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Sample records for sandeel ammodytes marinus

  1. Prey or predator – expanding the food web role of sandeel (Ammodytes marinus)

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Deurs, Mikael van; Behrens, Jane

    2014-01-01

    We report an unexpected observation of lesser sandeel Ammodytes marinus foraging on juveniles and late larval stages of the same species. This recording sheds new light on the cannibalistic and piscivorous capacity of forage fish and raises a number of questions about the role of forage fish in m...

  2. Assessments of the lesser sandeel ( Ammodytes marinus ) in the North Sea based on revised stock divisions

    DEFF Research Database (Denmark)

    Pedersen, S.A.; Lewy, Peter; Wright, P.

    1999-01-01

    effort, catch per unit effort, yield, fishing and natural mortality. A better understanding of sandeel growth is important for stock and catch predictions because previous studies indicate that the variability of mean weight-at-age is one of the most important factors influencing the precision......Recent investigations suggest that the current treatment of North Sea sandeel (Ammodytes marinus) as a single unit stock may have little biological basis. In order to study regional effects of the fishery on North Sea lesser sandeel it may therefore be important to assess stock dynamics...... for the different aggregations. Based on a geographical division of the North Sea in a number of proposed assessment regions, regional as well as whole North Sea sandeel assessments are presented based on revised data (e.g, catch in numbers at age and effort). The assessments suggest regional differences in fishing...

  3. Critical threshold size for overwintering sandeels (Ammodytes marinus)

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Hartvig, Martin; Steffensen, John Fleng

    2011-01-01

    . In the present study, we estimated the energetic cost of overwintering from a bioenergetic model. The model was parameterised using respirometry-based measurements of standard metabolic rate in buried A. tobianus (a close relative to A. marinus) at temperatures from 5.3 to 18.3C and validated with two......Several ecologically and commercially important fish species spend the winter in a state of minimum feeding activity and at lower risk of predation. To enable this overwintering behaviour, energetic reserves are generated prior to winter to support winter metabolism. Maintenance metabolism in fish...... scales with body size and increases with temperature, and the two factors together determine a critical threshold size for passive overwintering below which the organism is unlikely to survive without feeding. This is because the energetic cost of metabolism exceeds maximum energy reserves...

  4. The influence of sediment type on the distribution of the lesser sandeel, Ammodytes marinus

    DEFF Research Database (Denmark)

    Wright, P.J.; Jensen, Henrik; Tuck, I.

    2000-01-01

    the physical characteristics of the habitat of A. marinus in an attempt to predict the distribution of this species. The characteristics and topography of sandeel habitat were described from video observations. Data on abundance, sediment characteristics and depth were collected from benthic sampling....... Given the constraints of sediment requirements, densities of sandeels in benthic samples appeared to be influenced by water depth. (C) 2000 Elsevier Science B.V. All rights reserved....

  5. Influence of moderate and severe hypoxia on the diurnal activity pattern of lesser sandeel Ammodytes tobianus

    DEFF Research Database (Denmark)

    Behrens, Jane; Petersen, Jens Kjerulf; Ærtebjerg, G.

    2010-01-01

    The influence of prolonged moderate (c. 60% oxygen saturation) and severe hypoxia (c. 35% oxygen saturation) on the diurnal activity pattern of sandeel Ammodytes tobianus was examined. In moderate hypoxia, the emerging and burying rates were significantly higher compared to that in normoxia, wher...

  6. PIT-tagging method for small fishes: A case study using sandeel ( Ammodytes tobianus )

    DEFF Research Database (Denmark)

    Jørgensen, Michelle Grace Pinto; Deurs, Mikael van; Butts, Ian

    2017-01-01

    -rays and dissections). RSS was not different between tagged and untagged fish with means (± SD) of 60 ± 9% and 61 ± 12%. Tail beat frequency was not different between tagged and untagged fish at 2.8 ± 0.3 and 3.0 ± 0.4 beats s−1 for tagged and untagged fish, respectively. Likewise, hematocrit was not affected......Passive integrated transponder (PIT) tags are commonly used to assess fish movement for use in fisheries management. Here, we investigated physiological and behavioral effects of tagging on sandeels (Ammodytes tobianus) using PIT tags constituting 2.1 ± 0.9% of their body weight. Swimming stamina...

  7. Oxygen dynamics around buried lesser sandeels Ammodytes tobianus (Linnaeus 1785): mode of ventilation and oxygen requirements

    DEFF Research Database (Denmark)

    Behrens, Jane W; Stahl, Henrik J; Steffensen, John F

    2007-01-01

    down along the body, referred to as ;plume ventilation'. Yet, within approximately 30 min the oxic plume was replenished by oxygen-depleted water from the gills. The potential for cutaneous respiration by the buried fish was thus of no quantitative importance. Calculations derived by three independent......The oxygen environment around buried sandeels (Ammodytes tobianus) was monitored by planar optodes. The oxygen penetration depth at the sediment interface was only a few mm. Thus fish, typically buried at 1-4 cm depth, were generally in anoxic sediment. However, they induced an advective transport...... plume with fish extracted 86.2+/-4.8% (N=7) of the oxygen from the inspired water. However, 13% of the investigated fish (2 of 15) occasionally wriggled their bodies and thereby transported almost fully air-saturated water...

  8. Burrow distribution of three sandeel species relates to beam trawl fishing, sediment composition and water velocity, in Dutch coastal waters

    NARCIS (Netherlands)

    Tien, N.S.H.; Craeymeersch, J.; Damme, van C.; Couperus, A.S.; Adema, J.; Tulp, I.

    2017-01-01

    Sandeel partly spend their life buried in the sediment, without a permanent burrow opening or an inhalant opening in the sediment. We linked the presence of three sandeel species (Ammodytes tobianus, A. marinus and Hyperoplus lanceolatus) off the southern Dutch coast of the North Sea to sediment

  9. Primary versus secondary drivers of foraging activity in sandeel schools (Ammodytes tobianus)

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Behrens, Jane; Warnar, Thomas

    2011-01-01

    to fishery biologists and has consequences for a wide range of predators ranging from birds and mammals to commercially important species. However, experimental studies that shed light on the primary drivers of foraging activity in fish are rare. In the present study, whole schools of sandeel (A. tobianus...

  10. Spatial patterns and trends in abundance of larval sandeels in the North Sea: 1950–2005

    DEFF Research Database (Denmark)

    Lynam, Christopher P.; Halliday, Nicholas C.; Höffle, Hannes

    2013-01-01

    Early recruitment indices based on larval fish data from the Continuous Plankton Recorder (CPR) have the potential to inform stock assessments of Ammodytes marinus in the North Sea. We evaluate whether the CPR data are reliable for sandeel larvae. Spatially, CPR larval data were comparable...

  11. Life history of the Small Sandeel, Ammodytes tobianus, inferred from otolith microchemistry. A methodological approach

    Science.gov (United States)

    Laugier, F.; Feunteun, E.; Pecheyran, C.; Carpentier, A.

    2015-11-01

    Knowledge of life history and connectivity between essential ecological habitats are relevant for conservation and management of species and some natural tracers could be used to study the lifecycles of small or short-lived marine fishes. Although sandeels are central in marine food webs and are key species, there is incomplete knowledge about population mixing and migration patterns. For the first time the use of the otolith microchemistry on sandeel species is evaluated in the case of the Small Sandeel. Variations in microchemical fingerprints of 13 trace elements are performed with a Femtosecond LA-ICPM from the core to the margin of sagittal otolith and are compared within and between otoliths extracted from 34 fishes sampled in three different sites along the coast of the south-western English Channel in France. Firstly, preliminary investigations on the validity of the method revealed that Mg/Ca was the only ratio significantly dependant on fish ontogeny and sampling season. Secondly, the Mn/Ca, Zn/Ca, and Cu/Ca ratios enabled us to significantly discriminate among sampling sites. Thirdly, microchemical fingerprints of each life stage varied significantly among sampling sites but not within them, suggesting high site fidelity over relatively short distances. Finally, the fingerprints of all life stages were significantly different from those of the larval and metamorphosis stages. The otolith microchemistry could detect change of signature relative to the shift from a pelagic behaviour to a resident bentho-pelagic behaviour during the middle of the juvenile stage in Small Sandeels. Hence, analysis of trace element fingerprints in otoliths appears to be a valuable method to further studies on ontogenic habitat change, population mixing and variation of life history and be helpful for the management at local or regional scales of short-lived species such as those belonging to other Ammodytidae.

  12. Fatty acid biomarkers: validation of food web and trophic markers using C-13-labelled fatty acids in juvenile sandeel ( Ammodytes tobianus )

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; St. John, Michael

    2004-01-01

    A key issue in marine science is parameterizing trophic interactions in marine food webs, thereby developing an understanding of the importance of top-down and bottom-up controls on populations of key trophic players. This study validates the utility of fatty acid food web and trophic markers using...... C-13-labelled fatty acids to verify the conservative incorporation of fatty acid tracers by juvenile sandeel (Ammodytes tobianus) and assess their uptake, clearance, and metabolic turnover rates. Juvenile sandeel were fed for 16 days in the laboratory on a formulated diet enriched in (13)C16......), respectively. Lack of temporal trends in nonlabelled fatty acids confirmed the conservative incorporation of labelled fatty acids by the fish....

  13. Spatial differences in growth of lesser sandeel in the North Sea

    DEFF Research Database (Denmark)

    Rindorf, Anna; Wright, Peter J.; Jensen, Henrik

    2016-01-01

    at age and condition was higher on warmer, deeper and central/north eastern fishing grounds. Sandeel in the water column exhibited large changes in condition over the season, having an initially low condition following spring emergence rising to a pronounced peak by June. Weight at age varied......Lesser sandeel, Ammodytes marinus, is a key prey to a variety of North Sea predators, including species such as single load seabirds which are highly sensitive to prey size and condition. Whilst differences in weight at age across the North Sea have been investigated previously, the scale and cause...... considerably both spatially and temporally, resulting in 4 fold and 1.9 fold variations in the number of sandeels required to obtain a specific weight, respectively. Hence, the value of sandeel as prey to single load predators varies considerably with values in central and northeastern North Sea being...

  14. Distribution of the early larval stages of cod, plaice and lesser sandeel across haline fronts in the North Sea

    DEFF Research Database (Denmark)

    Munk, Peter; Wright, P.J.; Pihl, Niels Jørgen

    2002-01-01

    A number of commercially important fish species spawn in the coastal areas of the North Sea in the late winter, including cod (Gadus morhua), plaice (Pleuronectes platessa) and lesser sandeel (Ammodytes marinus). The distribution of the early stages of these species overlap to some extent...... zones between freshwater-influenced water masses and shelf water of the central North Sea, and larval abundances peaked in the vicinity of the haline fronts. (C) 2002 Elsevier Science Ltd. All rights reserved....

  15. Productivity and recovery of forage fish under climate change and fishing: North Sea sandeel as a case study

    DEFF Research Database (Denmark)

    Lindegren, Martin; van Deurs, Mikael; MacKenzie, Brian

    2017-01-01

    Forage fish occupy a central position in marine food-webs worldwide by mediating the transfer of energy and organic matter from lower to higher trophic levels. The lesser sandeel (Ammodytes marinus) is one of the ecologically and economically most important forage fish species in the North......-east Atlantic, acting as a key prey for predatory fish and sea birds, as well as supporting a large commercial fishery. In this case study, we investigate the underlying factors affecting recruitment and how these in turn affect productivity of the North Sea sandeel using long-term data and modelling. Our...... results demonstrate how sandeel productivity in the central North Sea (Dogger Bank) depends on a combination of external and internal regulatory factors, including fishing and climate effects, as well as density dependence and food availability of the preferred zooplankton prey (Calanus finmarchicus...

  16. Growth and survival of larval and early juvenile lesser sandeel in patchy prey field in the North Sea: An examination using individual-based modelling

    DEFF Research Database (Denmark)

    Gürkan, Zeren; Christensen, Asbjørn; Deurs, Mikael van

    2012-01-01

    concentrations is regarded important for survival. Intense aggregations of zooplankton in near-surface waters provide these conditions for larval fish. Simulation studies by individual-based modeling can help understanding of the mechanisms for survival during early life-stages. In this study, we examined how...... growth and survival of larvae and early juveniles of Lesser Sandeel (Ammodytes marinus) in the North Sea are influenced by availability and patchiness of the planktonic prey by adapting and applying a generic bioenergetic individual-based model for larval fish. Input food conditions were generated...... by modeling copepod size spectra dynamics and patchiness based on particle count transects and Continuous Plankton Recorder time series data. The study analyzes the effects of larval hatching time, presence of zooplankton patchiness and within patch abundance on growth and survival of sandeel early life...

  17. Connectivity in the early life history of sandeel inferred from otolith microchemistry

    Science.gov (United States)

    Gibb, Fiona M.; Régnier, Thomas; Donald, Kirsty; Wright, Peter J.

    2017-01-01

    Connectivity is a central issue in the development, sustainability and effectiveness of networks of Marine Protected Areas (MPAs). In populations with site attached adults, connectivity is limited to dispersal in the pelagic larval stage. While biophysical models have been widely used to infer early dispersal, empirical evidence through sources such as otolith microchemistry can provide a means of evaluating model predictions. In the present study, connectivity in the lesser sandeel, Ammodytes marinus, was investigated using LA-ICP-MS otolith microchemistry. Otoliths from juveniles (age 0) were examined from four Scottish spawning areas predicted to differ in terms of larval retention rates and connectivity based on past biophysical models. There were significant spatial differences in otolith post-settled juvenile chemistry among locations at a scale of 100-400 km. Differences in near core chemistry pointed to three chemically distinct natal sources, as identified by a cluster analysis, contributing to settlement locations.

  18. Sandeels and clams (Spisula sp.) in the wind turbine park at Horns Reef. Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Henrik; Sand Kristensen, P.; Hoffmann, E.

    2003-04-15

    Sandeels were found in the sediment at all of the sample locations in the area of the wind turbine park and in the control area. The mean density of sandeels in the sediment was 0.0102 m{sup -2} (10,200 km{sup -2}) in the control area and 0.0096 m{sup -2} (9,600 km{sup -2}) in the impact area. The most abundant species of sandeel in both the impact and the control area was H. lanceolatus followed by A. marinus and A. tobianus. No G. semisquamatus was caught during the surveys. The construction of the wind turbine park is not supposed to effect the sandeel population in the Horns Reef area because the impact area seems to constitute a small fraction of a larger area with sandeel habitat. However, within the area of the wind turbine park sandeel abundance might be affected if the surface sediment changes due to the construction of the wind turbine park or if the abundance of sandeel predators increases in the impact area after the wind turbine park has been build (the so called artificial reef effect). To investigate if these effects will occur the field programmethat was carried out in February/march 2002 (the subject of this report) will have to be repeated after the wind turbine park has been constructed. (au)

  19. Feeding ecology of Greenland halibut and sandeel larvae off West Greenland

    DEFF Research Database (Denmark)

    Stenberg, Claus; Munk, Peter; Folkvord, A.

    2006-01-01

    Feeding ecology of Greenland halibut (Gr. halibut) (Reinhardtius hippoglossoides) and sandeel (Ammodytes sp.) larvae on the West Greenland shelf was studied during the main part of the productive season (May, June and July). Copepods were the main prey item for larval Gr. halibut and sandeel......, constituting between 88 and 99% of the ingested prey biomass. For both species, absolute size of preferred prey increased during ontogeny. However, preferred copepod size in relation to larval length differed markedly. In Gr. halibut, the relative size of the prey declined during growth of the larvae, while...... Strait. In June and July, the prey-rich areas for both species were mainly located at the slopes of the banks and at the shelf break area. Gut fullness was higher in these areas than in neighbouring areas, suggesting that the larval food resource could be scarce. The feeding ecology of Gr. halibut...

  20. Sandeels in the wind farm area at Horns Reef. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Henrik; Sand Kristensen, P.; Hoffmann, E.

    2004-08-15

    This report summarises preliminary results from a survey carried out in the Horns Reef area in March 2004 and contrast these results to those from a previous survey carried out in February/March 2002. The surveys were designed to analyse the effect, if any, of the construction of a wind farm on sandeels in the area. The 2002 survey was done prior to construction of the wind turbines and the 2004 survey was done after the construction of the wind turbines. There are no indications that the construction of the wind farm has had any effect on the sediment composition in the impact area (the wind farm area). Especially there was no indication that the content of the finest particles, the Wentworth sediment classes silt/clay and very fine sand, has increased in the impact area from 2002 to 2004. In this respect the construction of the wind farm is not likely to have had any effect on sandeels in the area of the wind farm. The effect of the wind farm on sandeels was evaluated on the basis of changes in distribution and densities of all species of sandeels combined, as there is no information available to suggest that the possible effects, if any, on sandeels of the construction of a wind farm is dependent on the species. At all locations fished during both of the years a markedly increase in density of sandeels (all species combined) was observed in the impact area from 2002 to 2004. This increase coincides with a small decrease in densities in the control area (away from the wind farm/impact area). Average densities of sandeels in the impact area increased about 300% from 2002 to 2004, whereas densities decreased about 20% in the control area. It is therefore concluded that the construction of the wind farm has had no negative impact on sandeels in this area. A large change was found in the species composition and densities of sandeels from 2002 to 2004. The density of A. tobianus and H. lanceolatus increased markedly from 2002 to 2004 whereas the density of A. marinus

  1. How reliably can northeast Atlantic sand lances of the genera Ammodytes and Hyperoplus be distinguished? A comparative application of morphological and molecular methods

    Directory of Open Access Journals (Sweden)

    Ralf Thiel

    2016-09-01

    Full Text Available Accurate stock assessments for each of the dominant species of sand lances in the northeast Atlantic Ocean and adjacent areas are not available due to the lack of a reliable identification procedure; therefore, appropriate measures of fisheries management or conservation of sand lances cannot be implemented. In this study, detailed morphological and molecular features are assessed to discriminate between four species of sand lances belonging to the genera Ammodytes and Hyperoplus. Morphological characters described by earlier authors as useful for identification of the genera are confirmed, and two additional distinguishing characters are added. A combination of the following morphological characters is recommended to distinguish between the genera Hyperoplus and Ammodytes: the protrusibility of the premaxillae, the presence of hooked ends of the prevomer, the number of dermal plicae, and the pectoral-fin length as a percentage of the standard length. The discriminant function analysis revealed that morphometric data are not very useful to distinguish the species of each of the two genera. The following meristic characters improve the separation of H. lanceolatus from H. immaculatus: the number of lower arch gill rakers, total number of gill rakers, numbers of caudal vertebrae and total vertebrae, and numbers of dorsal-fin and anal-fin rays. It is confirmed that A. tobianus differs from A. marinus by its belly scales that are organised in tight chevrons, scales which are present over the musculature at the base of the caudal fin, as well as by the lower numbers of dermal plicae, dorsal-fin rays, and total vertebrae. In contrast to the morphological data, mitochondrial COI sequences (DNA barcodes failed to separate unambiguously the four investigated species. Ammodytes tobianus and H. lanceolatus showed an overlap between intraspecific and interspecific K2P genetic distances and cannot be reliably distinguished using the common DNA barcoding

  2. New insight into hybridization and unidirectional introgression between Ammodytes japonicus and Ammodytes heian (Trachiniformes, Ammodytidae.

    Directory of Open Access Journals (Sweden)

    Jin-Koo Kim

    Full Text Available Based on northern (NOL and southern (SOL mitochondrial lineages, recently, it proposed the new species Ammodytes heian and revived the species name Ammodytes japonicus to describe sand lances from the northwestern Pacific Ocean. This study used molecular methods to investigate genetic relationships between the two sand lance species in Korea and Japan. In total, 154 specimens were collected from four locations in Korea (Baengnyeongdo in the Yellow Sea, Tongyeong in the Korean Strait, and Jumunjin and Gijang in the East Sea, and 50 specimens were collected from a single location in Japan (Wakkanai in the Okhotsk Sea. Mitochondrial DNA analysis demonstrated that the individuals from Baengnyeongdo and Tongyeong all belonged to the SOL, whereas those from Gijang, Jumunjin, and Wakkanai included individuals from both the NOL and SOL (over 75% NOL. Population structure analyses were performed on the same individuals using seven microsatellite DNA markers. The population structure analysis based on 201 specimens identified two clusters (named as northern group and southern group, with the admixture proportion (q of < 0.1 for the northern group in the Backyeongdo and Tongyeong sand lances and < 0.1 for the southern group in the Wakkanai sand lances. The high heterogeneity indicated that the former was probably A. japonicus and the latter probably A. heian. However, the admixture proportion in the Jumunjin and Gijang sand lances was 0.71-0.75 for the southern group, indicating that hybridization and unidirectional introgression from SOL to NOL occurs in southwestern margin of the East Sea. Our findings illustrate the speciation process based on different patterns of gene flow between Korean and Japanese sand lance, which is strongly influenced by both the paleo-climatic change and the contemporary local oceanic current pattern.

  3. Sources of Variation in the Age Composition of Sandeel Landings

    DEFF Research Database (Denmark)

    Kvist, Trine; Gislason, Hannes; Thyregod, Poul

    2001-01-01

    The variation of the age composition of the landings of lesser sandeel in the Danish industrial fishery in the North Sea over the period From 1984-1993 is analysed by continuation-ratio logits and generalised linear models. The analysis takes the multinomial characteristics of the age composition....... Although the variation between ICES statistical rectangles is substantial there is a significant difference between the age composition in the northern and southern part of the North Sea. However, only one of the three finer geographical stratifications proposed to improve the assessment results...

