fixação superficial e implante profundo (ou intra-dérmico. Na fixação superficial, comum em diversas espécies (e.g., Loliginidae, Sepiidae, Ommastrephidae, a base dos espermatângios é aderida ao tecido-alvo aparentemente por meio do corpo cimentante, a partir de substâncias adesivas e, em alguns casos, estruturas de fixação. No implante profundo, comum em alguns grupos de lulas oceânicas e de águas profundas (e.g., Architeuthidae, Cranchiidae, Octopoteuthidae, Sepiolidae, os espermatóforos implantam-se inteiramente no corpo da fêmea, de forma autônoma. Permanece desconhecido o mecanismo responsável pelo implante profundo. Em Octopodiformes (polvos, o espermatóforo é inserido no gonoduto feminino, alcançando a glândula oviducal, onde estão localizadas as espermatecas, ou a cavidade do ovário. Como o funcionamento extracorpóreo dos espermatóforos depende exclusivamente da intrincada estrutura e organização de seus componentes (e.g., membranas e túnicas, somente investigações detalhadas dessas estruturas proverão as bases para a compreensão do funcionamento e da exata função do complexo espermatóforo dos coleóides. Recomenda-se o desenvolvimento de um protocolo simples e eficiente para coloração e preparação total de espermatóforos, de forma que seja possível expandir as descrições morfológicas do espermatóforo em estudos taxonômicos e anatômicos, permitindo, portanto, ampliação do conhecimento acerca desta enigmática estrutura.

  15. Taxonomical study on a sample of pulmonates from Santa Maria da Vitória, Bahia, Brazil, with description of a new genus and four new species (Mollusca: Orthalicidae and Megalobulimidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2012-01-01

    Full Text Available A sample of Pulmonata collected in Santa Maria da Vitória, interior of Bahia, Brazil, in Caatinga semi-arid environment, is studied taxonomically. From the five species, four are revealed as new, including a new genus. The new taxa are the Bulimulidae (1 Kora corallina gen. et sp. n. characterized by the elongated shell with aperture somewhat dislocated from the shell axis, and an oblique tooth in middle level of inner lip; (2 Spixia coltrorum, mainly characterized by an uneven spire, delicate sculpture and peristome with 4 equidistant teeth; (3 Anostoma tessa, mainly characterized by a broad spire and well-developed anal canal; and the Megalobulimidae (4 Megalobulimus amandus, mainly characterized by pointed protoconch sculptured by dense quantity of axial cords. Rhinus suturalis is the only previously known species, but its geographic distribution is expanded southwards to Bahia state. A discussion with respect to necessity for improving the study on the malacofauna from the interior region of the Brazilian Northeast and the importance for preservation of the Caatinga biome is also provided.

  16. Ciclo de vida de Dysopeas muibum (Mollusca, Subulinidae em laboratório: efeito do isolamento sobre padrões biológicos e conquiliomorfométricos

    Directory of Open Access Journals (Sweden)

    Vinícius J. Pilate

    2013-12-01

    Full Text Available O conhecimento dos aspectos biológicos e morfológicos dos moluscos terrestres é importante para o desenvolvimento de medidas de controle de pragas e de estratégias de conservação de espécies. O presente trabalho teve como objetivo caracterizar os padrões de biologia e conquiliomorfometria de Dysopeas muibum Marcus & Marcus, 1968 e verificar o efeito do isolamento sobre seu ciclo de vida e a morfometria da concha, em condições de laboratório. Foi realizado o acompanhamento do crescimento da concha, da liberação de filhotes e da mortalidade de 80 moluscos, dos quais 40 foram mantidos isolados e 40 agrupados (10 moluscos por grupo em condições naturais de temperatura, umidade relativa e fotoperíodo, desde o nascimento até 180 dias de vida, quando então foram aferidas as medidas da concha. Os moluscos foram criados em terrários plásticos vedados com tecido de algodão e elástico, tendo como substrato terra vegetal esterilizada e alimentados com ração para frangos enriquecida com carbonato de cálcio. Foi verificado que os indivíduos possuem a concha pequena, alongada e são capazes de se reproduzir por autofecundação. Possuem crescimento indeterminado, iteroparidade, baixa mortalidade antes e após a maturidade sexual e a fecundidade aumenta de acordo com o tamanho corporal. O isolamento atuou na fecundidade, embora não tenha influenciado o crescimento, o alcance da maturidade sexual, a relação crescimento-reprodução, a mortalidade e a conquiliomorfometria.

  17. Moluscos em área de horticultura no município de Porto Alegre, Rio Grande do Sul, Brasil Mollusca in horticultural production area in Porto Alegre county, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Gisela Bruschi-Figueiró

    2002-12-01

    Full Text Available Horticultural production areas are favorable to development and maintenance of land mollusks populations. To know the mollusk fauna diversity in that kind of production area a research project was conduced in a rural-urban district of Porto Alegre, Rio Grande do Sul, Brazil. The production property studied is located in the Southern zone of the city and has 17 ha of cultivated area. The sampling period was from August/2000 to August/2001, with monthly quantitative collects on the different culture production beds previously selected. Six taxa were registered: Deroceras leave (Müller, 1774 (1.389 specimens = 82,82%, Bradybaena similaris (Férussac, 1821 (195 specimens = 11,7%, Succinea meridionalis d'Orbigny, 1846 (82 specimens = 4,9%, Lamellaxis gracilis (Hutton, 1834 (03 specimens = 0,17%, Bulimulus (Bulimulus vesicalis angustus Weyrauch, 1966 (05 specimens = 0,3% and Megalobulimus abbreviatus (Bequaert, 1948 (02 specimens = 0,11 %, only the last two being natives.