  4. Characteristics and Dynamics of a Large Sub-Tidal Sand Wave Field—Habitat for Pacific Sand Lance (Ammodytes personatus, Salish Sea, Washington, USA

    Directory of Open Access Journals (Sweden)

    H. Gary Greene

    2017-10-01

    Full Text Available Deep-water sand wave fields in the San Juan Archipelago of the Salish Sea and Pacific Northwest Washington, USA, have been found to harbor Pacific sand lance (PSL, Ammodytes personatus, a critical forage fish of the region. Little is known of the dynamics of these sand waves and the stability of the PSL sub-tidal habitats. Therefore, we have undertaken an initial investigation to determine the dynamic conditions of a well-known PSL habitat in the San Juan Channel within the Archipelago using bottom sediment sampling, an acoustical doppler current profiling (ADCP system, and multi-beam echo sounder (MBES bathymetry. Our study indicates that the San Juan Channel sand wave field maintained its shape and bedforms geometry throughout the years it has been studied. Based on bed phase diagrams for channelized bedforms, the sand waves appear to be in a dynamic equilibrium condition. Sea level rise may change the current regime within the Archipelago and may alter some of the deep-water or sub-tidal PSL habitats mapped there. Our findings have global significance in that these dynamic bedforms that harbor PSL and sand-eels elsewhere along the west coast of North America and in the North Sea may also be in a marginally dynamic equilibrium condition and may be prone to alteration by sea level rise, indicating an urgency in locating and investigating these habitats in order to sustain the forage fish.

  5. Patchy zooplankton grazing and high energy conversion efficiency: ecological implications of sandeel behavior and strategy

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Christensen, Asbjørn; Rindorf, Anna

    2013-01-01

    Sandeel display strong site-fidelity, and spend most of their life buried in the seabed. This strategy carries important ecological implications. Sandeels save energy when they are not foraging but in return are unable to move substantially and therefore possibly are sensitive to local depletion...... largely on relatively large copepods in early spring. (ii) Lesser sandeel is an efficient converter making secondary production into fish tissue available for higher trophic levels. Hence, changes in species composition towards a more herring dominated system, as seen in recent times, may lead...

  6. Recruitment and condition of juvenile sandeel on the Faroe shelf in relation to primary production

    DEFF Research Database (Denmark)

    Eliasen, Kirstin; Reinert, Jákup; Gaard, Eilif

    The food of early-life sandeel is dominated by zooplankton, which again depends on primary production. On the Faroe Shelf, measurements of accumulated new primary production and chlorophyll a during spring and summer have been carried out since 1990 and 1997, respectively. Large inter-annual vari......The food of early-life sandeel is dominated by zooplankton, which again depends on primary production. On the Faroe Shelf, measurements of accumulated new primary production and chlorophyll a during spring and summer have been carried out since 1990 and 1997, respectively. Large inter...... spawns several months before the spring bloom, the onset of the spring bloom does not seem to have a significant influence on the number nor the length of juvenile sandeel. Number and length seems to be mainly determined by the phytoplankton concentration just before the survey. The established link...

  7. Effects of changes in sandeel availability on the reproductive output of seabirds

    DEFF Research Database (Denmark)

    Rindorf, Anna; Wanless, S.; Harris, M.P.

    2000-01-01

    productivity, breeding effort and diet in 3 species of seabird with contrasting foraging and dietary characteristics (common guillemot Uria aalge, black-legged kittiwake Rissa tridactyla, and European shag Phalacrocorax aristotelis) and an index of availability of 1 group and older sandeels derived from catch...

  8. Cromoblastomicosis Experimental en Bufo marinus

    OpenAIRE

    Trejos, A.

    2016-01-01

    Reviewing the observations of CARINI and the experimental work of ALMEIDA and AREA LEAO, MELLO & CURY on the pathogenicity of the etiologic agents of Chromoblastomycosis inyected intraperitonealy in Salientia species Leptodactylus ocellatus and L. pentadactylus, we decided to determine the pathogenicity of Fonsecaeae pedrosoi on Bufo marinus. Six specimens were innoculated with suspensions of cultures of this fungs obtained from six human cases, using one strain per animal.At autopsy, one obs...

  9. Preliminary evaluation of total protein concentration and electrophoretic protein fractions in fresh and frozen serum from wild Horned Vipers (Vipera ammodytes ammodytes).

    Science.gov (United States)

    Proverbio, Daniela; de Giorgi, Giada Bagnagatti; Della Pepa, Alessandra; Baggiani, Luciana; Spada, Eva; Perego, Roberta; Comazzi, Carlo; Belloli, Angelo

    2012-12-01

    Determination of the health status of reptiles is based on physical examination and evaluation of hematologic and biochemical values. Evaluation of serum total protein (TP) concentration and protein fractions plays an important role in health assessment; however, little is known about references value for these analytes in wild viperoid snakes. In addition, studies evaluating the stability of proteins in frozen viperoid serum are lacking. The aims of this study were to establish preliminary reference values for concentrations of TP and protein fractions in serum from wild vipers and to evaluate the stability of serum proteins in frozen serum samples from viperoid snakes. Blood samples were collected from wild Horned Vipers (Vipera ammodytes ammodytes). Using fresh serum, TP concentrations were determined using the biuret method and protein fractions were analyzed using agarose gel electrophoresis (AGE); albumin/globulin ratios were calculated. Analyses were also performed on serum frozen at -20°C for 70 days and then thawed. Pre- and post-storage results were compared using the Mann-Whitney U-test. Five adult wild Horned Vipers were sampled and comprised 4 males and 1 female. The female snake had higher TP concentrations than the male snakes. The electrophoretic patterns demonstrated 6 protein fractions that were similar for all 5 snakes. There were no significant changes in the concentrations of the 6 protein fractions post-storage; the percentage of the alpha-1 fraction was increased in frozen/thawed serum. Total protein concentrations in serum from Vipera ammodytes ammodytes were in agreement with published reference intervals for healthy reptiles and viperoid snakes. Serum protein fractions were easy to identify using AGE electrophoresis. © 2012 American Society for Veterinary Clinical Pathology.

  10. Spatio-temporal dynamics of growth and survival of Lesser Sandeel early life-stages in the North Sea: Predictions from a coupled individual-based and hydrodynamic-biogeochemical model

    DEFF Research Database (Denmark)

    Gurkan, Zeren; Christensen, Asbjørn; Maar, Marie

    2013-01-01

    Accounting for the individual variability and regional variations are important when predicting recruitment in fish species. Spatially explicit descriptions for recruitment in sandeels are necessary and sandeel growth and survival depend locally on zooplankton prey. We investigate the responses...... is validated by Continuous Plankton Recorder survey time series data. Spatio-temporal dynamics of the sandeel cohorts are simulated by the integrated model framework for the period 2004-2006 and five major area divisions of suitable sandeel habitats in the North Sea. This allows obtaining insight...

  11. Analyses of length and age distributions using continuation-ratio logits

    DEFF Research Database (Denmark)

    Rindorf, Anna; Lewy, Peter

    2001-01-01

    Sampling of length and age distributions of catches is important for the assessment of commercially fished stocks. This paper presents a new method for statistical analyses and comparisons of length and age distributions based on generalised linear models of continuation-ratio logits. The method...... to be multinomially distributed, but cases in which the variance exceeds that of this distribution may also be analysed. The implementation of the method in existing statistical analysis software is straightforward and is demonstrated using length and age distributions of the lesser sandeel, Ammodytes marinus Raitt...

  12. A Single Dose of ViperfavTM May Be Inadequate for Vipera ammodytes Snake Bite: A Case Report and Pharmacokinetic Evaluation

    Directory of Open Access Journals (Sweden)

    Tihana Kurtović

    2016-08-01

    Full Text Available ViperfavTM is a commercial F(ab’2 antivenom prepared against European vipers venom. It is safe and effective for treating envenomation caused by Vipera aspis and Vipera berus. Therapeutic efficacy for treating Vipera ammodytes ammodytes (V. a. ammodytes envenoming has not been yet described, although protective efficacy has been demonstrated in preclinical studies. We report on a 32-year-old man bitten by V. a. ammodytes who was treated with Viperfav™. Viperfav™ promptly reduced local extension and improved systemic pathological signs, but 24 h after the incident a recurrence of thrombocytopenia occurred despite a favorable pharmacokinetic profile with systemic clearance (1.64 (mL·h−1·kg−1 and elimination half-life (97 h among the highest ever reported. The recommended dose of Viperfav™ for V. aspis and V. berus bites may be inadequate for serious V. a. ammodytes envenomations. Following V. a. ammodytes bite, serial blood counts and coagulation profiles should be performed to help guide Viperfav™ treatment, along with supplemental administration as indicated.

  13. Detection of low-frequency tones and whale predator sounds by the American sand lance Ammodytes americanus.

    Science.gov (United States)

    Strobel, S M; Mooney, T A

    2012-10-01

    Auditory evoked potentials (AEP) were used to measure the hearing range and auditory sensitivity of the American sand lance Ammodytes americanus. Responses to amplitude-modulated tone pips indicated that the hearing range extended from 50 to 400 Hz. Sound pressure thresholds were lowest between 200 and 400 Hz. Particle acceleration thresholds showed an improved sensitivity notch at 200 Hz but not substantial differences between frequencies and only a slight improvement in hearing abilities at lower frequencies. The hearing range was similar to Pacific sand lance Ammodytes personatus and variations between species may be due to differences in threshold evaluation methods. AEPs were also recorded in response to pulsed sounds simulating humpback whale Megaptera novaeangliae foraging vocalizations termed megapclicks. Responses were generated with pulses containing significant energy below 400 Hz. No responses were recorded using pulses with peak energy above 400 Hz. These results show that A. americanus can detect the particle motion component of low-frequency tones and pulse sounds, including those similar to the low-frequency components of megapclicks. Ammodytes americanus hearing may be used to detect environmental cues and the pulsed signals of mysticete predators. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  14. Development of sea lamprey (Petromyzon marinus) larvicides

    Science.gov (United States)

    Howell, John H.; Lech, John J.; Allen, John L.

    1980-01-01

    Larvicides are used to control sea lamprey (Petromyzon marinus) in the Great Lakes. These larvicides are useful because they are more toxic to sea lamprey than fish species found in the same habitat. The lampricides come from two classes of chemical compounds: (1) halonitrophenols, and (2) halonitrosalicylanilides. Selectivity of the larvicides appears to be based on the differences in the ability of sea lamprey larvae and fishes to detoxify and/or excrete the chemicals. Glucuronide conjugation is an important mechanism for detoxification of these larvicides by fish, and selectivity of larvicides may be due to differences in glucuronyl transferase activity between lamprey and fishes. If more detailed information were available on uptake, metabolism, excretion, and the biochemistry and physiology of lamprey as compared to fishes, it might be possible to design chemicals that would be more selective than those now in use.

  15. Complete genome sequence of Staphylothermus marinus Stetter and Fiala 1986 type strain F1

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain [U.S. Department of Energy, Joint Genome Institute; Sun, Hui [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Barry, Kerrie [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Huber, Harald [Universitat Regensburg, Regensburg, Germany; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute

    2009-01-01

    Staphylothermus marinus Fiala and Stetter 1986 belongs to the order Desulfurococcales within the archaeal phylum Crenarchaeota. S. marinus is a hyperthermophilic, sulfur-dependent, anaerobic heterotroph. Strain F1 was isolated from geothermally heated sediments at Vulcano, Italy, but S. marinus has also been isolated from a hydrothermal vent on the East Pacific Rise. We report the complete genome of S. marinus strain F1, the type strain of the species. This is the fifth reported complete genome sequence from the order Desulfurococcales.

  16. The behavioural response of adult Petromyzon marinus to damage-released alarm and predator cues

    Science.gov (United States)

    Imre, István; Di Rocco, Richard; Belanger, Cowan; Brown, Grant; Johnson, Nicholas S.

    2014-01-01

    Using semi-natural enclosures, this study investigated (1) whether adult sea lamprey Petromyzon marinus show avoidance of damage-released conspecific cues, damage-released heterospecific cues and predator cues and (2) whether this is a general response to injured heterospecific fishes or a specific response to injured P. marinus. Ten replicate groups of 10 adult P. marinus, separated by sex, were exposed to one of the following nine stimuli: deionized water (control), extracts prepared from adult P. marinus, decayed adult P. marinus (conspecific stimuli), sympatric white sucker Catostomus commersonii, Amazon sailfin catfish Pterygoplichthys pardalis (heterospecific stimuli), 2-phenylethylamine (PEA HCl) solution, northern water snake Nerodia sipedon washing, human saliva (predator cues) and an adult P. marinus extract and human saliva combination (a damage-released conspecific cue and a predator cue). Adult P. marinus showed a significant avoidance response to the adult P. marinus extract as well as to C. commersonii, human saliva, PEA and the adult P. marinus extract and human saliva combination. For mobile P. marinus, the N. sipedon washing induced behaviour consistent with predator inspection. Exposure to the P. pardalis extract did not induce a significant avoidance response during the stimulus release period. Mobile adult female P. marinus showed a stronger avoidance behaviour than mobile adult male P. marinus in response to the adult P. marinus extract and the adult P. marinus extract and human saliva combination. The findings support the continued investigation of natural damage-released alarm cue and predator-based repellents for the behavioural manipulation of P. marinus populations in the Laurentian Great Lakes.

  17. The Alveolate Perkinsus marinus: Biological Insights from EST Gene Discovery

    Directory of Open Access Journals (Sweden)

    El-Sayed Najib M

    2010-04-01

    Full Text Available Abstract Background Perkinsus marinus, a protozoan parasite of the eastern oyster Crassostrea virginica, has devastated natural and farmed oyster populations along the Atlantic and Gulf coasts of the United States. It is classified as a member of the Perkinsozoa, a recently established phylum considered close to the ancestor of ciliates, dinoflagellates, and apicomplexans, and a key taxon for understanding unique adaptations (e.g. parasitism within the Alveolata. Despite intense parasite pressure, no disease-resistant oysters have been identified and no effective therapies have been developed to date. Results To gain insight into the biological basis of the parasite's virulence and pathogenesis mechanisms, and to identify genes encoding potential targets for intervention, we generated >31,000 5' expressed sequence tags (ESTs derived from four trophozoite libraries generated from two P. marinus strains. Trimming and clustering of the sequence tags yielded 7,863 unique sequences, some of which carry a spliced leader. Similarity searches revealed that 55% of these had hits in protein sequence databases, of which 1,729 had their best hit with proteins from the chromalveolates (E-value ≤ 1e-5. Some sequences are similar to those proven to be targets for effective intervention in other protozoan parasites, and include not only proteases, antioxidant enzymes, and heat shock proteins, but also those associated with relict plastids, such as acetyl-CoA carboxylase and methyl erythrithol phosphate pathway components, and those involved in glycan assembly, protein folding/secretion, and parasite-host interactions. Conclusions Our transcriptome analysis of P. marinus, the first for any member of the Perkinsozoa, contributes new insight into its biology and taxonomic position. It provides a very informative, albeit preliminary, glimpse into the expression of genes encoding functionally relevant proteins as potential targets for chemotherapy, and evidence

  18. ANTIOXIDANT ENZYMES, POTENTIAL VIRULENT FACTORS, IN DIFFERENT STRAINS OF THE OYSTER PROTOZOAN PARASITE, PERKINSUS MARINUS

    Science.gov (United States)

    The oyster protozoan parasite, Perkinsus marinus, is one of the two important parasites causing severe mortality in the eastern oysters (Crassostrea virginica) on the US east coast. Our recent study suggests that P. marinus cells and its extracellular products (ECP) could scaveng...

  19. The effect of meal size on gastric evacuation in whiting

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    1998-01-01

    Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe...

  20. Seabirds maintain offspring provisioning rate despite fluctuations in prey abundance: A multi-species functional response for guillemots in the North Sea

    DEFF Research Database (Denmark)

    Smout, Sophie; Rindorf, Anna; Wanless, Sarah

    2013-01-01

    . 3. We used annual time-series data on chick provisioning for the common guillemot Uria aalge together with abundance indices for its two main prey (lesser sandeel Ammodytes marinus and sprat Sprattus sprattus) to parameterize a multi-species functional response for parents provisioning chicks...... their parents despite fluctuating prey abundances, conferring some resilience in the face of environmental variation. The parameterized multi-species functional response model can be used to estimate levels of severe prey shortage that compromise provisioning. It also enables us to interpret predator......1. Seabirds that consume more than one prey type may adjust their foraging to maintain provisioning rates for their chicks. How energetically effective are these strategies, and what are the implications for the management of seabirds and their marine habitat? 2. A multi-species functional response...

  1. Systematic evaluation of factors controlling Perkinsus marinus transmission dynamics in lower Chesapeake Bay.

    Science.gov (United States)

    Ragone Calvo, Lisa M; Dungan, Christopher F; Roberson, Bob S; Burreson, Eugene M

    2003-08-15

    The transmission of Perkinsus marinus in eastern oysters Crassostrea virginica in relation to water temperature, host oyster mortality, and water-column abundance of anti-P. marinus antibody-labeled cells was systematically examined for 20 mo at a site in the lower York River, Virginia, USA. Uninfected sentinel oysters were naturally exposed to the parasite at 2 wk intervals throughout the course of the study to determine the periodicity and rates of parasite transmission. The timing and magnitude of disease-associated oyster mortalities in a local P. marinus-infected oyster population were estimated by monitoring a captive subset of the local oyster population. Flow cytometric immunodetection methods were employed to estimate the abundance of P. marinus cells in water samples collected 3 times each week. The acquisition of P. marinus infections by naïve sentinel oysters occurred sporadically at all times of the year; however, the highest incidence of infection occurred during the months of August and September. This window of maximum parasite transmission coincided with the death of infected hosts within the captive local oyster population. Counts of antibody-labeled cells ranged from 10 to 11900 cells l(-1), with the highest abundances in July and August coincident with maximum summer temperatures. A statistically significant relationship between water-column parasite abundance and infection-acquisition rate was not observed; however, highest parasite-transmission rates in both years occurred during periods of elevated water-column abundance of parasite cells. These results support the prevailing model of P. marinus transmission dynamics by which maximum transmission rates are observed during periods of maximum P. marinus-associated host mortality. However, our results also indicate that transmission can occur when host mortality is low or absent, so alternative mortality-independent dissemination mechanisms are likely. The results also suggest that atypically

  2. Evaluating potential artefacts of photo-reversal on behavioral studies with nocturnal invasive sea lamprey (Petromyzon marinus)

    Science.gov (United States)

    Barnett, Matthew; Imre, Istvan; Wagner, Michael C.; Di Rocco, Richard T.; Johnson, Nicholas; Brown, Grant E.

    2016-01-01

    Sea lampreys (Petromyzon marinus L., 1758) are nocturnal, so experiments evaluating their behaviour to chemosensory cues have typically been conducted at night. However, given the brief timeframe each year that adult P. marinus are available for experimentation, we investigated whether P. marinus exposed to a 12 h shifted diurnal cycle (reversed photoperiod) could be tested in a darkened arena during the day and show the same response to chemosensory cues as natural photoperiod P. marinus that were tested during the night. Ten replicates of 10 P. marinus, from each photoperiod, were exposed to deionized water (negative control), 2-phenylethylamine hydrochloride (PEA HCl, putative predator cue), or P. marinus whole-body extract (conspecific alarm cue). All P. marinus demonstrated a significant avoidance response to both cues. No significant differences were found in avoidance to PEA HCl between photoperiods. Avoidance of P. marinus whole-body extract was significantly stronger in natural compared with reversed photoperiod P. marinus. The use of reversed photoperiod subjects is suitable for examining the presence or absence of avoidance in response to novel chemosensory alarm cues, or the change in the magnitude of antipredator response. Studies investigating the natural magnitude of antipredator response should use natural photoperiod experimental subjects.

  3. Consumption and feeding preference of Echinogammarus marinus on two different algae: Fucus vesiculosus and Ulva intestinalis

    Science.gov (United States)

    Martins, Irene; Leite, Nuno; Constantino, Emanuel

    2014-01-01

    Echinogammarus marinus constitutes the most abundant amphipod species in Fucus spp. assemblages from many North Atlantic estuaries. However, there are some doubts about the real use of fucoids by the amphipod. Whilst some studies report the ingestion of Fucus vesiculosus by E. marinus, others suggest that the amphipod preference for fucoids is mostly related to sheltering rather than feeding, due to the high phlorotannin content of brown algae. The purpose of the present work was to disentangle this issue by checking the consumption rate and feeding preference of E. marinus on F. vesiculosus, its preferential habitat, and on Ulva intestinalis, a green algae abundant in the Mondego estuary (Western Coast of Portugal) and usually considered as highly palatable for herbivores. In a 2-stage laboratorial setup, fresh disks of the two types of algae were offered to E. marinus for three days. Consumption rates were estimated from differences between algal and animal initial and final fresh weights using a control correction factor, while preference was tested by differences in algal consumption rates when no choice was offered (stage 1) and when the two algae were offered simultaneously (stage 2). Results showed that E. marinus effectively consumed fresh F. vesiculosus in much higher amounts than U. intestinalis and significantly preferred to consume F. vesiculosus over U. intestinalis. Therefore, feeding habits must be one of the factors related to the close association of the amphipod with F. vesiculosus, although other factors may also be involved (e.g. sheltering).

  4. Natural and cultured populations of the mangrove oyster Saccostrea palmula from Sinaloa, Mexico, infected by Perkinsus marinus.

    Science.gov (United States)

    Cáceres-Martínez, Jorge; Ortega, Mauricio García; Vásquez-Yeomans, Rebeca; García, Teresa de Jesús Pineda; Stokes, Nancy A; Carnegie, Ryan B

    2012-07-01

    The mangrove oyster Saccostrea palmula coexists with the pleasure oyster Crassostrea corteziensis in coastal lagoons of northwest Mexico. Recent discovery of Perkinsus marinus infecting the pleasure oyster in the region prompted evaluation of S. palmula as an alternative P. marinus host. An analysis to determine the possible presence of P. marinus in natural and cultured populations of S. palmula at four coastal lagoons in Sinaloa, Mexico was carried out during October-November 2010. Tissues from apparently healthy S. palmula were evaluated using Ray's fluid thioglycollate method (RFTM), which revealed a Perkinsus sp. to be present in all four locations at 6.7-20.0% prevalence. Histopathological analysis of these specimens showed tissue alterations and parasite forms consistent with moderate P. marinus infection, which was confirmed by ribosomal non-transcribed spacer (NTS)-based PCR assays on DNA samples from oysters positive by RFTM and histology. DNA sequencing of amplified NTS fragments (307 bp) produced a sequence 98-100% similar to GenBank-deposited sequences of the NTS from P. marinus. Fluorescent in situ hybridization for Perkinsus spp. and P. marinus corroborated the PCR results, showing clear hybridization of P. marinus in host tissues. This is the first record of P. marinus infecting a species from genus Saccostrea and the first record of the parasite from coastal lagoons in Sinaloa, Mexico. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Mercury accumulation in sea lamprey (Petromyzon marinus) from Lake Huron

    Science.gov (United States)

    Madenjian, Charles P.; Johnson, Nicholas S.; Siefkes, Michael J.; Dettmers, John M.; Blum, Joel D.; Johnson, Marcus W.

    2014-01-01

    We determined whole-fish total mercury (Hg) concentrations of 40 male and 40 female adult sea lampreys (Petromyzon marinus) captured in the Cheboygan River, a tributary to Lake Huron, during May 2011. In addition, bioenergetics modeling was used to explore the effects of sex-related differences in activity and resting (standard) metabolic rate (SMR) on mercury accumulation. The grand mean for Hg concentrations was 519 ng/g (standard error of the mean = 46 ng/g). On average, males were 16% higher in Hg concentration than females. Bioenergetics modeling results indicated that 14% higher activity and SMR in males would account for this observed sex difference in Hg concentrations. We concluded that the higher Hg concentration in males was most likely due to higher rate of energy expenditure in males, stemming from greater activity and SMR. Our findings have implications for estimating the effects of sea lamprey populations on mercury cycling within ecosystems, as well as for the proposed opening of sea lamprey fisheries. Eventually, our results may prove useful in improving control of sea lamprey, a pest responsible for substantial damage to fisheries in lakes where it is not native.

  6. Heterologous Expression of Gene of Interest Using the Marine Protozoan Perkinsus marinus

    Science.gov (United States)

    Cold, E. R.

    2016-02-01

    Perkinsus marinus is a marine protozoan parasite that causes "Dermo" disease in eastern oysters (Crassostrea virginica). P. marinus is closely related to Plasmodium falciparum which causes malaria. A recent study has showed that P. marinus causes no pathology damage but an immune response in humanized mouse, providing the bases for a genetically modified P. marinus expressing Plasmodium genes to be used as a vaccination delivery system for malaria and other pathogenic diseases. A modified plasmid vector (pMOE-GFP) based on highly expressed gene tagged with green fluorescence protein and targeted to P. marinus cell wall was used to clone MSP8 and HAP2. MSP8 encodes for merozoite surface in P. falciparum and HAP2 is essential for fusion of male and female gametes; genetic disruption of the HAP2 locus revealed that parasite fertilization is prevented. Using electroporation, MSP8 and HAP2 plasmid were introduced into the P. marinus trophozoites. As controls pMOE-GFP was transfected into P. mediterraneus, P. atlanticus and P. chesapeaki. Transfection conditions included 5x107 Perkinsus trophozoites and 10 µg of plasmid using Nucleofector® technology (D-023 program). The cells were recovered in 3 mL of Perkinsus culture media and transfected trophozoites were examined for green fluorescence. To facilitate subcloning of cells expressing GFP, we optimized a DME: HAM's F12 -5% FBS -containing agar solid medium for plating Perkinsus. Examination of all transfected cells indicates expression of both MSP8 and HAP2. This is the first time that genes of a protozoan parasite have been expressed in a marine protozoan. It was also concluded that P. mediterraneus, P. atlanticus and P. chesapeaki were stable mutation and can be isolated for further research.

  7. The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, iain J.; Dharmarajan, Lakshmi; Rodriguez, Jason; Hooper, Sean; Porat, Iris; Ulrich, Luke E.; Elkins, James G.; Mavromatis, Kostas; Sun, Hui; Land, Miriam; Lapidus, Alla; Lucas, Susan; Barry, Kerrie; Huber, Harald; Zhulin, Igor B.; Whitman, William B.; Mukhopadhyay, Biswarup; Woese, Carl; Bristow, James; Kyrpides, Nikos

    2008-09-05

    Staphylothermus marinus is an anaerobic, sulfur-reducing peptide fermenter of the archaeal phylum Crenarchaeota. It is the third heterotrophic, obligate sulfur reducing crenarchaeote to be sequenced and provides an opportunity for comparative analysis of the three genomes. The 1.57 Mbp genome of the hyperthermophilic crenarchaeote Staphylothermus marinus has been completely sequenced. The main energy generating pathways likely involve 2-oxoacid:ferredoxin oxidoreductases and ADP-forming acetyl-CoA synthases. S. marinus possesses several enzymes not present in other crenarchaeotes including a sodium ion-translocating decarboxylase likely to be involved in amino acid degradation. S. marinus lacks sulfur-reducing enzymes present in the other two sulfur-reducing crenarchaeotes that have been sequenced - Thermofilum pendens and Hyperthermus butylicus. Instead it has three operons similar to the mbh and mbx operons of Pyrococcus furiosus, which may play a role in sulfur reduction and/or hydrogen production. The two marine organisms, S. marinus and H. butylicus, possess more sodium-dependent transporters than T. pendens and use symporters for potassium uptake while T. pendens uses an ATP-dependent potassium transporter. T. pendens has adapted to a nutrient-rich environment while H. butylicus is adapted to a nutrient-poor environment, and S. marinus lies between these two extremes. The three heterotrophic sulfur-reducing crenarchaeotes have adapted to their habitats, terrestrial vs. marine, via their transporter content, and they have also adapted to environments with differing levels of nutrients. Despite the fact that they all use sulfur as an electron acceptor, they are likely to have different pathways for sulfur reduction.

  8. The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota

    Directory of Open Access Journals (Sweden)

    Barry Kerrie

    2009-04-01

    Full Text Available Abstract Background Staphylothermus marinus is an anaerobic, sulfur-reducing peptide fermenter of the archaeal phylum Crenarchaeota. It is the third heterotrophic, obligate sulfur reducing crenarchaeote to be sequenced and provides an opportunity for comparative analysis of the three genomes. Results The 1.57 Mbp genome of the hyperthermophilic crenarchaeote Staphylothermus marinus has been completely sequenced. The main energy generating pathways likely involve 2-oxoacid:ferredoxin oxidoreductases and ADP-forming acetyl-CoA synthases. S. marinus possesses several enzymes not present in other crenarchaeotes including a sodium ion-translocating decarboxylase likely to be involved in amino acid degradation. S. marinus lacks sulfur-reducing enzymes present in the other two sulfur-reducing crenarchaeotes that have been sequenced – Thermofilum pendens and Hyperthermus butylicus. Instead it has three operons similar to the mbh and mbx operons of Pyrococcus furiosus, which may play a role in sulfur reduction and/or hydrogen production. The two marine organisms, S. marinus and H. butylicus, possess more sodium-dependent transporters than T. pendens and use symporters for potassium uptake while T. pendens uses an ATP-dependent potassium transporter. T. pendens has adapted to a nutrient-rich environment while H. butylicus is adapted to a nutrient-poor environment, and S. marinus lies between these two extremes. Conclusion The three heterotrophic sulfur-reducing crenarchaeotes have adapted to their habitats, terrestrial vs. marine, via their transporter content, and they have also adapted to environments with differing levels of nutrients. Despite the fact that they all use sulfur as an electron acceptor, they are likely to have different pathways for sulfur reduction.

  9. The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain [U.S. Department of Energy, Joint Genome Institute; Lakshmi, Lakshmi Dharmarajan [Virginia Polytechnic Institute and State University (Virginia Tech); Rodriquez, Jason [Virginia Polytechnic Institute and State University (Virginia Tech); Hooper, Sean [U.S. Department of Energy, Joint Genome Institute; Porat, I. [University of Georgia, Athens, GA; Ulrich, Luke [ORNL; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Sun, Hui [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Barry, Kerrie [U.S. Department of Energy, Joint Genome Institute; Huber, Harald [Universitat Regensburg, Regensburg, Germany; Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Whitman, W. B. [University of Georgia, Athens, GA; Mukhopadhyay, Biswarup [Virginia Polytechnic Institute and State University (Virginia Tech); Woese, Carl [University of Illinois, Urbana-Champaign; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute

    2009-01-01

    Background Staphylothermus marinus is an anaerobic, sulfur-reducing peptide fermenter of the archaeal phylum Crenarchaeota. It is the third heterotrophic, obligate sulfur reducing crenarchaeote to be sequenced and provides an opportunity for comparative analysis of the three genomes. Results The 1.57 Mbp genome of the hyperthermophilic crenarchaeote Staphylothermus marinus has been completely sequenced. The main energy generating pathways likely involve 2-oxoacid:ferredoxin oxidoreductases and ADP-forming acetyl-CoA synthases. S. marinus possesses several enzymes not present in other crenarchaeotes including a sodium ion-translocating decarboxylase likely to be involved in amino acid degradation. S. marinus lacks sulfur-reducing enzymes present in the other two sulfur-reducing crenarchaeotes that have been sequenced Thermofilum pendens and Hyperthermus butylicus. Instead it has three operons similar to the mbh and mbx operons of Pyrococcus furiosus, which may play a role in sulfur reduction and/or hydrogen production. The two marine organisms, S. marinus and H. butylicus, possess more sodium-dependent transporters than T. pendens and use symporters for potassium uptake while T. pendens uses an ATP-dependent potassium transporter. T. pendens has adapted to a nutrient-rich environment while H. butylicus is adapted to a nutrient-poor environment, and S. marinus lies between these two extremes. Conclusion The three heterotrophic sulfur-reducing crenarchaeotes have adapted to their habitats, terrestrial vs. marine, via their transporter content, and they have also adapted to environments with differing levels of nutrients. Despite the fact that they all use sulfur as an electron acceptor, they are likely to have different pathways for sulfur reduction.

  10. The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota.

    Science.gov (United States)

    Anderson, Iain J; Dharmarajan, Lakshmi; Rodriguez, Jason; Hooper, Sean; Porat, Iris; Ulrich, Luke E; Elkins, James G; Mavromatis, Kostas; Sun, Hui; Land, Miriam; Lapidus, Alla; Lucas, Susan; Barry, Kerrie; Huber, Harald; Zhulin, Igor B; Whitman, William B; Mukhopadhyay, Biswarup; Woese, Carl; Bristow, James; Kyrpides, Nikos

    2009-04-02

    Staphylothermus marinus is an anaerobic, sulfur-reducing peptide fermenter of the archaeal phylum Crenarchaeota. It is the third heterotrophic, obligate sulfur reducing crenarchaeote to be sequenced and provides an opportunity for comparative analysis of the three genomes. The 1.57 Mbp genome of the hyperthermophilic crenarchaeote Staphylothermus marinus has been completely sequenced. The main energy generating pathways likely involve 2-oxoacid:ferredoxin oxidoreductases and ADP-forming acetyl-CoA synthases. S. marinus possesses several enzymes not present in other crenarchaeotes including a sodium ion-translocating decarboxylase likely to be involved in amino acid degradation. S. marinus lacks sulfur-reducing enzymes present in the other two sulfur-reducing crenarchaeotes that have been sequenced -- Thermofilum pendens and Hyperthermus butylicus. Instead it has three operons similar to the mbh and mbx operons of Pyrococcus furiosus, which may play a role in sulfur reduction and/or hydrogen production. The two marine organisms, S. marinus and H. butylicus, possess more sodium-dependent transporters than T. pendens and use symporters for potassium uptake while T. pendens uses an ATP-dependent potassium transporter. T. pendens has adapted to a nutrient-rich environment while H. butylicus is adapted to a nutrient-poor environment, and S. marinus lies between these two extremes. The three heterotrophic sulfur-reducing crenarchaeotes have adapted to their habitats, terrestrial vs. marine, via their transporter content, and they have also adapted to environments with differing levels of nutrients. Despite the fact that they all use sulfur as an electron acceptor, they are likely to have different pathways for sulfur reduction.

  11. Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

    Energy Technology Data Exchange (ETDEWEB)

    Queiroga, Fernando Ramos [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Marques-Santos, Luis Fernando [Laboratório de Biologia Celular e do Desenvolvimento (LABID), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Hégaret, Hélène [Laboratoire des Sciences de l' Environnement Marin (LEMAR), UMR 6539 CNRS UBO IRD IFREMER, Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise, 29280, Plouzané (France); Sassi, Roberto [Laboratório de Ambientes Recifais e Biotecnologia de Microalgas (LARBIM), Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Farias, Natanael Dantas; Santana, Lucas Nunes [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); and others

    2017-06-15

    Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

  12. Electrical responses of rods in the retina of Bufo marinus

    Science.gov (United States)

    Cervetto, L.; Pasino, E.; Torre, V.

    1977-01-01

    1. Intracellular responses to flashes and steps of light have been recorded from the outer segment and the cell body of rods in the retina of the Bufo marinus. The identification of the origin of recorded responses has been confirmed by intracellular marking. 2. Responses to flashes delivered in darkness or superimposed on a background were analysed. Responses recorded from outer segments conform to the principle of `spectral univariance'. The shape of the response is not affected by enlarging the spot diameter from 150 to 1000 μm. 3. The membrane potential measured in darkness at the outer segments varied from -15 to -25 mV. Injection of steady hyperpolarizing currents increases the size of the response to light; depolarizing currents reduce the response. The mean value of the input resistance is 97 ± 30 MΩ in darkness and increases by 20-30% during illumination. 4. The responses obtained from the cell body of rods have the same shape, time course and spectral sensitivity of those recorded at the outer segment. Injection of steady current at the cell body produces different effects than at the outer segment: hyperpolarizing currents reduce the amplitude of the response to light; depolarizing currents increase the response. 5. The experimental data are fitted according to a model similar to that used to describe the responses of turtle cones (Baylor & Hodgkin, 1974; Baylor, Hodgkin & Lamb, 1974a, b). 6. The model reproduces the electrical responses of the rod outer segment to a variety of stimuli: (a) brief flashes and steps of light in dark adapted conditions; (b) bright flashes superimposed on background illuminations; (c) pairs of flashes delivered at different time intervals. Responses to hyperpolarizing steps of current are also reproduced by the model. ImagesABCD PMID:406383

  13. Minimal sulfur requirement for growth and sulfur-dependent metabolism of the hyperthermophilic archaeon Staphylothermus marinus

    Directory of Open Access Journals (Sweden)

    Xiaolei Hao

    2003-01-01

    Full Text Available Staphylothermus marinus is an anaerobic hyperthermophilic archaeon that uses peptides as carbon and energy sources. Elemental sulfur (S° is obligately required for its growth and is reduced to H2S. The metabolic functions and mechanisms of S° reduction were explored by examining S°-dependent growth and activities of key enzymes present in this organism. All three forms of S° tested—sublimed S°, colloidal S° and polysulfide—were used by S. marinus, and no other sulfur-containing compounds could replace S°. Elemental sulfur did not serve as physical support but appeared to function as an electron acceptor. The minimal S° concentration required for optimal growth was 0.05% (w/v. At this concentration, there appeared to be a metabolic transition from H2 production to S° reduction. Some enzymatic activities related to S°-dependent metabolism, including sulfur reductase, hydrogenase, glutamate dehydrogenase and electron transfer activities, were detected in cell-free extracts of S. marinus. These results indicate that S° plays an essential role in the heterotrophic metabolism of S. marinus. Reducing equivalents generated by the oxidation of amino acids from peptidolysis may be transferred to sulfur reductase and hydrogenase, which then catalyze the production of H2S and H2, respectively.

  14. Prey Range and Genome Evolution of Halobacteriovorax marinus Predatory Bacteria from an Estuary.

    Science.gov (United States)

    Enos, Brett G; Anthony, Molly K; DeGiorgis, Joseph A; Williams, Laura E

    2018-01-01

    Halobacteriovorax strains are saltwater-adapted predatory bacteria that attack Gram-negative bacteria and may play an important role in shaping microbial communities. To understand how Halobacteriovorax strains impact ecosystems and develop them as biocontrol agents, it is important to characterize variation in predation phenotypes and investigate Halobacteriovorax genome evolution. We isolated Halobacteriovorax marinus BE01 from an estuary in Rhode Island using Vibrio from the same site as prey. Small, fast-moving, attack-phase BE01 cells attach to and invade prey cells, consistent with the intraperiplasmic predation strategy of the H. marinus type strain, SJ. BE01 is a prey generalist, forming plaques on Vibrio strains from the estuary, Pseudomonas from soil, and Escherichia coli. Genome analysis revealed extremely high conservation of gene order and amino acid sequences between BE01 and SJ, suggesting strong selective pressure to maintain the genome in this H. marinus lineage. Despite this, we identified two regions of gene content difference that likely resulted from horizontal gene transfer. Analysis of modal codon usage frequencies supports the hypothesis that these regions were acquired from bacteria with different codon usage biases than H. marinus. In one of these regions, BE01 and SJ carry different genes associated with mobile genetic elements. Acquired functions in BE01 include the dnd operon, which encodes a pathway for DNA modification, and a suite of genes involved in membrane synthesis and regulation of gene expression that was likely acquired from another Halobacteriovorax lineage. This analysis provides further evidence that horizontal gene transfer plays an important role in genome evolution in predatory bacteria. IMPORTANCE Predatory bacteria attack and digest other bacteria and therefore may play a role in shaping microbial communities. To investigate phenotypic and genotypic variation in saltwater-adapted predatory bacteria, we isolated

  15. Helminth parasites in Chaunus marinus and Cranopis valliceps (Anura: Bufonidae) from Lagunas Yalahau, Yucatan, Mexico.

    Science.gov (United States)

    Espínola-Novelo, Juan Francisco; Guillén-Hernández, Sergio

    2008-06-01

    Eight helminth taxa were found parasitizing Chaunus marinus (n = 40) and Cranopsis valliceps (n = 40) from the Parque Estatal Lagunas Yalahau, Yucatan, Mexico. Seven taxa (2 digeneans: Langeronia macrocirra, Mesocoelium monas; 1 acanthocephalan: Oncicola sp.; 3 nematodes: Rhabdias füleborni, Aplectana itzocanensis, Cruzia morleyi; and a nematode larva) were found in C. marinus, while 4 taxa (all nematodes: Rhabdias fuelleborni, Aplectana itzocanensis, Ozwaldocruzia sp., and a nematode larva) were present in C. valliceps. Nematodes, particularly A. iztocanensis, showed high prevalence, mean abundance, and mean intensity values for both species of amphibians. The occurrence of R. fuelleborni, M. monas, L. macrocirra, and C. morleyi in these amphibians from the Yucatan Peninsula confirms their neotropical distribution, while the presence of A. itzocanensis increases its geographical distribution, suggesting a preference by neotropical, rather than neartic areas.

  16. Identification of MMV Malaria Box inhibitors of Perkinsus marinus using an ATP-based bioluminescence assay.

    Directory of Open Access Journals (Sweden)

    Yesmalie Alemán Resto

    Full Text Available "Dermo" disease caused by the protozoan parasite Perkinsus marinus (Perkinsozoa is one of the main obstacles to the restoration of oyster populations in the USA. Perkinsus spp. are also a concern worldwide because there are limited approaches to intervention against the disease. Based on the phylogenetic affinity between the Perkinsozoa and Apicomplexa, we exposed Perkinsus trophozoites to the Medicines for Malaria Venture Malaria Box, an open access compound library comprised of 200 drug-like and 200 probe-like compounds that are highly active against the erythrocyte stage of Plasmodium falciparum. Using a final concentration of 20 µM, we found that 4 days after exposure 46% of the compounds were active against P. marinus trophozoites. Six compounds with IC50 in the µM range were used to compare the degree of susceptibility in vitro of eight P. marinus strains from the USA and five Perkinsus species from around the world. The three compounds, MMV666021, MMV665807 and MMV666102, displayed a uniform effect across Perkinsus strains and species. Both Perkinsus marinus isolates and Perkinsus spp. presented different patterns of response to the panel of compounds tested, supporting the concept of strain/species variability. Here, we expanded the range of compounds available for inhibiting Perkinsus proliferation in vitro and characterized Perkinsus phenotypes based on their resistance to six compounds. We also discuss the implications of these findings in the context of oyster management. The Perkinsus system offers the potential for investigating the mechanism of action of the compounds of interest.

  17. Detection of Perkinsus marinus in the oyster Crassostrea rhizophorae in southern Bahia by proteomic analysis

    Directory of Open Access Journals (Sweden)

    Thiago Ramos Pinto

    2017-01-01

    Full Text Available This study reports the presence of the pathogen Perkinsus marinus, notifiable to the World Organization for Animal Health (Office International des Èpizooties = OIE in the oyster Crassostrea rhizophorae in southern Bahia via proteomic analysis. We analyzed Crassostrea brasiliana from a long-line cultivation system and C. rhizophorae from an adjacent mangrove in Porto do Campo, Camamu Bay, Bahia, Brazil. The collections (n = 100 were performed in October 2012. In the laboratory, the oysters were measured and opened to remove the meat, which was steeped in dry ice. For extraction of proteins, adaptation of a protocol used for mussels was used, after which separation in the first dimension was taken by isoelectric focusing (IEF. The peptides were transferred to a Mass Spectrometer. The obtained spectra were analyzed with the ProteinLynx Global Server 4.2 software tool and also by MASCOT (Matrix Science and compared to the databases of the SWISSPROT and NCBI, respectively. The identification was evidenced by beta-tubulin, Perkinsus marinus ATCC 50983 and protein homology code in the database NCBI = gi | 294889481. This is the first record of P. marinus in Bahia and the fourth in Brazil.

  18. Factors associated with the prevalence of Perkinsus marinus in Crassostrea virginica from the southern Gulf of Mexico.

    Science.gov (United States)

    Gullian-Klanian, M; Herrera-Silveira, J A; Rodríguez-Canul, R; Aguirre-Macedo, L

    2008-05-08

    The protozoan Perkinsus marinus is considered the most important pathogen of the eastern oyster Crassostrea virginica, causing high mortality in natural and farmed oysters on the Atlantic coast of the US. In Mexico, no serious P. marinus epizootic has been reported. This study describes the current state of P. marinus prevalence in Terminos Lagoon (Mexico) associated with environmental factors including salinity, temperature, ammonium, nitrate, nitrite, silica, and phosphorus. In addition, the association of physiological (hemocyte density, protein concentration) and immunological (lysozyme, agglutination) parameters with the infection were studied. The prevalence was significantly different among seasons with mean values of 70, 23, and 7% in the dry (February to May), rainy (June to September) and north-wind (October to January) seasons, respectively. Only light infection intensity (Mackin scale value Terminos Lagoon.