  18. Cuantificación de metales pesados en Anadara tuberculosa(Mollusca:bivalvia del estero Huaylá de Puerto Bolívar, por espectrofotometría de absorción atómica

    Directory of Open Access Journals (Sweden)

    Collaguazo-Collaguazo, Yadira

    2017-09-01

    Full Text Available The presence of heavy metals in bivalve molluscs implies a serious problem for the consumers health of this type of food. Therefore, the objective of the present investigation was to determine the presence of heavy metals in Anadara tuberculosa, mollusc of commercial importance at Puerto Bolívar, Ecuador. Atomic absorption spectrophotometry was the method used to quantify the concentration of heavy metals. The concentration of six metals was determined: lead (Pb, arsenic (As, mercury (Hg, cadmium (Cd, chromium (Cr and cobalt (Co. The average values obtained, expressed in mg.kg-1 were: Pb (7.52 ± 0.46; As (1.55 ± 0.14; Hg (364.38 ± 91.39; Cd (1.68 ± 0.28; Cr (3,89 ± 1,82 and Co (2,71 ± 0,34 in A. tuberculosa The results show that Pb, As, Cd, and Hg exceed the maximum permissible limits, mercury exceeds by more than 100 times the limit value. The smaller size (3-4 cm studied mollusc, has the capacity to bioaccumulate higher concentration of Pb, Cd and Cr.

  19. Genetic diversity of the biofilm covering Montacuta ferruginosa (Mollusca, bivalvia) as evaluated by denaturing gradient gel electrophoresis analysis and cloning of PCR-Amplified gene fragments coding for 16S rRNA

    NARCIS (Netherlands)

    Gillan, D.C.; Speksnijder, Arjen; Zwart, G.; De Ridder, C.

    1998-01-01

    The shell of the bivalve Montacuta ferruginosa, a symbiont living in the burrow of an echinoid, is covered with a rust- colored biofilm, This biofilm includes different morphotypes of bacteria that are encrusted with a mineral rich in ferric ion and phosphate, The aim of this research was to

  20. Use of Population Parameters in Examining Changes in the Status of the Short-Necked Clam Paphia undulata Born, 1778 (Mollusca, Pelecypoda: Veneridae in Coastal Waters of Southern Negros Occidental

    Directory of Open Access Journals (Sweden)

    Anabelle del Norte Campos

    2010-06-01

    Full Text Available Growth, recruitment, mortality and exploitation rate of the short-necked clam Paphia undulata (Born, 1778 were studied in southern Negros Occidental waters between August 2007 and July 2008 from length-frequency data derived from catches of divers, to be able to compare with earlier data derived and analyzed 13 years ago by Agasen et al. (1998. Both sets of data were analyzed using the FiSAT software (Gayanilo & Pauly, 1997. The asymptotic shell length (S¥ = 79 mm derived from the present data proved to be smaller compared to the earlier data (SL¥ = 81.5 mm due to the lack of bigger sizes in the present samples. The growth constant (K = 1.0 yr-1 was however comparable indicating it to be a more species-characteristic parameter. Two recruitment pulses for each study were derived and were found to be correlated with the spawning pattern in the species. The value of natural mortality (M = 1.57 yr-1 derived from bivalve literature, is deemed more appropriate compared to the earlier estimate (M = 2.89 yr-1 based on Pauly’s (1980 empirical equation developed for fish. Total mortality (Z values for both studies were comparable, but a higher level of fishing mortality (F = 4.61 yr-1 was estimated for the present data set, thus resulting likewise in a higher exploitation rate (E = 0.75. These, together with fishery information from an accompanying paper (Villarta & del Norte-Campos, 2010, not only validate the earlier findings of overexploitation due to lack of management, but reveal a worsening condition of the stock, most likely as a result of growth overfishing. Overexploitation can only be mitigated by imposing stringent restrictions in terms of the minimum size for exploitation (45 mm shell length and closed seasons during the spawning peak (August-November.

  1. Fresh-Water Mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at Selected Sites within the 9-Foot Channel Navigation Project on Behalf of the U.S. Army.

    Science.gov (United States)

    1978-06-16

    Nautilus, 92: 1-9. Cvancara, A. M., and Harrison, S. S. 1965. Distribution and ecology of mussels in the Turtle River, North Dakota. Proceedings of the...North Dakota Academy of Science, 19: 128-146. Cvancara, A. M., Heetderks, R. G., and lljana, F. J. 1969. Local distribution of mussels, Turtle River...Leggett, W. C. 1977. The ecology of fish migrations. Annual Review of Ecology and Systematics, 8: 285-308. Lillie, F. R. 1895. The embryology of the

  2. Freshwater Mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at Selected Sites Within the 9-Foot Navigation Channel Project for the St. Paul District, United States Army Corps of Engineers, 1977 - 1979. Volume I. Text.

    Science.gov (United States)

    1980-09-10

    motor’s vibration through the rope to the brail was minimized. Five-minute "brail runs" were generally used; at the end of a run, the brail was raised...River--1978. ASB Bulletin, 27(2): 54. 13! Parker, R . S. 19 79 O (bservat ions onl the rcp roduct ivxe hi 010 t~, of {Z §h22. (Lamarck) (Bi val1via

  3. Redescription of Temnocephala iheringi (Platyhelminthes: Temnocephalida based on specimens from Pomacea canaliculata (Mollusca: Ampullariidae of the state of Rio Grande do Sul, Brazil: the possible type host and type locality

    Directory of Open Access Journals (Sweden)

    Samantha A. Seixas

    2010-04-01

    Full Text Available The original description of Temnocephala iheringi Haswell, 1893 was based on specimens collected by Hermann von Ihering from undetermined ampullariid apple snails, which at that time were identified as Ampullaria sp., and sent to William H. Haswell, with the type locality simply indicated as Brazil. The type specimens studied by Haswell were not found in the scientific collections of Brazil, Europe or Australia, and should be considered lost. In 1941, Pereira & Cuocolo collected specimens from apple snails, identified as Pomacea lineata (Spix in Wagner, 1827, at two localities (Guaicurús and Salobra in the state of Mato Grosso do Sul, central Brazil. These specimens could not be located either and should, thus, be considered lost as well. Pomacea canaliculata (Lamarck, 1822, the main host of T. iheringi in southern Brazil, is known to have a geographical distribution that reaches Uruguay and 400 km beyond the province of Buenos Aires, Argentina. Three hundred and one mollusks were collected from 1999 to 2007. Temnocephalans found in the pallial cavity presented a greenish body pigmentation (adults and lacked eye pigment of any color, including the red-eye pigment, typical of Neotropical species of Temnocephala Blanchard, 1849; straight cirrus, with a thick band at base of the introvert' swelling; and a single, circular, asymmetric vaginal sphincter, wider in diameter in the posterior portion. As the species occurs concurrently with two other species, at least in P. canaliculata from Rio Grande do Sul, the eggs of T. iheringi could not be reliably distinguished. A redescription of the species is provided. A comparison of data from the present work with those of earlier papers published on T. iheringi from Argentina showed that the Argentinean specimens had the smallest measurements.

  4. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    Full Text Available Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818 no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior, eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M e 46,3% como fêmeas (F, não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, também, no mês de outubro de 2002.

  5. Density, size structure, shell orientation and epibiontic colonization of the fan mussel Pinna nobilis L. 1758 (Mollusca: Bivalvia in three contrasting habitats in an estuarine area of Sardinia (W Mediterranean

    Directory of Open Access Journals (Sweden)

    Piero Addis

    2009-03-01

    Full Text Available We investigated the spatial distribution, size structure, shell orientation and valve colonization by epibionts of the endangered Mediterranean bivalve Pinna nobilis in three continuous but different habitats in the Gulf of Oristano (Sardinia, western Mediterranean. The sampling stations chosen were: an estuarine area (E of coastal salt-marshes characterized by unvegetated sea-bottoms; and two areas in a seagrass meadow characterized by an extensive Posidonia oceanica meadow (Mw and patched mixed meadows of P. oceanica and Cymodocea nodosa (Me. We found significant differences in mean densities among stations and the highest value was found in the estuarine area. Shell orientation showed that there was uniform circular distribution of specimens in the Mw station and a unimodal distribution in the Me and E stations, where specimens were set at 0°N and 10°NNE, which is a pattern related to sea drift. Shell epibiosis displayed differences between habitats. The highest valve colonization was in the estuary, with filamentous dark algae and Ostrea edulis reaching almost 90 percent of shell coverage. This study provides new information on habitat preferences and data for assessing local populations of P. nobilis that is useful for its conservation and improving the knowledge of its ecology.

  6. Atual distribuição geográfica dos moluscos hospedeiros intermediários do Schistosoma mansoni em Belo Horizonte, MG, Brasil Current geographic distribution of intermediate hosts mollusca of Schistosoma mansoni in Belo Horizonte, MG, Brazil

    Directory of Open Access Journals (Sweden)

    Cecília Pereira de Souza

    1981-12-01

    Full Text Available Procedeu-se ao levantamento malacológico do município de Belo Horizonte, MG, com o objetivo de avaliar a distribuição, densidade e taxa de infecção dos moluscos hospedeiros intermediários do Schistosoma mansoni. Foram coletadas 3.261 Biomphalaria glabrata em 1979-81, das quais 100 (3,1% estavam infectadas com S. mansoni. Registrou-se a existência de 36 criadouros (35,0% de B. glabrata em 102 locais pesquisados, sendo 23 na bacia hidrográfica de Pampulha e 13 na do ribeirão do Arrudas. Foram encontrados 2 criadouros de B. tenagophila e 2 de B. straminea. Registrou-se também a presenca de exemplares de Pomacea haustrum, Physa sp e Drepanotrema cimex. Compararam-se os dados obtidos atualmente com os publicados em 1967. Houve reducao de mais de 50% no número de criadouros de B.glabrata, principalmente em decorrencias da expansão e progresso da cidade. Na zona periférica a esquistossomose continua endêmica, havendo necessidade de novas obras de saneamento básico para se conseguir o controle da doença.Malacological surveys were conducted in Belo Horizonte with a view to obtain new data on the distribution and density of schistosomose bearing snails and their natural rate of infection by Schistosoma mansoni. Of 3.261 Biomphalaria glabrata collected during 1979-81, 100 (3,1% were found naturally infected. One hundred and two water collections were surveyed and 36 (35% were found harboring the mentioned snail species (23 of them in the watershed of Pampulha, 13 in the tributaires of the Arrudas creek. The species B. tenagophila was found in two waterbodies, and B. straminea in two other. Other snail species collected were Pomacea haustrum, Physa sp and Drepanotrema cimex. Data of this survey were compared with data published in 1967 and 50% reduction in the snail breeding places was observed. This reduction was due mainly to public works and engineering activities accompanying the growth of city. Schistosomiasis is still present in the periphery of the city and only engineering works will be able to eliminate this health problem.

  7. Catálogo de los Uniónidos (Mollusca, Unionidae de la península Ibérica conservados en el Museo Nacional de Ciencias Naturales (CSIC

    Directory of Open Access Journals (Sweden)

    Soriano, Óscar

    2001-06-01

    Full Text Available From the 1987, we are working in the recuration process of the collections from the Museo Nacional de Ciencias Naturales (MNCN. In 1999, among other achievements, 1357 specimens of unionids from the Iberian Peninsula have been catalogued; these specimens are from the collections of González Hidalgo, Paz y Membiela, Azpeitia, Álvarez, Cobos, etc. The habitats of the species of unionids experienced a gradual deterioration during the second half of the XXth century due to their relative intolerance to pollution. Actually, most collecting localities of the specimens in the MNCN are not suitable habitat for unionids today. The fast regression suffered by the Iberian species underscores the need to proceed to the recovery and the conservation of the aquatic ecosystems where species belonging to this family are present, before their total disappearance takes place. It is necessary to gather the information deposited in public and private collections, that could contribute to determine more accurately the past distribution of these species.