  19. The Effects of the Toxic Cyanobacterium Limnothrix (Strain AC0243) on Bufo marinus Larvae

    Science.gov (United States)

    Daniels, Olivia; Fabbro, Larelle; Makiela, Sandrine

    2014-01-01

    Limnothrix (strain AC0243) is a cyanobacterium, which has only recently been identified as toxin producing. Under laboratory conditions, Bufo marinus larvae were exposed to 100,000 cells mL−1 of Limnothrix (strain AC0243) live cultures for seven days. Histological examinations were conducted post mortem and revealed damage to the notochord, eyes, brain, liver, kidney, pancreas, gastrointestinal tract, and heart. The histopathological results highlight the toxicological impact of this strain, particularly during developmental stages. Toxicological similarities to β-N-Methylamino-l-alanine are discussed. PMID:24662524

  20. Evaluation of the production of exopolysaccharides by two strains of the thermophilic bacterium Rhodothermus marinus.

    Science.gov (United States)

    Sardari, Roya R R; Kulcinskaja, Evelina; Ron, Emanuel Y C; Björnsdóttir, Snædís; Friðjónsson, Ólafur H; Hreggviðsson, Guðmundur Óli; Karlsson, Eva Nordberg

    2017-01-20

    The thermophile Rhodothermus marinus produces extracellular polysaccharides (EPSs) that forms a distinct cellular capsule. Here, the first data on EPS production in strains DSM4252(T) and MAT493 are reported and compared. Cultures of both strains, supplemented with either glucose, sucrose, lactose or maltose showed that the EPS were produced both in the exponential and stationary growth phase and that production in the exponential phase was boosted by maltose supplementation, while stationary phase production was boosted by lactose. The latter was higher, resulting in 8.8 (DSM4252(T)) and 13.7mg EPS/g cell dry weight (MAT493) in cultures in marine broth supplemented with 10g/L lactose. The EPSs were heteropolymeric with an average molecular weight of 8×10(4)Da and different monosaccharides, including arabinose and xylose. FT-IR spectroscopy revealed presence of hydroxyl, carboxyl, N-acetyl, amine, and sulfate ester groups, showing that R. marinus produces unusual sulfated EPS with high arabinose and xylose content. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Population dynamics of the Gyrinid beetle Gyrinus marinus Gyll. (Coleoptera, Gyrinidae) with special reference to its dispersal activities

    NARCIS (Netherlands)

    Eijk, van der R.H.

    1987-01-01

    Data concerning reproduction, survival and dispersal of the whirligig water beetle Gyrinus marinus Gyll . were collected between 1974 and 1983 by observations and experiments in the laboratory and in a field area with about 10 populations distributed over 15

  2. Carbon use efficiencies and allocation strategies in Prochlorococcus marinus strain PCC 9511 during nitrogen-limited growth

    Czech Academy of Sciences Publication Activity Database

    Felcmanová, Kristina; Lukeš, Martin; Kotabová, Eva; Lawrenz, Evelyn; Halsey, K.H.; Prášil, Ondřej

    2017-01-01

    Roč. 134, č. 1 (2017), s. 71-82 ISSN 0166-8595 R&D Projects: GA MŠk(CZ) LO1416; GA MŠk(CZ) LH11064 Institutional support: RVO:61388971 Keywords : Prochlorococcus marinus * Cyanobacteria * Primary production Subject RIV: EE - Microbiology, Virology Impact factor: 3.864, year: 2016

  3. Rhabdias pseudosphaerocephala infection in Bufo marinus: lung nematodes reduce viability of metamorph cane toads.

    Science.gov (United States)

    Kelehear, C; Webb, J K; Shine, R

    2009-07-01

    Cane toads (Bufo marinus) were introduced to Australia in 1935 and have since spread widely over the continent, generating concern regarding ecological impacts on native predators. Most Australian cane toad populations are infected with lung nematodes Rhabdias pseudosphaerocephala, a parasite endemic to New World (native-range) cane toad populations; presumably introduced to Australia with its toad host. Considering the high intensities and prevalence reached by this parasite in Australian toad populations, and public ardour for developing a control plan for the invasive host species, the lack of experimental studies on this host-parasite system is surprising. To investigate the extent to which this lungworm influences cane toad viability, we experimentally infected metamorph toads (the smallest and presumably most vulnerable terrestrial phase of the anuran life cycle) with the helminth. Infected toads exhibited reduced survival and growth rates, impaired locomotor performance (both speed and endurance), and reduced prey intake. In summary, R. pseudosphaerocephala can substantially reduce the viability of metamorph cane toads.

  4. Sequencing of the sea lamprey (Petromyzon marinus) genome provides insights into vertebrate evolution

    Science.gov (United States)

    Smith, Jeramiah J; Kuraku, Shigehiro; Holt, Carson; Sauka-Spengler, Tatjana; Jiang, Ning; Campbell, Michael S; Yandell, Mark D; Manousaki, Tereza; Meyer, Axel; Bloom, Ona E; Morgan, Jennifer R; Buxbaum, Joseph D; Sachidanandam, Ravi; Sims, Carrie; Garruss, Alexander S; Cook, Malcolm; Krumlauf, Robb; Wiedemann, Leanne M; Sower, Stacia A; Decatur, Wayne A; Hall, Jeffrey A; Amemiya, Chris T; Saha, Nil R; Buckley, Katherine M; Rast, Jonathan P; Das, Sabyasachi; Hirano, Masayuki; McCurley, Nathanael; Guo, Peng; Rohner, Nicolas; Tabin, Clifford J; Piccinelli, Paul; Elgar, Greg; Ruffier, Magali; Aken, Bronwen L; Searle, Stephen MJ; Muffato, Matthieu; Pignatelli, Miguel; Herrero, Javier; Jones, Matthew; Brown, C Titus; Chung-Davidson, Yu-Wen; Nanlohy, Kaben G; Libants, Scot V; Yeh, Chu-Yin; McCauley, David W; Langeland, James A; Pancer, Zeev; Fritzsch, Bernd; de Jong, Pieter J; Zhu, Baoli; Fulton, Lucinda L; Theising, Brenda; Flicek, Paul; Bronner, Marianne E; Warren, Wesley C; Clifton, Sandra W; Wilson, Richard K; Li, Weiming

    2013-01-01

    Lampreys are representatives of an ancient vertebrate lineage that diverged from our own ~500 million years ago. By virtue of this deeply shared ancestry, the sea lamprey (P. marinus) genome is uniquely poised to provide insight into the ancestry of vertebrate genomes and the underlying principles of vertebrate biology. Here, we present the first lamprey whole-genome sequence and assembly. We note challenges faced owing to its high content of repetitive elements and GC bases, as well as the absence of broad-scale sequence information from closely related species. Analyses of the assembly indicate that two whole-genome duplications likely occurred before the divergence of ancestral lamprey and gnathostome lineages. Moreover, the results help define key evolutionary events within vertebrate lineages, including the origin of myelin-associated proteins and the development of appendages. The lamprey genome provides an important resource for reconstructing vertebrate origins and the evolutionary events that have shaped the genomes of extant organisms. PMID:23435085

  5. Migratory-stage sea lamprey Petromyzon marinus stop responding to conspecific damage-released alarm cues after 4 h of continuous exposure in laboratory conditions

    Science.gov (United States)

    Imre, Istvan; Di Rocco, Richard T.; McClure, Haley; Johnson, Nicholas; Brown, Grant E.

    2016-01-01

    This study investigated the length of avoidance response of migratory-stage sea lamprey Petromyzon marinus exposed continuously to conspecific damage-released alarm cues for varying lengths of time in laboratory stream channels. Ten replicate groups of P. marinus, separated by sex, were exposed to either deionized water control or to P. marinus extract for 0, 2 or 4 h continuously. Petromyzon marinus maintained their avoidance response to the conspecific damage-released alarm cue after continuous exposure to the alarm cue for 0 and 2 h but not 4 h. Beyond being one of the first studies in regards to sensory–olfactory adaptation–acclimation of fishes to alarm cues of any kind, these results have important implications for use of conspecific alarm cues in P. marinus control. For example, continuous application of conspecific alarm cue during the day, when P. marinus are inactive and hiding, may result in sensory adaptation to the odour by nightfall when they migrate upstream.

  6. The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.)

    Science.gov (United States)

    Killorn, Erin E; Toews, Daniel P

    2001-01-01

    Background Venous return from the posterior region of amphibians travels by either two renal portal veins to the kidney or a central abdominal vein that drains into the hepatic portal system. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts. Results Venous return from the posterior region of Bufo marinus was measured under resting conditions and in response to a systemic hypervolemia. Doppler flow probes were positioned on the renal portal and ventral abdominal veins, and flow was recorded as injections of artificial plasma equaling 100% of the animal's plasma volume were administered through the sciatic artery. Resting flow was found to be 5.54 ± 2.03 ml min-1 kg-1 in the paired renal portal veins, and 7.31 ± 0.89 ml min-1 kg-1 in the ventral abdominal vein. While renal portal flow was found to increase by a factor of 2.4 times during the first 10 min of hypervolemia, ventral abdominal flow only increased by a factor of 1.3. Conclusions Our results quantify the contribution to circulation from posterior venous return in the toad Bufo marinus. A preferential movement of excess fluid through the renal portal pathway was also demonstrated, supporting the possibility of water elimination via the renal portal circulation, especially during periods of high water influx into the animals. PMID:11696249

  7. Flow cytometric analysis of lectin binding to in vitro-cultured Perkinsus marinus surface carbohydrates

    Science.gov (United States)

    Gauthier, J.D.; Jenkins, J.A.; La Peyre, Jerome F.

    2004-01-01

    Parasite surface glycoconjugates are frequently involved in cellular recognition and colonization of the host. This study reports on the identification of Perkinsus marinus surface carbohydrates by flow cytometric analyses of fluorescein isothiocyanate-conjugated lectin binding. Lectin-binding specificity was confirmed by sugar inhibition and Kolmogorov-Smirnov statistics. Clear, measurable fluorescence peaks were discriminated, and no parasite autofluorescence was observed. Parasites (GTLA-5 and Perkinsus-1 strains) harvested during log and stationary phases of growth in a protein-free medium reacted strongly with concanavalin A and wheat germ agglutinin, which bind to glucose-mannose and N-acetyl-D-glucosamine (GlcNAc) moieties, respectively. Both P. marinus strains bound with lower intensity to Maclura pomifera agglutinin, Bauhinia purpurea agglutinin, soybean agglutinin (N-acetyl-D-galactosamine-specific lectins), peanut agglutinin (PNA) (terminal galactose specific), and Griffonia simplicifolia II (GlcNAc specific). Only background fluorescence levels were detected with Ulex europaeus agglutinin I (L-fucose specific) and Limulus polyphemus agglutinin (sialic acid specific). The lectin-binding profiles were similar for the 2 strains except for a greater relative binding intensity of PNA for Perkinsus-1 and an overall greater lectin-binding capacity of Perkinsus-1 compared with GTLA-5. Growth stage comparisons revealed increased lectin-binding intensities during stationary phase compared with log phase of growth. This is the first report of the identification of surface glycoconjugates on a Perkinsus spp. by flow cytometry and the first to demonstrate that differential surface sugar expression is growth phase and strain dependent. ?? American Society of Parasitologists 2004.

  8. Morphological and functional aspects of the epidermis of the sea lamprey Petromyzon marinus throughout development.

    Science.gov (United States)

    Rodríguez-Alonso, R; Megías, M; Pombal, M A; Molist, P

    2017-07-01

    The development of the epidermis of sea lamprey Petromyzon marinus along the whole life cycle was studied using conventional staining techniques and lectin histochemistry. The epidermis undergoes variations in morphology and thickness throughout development. The simple cuboidal epithelium found in the epidermis of prolarvae becomes stratified cubic in the adult by increasing the number of cell layers. The cuticle thickness undergoes a steady increase during the larval period. There are changes in the glycoconjugate composition of the three main cell types of the P. marinus epidermis, mucous, granular and skein cells, which are more pronounced after metamorphosis. The Alcian blue-periodic acid Schiff (AB-PAS) histochemical method shows the presence of both acidic and neutral glycoconjugates in the mucous cells, indicating their secretory function. Moreover, lectin analysis reveals a mucous secretion containing glycoconjugates such as sulphated glycosaminoglycans (N-acetylglucosamine and N-acetylgalactosamine) and N-glycoproteins rich in mannose. Although granular cells are AB-PAS negative, they exhibit a similar glycoconjugate composition to the mucous cells. Moreover, granular cells show sialic acid positivity in larvae but this monosaccharide residue is not detected after metamorphosis. The skein cells, a unique cell of lampreys, are negative to AB-PAS staining but they mostly contain l-fucose and sialic acid residues, which also disappear after metamorphosis. The function of the granular and skein cells is still unknown but the role of their glycoconjugate composition is discussed. In addition, a different cellular origin is suggested for these two types of cells. © 2017 The Fisheries Society of the British Isles.

  9. Influences of potential predictor variables on gastric evacuation in Atlantic cod Gadus morhua L. feeding on fish prey

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    2012-01-01

    The parameter values of a generic model of gastric evacuation were estimated from evacuation data on Atlantic cod Gadus morhua fed meals of four fish prey: herring Clupea harengus, sprat Sprattus sprattus, lesser sandeel Ammodytes tobianus and dab Limanda limanda. The effects on evacuation...

  10. Sterility method of pest control and its potential role in an integrated sea lamprey (Petromyzon marinus) control program

    Science.gov (United States)

    Hanson, Lee H.; Manion, Patrick J.

    1980-01-01

    The sterility method of pest control could be an effective tool in the sea lamprey (Petromyzon marinus) control program in the Great Lakes. Some of the requirements for its successful application have been met. A field study demonstrated that the release of male sea lampreys, sterilized by the injection of 100 mg/kg of P,P-bis(1-aziridinyl)-N-methylphosphinothioic amide (bisazir), will reduce the number of viable larvae produced. The actual reduction in reproductive success that occurred was directly related to the ratio of sterile to normal males in the population. The technique can be used in many ways in an integrated control program and has considerable potential for the more effective control of the sea lamprey. Eradication is a distinct possibility.Key words: sea lamprey, Petromyzon marinus; pest control, fish control, sterile-male technique, sterilization, chemosterilants, bisazir, Great Lakes

  11. Use of physiological knowledge to control the invasive sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes

    OpenAIRE

    Siefkes, Michael J.

    2017-01-01

    Abstract Sea lamprey (Petromyzon marinus) control in the Laurentian Great Lakes of North America is an example of using physiological knowledge to successfully control an invasive species and rehabilitate an ecosystem and valuable fishery. The parasitic sea lamprey contributed to the devastating collapse of native fish communities after invading the Great Lakes during the 1800s and early 1900s. Economic tragedy ensued with the loss of the fishery and severe impacts to property values and tour...

  12. Humanized HLA-DR4 mice fed with the protozoan pathogen of oysters Perkinsus marinus (Dermo do not develop noticeable pathology but elicit systemic immunity.

    Directory of Open Access Journals (Sweden)

    Wathsala Wijayalath

    Full Text Available Perkinsus marinus (Phylum Perkinsozoa is a marine protozoan parasite responsible for "Dermo" disease in oysters, which has caused extensive damage to the shellfish industry and estuarine environment. The infection prevalence has been estimated in some areas to be as high as 100%, often causing death of infected oysters within 1-2 years post-infection. Human consumption of the parasites via infected oysters is thus likely to occur, but to our knowledge the effect of oral consumption of P. marinus has not been investigated in humans or other mammals. To address the question we used humanized mice expressing HLA-DR4 molecules and lacking expression of mouse MHC-class II molecules (DR4.EA(0 in such a way that CD4 T cell responses are solely restricted by the human HLA-DR4 molecule. The DR4.EA(0 mice did not develop diarrhea or any detectable pathology in the gastrointestinal tract or lungs following single or repeated feedings with live P. marinus parasites. Furthermore, lymphocyte populations in the gut associated lymphoid tissue and spleen were unaltered in the parasite-fed mice ruling out local or systemic inflammation. Notably, naïve DR4.EA(0 mice had antibodies (IgM and IgG reacting against P. marinus parasites whereas parasite specific T cell responses were undetectable. Feeding with P. marinus boosted the antibody responses and stimulated specific cellular (IFNγ immunity to the oyster parasite. Our data indicate the ability of P. marinus parasites to induce systemic immunity in DR4.EA(0 mice without causing noticeable pathology, and support rationale grounds for using genetically engineered P. marinus as a new oral vaccine platform to induce systemic immunity against infectious agents.

  13. Stone-dwelling actinobacteria Blastococcus saxobsidens, Modestobacter marinus and Geodermatophilus obscurus proteogenomes

    KAUST Repository

    Sghaier, Haïtham

    2015-06-30

    The Geodermatophilaceae are unique model systems to study the ability to thrive on or within stones and their proteogenomes (referring to the whole protein arsenal encoded by the genome) could provide important insight into their adaptation mechanisms. Here we report the detailed comparative genome analysis of Blastococcus saxobsidens (Bs), Modestobacter marinus (Mm) and Geodermatophilus obscurus (Go) isolated respectively from the interior and the surface of calcarenite stones and from desert sandy soils. The genome-scale analysis of Bs, Mm and Go illustrates how adaptation to these niches can be achieved through various strategies including ‘molecular tinkering/opportunism’ as shown by the high proportion of lost, duplicated or horizontally transferred genes and ORFans. Using high-throughput discovery proteomics, the three proteomes under unstressed conditions were analyzed, highlighting the most abundant biomarkers and the main protein factors. Proteomic data corroborated previously demonstrated stone-related ecological distribution. For instance, these data showed starvation-inducible, biofilm-related and DNA-protection proteins as signatures of the microbes associated with the interior, surface and outside of stones, respectively.

  14. Measuring Energetics and Behaviour Using Accelerometry in Cane Toads Bufo marinus

    Science.gov (United States)

    Halsey, Lewis G.; White, Craig R.

    2010-01-01

    Cane toads Bufo marinus were introduced to Australia as a control agent but now have a rapidly progressing invasion front and damage new habitats they enter. Predictive models that can give expansion rates as functions of energy supply and feeding ground distribution could help to maximise control efficiency but to date no study has measured rates of field energy expenditure in an amphibian. In the present study we used the accelerometry technique to generate behavioural time budgets and, through the derivation of ODBA (overall dynamic body acceleration), to obtain estimates of energetics in free ranging cane toads. This represents the first time that accelerometers have been used to not only quantify the behaviour of animals but also assign to those behaviours rates of energy expenditure. Firstly, laboratory calibrations between ODBA and metabolic rate were obtained and used to generate a common prediction equation for the subject toads (R2 = 0.74). Furthermore, acceleration data recorded during different behaviours was studied to ascertain threshold values for objectively defining behaviour categories. Importantly, while subsequent accelerometer field deployments were relatively short they agreed with previous studies on the proportion of time that cane toads locomote yet suggest that the metabolic rate of cane toads in the wild may sometimes be considerably higher than might be assumed based on data for other species. PMID:20422048

  15. Effects of sex pheromones and sexual maturation on locomotor activity in female sea lamprey (Petromyzon marinus)

    Science.gov (United States)

    Walaszczyk, Erin J.; Johnson, Nicholas S.; Steibel, Juan Pedro; Li, Weiming

    2013-01-01

    Synchronization of male and female locomotor rhythmicity can play a vital role in ensuring reproductive success. Several physiological and environmental factors alter these locomotor rhythms. As sea lamprey, Petromyzon marinus, progress through their life cycle, their locomotor activity rhythm changes multiple times. The goal of this study was to elucidate the activity patterns of adult female sea lamprey during the sexual maturation process and discern the interactions of these patterns with exposure to male pheromones. During these stages, preovulated and ovulated adult females are exposed to sex pheromone compounds, which are released by spermiated males and attract ovulated females to the nest for spawning. The locomotor behavior of adult females was monitored in a natural stream with a passive integrated tag responder system as they matured, and they were exposed to a sex pheromone treatment (spermiated male washings) or a control (prespermiated male washings). Results showed that, dependent on the hour of day, male sex pheromone compounds reduce total activity (p rhythm in a vertebrate, and they suggest that the interaction between maturity stage and sex pheromone exposure contributes to the differential locomotor rhythms found in adult female sea lamprey. This phenomenon may contribute to the reproductive synchrony of mature adults, thus increasing reproductive success in this species.

  16. Membranes during yolk-platelet development in oocytes of the toad Bufo marinus.

    Science.gov (United States)

    Richter, H -P

    1987-09-01

    Oocytes of the toad Bufo marinus have been studied by means of thin section and particularly freeze-fracture electron microscopy to characterize the cytoplasmic membranes around the yolk organelle, and the storage of yolk material in precursors and platelets. This appears to be a previously unknown type of yolk-platelet formation. During yolk-organelle development from the primordial precursor to the bi-partite fully grown yolk platelet, numerous lipoid droplets are attached to the periphery of the platelet, indicating an intense uptake of lipids. As is typical for amphibians, the fully grown yolk platelet has a crystalline internum covered by a dense osmiophilic externum, and the whole organelle is enveloped by a plasma membrane that shows no direct connection or fusion with endocytotic vesicles. The yolk membrane exhibits few intramembraneous particles (IMPs) at the core areas and some more where it borders fields of lipoid droplets. Here the IMPs show a net-like arrangement in the furrows between adjacent droplets.

  17. PCB concentrations and activity of sea lamprey Petromyzon marinus vary by sex

    Science.gov (United States)

    Madenjian, Charles P.; Johnson, Nicholas S.; Binder, Thomas R.; Rediske, Richard R.; O'Keefe, James P.