    Desde el año 1987 se están recuperando las colecciones del Museo Nacional de Ciencias Naturales. Durante 1999, entre otros trabajos, se han catalogado los 1363 ejemplares de uniónidos de la península Ibérica, que procedentes de las colecciones de González Hidalgo, Paz y Membiela, Azpeitia, Álvarez, Cobos, etc., se conservan en el museo. El progresivo deterioro que, en la segunda mitad del siglo XX, han tenido los hábitats de las especies de la familia que aquí tratamos, ha producido, su desaparición en gran parte de las localidades de las que se conserva representación en las colecciones del museo. La rápida regresión sufrida por las especies ibéricas, nos pone de manifiesto la necesidad de proceder a la recuperación y a la conservación de los ecosistemas acuáticos con presencia de especies pertenecientes a esta familia, antes de que se produzca su total desaparición. Por todo ello, se hace necesario conocer la información que se recoge en colecciones públicas o privadas y que podría contribuir a conocer la distribución que, en tiempos pasados, tenían estas especies.

  8. Vertical distribution, segregation by size and recruitment of the yellow clam Mesodesma mactroides Deshayes, 1854 (Mollusca, Bivalvia, Mesodesmatidae) in exposed sandy beaches of the Rio Grande do Sul state, Brazil.

    Science.gov (United States)

    Bergonci, P E A; Thomé, J W

    2008-05-01

    The vertical distribution and the segregation by size of the yellow clam Mesodesma mactroides Deshayes, 1854 were investigated in the intertidal zone and its limits with the lower and upper shores at exposed sandy beaches of Rio Grande do Sul state, Brazil. The gathering was made throughout 12 months; from the Pinhal beach towards the south of the State, in six 15 km equidistant transects, determined through random selection. In these transects, the calculation of 30 consecutive waves was made in order to determine its average amplitude point (P0), from which two points were marked towards the lower shore (P-1 and P-2) and three towards the upper shore (P1, P2 and P3). A 30 by 50 cm cylinder was buried down to the depth of 40 cm, the material was separated with a 0.25 cm mesh and the specimens were quantified and measured in length. The yellow clam presented segregation by size, especially between recruit and adult individuals, with recruits occupying preferably the zones above P0 and adults from this point towards the sea. The young specimens are distributed through all zones, mixed with adult and recruit specimens, which dismisses the hypothesis of segregation by size in function of competition for space and food, once the burying depth is directly proportional to their length. However, the segregation between recruits and adults might be related to the filtering mechanism of the adults, which could ingest the larva, as well as the fact that the recruits, being small and light, are easily transported to the regions above P0. Seasonal migration was observed for adult individuals during winter and spring, probably associated to the reproduction period of the species, being that the peak of recruitment was greater in the end of the winter and the beginning of spring.

  9. Localitzada una nova població de Xerosecta explanata (O.F. Müller, 1774) (Mollusca: Gastropoda) al litoral de Castelló (est de la península Ibèrica)

    OpenAIRE

    Prades Bataller, Ramón; Llopis Raimundo, Ana

    2014-01-01

    Es comunica la localització de Xerosecta explanata (O. F. Müller, 1774) al litoral de Castelló, a Alcossebre, terme municipal d’Alcalà de Xivert (el Baix Maestrat). Aquesta espècie, exclusiva d’ambients dunars de la Mediterrània occidental, només havia estat citada a Castelló al terme de Peníscola (Bofill, 1915; Gasull, 1975, 1981) i, des d’aleshores ençà, no s’ha tornat a trobar. X. explanata presenta greus problemes de conservació per l’alteració de l’hàbitat on viu.New Xerosecta explanata ...

  10. The Mass-Dimension Relationships in the Mussels Mytilus Galloprovincialis (Mollusca, Bivalvia from Different Phenotypical Groups in Periphyton Populations near Odessa Coast, the North-Western Part of Black Sea

    Directory of Open Access Journals (Sweden)

    Govorin I. A.

    2016-06-01

    Full Text Available The data of the size-mass indices in the mussels Mytilus galloprovincialis (Lamarck, 1819 from three phenotypic groups - brown, dark violet (black and “zebra” (brown with radial black stripes shells in the periphyton settlements on the concrete traverses near Odessa coast, the North-western part of Black Sea (Ukraine, in March-November 2014-2015 are presented. A comparative evaluation has been made on the relationships of total mass of the mollusks, wet and dry mass of their soft body and mass of the shells on the one hand, and the size of animals (length of its shells on the other hand, in the each of phenotypical groups from the five marine beach areas. It is shown, that in the marine areas with different degrees of isolation from the open sea by coast-protection engineering constructions, the mussels from different phenotypes have almost the same size-mass characteristics. Only the dry weight of soft animal body, which indicated to fatness of mollusk and therefore demonstrated his biological prosperity in specific hydrological conditions, can serve as a reliable criterion which can mark the shellfish habitats with different gradients of environmental factors.

  11. Phylogeny of Selected Sepiidae (Mollusca, Cephalopoda) Based on 12S, 16S, and COI Sequences, with Comments on the Taxonomic Reliability of Several Morphological Characters(Animal Diversity and Evolution)

    OpenAIRE

    Masa-aki, Yoshida; Kazuhiko, Tsuneki; Hidetaka, Furuya; Department of Biology, Graduate School of Science, Osaka University; Department of Biology, Graduate School of Science, Osaka University; Department of Biology, Graduate School of Science, Osaka University

    2006-01-01

    Phylogenetic relationships among 11 species of sepiids from Japanese waters and Sepia officinalis from Mediterranean were studied using partial sequences of the mitochondrial 12S rRNA, 16S rRNA, and cytochrome c oxidase subunit I genes. These three genes had been analyzed in an Atlantic species S. elagans and was obtained from database. In the two-gene set analysis (16S+COI), sequence data of another 4 species were added from database. We also studied morphological characters of radulae, tent...