    2013-01-01

    We determined the polychlorinated biphenyl (PCB) concentrations of 40 male and 40 female adult sea lampreys Petromyzon marinus captured in the Cheboygan River, a tributary to Lake Huron, during May 2011. In addition, we performed a laboratory experiment using passive integrated transponder tags to determine whether male adult sea lampreys were more active than female adult sea lampreys. Sex had a significant effect on PCB concentration, and PCB concentration at a given level of sea lamprey condition was approximately 25 % greater in males than in females. Adjusting for the difference in condition between the sexes, males averaged a 17 % greater PCB concentration compared with females. Results from the laboratory experiment indicated that males were significantly more active than females. The observed sex difference in PCB concentrations was not due to female sea lampreys releasing eggs at spawning because the sea lamprey is semelparous, and we caught the sea lampreys before spawning. Rather, we attributed the sex difference in PCB concentrations to a greater rate of energy expenditure in males compared with females. We proposed that this greater rate of energy expenditure was likely due to greater activity. Our laboratory experiment results supported this hypothesis. A greater resting metabolic rate may also have contributed to a greater rate of energy expenditure. Our findings should eventually be applicable toward improving control of sea lamprey, a pest responsible for considerable damage to fisheries in lakes where it is not native.

  18. A new clarification method to visualize biliary degeneration during liver metamorphosis in sea lamprey (Petromyzon marinus)

    Science.gov (United States)

    Chung-Davidson, Yu-Wen; Davidson, Peter J.; Scott, Anne M.; Walaszczyk, Erin J.; Brant, Cory O.; Buchinger, Tyler; Johnson, Nicholas S.; Li, Weiming

    2014-01-01

    Biliary atresia is a rare disease of infancy, with an estimated 1 in 15,000 frequency in the southeast United States, but more common in East Asian countries, with a reported frequency of 1 in 5,000 in Taiwan. Although much is known about the management of biliary atresia, its pathogenesis is still elusive. The sea lamprey (Petromyzon marinus) provides a unique opportunity to examine the mechanism and progression of biliary degeneration. Sea lamprey develop through three distinct life stages: larval, parasitic, and adult. During the transition from larvae to parasitic juvenile, sea lamprey undergo metamorphosis with dramatic reorganization and remodeling in external morphology and internal organs. In the liver, the entire biliary system is lost, including the gall bladder and the biliary tree. A newly-developed method called “CLARITY” was modified to clarify the entire liver and the junction with the intestine in metamorphic sea lamprey. The process of biliary degeneration was visualized and discerned during sea lamprey metamorphosis by using laser scanning confocal microscopy. This method provides a powerful tool to study biliary atresia in a unique animal model.

  19. Daytime avoidance of chemosensory alarm cues by adult sea lamprey (Petromyzon marinus)

    Science.gov (United States)

    Di Rocco, Richard; Belanger, Cowan; Imre, István; Brown, Grant; Johnson, Nicholas S.

    2014-01-01

    Sea lamprey (Petromyzon marinus) avoid damage-released and predator chemosensory cues at night, but their response to these cues during the day is unknown. Here, we explored (i) whether sea lamprey avoid these cues during the day and (ii) the effect of water temperature on the avoidance of chemosensory alarm cues in two diurnal laboratory experiments. We hypothesized that daytime activity would be temperature-dependent and that only sea lamprey vulnerable to predation (i.e., not hiding) would behaviourally respond to chemosensory alarm cues. Ten groups of ten sea lamprey were exposed to one of a variety of potential chemosensory cues. The experiments were conducted over a range of temperatures to quantify the effect of temperature on avoidance behaviour. Consistent with our hypothesis, a higher proportion of animals were active during daytime as water temperature increased. Moving sea lamprey showed an avoidance response to 2-phenylethylamine (a compound found in mammalian urine) and human saliva once water temperatures had risen to mean (±SD) = 13.7 (±1.4) °C. Resting and hiding sea lamprey did not show an avoidance response to any of the experimental stimuli.

  20. Measuring energetics and behaviour using accelerometry in cane toads Bufo marinus.

    Directory of Open Access Journals (Sweden)

    Lewis G Halsey

    Full Text Available Cane toads Bufo marinus were introduced to Australia as a control agent but now have a rapidly progressing invasion front and damage new habitats they enter. Predictive models that can give expansion rates as functions of energy supply and feeding ground distribution could help to maximise control efficiency but to date no study has measured rates of field energy expenditure in an amphibian. In the present study we used the accelerometry technique to generate behavioural time budgets and, through the derivation of ODBA (overall dynamic body acceleration, to obtain estimates of energetics in free ranging cane toads. This represents the first time that accelerometers have been used to not only quantify the behaviour of animals but also assign to those behaviours rates of energy expenditure. Firstly, laboratory calibrations between ODBA and metabolic rate were obtained and used to generate a common prediction equation for the subject toads (R(2 = 0.74. Furthermore, acceleration data recorded during different behaviours was studied to ascertain threshold values for objectively defining behaviour categories. Importantly, while subsequent accelerometer field deployments were relatively short they agreed with previous studies on the proportion of time that cane toads locomote yet suggest that the metabolic rate of cane toads in the wild may sometimes be considerably higher than might be assumed based on data for other species.

  1. Guiding out-migrating juvenile sea lamprey (Petromyzon marinus) with pulsed direct current

    Science.gov (United States)

    Johnson, Nicholas S.; Miehls, Scott M.

    2014-01-01

    Non-physical stimuli can deter or guide fish without affecting water flow or navigation and therefore have been investigated to improve fish passage at anthropogenic barriers and to control movement of invasive fish. Upstream fish migration can be blocked or guided without physical structure by electrifying the water, but directional downstream fish guidance with electricity has received little attention. We tested two non-uniform pulsed direct current electric systems, each having different electrode orientations (vertical versus horizontal), to determine their ability to guide out-migrating juvenile sea lamprey (Petromyzon marinus) and rainbow trout (Oncorhynchus mykiss). Both systems guided significantly more juvenile sea lamprey to a specific location in our experimental raceway when activated than when deactivated, but guidance efficiency decreased at the highest water velocities tested. At the electric field setting that effectively guided sea lamprey, rainbow trout were guided by the vertical electrode system, but most were blocked by the horizontal electrode system. Additional research should characterize the response of other species to non-uniform fields of pulsed DC and develop electrode configurations that guide fish over a range of water velocity.

  2. Olfactory-mediated stream-finding behavior of migratory adult sea lamprey (Petromyzon marinus)

    Science.gov (United States)

    Vrieze, L.A.; Bergstedt, R.A.; Sorensen, P.W.

    2011-01-01

    Stream-finding behavior of adult sea lamprey (Petromyzon marinus), an anadromous fish that relies on pheromones to locate spawning streams, was documented in the vicinity of an important spawning river in the Great Lakes. Untreated and anosmic migrating sea lampreys were implanted with acoustic transmitters and then released outside the Ocqueoc River. Lampreys swam only at night and then actively. When outside of the river plume, lampreys pursued relatively straight bearings parallel to the shoreline while making frequent vertical excursions. In contrast, when within the plume, lampreys made large turns and exhibited a weak bias towards the river mouth, which one-third of them entered. The behavior of anosmic lampreys resembled that of untreated lampreys outside of the plume, except they pursued a more northerly compass bearing. To locate streams, sea lampreys appear to employ a three-phase odor-mediated strategy that involves an initial search along shorelines while casting vertically, followed by river-water-induced turning that brings them close to the river's mouth, which they then enter using rheotaxis. This novel strategy differs from that of salmonids and appears to offer this poor swimmer adaptive flexibility and suggests ways that pheromonal odors might be used to manage this invasive species.

  3. Sensory and nonsensory ciliated cells in the ear of the sea lamprey, Petromyzon marinus.

    Science.gov (United States)

    Popper, A N; Hoxter, B

    1987-01-01

    The inner ear of the sea lamprey, Petromyzon marinus, was examined using scanning and transmission electron microscopy. Many of the nonsensory surfaces of the ear chamber are lined by numerous, noninnervated, multiciliated epithelial cells. Each multiciliated epithelial cell has 43-66 true cilia projecting from its apical surface into the lumen of the ear. Although the cilia leave the cell individually, all of the cilia from a single cell come together just above the apical cell surface and are held together by a cross-network of fibrillar material. The cell bodies of the multiciliated cells sit upon a basal lamina which overlies a collagen-filled matrix. Petromyzon has typical vertebrate sensory hair cells on the cristae of the two semicircular canals as well as on the main sensory epithelium, the macula communis. Cell bodies of the sensory hair cells are similar to hair cells of other vertebrates. However, unlike other fishes, the sensory hair cells in Petromyzon have striated organelles between the nucleus and the apical cell membrane. The hair cells are innervated by afferent and efferent nerve fibers.

  4. Sea lamprey (Petromyzon marinus) parasite-host interactions in the Great Lakes

    Science.gov (United States)

    Bence, James R.; Bergstedt, Roger A.; Christie, Gavin C.; Cochran, Phillip A.; Ebener, Mark P.; Koonce, Joseph F.; Rutter, Michael A.; Swink, William D.

    2003-01-01

    Prediction of how host mortality responds to efforts to control sea lampreys (Petromyzon marinus) is central to the integrated management strategy for sea lamprey (IMSL) in the Great Lakes. A parasite-host submodel is used as part of this strategy, and this includes a type-2 multi-species functional response, a developmental response, but no numerical response. General patterns of host species and size selection are consistent with the model assumptions, but some observations appear to diverge. For example, some patterns in sea lamprey marking on hosts suggest increases in selectivity for less preferred hosts and lower host survival when preferred hosts are scarce. Nevertheless, many of the IMSL assumptions may be adequate under conditions targeted by fish community objectives. Of great concern is the possibility that the survival of young parasites (parasitic-phase sea lampreys) varies substantially among lakes or over time. Joint analysis of abundance estimates for parasites being produced in streams and returning spawners could address this. Data on sea lamprey marks is a critical source of information on sea lamprey activity and potential effects. Theory connecting observed marks to sea lamprey feeding activity and host mortality is reviewed. Uncertainties regarding healing and attachment times, the probability of hosts surviving attacks, and problems in consistent classification of marks have led to widely divergent estimates of damages caused by sea lamprey. Laboratory and field studies are recommended to provide a firmer linkage between host blood loss, host mortality, and observed marks on surviving hosts, so as to improve estimates of damage.

  5. A synthesized mating pheromone component increases adult sea lamprey (Petromyzon marinus) trap capture in management scenarios

    Science.gov (United States)

    Johnson, Nicholas S.; Siefkes, Michael J.; Wagner, C. Michael; Dawson, Heather; Wang, Huiyong; Steeves, Todd; Twohey, Michael; Li, Weiming

    2013-01-01

    Application of chemical cues to manipulate adult sea lamprey (Petromyzon marinus) behavior is among the options considered for new sea lamprey control techniques in the Laurentian Great Lakes. A male mating pheromone component, 7a,12a,24-trihydroxy-3-one-5a-cholan-24-sulfate (3kPZS), lures ovulated female sea lamprey upstream into baited traps in experimental contexts with no odorant competition. A critical knowledge gap is whether this single pheromone component influences adult sea lamprey behavior in management contexts containing free-ranging sea lampreys. A solution of 3kPZS to reach a final in-stream concentration of 10-12 mol·L-1 was applied to eight Michigan streams at existing sea lamprey traps over 3 years, and catch rates were compared between paired 3kPZS-baited and unbaited traps. 3kPZS-baited traps captured significantly more sexually immature and mature sea lampreys, and overall yearly trapping efficiency within a stream averaged 10% higher during years when 3kPZS was applied. Video analysis of a trap funnel showed that the likelihood of sea lamprey trap entry after trap encounter was higher when the trap was 3kPZS baited. Our approach serves as a model for the development of similar control tools for sea lamprey and other aquatic invaders.

  6. A spatial age-structured model for describing sea lamprey (Petromyzon marinus) population dynamics

    Science.gov (United States)

    Robinson, Jason M.; Wilberg, Michael J.; Adams, Jean V.; Jones, Michael L.

    2013-01-01

    The control of invasive sea lampreys (Petromyzon marinus) presents large scale management challenges in the Laurentian Great Lakes. No modeling approach has been developed that describes spatial dynamics of lamprey populations. We developed and validated a spatial and age-structured model and applied it to a sea lamprey population in a large river in the Great Lakes basin. We considered 75 discrete spatial areas, included a stock-recruitment function, spatial recruitment patterns, natural mortality, chemical treatment mortality, and larval metamorphosis. Recruitment was variable, and an upstream shift in recruitment location was observed over time. From 1993–2011 recruitment, larval abundance, and the abundance of metamorphosing individuals decreased by 80, 84, and 86%, respectively. The model successfully identified areas of high larval abundance and showed that areas of low larval density contribute significantly to the population. Estimated treatment mortality was less than expected but had a large population-level impact. The results and general approach of this work have applications for sea lamprey control throughout the Great Lakes and for the restoration and conservation of native lamprey species globally.

  7. Predicting the variation in Echinogammarus marinus at its southernmost limits under global warming scenarios: can the sex-ratio make a difference?

    Science.gov (United States)

    Guerra, Alexandra; Leite, Nuno; Marques, João Carlos; Ford, Alex T; Martins, Irene

    2014-01-01

    Understanding the environmental parameters that constrain the distribution of a species at its latitudinal extremes is critical for predicting how ecosystems react to climate change. Our first aim was to predict the variation in the amphipod populations of Echinogammarus marinus from the southernmost limit of its distribution under global warming scenarios. Our second aim was to test whether sex-ratio fluctuations - a mechanism frequently displayed by amphipods - respond to the variations in populations under altered climate conditions. To achieve these aims, scenarios were run with a validated model of E. marinus populations. Simulations were divided into: phase I - simulation of the effect of climate change on amphipod populations, and phase II - simulation of the effect of climate change on populations with male and female proportions. In both phases, temperature (T), salinity (S) and temperature and salinity (T-S) were tested. Results showed that E. marinus populations are highly sensitive to increases in temperature (>2 °C), which has adverse effects on amphipod recruitment and growth. Results from the climate change scenarios coupled with the sex-ratio fluctuations depended largely on the degree of female bias within population. Temperature increase of 2 °C had less impact on female-biased populations, particularly when conjugated with increases in salinity. Male-biased populations were highly sensitive to any variation in temperature and/or salinity; these populations exhibited a long-term decline in density. Simulations in which temperature increased more than 4 °C led to a continuous decline in the E. marinus population. According to this work, E. marinus populations at their southernmost limit are vulnerable to global warming. We anticipate that in Europe, temperature increases of 2 °C will incite a withdrawal of the population of 5°N from the amphipod species located at southernmost geographical borders. This effect is discussed in relation to the

  8. Composição centesimal, colesterol e maturação ovariana do Acetes marinus Omori, 1975 coletado no Baixo Tocantins

    OpenAIRE

    ASSUNÇÃO, Antônia do Socorro Américo de

    2007-01-01

    A espécie Acetes marinus Omori, 1975, possui total aproveitamento alimentar constituindo-se em uma espécie de grande importância nutritiva para a população regional onde ocorre, porém, é muito pouco estudada. Visando contribuir com um melhor aproveitamento deste recurso foram realizadas coletas mensais de A. marinus durantes os meses de janeiro de 2006 a junho de 2007, em duas praias, próximas da cidade de Cametá, no baixo Tocantins. Foram determinadas a composição centesimal (%) e o teor de ...

  9. A small predatory core genome in the divergent marine Bacteriovorax marinus SJ and the terrestrial Bdellovibrio bacteriovorus.

    Science.gov (United States)

    Crossman, Lisa C; Chen, Huan; Cerdeño-Tárraga, Ana-M; Brooks, Karen; Quail, Michael A; Pineiro, Silvia A; Hobley, Laura; Sockett, R Elizabeth; Bentley, Stephen D; Parkhill, Julian; Williams, Henry N; Stine, O Colin

    2013-01-01

    Bacteriovorax marinus SJ is a predatory delta-proteobacterium isolated from a marine environment. The genome sequence of this strain provides an interesting contrast to that of the terrestrial predatory bacterium Bdellovibrio bacteriovorus HD100. Based on their predatory lifestyle, Bacteriovorax were originally designated as members of the genus Bdellovibrio but subsequently were re-assigned to a new genus and family based on genetic and phenotypic differences. B. marinus attaches to gram-negative bacteria, penetrates through the cell wall to form a bdelloplast, in which it replicates, as shown using microscopy. Bacteriovorax is distinct, as it shares only 30% of its gene products with its closest sequenced relatives. Remarkably, 34% of predicted genes over 500 nt in length were completely unique with no significant matches in the databases. As expected, Bacteriovorax shares several characteristic loci with the other delta-proteobacteria. A geneset shared between Bacteriovorax and Bdellovibrio that is not conserved among other delta-proteobacteria such as Myxobacteria (which destroy prey bacteria externally via lysis), or the non-predatory Desulfo-bacteria and Geobacter species was identified. These 291 gene orthologues common to both Bacteriovorax and Bdellovibrio may be the key indicators of host-interaction predatory-specific processes required for prey entry. The locus from Bdellovibrio bacteriovorus is implicated in the switch from predatory to prey/host-independent growth. Although the locus is conserved in B. marinus, the sequence has only limited similarity. The results of this study advance understanding of both the similarities and differences between Bdellovibrio and Bacteriovorax and confirm the distant relationship between the two and their separation into different families.

  10. Anadromous sea lampreys (Petromyzon marinus) are ecosystem engineers in a spawning tributary

    Science.gov (United States)

    Hogg, Robert S.; Coghlan, Stephen M.; Zydlewski, Joseph D.; Simon, Kevin S.

    2014-01-01

    Sea lampreys (Petromyzon marinus) disturb the substratum during nest construction and alter the physical habitat, potentially affecting other stream organisms. We quantified differences in depth, velocity, fine-sediment coverage, embeddedness, intragravel permeability and benthic invertebrate assemblages (density and diversity) among nest mounds, nest pits and undisturbed reference locations over a 4-month period after June spawning. In 2010 and 2011, immediate and persistent effects of nest construction were assessed in summer (July) and in autumn (late September to early October), respectively. Randomly selected nests were sampled annually (25 each in summer and autumn). Nest construction increased stream-bed complexity by creating and juxtaposing shallow, swift, rocky habitat patches with deep, slow, sandy habitat patches. Mounds had a 50–143% less cover of fine sediment, and a 30–62% reduction in embeddedness, compared to pits and reference locations. These physical changes persisted into the autumn (almost 4 months). Five insect families contributed 74% of the benthic invertebrate abundance: Chironomidae (27%), Hydropsychidae (26%), Heptageniidae (8%), Philopotamidae (7%) and Ephemerellidae (6%). Densities of Hydropsychidae, Philopotamidae and Heptageniidae were up to 10 times greater in mounds than in pits and adjacent reference habitat. In summer, mounds had twice the density of Chironomidae than did pits, and 1.5 times more than reference habitats, but densities were similar among the habitats in autumn. These results suggest that spawning sea lampreys are ecosystem engineers. The physical disturbance caused by nest-building activity was significant and persistent, increasing habitat heterogeneity and favouring pollution-sensitive benthic invertebrates and, possibly, drift-feeding fish.

  11. Serum and hepatic vitamin A levels in captive and wild marine toads (Bufo marinus).

    Science.gov (United States)

    Berkvens, Charlene N; Lentini, Andrew; Dutton, Christopher J; Pearl, David L; Barker, Ian K; Crawshaw, Graham J

    2014-01-01

    The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called "Brown Skin Disease" (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine toad (Bufo marinus) as a model for the PRCT, examining vitamin A deficiency as a potential cause of BSD. Wild caught marine toads had significantly higher liver vitamin A concentrations (61.89 ± 63.49 µg/g) than captive born marine toads (0.58 ± 0.59 µg/g); P<0.001). A significant difference in serum vitamin A concentration was found between the captive and wild caught toads (P=0.013) and between the low vitamin A-fed and wild caught toads (P=0.004), when controlling for liver vitamin A concentrations. After captive toads were treated with topical and/or oral vitamin A, their hepatic vitamin A concentrations were similar to those of the wild toads, averaging 48.41 ± 37.03 µg/g. However, plasma vitamin A concentrations pre- and post-vitamin A supplementation did not differ statistically. We concluded that plasma vitamin A concentrations do not provide a linear indication of liver/body vitamin A status, and that both topical and oral supplementation with an oil-based vitamin A formulation can increase liver stores in amphibians. No evidence of BSD or other signs of deficiency were noted in the marine toads, although this feeding trial was relatively short (127 days). To date, clinical, pathological and research findings do not support vitamin A deficiency as a primary factor underlying BSD. © 2014 Wiley Periodicals, Inc.

  12. Characterization of a novel bile alcohol sulfate released by sexually mature male sea lamprey (Petromyzon marinus.

    Directory of Open Access Journals (Sweden)

    Ke Li

    Full Text Available A sulphate-conjugated bile alcohol, 3,12-diketo-4,6-petromyzonene-24-sulfate (DKPES, was identified using bioassay-guided fractionation from water conditioned with sexually mature male sea lamprey (Petromyzon marinus. The structure and relative stereochemistry of DKPES was established using spectroscopic data. The electro-olfactogram (EOG response threshold of DKPES was 10(-7 Molar (M and that of 3-keto petromyzonol sulfate (3 KPZS; a known component of the male sea lamprey sex pheromone was 10(-10 M. Behavioural studies indicated that DKPES can be detected at low concentrations by attracting sexually mature females to nests when combined with 3 KPZS. Nests baited with a mixture of DKPES and 3 KPZS (ratio 1∶29.8 attracted equal numbers of sexually mature females compared to an adjacent nest baited with 3 KPZS alone. When DKPES and 3 KPZS mixtures were applied at ratios of 2∶29.8 and 10∶29.8, the proportion of sexually mature females that entered baited nests increased to 73% and 70%, respectively. None of the sexually mature females released were attracted to nests baited with DKPES alone. These results indicated that DKPES is a component of the sex pheromone released by sexually mature male sea lamprey, and is the second biologically active compound identified from this pheromone. DKPES represents the first example that a minor component of a vertebrate pheromone can be combined with a major component to elicit critical sexual behaviors. DKPES holds considerable promise for increasing the effectiveness of pheromone-baited trapping as a means of sea lamprey control in the Laurentian Great Lakes.

  13. A role for tight junction-associated MARVEL proteins in larval sea lamprey (Petromyzon marinus) osmoregulation.

    Science.gov (United States)

    Kolosov, Dennis; Bui, Phuong; Donini, Andrew; Wilkie, Mike P; Kelly, Scott P

    2017-10-15

    This study reports on tight junction-associated MARVEL proteins of larval sea lamprey (Petromyzon marinus) and their potential role in ammocoete osmoregulation. Two occludin isoforms (designated Ocln and Ocln-a) and a tricellulin (Tric) were identified. Transcripts encoding ocln, ocln-a and tric were broadly expressed in larval lamprey, with the greatest abundance of ocln in the gut, liver and kidney, ocln-a in the gill and skin, and tric in the kidney. Ocln and Ocln-a resolved as ∼63 kDa and ∼35 kDa MW proteins, respectively, while Tric resolved as a ∼50 kDa protein. Ocln immunolocalized to the gill vasculature and in gill mucous cells while Ocln-a localized to the gill pouch and gill epithelium. Both Ocln and Ocln-a localized in the nephron, the epidermis and the luminal side of the gut. In branchial tissue, Tric exhibited punctate localization, consistent with its presence at regions of tricellular contact. Following ion-poor water (IPW) acclimation of ammocoetes, serum [Na+] and [Cl-] decreased, but not [Ca2+], and carcass moisture content increased. In association, Ocln abundance increased in the skin and kidney, but reduced in the gill of IPW-acclimated ammocoetes while Ocln-a abundance reduced in the kidney only. Tric abundance increased in the gill. Region-specific alterations in ocln, ocln-a and tric mRNA abundance were also observed in the gut. Data support a role for Ocln, Ocln-a and Tric in the osmoregulatory strategies of a basal vertebrate. © 2017. Published by The Company of Biologists Ltd.

  14. Associations between land use and Perkinsus marinus infection of eastern oysters in a high salinity, partially urbanized estuary

    Science.gov (United States)

    Gray, Brian R.; Bushek, David; Drane, J. Wanzer; Porter, Dwayne

    2009-01-01

    Infection levels of eastern oysters by the unicellular pathogen Perkinsus marinus have been associated with anthropogenic influences in laboratory studies. However, these relationships have been difficult to investigate in the field because anthropogenic inputs are often associated with natural influences such as freshwater inflow, which can also affect infection levels. We addressed P. marinus-land use associations using field-collected data from Murrells Inlet, South Carolina, USA, a developed, coastal estuary with relatively minor freshwater inputs. Ten oysters from each of 30 reefs were sampled quarterly in each of 2 years. Distances to nearest urbanized land class and to nearest stormwater outfall were measured via both tidal creeks and an elaboration of Euclidean distance. As the forms of any associations between oyster infection and distance to urbanization were unknown a priori, we used data from the first and second years of the study as exploratory and confirmatory datasets, respectively. With one exception, quarterly land use associations identified using the exploratory dataset were not confirmed using the confirmatory dataset. The exception was an association between the prevalence of moderate to high infection levels in winter and decreasing distance to nearest urban land use. Given that the study design appeared adequate to detect effects inferred from the exploratory dataset, these results suggest that effects of land use gradients were largely insubstantial or were ephemeral with duration less than 3 months.

  15. Mortality and toxin bioaccumulation in Bufo marinus following exposure to Cylindrospermopsis raciborskii cell extracts and live cultures

    Energy Technology Data Exchange (ETDEWEB)

    White, S.H. [Freshwater Ecology Group, Centre for Environmental Management, Central Queensland University, Building 6, Bruce Highway, Rockhampton, QLD 4702 (Australia)]. E-mail: s.white@cqu.edu.au; Duivenvoorden, L.J. [Freshwater Ecology Group, Centre for Environmental Management, Central Queensland University, Building 6, Bruce Highway, Rockhampton, QLD 4702 (Australia)]. E-mail: l.duivenvoorden@cqu.edu.au; Fabbro, L.D. [Freshwater Ecology Group, Centre for Environmental Management, Central Queensland University, Building 6, Bruce Highway, Rockhampton, QLD 4702 (Australia)]. E-mail: l.fabbro@cqu.edu.au; Eaglesham, G.K. [Queensland Health Scientific Services, Kessels Road, Coopers Plains, QLD 4109 (Australia)]. E-mail: geoff_eaglesham@health.qld.gov.au

    2007-05-15

    Cylindrospermopsis raciborskii is a cyanobacterium responsible for the production of the toxin, cylindrospermopsin (CYN). Tadpoles of the cane toad Bufo marinus were exposed to freeze-thawed whole cell extracts or live cultures of C. raciborskii containing maximum CYN concentrations of 400 {mu}g L{sup -1} or 232 {mu}g L{sup -1}, respectively. Exposure to live culture treatment solutions resulted in up to 66% mortality of B. marinus, whereas tadpoles exposed to whole cell extracts containing similar toxin concentrations survived. Decreases in relative growth rates and time spent for swimming were recorded from tadpoles during both types of exposure regimes. Bioconcentration of CYN was not evident following exposure to whole cell extracts containing extracellular toxin. In contrast exposure to live cultures, which contained cell-bound toxin, resulted in maximum average tissue concentrations of 895 {mu}g free-CYN kg{sup -1} fresh weight. This is the first investigation of C. raciborskii exposure effects and toxin bioaccumulation in the developmental stages of an amphibian. - Cane toad tadpoles experienced adverse effects and bioaccumulation of toxin following exposure to the cyanobacterium Cylindrospermopsis raciborskii.

  16. Willem Marinus Dudok : la escuela como obra de arquitectura y urbanismo =

    Directory of Open Access Journals (Sweden)

    Herman van Bergeijk

    2014-12-01

    Full Text Available Resumen Las escuelas construidas por Dudok en Hilversum en el periodo de entreguerras forman un conjunto considerado de referencia dentro de la arquitectura escolar. Además de permitir apreciar la evolución estilística de Dudok durante esos años, su interés estriba en el carácter de monumentos civiles e hitos urbanos con que fueron concebidas. De reducidas dimensiones y con un limitado número de aulas, cada escuela fue diseñada de forma diferente, como un claro elemento de reconocimiento de cada barrio. Su variedad de formas se adaptó también  psicológicamente a las diferentes edades de los alumnos. En el artículo se pasa revista ordenadamente y de forma crítica a todo el conjunto y se comentan las relaciones e influencias con los movimientos coetánes de renovación escolar, especialmente en Alemania. Abstract The schools build by Dudok in Hilversum in the periode between the two World Wars form a serie considered as a reference within the educational architecture. Their interest rely no only in that they show the stylistic evolution of Dudok in that years but also in the character as civil monuments and urban milestones which they were conceived. Reduced in their dimensions and with only a small number of classrooms, each school had a different design becoming in this way a recogntion element in his neighbourhood. The variety of forms was also psycologicaly addapted to the age of the children. The article is a translation from Dutch to Spanish of the chapter “De school als  architectonische en stedebouwkundige opgave” in the book Willem Marinus Dudok. Architect-stedebouwkundige 1884-1974, by Herman van Bergeijk, and offers a critic overview of the whole group of schools. Also includes information on the relationships and influences received from the contemporary movements of school reform, especially those initiated in Germany.

  17. Effects of salinity on upstream-migrating, spawning sea lamprey, Petromyzon marinus

    Science.gov (United States)

    Ferreira-Martins, D.; Coimbra, J.; Antunes, C.; Wilson, J. M.

    2016-01-01

    The sea lamprey, Petromyzon marinus, is an anadromous, semelparous species that is vulnerable to endangered in parts of its native range due in part to loss of spawning habitat because of man-made barriers. The ability of lampreys to return to the ocean or estuary and search out alternative spawning river systems would be limited by their osmoregulatory ability in seawater. A reduction in tolerance to salinity has been documented in migrants, although the underlying mechanisms have not been characterized. We examined the capacity for marine osmoregulation in upstream spawning migrants by characterizing the physiological effects of salinity challenge from a molecular perspective. Estuarine-captured migrants held in freshwater (FW) for ∼1 week (short-term acclimation) or 2 months (long-term acclimation) underwent an incremental salinity challenge until loss of equilibrium occurred and upper thresholds of 25 and 17.5, respectively, occurred. Regardless of salinity tolerance, all lamprey downregulated FW ion-uptake mechanisms [gill transcripts of Na+:Cl− cotransporter (NCC/slc12a3) and epithelial Na+ channel (ENaC/scnn1) and kidney Na+/K+-ATPase (NKA) protein and activity but not transcript]. At their respective salinity limits, lamprey displayed a clear osmoregulatory failure and were unable to regulate [Na+] and [Cl−] in plasma and intestinal fluid within physiological limits, becoming osmocompromised. A >90% drop in haematocrit indicated haemolysis, and higher plasma concentrations of the cytosolic enzymes alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase indicated damage to other tissues, including liver. However, >80% of short-term FW-acclimated fish were able to osmoregulate efficiently, with less haemolysis and tissue damage. This osmoregulatory ability was correlated with significant upregulation of the secretory form of Na+:K+:2Cl− cotransporter (NKCC1/slc12a2) transcript levels and the re-emergence of seawater

  18. The ecological impact of invasive cane toads (Bufo marinus) in Australia.

    Science.gov (United States)

    Shine, Richard

    2010-09-01

    Although invasive species are viewed as major threats to ecosystems worldwide, few such species have been studied in enough detail to identify the pathways, magnitudes, and timescales of their impact on native fauna. One of the most intensively studied invasive taxa in this respect is the cane toad (Bufo marinus), which was introduced to Australia in 1935. A review of these studies suggests that a single pathway-lethal toxic ingestion of toads by frog-eating predators-is the major mechanism of impact, but that the magnitude of impact varies dramatically among predator taxa, as well as through space and time. Populations of large predators (e.g., varanid and scincid lizards, elapid snakes, freshwater crocodiles, and dasyurid marsupials) may be imperilled by toad invasion, but impacts vary spatially even within the same predator species. Some of the taxa severely impacted by toad invasion recover within a few decades, via aversion learning and longer-term adaptive changes. No native species have gone extinct as a result of toad invasion, and many native taxa widely imagined to be at risk are not affected, largely as a result of their physiological ability to tolerate toad toxins (e.g., as found in many birds and rodents), as well as the reluctance of many native anuran-eating predators to consume toads, either innately or as a learned response. Indirect effects of cane toads as mediated through trophic webs are likely as important as direct effects, but they are more difficult to study. Overall, some Australian native species (mostly large predators) have declined due to cane toads; others, especially species formerly consumed by those predators, have benefited. For yet others, effects have been minor or have been mediated indirectly rather than through direct interactions with the invasive toads. Factors that increase a predator's vulnerability to toad invasion include habitat overlap with toads, anurophagy, large body size, inability to develop rapid behavioral

  19. Upstream migration, reproduction and fishery of sea lamprey (Petromyzon marinus Linnaeus, 1758 in the River Ulla (NW Spain

    Directory of Open Access Journals (Sweden)

    Sergio Silva

    2015-11-01

    Full Text Available After a juvenile haematophagous stage developed mainly at sea, the sea lamprey Petromyzon marinus Linnaeus, 1758 stop feeding and return to the river to spawn. One of the main pressures in this stage is the presence of obstacles that reduce the accessible habitat, the mobility of individuals within this section and the energy resources available for gonad development and spawning. In addition, in the River Ulla, adults are targeted in a commercial fishery, using fyke-nets in the upper estuary and fishing in pesqueiras, which are stone constructions placed on the river bed, in the low section of the river. This study advances in the knowledge of the upstream migration (and related impact of barriers, reproduction and fishery of P. marinus in the River Ulla. The study combined fieldwork (radiotelemetry tracking of 19 adults in years 2012 and 2013 and inventory and characterization of obstacles, with information on the capture of lampreys (years 2000 to 2010 by commercial fishing and by a fixed trap located in the middle section of the river. The migration period in this river runs from January, or even December, until June, followed by reproduction in May and June. A total of 48 anthropogenic obstacles (all small-medium sized barriers except the last three, which are impassable, including 20 pesqueiras, were identified as a relevant obstacle for sea lamprey migration (which joins the impact of fishing performed in these sites. Hence, still more attention must be paid to "small" barriers, as pesqueiras, and to fisheries to properly conserve and manage populations of this and other anadromous lamprey species.

  20. Timing the tides: genetic control of diurnal and lunar emergence times is correlated in the marine midge Clunio marinus.

    Science.gov (United States)

    Kaiser, Tobias S; Neumann, Dietrich; Heckel, David G

    2011-05-20

    The intertidal zone of seacoasts, being affected by the superimposed tidal, diurnal and lunar cycles, is temporally the most complex environment on earth. Many marine organisms exhibit lunar rhythms in reproductive behaviour and some show experimental evidence of endogenous control by a circalunar clock, the molecular and genetic basis of which is unexplored. We examined the genetic control of lunar and diurnal rhythmicity in the marine midge Clunio marinus (Chironomidae, Diptera), a species for which the correct timing of adult emergence is critical in natural populations. We crossed two strains of Clunio marinus that differ in the timing of the diurnal and lunar rhythms of emergence. The phenotype distribution of the segregating backcross progeny indicates polygenic control of the lunar emergence rhythm. Diurnal timing of emergence is also under genetic control, and is influenced by two unlinked genes with major effects. Furthermore, the lunar and diurnal timing of emergence is correlated in the backcross generation. We show that both the lunar emergence time and its correlation to the diurnal emergence time are adaptive for the species in its natural environment. The correlation implies that the unlinked genes affecting lunar timing and the two unlinked genes affecting diurnal timing could be the same, providing an unexpectedly close interaction of the two clocks. Alternatively, the genes could be genetically linked in a two-by-two fashion, suggesting that evolution has shaped the genetic architecture to stabilize adaptive combinations of lunar and diurnal emergence times by tightening linkage. Our results, the first on genetic control of lunar rhythms, offer a new perspective to explore their molecular clockwork.

  1. Changes in the ventral dermis and development of iridophores in the anadromous sea lamprey, Petromyzon marinus, during metamorphosis: an ultrastructural study

    OpenAIRE

    Wright, Glenda M; McBurney, Kim M.

    1992-01-01

    The ultrastructural changes that take place in the ventral dermisalong with the development of iridophores were examined in the anadromous sea lamprey, Petromyzon marinus, during metamorphosis. There is a disruption of al1 components of the ventral dermis and a reformation that results in a sturcture very similar to that prior to metamorphosis. Although not a dermal component, a layer of iridophores develops directly beneath the dermis during late metamorph...

  2. Subcellular localization of the magnetosome protein MamC in the marine magnetotactic bacterium Magnetococcus marinus strain MC-1 using immunoelectron microscopy.

    Science.gov (United States)

    Valverde-Tercedor, C; Abadía-Molina, F; Martinez-Bueno, M; Pineda-Molina, Estela; Chen, Lijun; Oestreicher, Zachery; Lower, Brian H; Lower, Steven K; Bazylinski, Dennis A; Jimenez-Lopez, C

    2014-07-01

    Magnetotactic bacteria are a diverse group of prokaryotes that biomineralize intracellular magnetosomes, composed of magnetic (Fe3O4) crystals each enveloped by a lipid bilayer membrane that contains proteins not found in other parts of the cell. Although partial roles of some of these magnetosome proteins have been determined, the roles of most have not been completely elucidated, particularly in how they regulate the biomineralization process. While studies on the localization of these proteins have been focused solely on Magnetospirillum species, the goal of the present study was to determine, for the first time, the localization of the most abundant putative magnetosome membrane protein, MamC, in Magnetococcus marinus strain MC-1. MamC was expressed in Escherichia coli and purified. Monoclonal antibodies were produced against MamC and immunogold labeling TEM was used to localize MamC in thin sections of cells of M. marinus. Results show that MamC is located only in the magnetosome membrane of Mc. marinus. Based on our findings and the abundance of this protein, it seems likely that it is important in magnetosome biomineralization and might be used in controlling the characteristics of synthetic nanomagnetite.

  3. Subcellular localization of the magnetosome protein MamC in the marine magnetotactic bacterium Magnetococcus marinus strain MC-1 using immunoelectron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Valverde-Tercedor, C [Universidad de Granada; Abada-Molina, F [Universidad de Granada; Martinez-Bueno, M [Universidad de Granada; Pineda-Molina, Estela [Laboratorio de Estudios Cristalograficos; Chen, Lijun [Ohio State University; Oestreicher, Zachery [Ohio State University; Lower, Brian H [Ohio State University; Lower, Steven K [Ohio State University; Bazylinski, Dennis A [Ames Laboratory; Jimenez-Lopez, C [Universidad de Granada

    2014-04-24

    Magnetotactic bacteria are a diverse group of prokaryotes that biomineralize intracellular magnetosomes, composed of magnetic (Fe3O4) crystals each enveloped by a lipid bilayer membrane that contains proteins not found in other parts of the cell. Although partial roles of some of these magnetosome proteins have been determined, the roles of most have not been completely elucidated, particularly in how they regulate the biomineralization process. While studies on the localization of these proteins have been focused solely on Magnetospirillum species, the goal of the present study was to determine, for the first time, the localization of the most abundant putative magnetosome membrane protein, MamC, in Magnetococcus marinus strain MC-1. MamC was expressed in Escherichia coli and purified. Monoclonal antibodies were produced against MamC and immunogold labeling TEM was used to localize MamC in thin sections of cells of M. marinus. Results show that MamC is located only in the magnetosome membrane of Mc. marinus. Based on our findings and the abundance of this protein, it seems likely that it is important in magnetosome biomineralization and might be used in controlling the characteristics of synthetic nanomagnetite.

  4. Three Novel Bile Alcohols of Mature Male Sea Lamprey (Petromyzon marinus) Act as Chemical Cues for Conspecifics.

    Science.gov (United States)

    Li, Ke; Scott, Anne M; Riedy, Joseph J; Fissette, Skye; Middleton, Zoe E; Li, Weiming

    2017-06-01

    Sea lamprey, Petromyzon marinus, rely heavily on chemical cues that mediate their life history events, such as migration and reproduction. Here, we describe petromyzone A-C (1-3), three novel bile alcohols that are highly oxidized and sulfated, isolated from water conditioned with spermiated male sea lamprey. Structures of these compounds were unequivocally established by spectroscopic analyses and by comparison with spectra of known compounds. Electro-olfactogram recordings showed that 1 at 10-11 M was stimulatory to the adult sea lamprey olfactory epithelium, while 2 and 3 were stimulatory at 10-13 M. Behavioral assays indicated that 1 is attractive, 2 is not attractive or repulsive, and 3 is repulsive to ovulated female sea lamprey. The results suggest that 1 and 2 may be putative pheromones that mediate chemical communication in sea lamprey. The identification of these three components enhances our understanding of the structures and functions of sex pheromone components in this species and may provide useful behavioral manipulation tools for the integrated management of sea lamprey, a destructive invader in the Laurentian Great Lakes.

  5. Behavioural response of adult sea lamprey (Petromyzon marinus) to predator and conspecific alarm cues: evidence of additive effects

    Science.gov (United States)

    Di Rocco, Richard T.; Imre, Istvan; Johnson, Nicholas; Brown, Grant B

    2016-01-01

    Sea lampreys Petromyzon marinus, an invasive pest in the Upper Great Lakes, avoid odours that represent danger in their habitat. These odours include conspecific alarm cues and predator cues, like 2-phenylethylamine hydrochloride (PEA HCl), which is found in the urine of mammalian predators. Whether conspecific alarm cues and predator cues function additively or synergistically when mixed together is unknown. The objectives of this experimental study were to determine if the avoidance response of sea lamprey to PEA HCl is proportional to the concentration delivered, and if the avoidance response to the combination of a predator cue (PEA HCl) and sea lamprey alarm cue is additive. To accomplish the first objective, groups of ten sea lampreys were placed in an artificial stream channel and presented with stepwise concentrations of PEA HCl ranging from 5 × 10−8 to 5 × 10−10 M and a deionized water control. Sea lampreys exhibited an increase in their avoidance behaviour in response to increasing concentrations of PEA HCl. To accomplish the second objective, sea lampreys were exposed to PEA HCl, conspecific alarm cue and a combination of the two. Sea lampreys responded to the combination of predator cue and conspecific alarm cue in an additive manner.

  6. Decomposition of sea lamprey Petromyzon marinus carcasses: temperature effects, nutrient dynamics, and implications for stream food webs

    Science.gov (United States)

    Weaver, Daniel M.; Coghlan, Stephen M.; Zydlewski, Joseph D.; Hogg, Robert S.; Canton, Michael

    2015-01-01

    Anadromous fishes serve as vectors of marine-derived nutrients into freshwaters that are incorporated into aquatic and terrestrial food webs. Pacific salmonines Oncorhynchus spp. exemplify the importance of migratory fish as links between marine and freshwater systems; however, little attention has been given to sea lamprey (Petromyzon marinus Linnaeus, 1758) in Atlantic coastal systems. A first step to understanding the role of sea lamprey in freshwater food webs is to characterize the composition and rate of nutrient inputs. We conducted laboratory and field studies characterizing the elemental composition and the decay rates and subsequent water enriching effects of sea lamprey carcasses. Proximate tissue analysis demonstrated lamprey carcass nitrogen:phosphorus ratios of 20.2:1 (±1.18 SE). In the laboratory, carcass decay resulted in liberation of phosphorus within 1 week and nitrogen within 3 weeks. Nutrient liberation was accelerated at higher temperatures. In a natural stream, carcass decomposition resulted in an exponential decline in biomass, and after 24 days, the proportion of initial biomass remaining was 27% (±3.0% SE). We provide quantitative results as to the temporal dynamics of sea lamprey carcass decomposition and subsequent nutrient liberation. These nutrient subsidies may arrive at a critical time to maximize enrichment of stream food webs.

  7. White sucker Catostomus commersonii respond to conspecific and sea lamprey Petromyzon marinus alarm cues but not potential predator cues

    Science.gov (United States)

    Jordbro, Ethan J.; Di Rocco, Richard T.; Imre, Istvan; Johnson, Nicholas; Brown, Grant E.