  12. Análisis morfológico del sistema reproductor e identificación molecular a través de los marcadores mitocondriales COI y 16S rRNA de Megalobulimus oblongus (Mollusca, Strophocheilidae de Colombia

    Directory of Open Access Journals (Sweden)

    Erika Jaramillo Roldán

    2014-05-01

    Full Text Available En este trabajo se hizo el análisis morfológico y molecular a 28 caracoles terrestres de Megalobulimus oblongus, colectados en diferentes departamentos de Colombia, depositados en una colección de referencia. Para la caracterización morfológica, los animales se disecaron al estéreomicroscopio. Se describieron el sistema reproductor y la concha. Del sistema reproductor se tomaron medidas a las estructuras que lo componen. De la concha se describió la forma, el color, el número de espiras y la ornamentación e igualmente se tomaron medidas básicas usando un calibrador digital. Para el análisis molecular se usaron dos marcadores mitocondriales, el 16S rRNA y el gen Citocromo Oxidasa C subunidad I (COI. Ambos marcadores confirmaron la presencia de un único haplotipo en los ejemplares, aun para individuos situados en regiones biogeográficas diferentes y distantes. Este estudio sugiere que en Colombia M. oblongus se encuentra en peligro, por lo que urgen investigaciones sobre reproducción, genética poblacional y biogeografía que esclarezcan su situación en el país. Demuestra además que las colecciones de referencia y los bancos de tejidos son fuentes de información de gran valor, ya que permiten conocer aspectos relacionados con el riesgo en que se encuentran las especies y que sirven de insumo para el diseño de acciones de conservación.

  13. Distribution and habitats of Melanoides tuberculata (Müller, 1774 ...

    African Journals Online (AJOL)

    The conservation status of these 2 species and the possible influence of global warming and climatic changes on their geographical distribution are briefly discussed. Keywords: Melanoides tuberculata, Melanoides victoriae, geographical distribution, habitat preferences, biological control, Trematoda, freshwater Mollusca, ...

  14. Molluscan shell evolution with review of shell calcification hypothesis

    Czech Academy of Sciences Publication Activity Database

    Furuhashi, T.; Schwarzinger, C.; Mikšík, Ivan; Smrž, Miloslav; Beran, A.

    2009-01-01

    Roč. 154, č. 3 (2009), s. 351-371 ISSN 1096-4959 Institutional research plan: CEZ:AV0Z50110509 Keywords : mollusca * shell * biomineralization Subject RIV: CE - Biochemistry Impact factor: 1.607, year: 2009

  15. Ledová doba z pohledu zoologa. II. Glaciál ve světle rozboru fosilních zoocenóz

    Czech Academy of Sciences Publication Activity Database

    Ložek, Vojen; Horáček, I.

    -, č. 2 (2004), s. 50-54 ISSN 0044-4812 Institutional research plan: CEZ:AV0Z3013912 Keywords : glacial Mollusca (Vertebrata, Warm Summers, Refugia) * SE Carpathians * Balkans Subject RIV: DB - Geology ; Mineralogy

  16. Browse Title Index

    African Journals Online (AJOL)

    Mollusca: Basommatophora: Ancylidae), Abstract PDF ... Aspects of the anatomy and histology of the alimentary canal of the greater cane rat, Thryonomys swinderianus, with reference to its feeding physiology, Abstract.

  17. Měkkýši údolí Vltavy (Čechy)

    Czech Academy of Sciences Publication Activity Database

    Horáčková, J.; Ložek, V.; Beran, L.; Juřičková, L.; Podroužková, Š.; Peterka, Jiří; Čech, Martin

    2014-01-01

    Roč. 13, - (2014), s. 12-105 ISSN 1336-6939 Institutional support: RVO:60077344 Keywords : faunistics * inventory * Mollusca * river floodplain * Lucilla scintilla * Margaritifera margaritifera Subject RIV: EH - Ecology, Behaviour

  18. Variações no comprimento dos indivíduos de uma população do mexilhão dourado, Limnoperna fortunei (Mollusca: Bivalvia: Mytilidae, ao longo do ano, na Praia do Veludo, Lago Guaíba, Rio Grande do Sul, Brasil Length variation over a one-year period in specimens of the golden mussel, Limnoperna fortunei (Mollusca: Bivalvia: Mytilidae from Veludo Beach, Guaíba Lake, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Cintia P. dos Santos

    2008-09-01

    Full Text Available The individual size of Limnoperna fortunei (Dunker, 1857 was evaluated twice a month, for a year, based on samples from Veludo Beach (30º12'35"S, 51º11'68"W in Guaiba Lake, southern Porto Alegre, Brazil. Physical and chemical data on water quality, such as temperature, transparency, depth, pH, dissolved oxygen, phosphorus, nitrogen, chlorophyll "a", and conductivity were also recorded. Adult samples were collected from underwater "sarandi" branches, Cephalanthus glabratus (Spreng K. Schum (Rubiaceae, an aquatic macrophyte available at each site. Adults placed on artificial substrates were also checked every six months. Data were analyzed by applying multivariate statistics techniques related to the physical and chemical variables of the water and the density of individuals to estimate the patterns of the individual growth over the year. The adults were separated into three groups according to length classes: G1, G2 and G3 (groups 1 through 3. These three groups are related to the differences in behavior, namely, the ability of locomotion and fixation capacity. Individuals from Group 1 (5 to 7 mm in length were the most abundant and were present in all the sampled months. Adults from artificial substrates were shown to display significant differences in seasonal growth and faster growth during spring and summer months.

  19. The anatomy of the serotonergic nervous system of an entoproct creeping-type larva and its phylogenetic implications

    DEFF Research Database (Denmark)

    Wanninger, Andreas Wilhelm Georg; Fuchs, Judith; Haszprunar, Gerhard

    2007-01-01

    Abstract. Although the internal phyletic relationships of Spiralia (and Lophotrochozoa) remain unresolved, recent progress has been made due to molecular phylogenetic analyses as well as developmental studies of crucial taxa such as Mollusca, Sipuncula, or Annelida. Despite this progress, the phy......Abstract. Although the internal phyletic relationships of Spiralia (and Lophotrochozoa) remain unresolved, recent progress has been made due to molecular phylogenetic analyses as well as developmental studies of crucial taxa such as Mollusca, Sipuncula, or Annelida. Despite this progress...

  20. Early development of the aplacophoran mollusc Chaetoderma

    DEFF Research Database (Denmark)

    Nielsen, Claus; Haszprunar, Gerhard; Ruthensteiner, Bernhard

    2007-01-01

    The early development of the trochophore larva of the aplacophoran Chaetoderma nitidulum (Mollusca: Caudofoveata = Chaetodermomorpha) is described using scanning and transmission electron microscopy and using fluorescence staining and confocal laser scanning microscopy of the muscle system. The m...... of the early anlagen of the circular body wall muscles does not show the anterior-posterior mode of formation that is typical for annelids, thus strengthening the hypothesis of a non-segmented ancestry of Mollusca....

  1. A revised geographical range for Liolaemus elongates Koslowsky, 1896 (Squamata: Liolaemini in Argentina: review of reported and new-data based distribution with new localities

    Directory of Open Access Journals (Sweden)

    Ignacio Minoli

    2013-12-01

    Full Text Available Estimating the effective geographical ranges of species is central to species-oriented conservation and management. In this paper, we review the geographical distribution of Liolaemus elongatus Koslowsky, 1896 with three new records for northern Chubut and southern Río Negro provinces, Argentina. Based on detailed locality records pooled from multiple data sources, including new records obtained for this study, we revise the range of L. elongatus sensu stricto and provide geographical distribution maps comparing the previously recognized range to that proposed herein. Our results show that L. elongatus possesses a much more limited geographic distribution than previously thought, being restricted to areas south of 38°S latitude; the newly proposed range is merely half the species formerly recognized geographical distribution.

  2. NMSBA: Aken Technologies Final Report: Toxicity Testing of Liquidoff

    Energy Technology Data Exchange (ETDEWEB)

    Ruffing, Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jensen, Travis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Strickland, Lucas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    To determine the effect of Liquidoff on bacteria, three bacterial strains were tested: Escherichia coli DH5α, Synechococcus sp. PCC 7002, and Synechococcus elongatus PCC 7942. E. coli DH5α is a Gram-negative, aerobic bacterium that is often found in normal gut flora and is commonly used the laboratory due to its fast growth rate. Synechococcus sp. PCC 7002 and S. elongatus PCC 7942 are Gram-negative, aquatic, autophototrophic cyanobacteria. Synechococcus sp. PCC 7002 is a marine cyanobacterium isolated from ‘fish pens’ on Magueyes Island, Puerto Rico in 1962, while S. elongatus PCC 7942 is a freshwater cyanobacterium. It should be noted that no Gram-positive bacterium was tested in this study.

  3. Molluscan Evolutionary Development

    DEFF Research Database (Denmark)

    Wanninger, Andreas Wilhelm Georg; Koop, Damien; Moshel-Lynch, Sharon

    2008-01-01

    Brought together by Winston F. Ponder and David R. Lindberg, thirty-six experts on the evolution of the Mollusca provide an up-to-date review of its evolutionary history. The Mollusca are the second largest animal phylum and boast a fossil record of over 540 million years. They exhibit remarkable...... anatomical diversity and include the bivalves (scallops, oysters, and clams), gastropods (limpets, snails, and slugs), and cephalopods (squid, cuttlefish, and octopus). This study treats each major taxon and supplies general information as well as overviews of evolution and phylogeny using data from...... different sources--morphological, ultrastructural, molecular, developmental, and from the fossil record....

  4. The heavy metals in the muscle of some imported frozen fish in ...

    African Journals Online (AJOL)

    The heavy metal levels in the edible muscles of eight species of imported frozen fishes in four major markets in Ibadan were examined. The species examined were Ethmalosa harengus, Micromesistius poutassou, Sardinella eba, Trachurus trachurus, Scomber scombrus, Scomberomorous tritor, Pseudotololithus elongatus ...

  5. Browse Title Index

    African Journals Online (AJOL)

    Items 851 - 900 of 1255 ... Vol 10, No 4 (2004), Occurrence of Parasites in Pseudotolithus elongatus and Cynoglossus seneglensis in Cross River Estuary, Nigeria, Abstract PDF. JT Abraham, PA ... P C Chikezie. Vol 9, No 1 (2003), Parasitic contamination of leafy vegetables: a function of the leaf area index (lai), Abstract PDF.

  6. Description d’une nouvelle espèce de Gyrinide du Musée de Leyde

    NARCIS (Netherlands)

    Regimbart, M.

    1884-01-01

    Long. 6 3/4 mm. (ano excepto). — Oblongo-ovalis, elongatus, mediocriter convexus; supra in regionibus glabris purpureocupreus, nitidus, subtilissime reticulatus, in regionibus punctato-tomentosis obscure cœruleus et subopacus, anguste pallide testaceo limbatus; infra pallide testaceus, pedibus

  7. Deux espèces nouvelles de Dytiscides du Musée de Leyde

    NARCIS (Netherlands)

    Régimbart, M.

    1893-01-01

    Long. 2 mill. — Oblongo-ovalis, elongatus, subparallelus; capite et pronoto rufis, hoc ad basin late transversim nigricante, sat tenuiter in disco et fortius apud basin punctato; elytris nigris, margine laterali ad apicem dilatato, macula elongata minuta post medium ad latera, fasciaque post basali

  8. Two new Liolaemus lizards from the Andean highlands of Southern Chile (Squamata, Iguania, Liolaemidae)

    Science.gov (United States)

    Troncoso-Palacios, Jaime; Diaz, Hugo A.; Puas, German I.; Riveros-Riffo, Edvin; Elorza, Alvaro A.