    2016-01-01

    Recent studies proposed the use of chemosensory alarm cues to control the distribution of invasive sea lamprey Petromyzon marinus populations in the Laurentian Great Lakes and necessitate the evaluation of sea lamprey chemosensory alarm cues on valuable sympatric species such as white sucker. In two laboratory experiments, 10 replicate groups (10 animals each) of migratory white suckers were exposed to deionized water (control), conspecific whole-body extract, heterospecific whole-body extract (sea lamprey) and two potential predator cues (2-phenylethylamine HCl (PEA HCl) and human saliva) during the day, and exposed to the first four of the above cues at night. White suckers avoided the conspecific and the sea lamprey whole-body extract both during the day and at night to the same extent. Human saliva did not induce avoidance during the day. PEA HCl did not induce avoidance at a higher concentration during the day, or at night at the minimum concentration that was previously shown to induce maximum avoidance by sea lamprey under laboratory conditions. Our findings suggest that human saliva and PEA HCl may be potential species-specific predator cues for sea lamprey.

  8. Nonlabens antarcticus sp. nov., a psychrophilic bacterium isolated from glacier ice, and emended descriptions of Nonlabens marinus Park et al. 2012 and Nonlabens agnitus Yi and Chun 2012.

    Science.gov (United States)

    Kwon, Yong Min; Yang, Sung-Hyun; Kwon, Kae Kyoung; Kim, Sang-Jin

    2014-02-01

    A Gram-negative, proteorhodopsin-containing, orange pigmented, rod-shaped and strictly aerobic bacterium, designated strain AKS622(T), was isolated from a glacier core collected from the coast of King George Island, Antarctica. 16S rRNA gene sequence analysis revealed that strain AKS622(T) was affiliated to the genus Nonlabens of the family Flavobacteriaceae and showed highest similarity to Nonlabens marinus S1-08(T) (97.9%). The level of DNA-DNA relatedness between strain AKS622(T) and N. marinus S1-08(T) was 46%. Optimal growth of strain AKS622(T) was observed at pH 7.0, at 15 °C and with 2.0% NaCl. The predominant cellular fatty acids were anteiso-C(15 : 0), iso-C(16 : 0), iso-C(16 : 0) 3-OH, C17:0 2-OH and summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c). The DNA G+C content was 37.9 mol%. The major respiratory quinone was MK-6. Phosphatidylethanolamine, four unidentified glycolipids, three unidentified aminolipids and one unidentified lipid were detected as major polar lipids. On the basis of the data from this polyphasic taxonomic study, it was concluded that strain AKS622(T) represents a novel species within the genus Nonlabens, for which the name Nonlabens antarcticus sp. nov. is proposed. The type strain is AKS622(T) ( = KCCM 43019(T) = JCM 14068(T)). Emended descriptions of N. marinus Park et al. 2012 and Nonlabens agnitus Yi and Chun 2012 are given.

  9. Mitochondrial Ca2+ homeostasis during Ca2+ influx and Ca2+ release in gastric myocytes from Bufo marinus

    Science.gov (United States)

    Drummond, Robert M; Mix, T Christian H; Tuft, Richard A; Walsh, John V; Fay, Fredric S

    2000-01-01

    The Ca2+-sensitive fluorescent indicator rhod-2 was used to monitor mitochondrial Ca2+ concentration ([Ca2+]m) in gastric smooth muscle cells from Bufo marinus. In some studies, fura-2 was used in combination with rhod-2, allowing simultaneous measurement of cytoplasmic Ca2+ concentration ([Ca2+]i) and [Ca2+]m, respectively. During a short train of depolarizations, which causes Ca2+ influx from the extracellular medium, there was an increase in both [Ca2+]i and [Ca2+]m. The half-time (t½) to peak for the increase in [Ca2+]m was considerably longer than the t½ to peak for the increase in [Ca2+]i. [Ca2+]m remained elevated for tens of seconds after [Ca2+]i had returned to its resting value. Stimulation with caffeine, which causes release of Ca2+ from the sarcoplasmic reticulum (SR), also produced increases in both [Ca2+]i and [Ca2+]m. The values of t½ to peak for the increase in [Ca2+] in both cytoplasm and mitochondria were similar; however, [Ca2+]i returned to baseline values much faster than [Ca2+]m. Using a wide-field digital imaging microscope, changes in [Ca2+]m were monitored within individual mitochondria in situ, during stimulation of Ca2+ influx or Ca2+ release from the SR. Mitochondrial Ca2+ uptake during depolarizing stimulation caused depolarization of the mitochondrial membrane potential. The mitochondrial membrane potential recovered considerably faster than the recovery of [Ca2+]m. This study shows that Ca2+ influx from the extracellular medium and Ca2+ release from the SR are capable of increasing [Ca2+]m in smooth muscle cells. The efflux of Ca2+ from the mitochondria is a slow process and appears to be dependent upon the amount of Ca2+ in the SR. PMID:10713963

  10. Prevalence of Salmonella spp. in cane toads (Bufo marinus) from Grenada, West Indies, and their antimicrobial susceptibility.

    Science.gov (United States)

    Drake, M; Amadi, V; Zieger, U; Johnson, R; Hariharan, H

    2013-09-01

    Cloacal swabs and caecal contents sampled from 58 cane toads (Bufo marinus) in St George's parish, Grenada, during a 7-month period in 2011 were examined by an enrichment and selective culture method for presence of Salmonella spp. Twenty-four (41%) toads were positive for Salmonella spp. of which eight were Salmonella enterica serovar Javiana, and eight were S. enterica serovar Rubislaw. The other serovars were as follows: Montevideo, 6; Arechavaleta, 1; and serovar: IV:43:-:-, 1. The high frequency of isolation of serovar Javiana, an emerging human pathogen associated with several outbreaks in the recent years in the eastern United States, suggests a possible role for cane toads in transmission of this serovar. Although S. Rubislaw has been isolated from lizards, bats and cases of some human infections, there is no report of its carriage by cane toads, and in such high frequency. The rate of carriage of S. Montevideo, a cause for human foodborne outbreaks around the world was also over 10% in the 58 toads sampled in this study. The antimicrobial drug susceptibility tests against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, imipenem, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal and is of little concern. Antimicrobial resistance was limited to ampicillin and amoxicillin-clavulanic acid in one isolate of S. Javiana and one isolate of S. Rubislaw. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars not identified previously in cane toads in Grenada, West Indies. © 2012 Blackwell Verlag GmbH.

  11. Effects of Salinity Challenge on Ion Regulation in Early and Late Upstream Migrating Sea Lamprey, Petromyzon marinus.

    Directory of Open Access Journals (Sweden)

    Diogo Ferreira-Martins

    2015-10-01

    Full Text Available The sea lamprey, Petromyzon marinus, is an anadromous species in which the adults re-enter freshwater, and migrate upstream for terminal spawning. A reduction in salinity tolerance has been document in migrants although the underlying mechanisms have not been characterized. The aim of this study was to determine the capacity for marine osmoregulation in late, upstream migrants by characterizing the morphological and physiological effects of salinity challenge from a molecular perspective. For this two experiments were performed using early and late upstream migrants. Animals salinity limited was found to be 17.5‰ for late upstream migrants, thought some early migrants were able to perform at 24‰. A number of relevant blood and intestinal parameters were measured to assess ionoregulatory and biochemical changes as well as the expression of key ion-transport related proteins by immunoblotting (IB [Na+/K+-ATPase (NKA, vacuolar-type H+-ATPase, carbonic anhydrase, and Na+:K+:2Cl-contransporter]. NKA activity was also measured, in addition to oxidative stress indicators. The Na+ and Cl- levels with plasma and intestinal fluid were quantified and it was found that in non performing animals these fluids approached environmental concentrations (osmoconforming and failure of drinking mechanism, respectively. A drop in hematocrit was also observed with plasma lactate indicating hemolytic anemia. Plasma [ALT], GST activity and [GSH] were used to assess oxidative damage to tissues. An increase in Na+/K+-ATPase activity in mid-intestine in late migrants and posterior intestine in early migrates showed a potentially adaptive ionoregulatory response to salinity increase. (FCT grant PTDC/MAR/98035/2008.

  12. Survival and metamorphosis of larval sea lamprey (Petromyzon marinus) residing in Lakes Michigan and Huron near river mouths

    Science.gov (United States)

    Johnson, Nicholas S.; Brenden, Travis O.; Swink, William D.; Lipps, Mathew A.

    2016-01-01

    Although population demographics of larval lampreys in streams have been studied extensively, demographics in lake environments have not. Here, we estimated survival and rates of metamorphosis for larval sea lamprey (Petromyzon marinus) populations residing in the Great Lakes near river mouths (hereafter termed lentic areas). Tagged larvae were stocked and a Bayesian multi-state tag-recovery model was used to investigate population parameters associated with tag recovery, including survival and metamorphosis probabilities. Compared to previous studies of larvae in streams, larval growth in lentic areas was substantially slower (Brody growth coefficient = 0.00132; estimate based on the recovery of six tagged larvae), survival was slightly greater (annual survival = 63%), and the length at which 50% of the larvae would be expected to metamorphose was substantially shorter (126 mm). Stochastic simulations were used to estimate the production of parasitic stage (juvenile) sea lamprey from a hypothetical population of larvae in a lentic environment. Production of juvenile sea lamprey was substantial because, even though larval growth in these environments was slow relative to stream environments, survival was high and length at metamorphosis was less. However, estimated production of juvenile sea lamprey was less for the lentic environment than for similar simulations for river environments where larvae grew faster. In circumstances where the cost to kill a larva with lampricide was equal and control funds are limited, sea lamprey control effort may be best directed toward larvae in streams with fast-growing larvae, because stream-produced larvae will most likely contribute to juvenile sea lamprey populations.

  13. Comparing methods for estimating larval sea lamprey (Petromyzon marinus) density in the St. Marys River for the purposes of control

    Science.gov (United States)

    Robinson, Jason M.; Wilberg, Michael J.; Adams, Jean V.; Jones, Michael L.

    2015-01-01

    The St. Marys River is a major producer of parasitic sea lampreys (Petromyzon marinus) to Lake Huron making it an important area for larval control. Bayluscide treatments are conducted in areas of high larval density requiring density estimation at fine spatial scales to inform treatment decisions. We evaluated six methods of estimating spatially specific density including the currently used sampling-based estimates, a generalized linear model (GLM) based on mean larval density per plot, a GLM based on larval density per sample, a generalized additive model based on mean larval density per plot, a spatial age-structured population model, and a hybrid approach, which averaged the best performing sampling- and model-based methods. Methods were evaluated based on accuracy in matching independent validation data. Specifically, the methods were evaluated based on their ability to project plot-level larval density, identify high density plots for treatment, and rank plots in order based on density resulting in high numbers of sea lampreys killed per hectare treated. Performance was variable, and no single method outperformed the others for all metrics. Although the sampling-based estimation method and the GLM based on catch data performed adequately for estimating density and identifying high density plots, the hybrid approach was identified as the best method to inform sea lamprey control decisions in the St. Marys River due to its consistent performance. Incorporating model-based approaches should lead to a more efficient and effective treatment program in the St. Marys River and aid in making decisions about the allocation of control resources.

  14. Survival and metamorphosis of low-density populations of larval sea lampreys (Petromyzon marinus) in streams following lampricide treatment

    Science.gov (United States)

    Johnson, Nicholas S.; Swink, William D.; Brenden, Travis O.; Slade, Jeffrey W.; Steeves, Todd B.; Fodale, Michael F.; Jones, Michael L.

    2014-01-01

    Sea lamprey Petromyzon marinus control in the Great Lakes primarily involves application of lampricides to streams where larval production occurs to kill larvae prior to their metamorphosing and entering the lakes as parasites (juveniles). Because lampricides are not 100% effective, larvae that survive treatment maymetamorphose before streams are again treated. Larvae that survive treatment have not beenwidely studied, so their dynamics are notwell understood.Wetagged and released larvae in six Great Lake tributaries following lampricide treatment and estimated vital demographic rates using multistate tag-recovery models. Model-averaged larval survivals ranged from 56.8 to 57.6%. Model-averaged adult recovery rates, which were the product of juvenile survivals and adult capture probabilities, ranged from 6.8 to 9.3%. Using stochastic simulations, we estimated production of juvenile sea lampreys from a hypothetical population of treatment survivors under different growth conditions based on parameter estimates from this research. For fast-growing populations, juvenile production peaked 2 years after treatment. For slow-growing populations, juvenile production was approximately one-third that of fast-growing populations,with production not peaking until 4 years after treatment. Our results suggest that dynamics (i.e., survival, metamorphosis) of residual larval populations are very similar to those of untreated larval populations. Consequently, residual populations do not necessarily warrant special consideration for the purpose of sea lamprey control and can be ranked for treatment along with other populations. Consecutive lampricide treatments, which are under evaluation by the sea lamprey control program, would bemost effective for reducing juvenile production in large, fast-growing populations.

  15. A sea lamprey (Petromyzon marinus) sex pheromone mixture increases trap catch relative to a single synthesized component in specific environments

    Science.gov (United States)

    Johnson, Nicholas S.; Tix, John A.; Hlina, Benjamin L.; Wagner, C. Michael; Siefkes, Michael J.; Wang, Huiyong; Li, Weiming

    2015-01-01

    Spermiating male sea lamprey (Petromyzon marinus) release a sex pheromone, of which a component, 7α, 12α, 24-trihydoxy-3-one-5α-cholan-24-sulfate (3kPZS), has been identified and shown to induce long distance preference responses in ovulated females. However, other pheromone components exist, and when 3kPZS alone was used to control invasive sea lamprey populations in the Laurentian Great Lakes, trap catch increase was significant, but gains were generally marginal. We hypothesized that free-ranging sea lamprey populations discriminate between a partial and complete pheromone while migrating to spawning grounds and searching for mates at spawning grounds. As a means to test our hypothesis, and to test two possible uses of sex pheromones for sea lamprey control, we asked whether the full sex pheromone mixture released by males (spermiating male washings; SMW) is more effective than 3kPZS in capturing animals in traditional traps (1) en route to spawning grounds and (2) at spawning grounds. At locations where traps target sea lampreys en route to spawning grounds, SMW-baited traps captured significantly more sea lampreys than paired 3kPZS-baited traps (~10 % increase). At spawning grounds, no difference in trap catch was observed between 3kPZS and SMW-baited traps. The lack of an observed difference at spawning grounds may be attributed to increased pheromone competition and possible involvement of other sensory modalities to locate mates. Because fishes often rely on multiple and sometimes redundant sensory modalities for critical life history events, the addition of sex pheromones to traditionally used traps is not likely to work in all circumstances. In the case of the sea lamprey, sex pheromone application may increase catch when applied to specifically designed traps deployed in streams with low adult density and limited spawning habitat.

  16. Application of a putative alarm cue hastens the arrival of invasive sea lamprey (Petromyzon marinus) at a trapping location

    Science.gov (United States)

    Hume, John B.; Meckley, Trevor D.; Johnson, Nicholas; Luhring, Thomas M; Siefkes, Michael J; Wagner, C. Michael

    2015-01-01

    The sea lamprey Petromyzon marinus is an invasive pest in the Laurentian Great Lakes basin, threatening the persistence of important commercial and recreational fisheries. There is substantial interest in developing effective trapping practices via the application of behavior-modifying semiochemicals (odors). Here we report on the effectiveness of utilizing repellent and attractant odors in a push–pull configuration, commonly employed to tackle invertebrate pests, to improve trapping efficacy at permanent barriers to sea lamprey migration. When a half-stream channel was activated by a naturally derived repellent odor (a putative alarm cue), we found that sea lamprey located a trap entrance significantly faster than when no odor was present as a result of their redistribution within the stream. The presence of a partial sex pheromone, acting as an attractant within the trap, was not found to further decrease the time to when sea lamprey located a trap entrance relative to when the alarm cue alone was applied. Neither the application of alarm cue singly nor alarm cue and partial sex pheromone in combination was found to improve the numbers of sea lamprey captured in the trap versus when no odor was present — likely because nominal capture rate during control trials was unusually high during the study period. Behavioural guidance using these odors has the potential to both improve control of invasive non-native sea lamprey in the Great Lakes as well as improving the efficiency of fish passage devices used in the restoration of threatened lamprey species elsewhere.

  17. Differential effects of a local industrial sand lance fishery on seabird breeding performance

    DEFF Research Database (Denmark)

    Frederiksen, M.; Jensen, Henrik; Daunt, F.

    2008-01-01

    fluctuations. We evaluated the effects of an industrial sand lance (Ammodytes marinus) fishery off the North Sea coast of the United Kingdom, which has been opened and closed in a quasi-experimental fashion, on sand-lance-dependent breeding seabirds. Controlling for environmental variation ( sea surface...

  18. The modular xylanase Xyn10A from Rhodothermus marinus is cell-attached, and its C-terminal domain has several putative homologues among cell-attached proteins within the phylum Bacteroidetes

    DEFF Research Database (Denmark)

    Karlsson, Eva Nordberg; Hachem, Maher Abou; Ramchuran, Santosh

    2004-01-01

    Until recently, the function of the fifth domain of the thermostable modular xylanase Xyn10A from Rhodothermus marinus was unresolved. A putative homologue to this domain was however identified in a mannanase (Man26A) from the same microorganism which raised questions regarding a common function....... An extensive search of all accessible data-bases as well as the partially sequenced genomes of R. marinus and Cytophaga hutchinsonii showed that homologues of this domain were encoded by multiple genes in microorganisms in the phylum Bacteroidetes. Moreover, the domain occurred invariably at the C......-termini of proteins that were predominantly extra-cellular/cell attached. A primary structure motif of three conserved regions including structurally important glycines and a proline was also identified suggesting a conserved 3D fold. This bioinformatic evidence suggested a possible role of this domain in mediating...

  19. Changes in the ventral dermis and development of iridophores in the anadromous sea lamprey, Petromyzon marinus, during metamorphosis: an ultrastructural study.

    Science.gov (United States)

    Wright, G M; McBurney, K M

    1992-04-01

    The ultrastructural changes that take place in the ventral dermis along with the development of iridophores were examined in the anadromous sea lamprey, Petromyzon marinus, during metamorphosis. There is a disruption of all components of the ventral dermis and a reformation that results in a structure very similar to that prior to metamorphosis. Although not a dermal component, a layer of iridophores develops directly beneath the dermis during late metamorphosis. The dermal endothelium is lost by mid metamorphosis (stage 4) and the highly organized collagenous lamellae making up the bulk of the dermis become disrupted by the migration of fibroblasts into the region. Many of these fibroblasts are involved in the degradation of the lamellae. By stage 5 of metamorphosis some fibroblasts become highly active collagen synthesizing cuboidal shaped cells that align to form a layer above the reformed dermal endothelium. New lamellae are formed by these cuboidal cells which then divide and migrate into the lamellae where they assume the characteristic attenuated appearance of fibroblasts in the adult dermal lamellae region. Iridophores first appear during stage 5 directly beneath the dermal endothelium. Reflecting platelets develop from double membraned vesicles associated with the Golgi apparatus. By late metamorphosis, stacks of trapezoidal shaped platelets fill the cytoplasm of the iridophores. The significance of the changes in the dermis during metamorphosis are discussed. This work is part of a continuing series of studies on the connective tissues in the anadromous sea lamprey.

  20. Detection of Met-enkephalin and Leu-enkephalin in the brain of the hagfish, Eptatretus stouti, and the lamprey, Petromyzon marinus.

    Science.gov (United States)

    Dores, R M; Gorbman, A

    1990-03-01

    Acid extracts of the brain of the pacific hagfish, Eptatretus stouti, and the marine lamprey, Petromyzon marinus, were each fractionated by gel filtration chromatography and aliquots of column fractions were screened with radioimmunoassays (RIAs) specific for pro-dynorphin-related end products and for pro-enkephalin-related end products. Only pro-enkephalin-related immunoreactive forms were detected. The enkephalin-sized immunoreactive material, isolated for each species, was separately fractionated by reverse-phase high-performance liquid chromatography (HPLC). Aliquots of column fractions were screened with RIAs specific for Met-enkephalin, Leu-enkephalin, Met-enkephalin-Arg-Phe, and Met-enkephalin-Arg-Gly-Leu. In the hagfish brain, immunoreactive forms with the same retention times as synthetic Met-enkephalin and Leu-enkephalin were detected in a ratio of approximately 2:1. In addition, an immunoreactive form was detected with the Met-enkephalin-Arg-Phe-specific RIA. This form had the same chromatographic properties as synthetic Met-enkephalin-Arg-Phe. Analyses with the Met-enkephalin-Arg-Gly-Leu RIA were negative. HPLC analysis of the lamprey enkephalin-related material revealed the presence of authentic Met-enkaphalin and Leu-enkephalin in a molar ratio of 3:1. C-terminally extended forms of Met-enkaphalin were not detected in the lamprey extracts. Collectively these observations indicate that pro-enkephalin-related opioid peptides are present in the brain of cyclostomes.

  1. Evidence that sea lampreys (Petromyzon marinus) complete their life cycle within a tributary of the Laurentian Great Lakes by parasitizing fishes in inland lakes

    Science.gov (United States)

    Johnson, Nicholas; Twohey, Michael B.; Miehls, Scott M.; Cwalinski, Tim A; Godby, Neal A; Lochet, Aude; Slade, Jeffrey W.; Jubar, Aaron K.; Siefkes, Michael J.

    2016-01-01

    The sea lamprey (Petromyzon marinus) invaded the upper Laurentian Great Lakes and feeds on valued fish. The Cheboygan River, Michigan, USA, is a large sea lamprey producing tributary to Lake Huron and despite having a renovated dam 2 km from the river mouth that presumably blocks sea lamprey spawning migrations, the watershed upstream of the dam remains infested with larval sea lamprey. A navigational lock near the dam has been hypothesized as the means of escapement of adult sea lampreys from Lake Huron and source of the upper river population (H1). However, an alternative hypothesis (H2) is that some sea lampreys complete their life cycle upstream of the dam, without entering Lake Huron. To evaluate the alternative hypothesis, we gathered angler reports of lamprey wounds on game fishes upstream of the dam, and captured adult sea lampreys downstream and upstream of the dam to contrast abundance, run timing, size, and statolith microchemistry. Results indicate that a small population of adult sea lampreys (n life cycle upstream of the dam during 2013 and 2014. This is the most comprehensive evidence that sea lampreys complete their life history within a tributary of the upper Great Lakes, and indicates that similar landlocked populations could occur in other watersheds. Because the adult sea lamprey population upstream of the dam is small, complete elimination of the already low adult escapement from Lake Huron might allow multiple control tactics such as lampricides, trapping, and sterile male release to eradicate the population.