    2016-01-01

    Abstract Liolaemus is a diverse genus of lizards, subdivided into two subgenera: Liolaemus (sensu stricto) and Eulaemus, distributed mainly in Chile and Argentina. The Liolaemus elongatus-kriegi complex is the most diverse group within Liolaemus (sensu stricto), especially the species closely related to Liolaemus elongatus, which form a clade currently comprising nine species. Several Chilean species of this group have been recently described, mainly from volcanoes and poorly explored mountains. Here molecular and morphological evidence are provided for a new species of the Liolaemus elongatus clade, which is characterized by its small size and lack of dorsal pattern, unusual features for the species of this group of lizards. Additionally, the lack of precloacal pores in males of Liolaemus (sensu stricto) is a trait found in few species, which do not constitute a monophyletic group. A second new southern Chilean species is also described, without precloacal pores and supported by molecular phylogenetics to be related to Liolaemus villaricensis. Both new species were found in the same locality, near a lake located in a pre-Andean zone with Araucaria and Nothofagus forest. The two species are dedicated to prominent Lonkos (tribal chiefs) of the Mapuche and Pehuenche people: Janequeo and Leftraru. Additionally, the phylogenetic results suggest that Liolaemus lonquimayensis is a synonym of Liolaemus elongatus. PMID:27920609

  9. Gclust Server: 121285 [Gclust Server

    Lifescience Database Archive (English)

    Full Text Available 121285 Npun1_NpF1957 Cluster Sequences Related Sequences(19) 329 ORF_ID:tlr1497~hyp...othetical protein [Thermosynechococcus elongatus BP-1] 1 1.00e-10 0.0 0.0 4.0 0.0 0.0 0.0 Show 121285 Cluster ID 1212

  10. The Holarctic species of the subgenus Allodorus Foerster s.s. of the genus Eubazus Nees (Hymenoptera: Braconidae)ae)

    NARCIS (Netherlands)

    Achterberg, van C.; Kenis, M.

    2000-01-01

    Four new species of the subgenus Allodorus Foerster s.s. (= Eubazus semirugosus (Nees)-group s.s.; Braconidae: Helconinae) are described and illustrated: E. abieticola spec. nov. from France, Austria, Switzerland and Germany, E. elongatus spec. nov., E. ochyrus spec. nov., and E. heothinus spec.

  11. A synthetic, light-driven consortium of cyanobacteria and heterotrophic bacteria enables stable polyhydroxybutyrate production.

    Science.gov (United States)

    Weiss, Taylor L; Young, Eric J; Ducat, Daniel C

    2017-11-01

    We previously reported that Synechococcus elongatus PCC 7942, engineered with the sucrose transporter CscB, can export up to 85% of its photosynthetically-fixed carbon as sucrose and shows considerable promise as an alternative carbohydrate source. One approach to effectively utilize this cyanobacterium is to generate synthetic, light-driven consortia in which sucrose-metabolizing heterotrophs catalyze the conversion of the low-value carbohydrate into higher-value compounds in co-culture. Here, we report an improved synthetic photoautotroph/chemoheterotroph consortial design in which sucrose secreted by S. elongatus CscB directly supports the bacterium Halomonas boliviensis, a natural producer of the bioplastic precursor, PHB. We show that alginate encapsulation of S. elongatus CscB enhances sucrose-export rates ~2-fold within 66h, to ~290mg sucrose L -1 d -1 OD 750 -1 and enhances the co-culture stability. Consortial H. boliviensis accumulate up to 31% of their dry-weight as PHB, reaching productivities up to 28.3mg PHB L -1 d -1 . This light-driven, alginate-partitioned co-culture platform achieves PHB productivities that match or exceed those of traditionally engineered cyanobacterial monocultures. Importantly, S. elongatus CscB/H. boliviensis co-cultures were continuously productive for over 5 months and resisted invasive microbial species without the application of antibiotics or other chemical selection agents. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  12. Scandinavian Oncophorus (Bryopsida, Oncophoraceae: species, cryptic species, and intraspecific variation

    Directory of Open Access Journals (Sweden)

    Lars Hedenäs

    2017-05-01

    Full Text Available Scandinavian members of the acrocarpous moss genus Oncophorus were revised after field observations had suggested unrecognized diversity. Based on molecular (nuclear: internal transcribed spacers 1 and 2, ITS; plastid: trnGUCC G2 intron, trnG, rps4 gene + trnS-rps4 spacer, rps4 and morphological evidence, four morphologically distinguishable species are recognized, Oncophorus elongatus (I.Hagen Hedenäs, O. integerrimus Hedenäs sp. nov. (syn. O. virens var. elongatus Limpr., O. virens (Hedw. Brid., and O. wahlenbergii Brid. (O. sardous Herzog, syn. nov.. Oncophorus elongatus was earlier recognized, but much of its variation was hidden within O. wahlenbergii. Its circumscription is here expanded to include plants with long leaves having mostly denticulate or sharply denticulate upper margins and with long and narrow marginal cells in the basal portion of the sheathing leaf lamina. The new species O. integerrimus sp. nov. differs from O. virens in having more loosely incurved leaves and entire or almost entire upper leaf margins. Besides these characters, the species in the respective pairs differ in quantitative features of the leaf lamina cells. Several cryptic entities were found, in several cases as molecularly distinct as some of the morphologically recognizable species, and phylogeographic structure is present within O. elongatus and O. virens.

  13. Two newLiolaemuslizards from the Andean highlands of Southern Chile (Squamata, Iguania, Liolaemidae).

    Science.gov (United States)

    Troncoso-Palacios, Jaime; Diaz, Hugo A; Puas, German I; Riveros-Riffo, Edvin; Elorza, Alvaro A

    2016-01-01

    Liolaemus is a diverse genus of lizards, subdivided into two subgenera: Liolaemus ( sensu stricto ) and Eulaemus , distributed mainly in Chile and Argentina. The Liolaemus elongatus-kriegi complex is the most diverse group within Liolaemus ( sensu stricto ), especially the species closely related to Liolaemus elongatus , which form a clade currently comprising nine species. Several Chilean species of this group have been recently described, mainly from volcanoes and poorly explored mountains. Here molecular and morphological evidence are provided for a new species of the Liolaemus elongatus clade, which is characterized by its small size and lack of dorsal pattern, unusual features for the species of this group of lizards. Additionally, the lack of precloacal pores in males of Liolaemus ( sensu stricto ) is a trait found in few species, which do not constitute a monophyletic group. A second new southern Chilean species is also described, without precloacal pores and supported by molecular phylogenetics to be related to Liolaemus villaricensis . Both new species were found in the same locality, near a lake located in a pre-Andean zone with Araucaria and Nothofagus forest. The two species are dedicated to prominent Lonkos (tribal chiefs) of the Mapuche and Pehuenche people: Janequeo and Leftraru. Additionally, the phylogenetic results suggest that Liolaemus lonquimayensis is a synonym of Liolaemus elongatus .

  14. Two new Liolaemus lizards from the Andean highlands of Southern Chile (Squamata, Iguania, Liolaemidae

    Directory of Open Access Journals (Sweden)

    Jaime Troncoso-Palacios

    2016-11-01

    Full Text Available Liolaemus is a diverse genus of lizards, subdivided into two subgenera: Liolaemus (sensu stricto and Eulaemus, distributed mainly in Chile and Argentina. The L. elongatus-kriegi complex is the most diverse group within Liolaemus (sensu stricto, especially the species closely related to L. elongatus, which form a clade currently comprising nine species. Several Chilean species of this group have been recently described, mainly from volcanoes and poorly explored mountains. Here molecular and morphological evidence are provided for a new species of the L. elongatus clade, which is characterized by its small size and lack of dorsal pattern, unusual features for the species of this group of lizards. Additionally, the lack of precloacal pores in males of Liolaemus (sensu stricto is a trait found in few species, which do not constitute a monophyletic group. A second new southern Chilean species is also described, without precloacal pores and supported by molecular phylogenetics to be related to Liolaemus villaricensis. Both new species were found in the same locality, near a lake located in a pre-Andean zone with Araucaria and Nothofagus forest. The two species are dedicated to prominent Lonkos (tribal chiefs of the Mapuche and Pehuenche people: Janequeo and Leftraru. Additionally, the phylogenetic results suggest that L. lonquimayensis is a synonym of L. elongatus.

  15. Annual and spatial variability in endo- and ectoparasite infections of North Sea cod (Gadus morhua Linnaeus, 1758) larvae, post-larvae and juveniles

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Bahlool, Qusay Z. M.; Skovgaard, Alf

    2014-01-01

    A parasitological investigation was performed on a total of 5380 Atlantic cod larvae, post-larvae and small juveniles sampled from the North Sea during a period of five years. The copepod Caligus elongatus (Von Nordmann, 1832) and the nematode Hysterothylacium aduncum (Rudolphi, 1802) were found ...

  16. Coléoptères nouveaux de l’Afrique du Musée de Leyde

    NARCIS (Netherlands)

    Fairmaire, L.

    1888-01-01

    Long. 22 à 25 mill. — Elongatus, convexus, fuscus aut brunneo-castaneus, modice nitidus, fulvo-pubescens; capite dense punctato, inter oculos sat late impresso, antice declivi, margine obtuse rotundato; antennis fuscis, medium corporis attingentibus, articulo 1° punctato, 2° minuto, 3° vix majore,

  17. Species composition, length-weight relationship and condition factor ...

    African Journals Online (AJOL)

    Chrysichthys nigrodigitatus (b=3.75), Mugil cephalus (b=3.02) and Atherina formis (b=3.46) exhibited positive allometry growth while Pseudotolithus elongatus (b=2.55), Eleotris africana (b=2.79), Sardinella maderemsis (b=2.04), Periophthalmus barbarous (b=2.77), Microchirus poscanion had negative allometry growth.

  18. Electric field effects on red chlorophylls, b-carotenes and P700 in cyanobacterial photosystem I complexes.

    NARCIS (Netherlands)

    Frese, R.N.; Palacios, M.A.; Azzizi, A.; van Stokkum, I.H.M.; Kruip, J.; Rögner, M.; Karapetyan, N.V.; Schlodder, E.; van Grondelle, R.; Dekker, J.P.

    2002-01-01

    We have probed the absorption changes due to an externally applied electric field (Stark effect) of Photosystem I (PSI) core complexes from the cyanobacteria Synechocystis sp. PCC 6803, Synechococcus elongatus and Spirulina platensis. The results reveal that the so-called C719 chlorophylls in S.

  19. Author Details

    African Journals Online (AJOL)

    Abraham, JT. Vol 5, No 1 (2006) - Articles Abundance of Pseudotolithus elongatus in the Niger Delta area - a case study in the Cross River estuary. Abstract PDF · Vol 14, No 1 (2015) - Articles Parasites of crayfish (P. clarki) and lobsters (Macrobrachium vollenhovenic) as indicators of metallic pollution in great, Kwa river, ...

  20. DOE final report 100608.doc

    Energy Technology Data Exchange (ETDEWEB)

    Golden, Susan S

    2008-10-16

    The aim of this project was to inactivate each locus of the genome of the cyanobacterium Synechococcus elongatus PCC 7942 and screen resulting mutants for altered circadian phenotypes. The immediate goal was to identify all open reading frames (ORFs) that contribute to circadian timing. An additional result was to create a complete archived set of mutagenesis templates, of great utility for the wider research community, that will allow inactivation of any given locus in the genome of S. elongatus. Clones that carry segments of the S. elongatus genome were saturated with transposon insertions in vitro. We completed saturation mutagenesis of the chromosome (~2800 ORFs). The positions of insertions were sequenced for 17,767 mutagenized clones. Each individual insertion into the S. elongatus DNA in a cosmid or plasmid is a substrate for mutagenesis of the genome via homologous recombination. Because the complete insertion mutation clone set is 5-7 fold redundant, we produced a streamlined set of clones that contains one insertion mutation per locus in the genome, a unigene set. All clones are archived as Escherichia coli stocks frozen in glycerol in 96-well plates at -85ºC and as replicas of these plates on Whatman CloneSaver cards. Each of the mutagenesis substrates from the unigene set has been recombined into the chromosome of wild-type S. elongatus and these cyanobacterial mutants have been archived at -85ºC as well. S. elongatus insertion mutants defective for than 1400 independent genes have screened in luciferase reporter gene backgrounds to evaluate the effect of each mutation on circadian rhythms of gene expression. For the first 700 genes tested, mutagenesis of 71 different ORFs resulted in circadian phenotypes. The mutagenesis project also created insertion mutations in the endogenous large plasmid of S. elongatus, pANL. The sequence of pANL revealed two potential addiction cassettes that appear to account for selection for plasmid persistence. Genetic