  2. Morphological and electrophysiological examination of olfactory sensory neurons during the early developmental prolarval stage of the sea lamprey Petromyzon marinus L

    Science.gov (United States)

    Zielinski, B.S.; Fredricks, Keith; McDonald, R.; Zaidi, A.U.

    2005-01-01

    This study examined olfactory sensory neuron morphology and physiological responsiveness in newly hatched sea lamprey, Petromyzon marinus L. These prolarvae hatch shortly after neural tube formation, and stay within nests for approximately 18 days, before moving downstream to silty areas where they burrow, feed and pass to the larval stage. To explore the possibility that the olfactory system is functioning during this prolarval stage, morphological and physiological development of olfactory sensory neurons was examined. The nasal cavity contained an olfactory epithelium with ciliated olfactory sensory neurons. Axons formed aggregates in the basal portion of the olfactory epithelium and spanned the narrow distance between the olfactory epithelium and the brain. The presence of asymmetric synapses with agranular vesicles within fibers in the brain, adjacent to the olfactory epithelium suggests that there was synaptic connectivity between olfactory sensory axons and the brain. Neural recordings from the surface of the olfactory epithelium showed responses following the application of L-arginine, taurocholic acid, petromyzonol sulfate (a lamprey migratory pheromone), and water conditioned by conspecifics. These results suggest that lampreys may respond to olfactory sensory input during the prolarval stage. ?? 2006 Springer Science + Business Media, LLC.

  3. Passage of four teleost species prior to sea lamprey (Petromyzon marinus) migration in eight tributaries of Lake Superior, 1954-1979

    Science.gov (United States)

    Klinger, Gregory L.; Adams, Jean V.; Heinrich, John W.

    2003-01-01

    Seasonally operated barriers in rivers are used by the Great Lakes Fishery Commission to block adult sea lamprey (Petromyzon marinus) migrations, yet pass other fish during some part of the year. Knowledge of the overlap of spawning migrations of sea lampreys and other fish species are vital for the efficient operation of the Commission's barrier program. The migration of sea lamprey spawners was compared with the migration of four other fish species using trap captures at electric barriers on eight Lake Superior tributaries during 1954 to 1979. The passage of rainbow trout (Oncorhynchus mykiss), rainbow smelt (Osmerus mordax), longnose suckers (Catostomus catostomus), and white suckers (Catostomus commersoni) prior to the capture of sea lampreys was quantified as the proportion of the annual catch of each species. Average passage over all streams and years was smallest (5%) for longnose sucker and largest (21%) for rainbow smelt. Passage prior to first sea lamprey catch was significantly different among rivers for all four species and significantly different among years for rainbow trout. Much of the variability in annual passage was unexplained by river or year effects. It is suggested that stream-specific information on run times of sea lampreys and other fishes be used to define timing of seasonal barrier operations. If barrier operations are timed to block the entire sea lamprey spawning run, then fish passage devices are needed to pass rainbow trout, rainbow smelt, longnose suckers, and white suckers.

  4. Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe

    Science.gov (United States)

    Hansen, Michael J.; Madenjian, Charles P.; Slade, Jeffrey W.; Steeves, Todd B.; Almeida, Pedro R.; Quintella, Bernardo R.

    2016-01-01

    The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range.

  5. Investigating Population Structure of Sea Lamprey (Petromyzon marinus, L.) in Western Iberian Peninsula Using Morphological Characters and Heart Fatty Acid Signature Analyses

    Science.gov (United States)

    Lança, Maria João; Machado, Maria; Mateus, Catarina S.; Lourenço, Marta; Ferreira, Ana F.; Quintella, Bernardo R.; Almeida, Pedro R.

    2014-01-01

    This study hypothesizes the existence of three groups of sea lamprey Petromyzon marinus L. in Portugal (North/Central group, Tagus group, and Guadiana group), possibly promoted by seabed topography isolation during the oceanic phase of the life cycle. Within this context, our purpose was to analyze the existence of a stock structure on sea lamprey populations sampled in the major Portuguese river basins using both morphological characters and heart tissue fatty acid signature. In both cases, the multiple discriminant analysis revealed statistically significant differences among groups, and the overall corrected classification rate estimated from cross-validation procedure was particularly high for the cardiac muscle fatty acid profiles (i.e. 83.8%). Morphometric characters were much more useful than meristic ones to discriminate stocks, and the most important variables for group differentiation were eye length, second dorsal fin length and branchial length. Fatty acid analysis showed that all lampreys from the southern Guadiana group were correctly classified and not mixing with individuals from any other group, reflecting a typical heart fatty acid signature. Our results revealed that 89.5% and 72.2% of the individuals from the Tagus and North/Central groups, respectively, were also correctly classified, despite some degree of overlap between individuals from these groups. The fatty acids that contributed to the observed segregation were C16:0; C17:0; C18:1ω9; C20:3ω6 and C22:2ω6. Detected differences are probably related with environmental variables to which lampreys may have been exposed, which leaded to different patterns of gene expression. These results suggest the existence of three different sea lamprey stocks in Portugal, with implication in terms of management and conservation. PMID:25259723

  6. Investigating population structure of Sea Lamprey (Petromyzon marinus, L. in Western Iberian Peninsula using morphological characters and heart fatty acid signature analyses.

    Directory of Open Access Journals (Sweden)

    Maria João Lança

    Full Text Available This study hypothesizes the existence of three groups of sea lamprey Petromyzon marinus L. in Portugal (North/Central group, Tagus group, and Guadiana group, possibly promoted by seabed topography isolation during the oceanic phase of the life cycle. Within this context, our purpose was to analyze the existence of a stock structure on sea lamprey populations sampled in the major Portuguese river basins using both morphological characters and heart tissue fatty acid signature. In both cases, the multiple discriminant analysis revealed statistically significant differences among groups, and the overall corrected classification rate estimated from cross-validation procedure was particularly high for the cardiac muscle fatty acid profiles (i.e. 83.8%. Morphometric characters were much more useful than meristic ones to discriminate stocks, and the most important variables for group differentiation were eye length, second dorsal fin length and branchial length. Fatty acid analysis showed that all lampreys from the southern Guadiana group were correctly classified and not mixing with individuals from any other group, reflecting a typical heart fatty acid signature. Our results revealed that 89.5% and 72.2% of the individuals from the Tagus and North/Central groups, respectively, were also correctly classified, despite some degree of overlap between individuals from these groups. The fatty acids that contributed to the observed segregation were C16:0; C17:0; C18:1ω9; C20:3ω6 and C22:2ω6. Detected differences are probably related with environmental variables to which lampreys may have been exposed, which leaded to different patterns of gene expression. These results suggest the existence of three different sea lamprey stocks in Portugal, with implication in terms of management and conservation.

  7. Life stage dependent responses to the lampricide, 3-trifluoromethyl-4-nitrophenol (TFM), provide insight into glucose homeostasis and metabolism in the sea lamprey (Petromyzon marinus).

    Science.gov (United States)

    Henry, Matthew; Birceanu, Oana; Clifford, Alexander M; McClelland, Grant B; Wang, Yuxiang S; Wilkie, Michael P

    2015-03-01

    The primary method of sea lamprey (Petromyzon marinus) control in the Great Lakes is the treatment of streams and rivers with the pesticide 3-trifluoromethyl-4-nitrophenol (TFM), which targets larval sea lamprey. However, less is known about the effects of TFM on other stages of the sea lamprey's complex life cycle. The goal of this study was to determine how TFM affected internal energy stores, metabolites, and ion balance in larval, juvenile (parasitic) and adult sea lamprey. The larvae were more tolerant to TFM than the adults, with a 2-fold higher 12h TFM LC50 and a 1.5-fold higher LC99.9. Acute (3h) exposure of the larvae, parasites and adults to their respective 12h TFM LC99.9 led to marked reductions in glycogen and phosphocreatine in the adult brain, with lesser or no effect in the larvae and parasites. Increased lactate in the brain, at less than the expected stoichiometry, suggested that it was exported to the blood. Kidney glycogen declined after TFM exposure, suggesting that this organ plays an important role in glucose homeostasis. TFM-induced disturbances to ion balance were minimal. In conclusion, TFM perturbs energy metabolism in all major stages of the sea lamprey life cycle in a similar fashion, but the adults appear to be the most sensitive. Thus, the adult stage could be a viable and effective target for TFM treatment, particularly when used in combination with other existing and emerging strategies of sea lamprey control. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Structure and stability of metagenome-derived glycoside hydrolase family 12 cellulase (LC-CelA) a homolog of Cel12A from Rhodothermus marinus.

    Science.gov (United States)

    Okano, Hiroyuki; Ozaki, Masashi; Kanaya, Eiko; Kim, Joong-Jae; Angkawidjaja, Clement; Koga, Yuichi; Kanaya, Shigenori

    2014-01-01

    Ten genes encoding novel cellulases with putative signal peptides at the N-terminus, termed pre-LC-CelA-J, were isolated from a fosmid library of a leaf-branch compost metagenome by functional screening using agar plates containing carboxymethyl cellulose and trypan blue. All the cellulases except pre-LC-CelG have a 14-29 residue long flexible linker (FL) between the signal peptide and the catalytic domain. LC-CelA without a signal peptide (residues 20-261), which shows 76% amino acid sequence identity to Cel12A from Rhodothermus marinus (RmCel12A), was overproduced in Escherichia coli, purified and characterized. LC-CelA exhibited its highest activity across a broad pH range (pH 5-9) and at 90 °C, indicating that LC-CelA is a highly thermostable cellulase, like RmCel12A. The crystal structure of LC-CelA was determined at 1.85 Å resolution and is nearly identical to that of RmCel12A determined in a form without the FL. Both proteins contain two disulfide bonds. LC-CelA has a 16-residue FL (residues 20-35), most of which is not visible in the electron density map, probably due to structural disorder. However, Glu34 and Pro35 form hydrogen bonds with the central region of the protein. ΔFL-LC-CelA (residues 36-261) and E34A-LC-CelA with a single Glu34 → Ala mutation were therefore constructed and characterized. ΔFL-LC-CelA and E34A-LC-CelA had lower melting temperatures (T m) than LC-CelA by 14.7 and 12.0 °C respectively. The T m of LC-CelA was also decreased by 28.0 °C in the presence of dithiothreitol. These results suggest that Glu34-mediated hydrogen bonds and the two disulfide bonds contribute to the stabilization of LC-CelA.

  9. Neptuniibacter pectenicola sp. nov. and Neptuniibacter marinus sp. nov., two novel species isolated from a Great scallop (Pecten maximus) hatchery in Norway and emended description of the genus Neptuniibacter.

    Science.gov (United States)

    Diéguez, Ana L; Balboa, Sabela; Magnesen, Thorolf; Romalde, Jesús L

    2017-03-01

    Nine isolates obtained from a great scallop hatchery in Norway were characterized using a polyphasic approach. Strains were Gram-negative, aerobic and motile rods with oxidative metabolism. Phylogenetic analysis based on the sequences of 16S rRNA and rpoB genes showed that these strains formed two different groups associated with members of the genus Neptuniibacter. DNA-DNA hybridization (DDH) and Average Nucleotide Identity (ANI) demonstrated that the isolates constituted two novel species of this genus, which can be phenotypically differentiated from their closest relatives. The names Neptuniibacter marinus sp. nov. and Neptuniibacter pectenicola sp. nov are proposed, with ATR 1.1T (=CECT 8938T=DSM 100783T) and LFT 1.8T (=CECT 8936T=DSM 100781T) as respective type strains. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Geographical, and seasonal variation in the diet of harbour porpoises (Phocoena phocoena in Icelandic coastal waters

    Directory of Open Access Journals (Sweden)

    Gísli A Víkingsson

    2003-07-01

    Overall capelin (Mallotus villosus comprised the predominant prey, followed by sandeel (Ammodytidae sp., then gadids, cephalopods and redfish (Sebastes marinus, while other taxa were of less importance. Differences were detected in diet composition among 5 areas around Iceland with redfish and gadids more prominent in the northern areas. Off SW Iceland there was considerable seasonal variation in the porpoise diet, where capelin appeared to be dominant in late winter and spring and sandeel in the summer through early winter. Predominance of capelin in the diet coincided with the spawning migration of capelin from northern waters along the east, south and west coasts of Iceland. Mature females appeared to have a more diverse diet than other reproductive classes. The length distributions of fish consumed by the porpoises ranged from 1 to 51 cm although most fish prey were less than 30 cm.

  11. Influence of body size, metabolic rate and life history stage on the uptake and excretion of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) by invasive sea lampreys (Petromyzon marinus).

    Science.gov (United States)

    Tessier, Laura R; Long, Tristan A F; Wilkie, Michael P

    2018-01-01

    Invasive sea lamprey (Petromyzon marinus) are controlled in the Great Lakes using the lampricide 3-trifluoromethyl-4-nitrophenol (TFM), which is applied to streams infested with larval lamprey. However, lamprey that survive treatments (residuals) remain a challenge because they may subsequently undergo metamorphosis into parasitic juvenile animals that migrate downstream to the Great Lakes, where they feed on important sport and commercial fishes. The goal of this study was to determine if body size and life stage could potentially influence sea lamprey tolerance to TFM by influencing patterns of TFM uptake and elimination. Because mass specific rates of oxygen consumption (M˙O 2 ) are lower in larger compared to smaller lamprey, we predicted that TFM uptake would be negatively correlated to body size, suggesting that large larvae would be more tolerant to TFM exposure. Accordingly, TFM uptake and M˙O 2 were measured in larvae ranging in size from 0.2-4.2g using radio-labelled TFM ( 14 C-TFM) and static respirometry. Both were inversely proportional to wet mass (M), and could be described usingthe allometric power relationship: Y=aM b , in which M˙O 2 =1.86M 0.53 and TFM Uptake=7.24M 0.34 . We also predicted that body size would extend to rates of TFM elimination, which was measured following the administration of 14 C-TFM (via intraperitoneal injection). However, there were no differences in the half-lives of elimination of TFM (T 1/2 -TFM). There were also no differences in M˙O 2 or TFM uptake amongst size-matched larval, metamorphosing (stages 6-7), or post-metamorphic (juvenile) sea lamprey. However, the T 1/2 -TFM was significantly lower in larval than post-metamorphic lamprey (juvenile), indicating the larval lamprey cleared TFM more efficiently than juvenile lamprey. We conclude that larger larval sea lamprey are more likely to survive TFM treatments suggesting that body size might be an important variable to consider when treating streams with TFM to

  12. Detection of arsenic-containing hydrocarbons in a range of commercial fish oils by GC-ICPMS analysis

    DEFF Research Database (Denmark)

    Sele, Veronika; Amlund, Heidi; Berntssen, Marc H. G.

    2013-01-01

    the analysis of a small sample amount, and the method was applied on a range of different commercial fish oils, including oils of anchovy (Engraulis ringens), Atlantic herring (Clupea harengus), sand eel (Ammodytes marinus), blue whiting (Micromesistius poutassou) and a commercial mixed fish oil (mix of oils...... concentration was seen in the decontaminated fish oils. This provided an insight to how a decontamination procedure originally ascribed for the removal of persistent organic pollutants affects the level of arsenolipids present in fish oils. © 2013 Springer-Verlag Berlin Heidelberg....

  13. Effects of copepod size on fish growth: A model based on data for North Sea sandeel

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Jørgensen, C.; Fiksen, Ø.

    2015-01-01

    In productive marine off-shore ecosystems, the flow of energy from zooplankton to large predators is channeled through a few species of short-lived, highly abundant schooling planktivorous fish. There are indications that these species respond to qualitative and phenological changes in the zoopla...... was the most important factor, followed by handling time limitation and prey energy content. These limitations became stronger with increasing fish length, showing that copepod size and energy content have a strong effect on the specific growth potential of these fish......In productive marine off-shore ecosystems, the flow of energy from zooplankton to large predators is channeled through a few species of short-lived, highly abundant schooling planktivorous fish. There are indications that these species respond to qualitative and phenological changes...... in the zooplankton. If so, the climate-induced alterations of the local copepod communities that we see in temperate and arctic regions may influence the energy flux in marine food chains. In order to investigate how different processes contribute to the relationship between copepod size and fish growth, we merged 2...

  14. Intertwined evolutionary histories of marine Synechococcus and Prochlorococcus marinus.

    Science.gov (United States)

    Zhaxybayeva, Olga; Doolittle, W Ford; Papke, R Thane; Gogarten, J Peter

    2009-09-02

    Prochlorococcus is a genus of marine cyanobacteria characterized by small cell and genome size, an evolutionary trend toward low GC content, the possession of chlorophyll b, and the absence of phycobilisomes. Whereas many shared derived characters define Prochlorococcus as a clade, many genome-based analyses recover them as paraphyletic, with some low-light adapted Prochlorococcus spp. grouping with marine Synechococcus. Here, we use 18 Prochlorococcus and marine Synechococcus genomes to analyze gene flow within and between these taxa. We introduce embedded quartet scatter plots as a tool to screen for genes whose phylogeny agrees or conflicts with the plurality phylogenetic signal, with accepted taxonomy and naming, with GC content, and with the ecological adaptation to high and low light intensities. We find that most gene families support high-light adapted Prochlorococcus spp. as a monophyletic clade and low-light adapted Prochlorococcus sp. as a paraphyletic group. But we also detect 16 gene families that were transferred between high-light adapted and low-light adapted Prochlorococcus sp. and 495 gene families, including 19 ribosomal proteins, that do not cluster designated Prochlorococcus and Synechococcus strains in the expected manner. To explain the observed data, we propose that frequent gene transfer between marine Synechococcus spp. and low-light adapted Prochlorococcus spp. has created a "highway of gene sharing" (Beiko RG, Harlow TJ, Ragan MA. 2005. Highways of gene sharing in prokaryotes. Proc Natl Acad Sci USA. 102:14332-14337) that tends to erode genus boundaries without erasing the Prochlorococcus-specific ecological adaptations.

  15. Etiek en teologie – aktuele bespreking van Marinus Schoeman se ...

    African Journals Online (AJOL)

    ... is given of some of the most important issues in comparison to a Christian viewpoint. The following topics are discussed: Resentment; Revaluation of all values; Purpose driven universe; Critique of moral values; The aristocrat; Hannah Arendt's view on the publicpolitical realm and private sphere; Plurality and conformity.

  16. Feeding habits of harp and hooded seals in Greenland waters

    Directory of Open Access Journals (Sweden)

    Finn O Kapel

    2000-05-01

    Full Text Available Results of stomach contents analyses of harp and hooded seals collected in West Greenland waters in the period 1986-1993 are reviewed, and compared with published data and circumstantial information from local hunters.  The diet of harp seals in this region is variable but consists mainly of pelagic crustaceans (Thysanoessa spp. and Parathemisto libellula and small fish species like capelin (Mallotus villosus, sandeel (Ammodytes spp., polar cod (Boreogadus saida and Arctic cod (Arctogadus glacialis. Species of importance for commercial fisheries in Greenland, such as Northern prawn (Pandalus borealis, Atlantic cod (Gadus morhua, and Greenland halibut (Reinhardtius hippoglossoides play a minor role in the diet of harp seals in this area. Variation in the diet of hooded seals is less well documented, but in addition to the species also taken by harp seals, larger demersal fishes like Greenland halibut, redfish (Sebastes spp., cod, and wolffish (Anarhichas minor are apparently important prey items.

  17. Are the dynamics of gastric evacuation of natural prey in a piscivorous flatfish different from what is going on in a gadoid?

    Science.gov (United States)

    Krog, C; Andersen, N G

    2009-11-01

    Despite the fact that the stomach of turbot Psetta maxima is a curved tube that forms a half circle, it was demonstrated that gastric evacuation in this predatory flatfish fed natural prey closely followed the surface-dependent cylinder model developed from studies on gadoids with a straight stomach. Evacuation experiments were performed on two size groups of P. maxima fed sandeel Ammodytes tobianus as well as on P. maxima fed brown shrimp Crangon crangon at three different temperatures. This enabled the provision of a gastric evacuation model for studies on P. maxima, which takes into account the effects of the explanatory variables predator size, temperature, prey energy density and resistance of prey to the digestive processes in the stomach. Basically, the cylinder model predicts that a square-root function accurately describes gastric evacuation, which is inconsistent with the conclusion of a previous study on P. maxima that evacuation of A. tobianus is essentially linear with time. Use of the cylinder model to the values of the explanatory variables presented in the latter study, however, gave accurate predictions of the actually acquired evacuation data, which points to the generic value of the model.

  18. Venom peptide analysis of Vipera ammodytes meridionalis (Viperinae) and Bothrops jararacussu (Crotalinae) demonstrates subfamily-specificity of the peptidome in the family Viperidae.

    Science.gov (United States)

    Munawar, Aisha; Trusch, Maria; Georgieva, Dessislava; Spencer, Patrick; Frochaux, Violette; Harder, Sönke; Arni, Raghuvir K; Duhalov, Deyan; Genov, Nicolay; Schlüter, Hartmut; Betzel, Christian

    2011-12-01

    Snake venom peptidomes are valuable sources of pharmacologically active compounds. We analyzed the peptidic fractions (peptides with molecular masses Viperidae family: BPPs are the major peptide component of the Crotalinae venom peptidome lacking Kunitz-type inhibitors (with one exception) while the Viperinae venom, in addition to BPPs, can contain peptides of the bovine pancreatic trypsin inhibitor family. We found indications for a post-translational phosphorylation of serine residues in Bothrops jararacussu venom BPP (S[combining low line]QGLPPGPPIP), which could be a regulatory mechanism in their interactions with ACE, and might influence the hypotensive effect. Homology between venom BPPs from Viperidae snakes and venom natriuretic peptide precursors from Elapidae snakes suggests a structural similarity between the respective peptides from the peptidomes of both snake families. The results demonstrate that the venoms of both snakes are rich sources of peptides influencing important physiological systems such as blood pressure regulation and hemostasis. The data can be used for pharmacological and medical applications.

  19. Ventilatory behaviors of the toad Bufo marinus revealed by coherence analysis

    Directory of Open Access Journals (Sweden)

    F. C. Coelho

    Full Text Available Breathing in amphibians is a remarkably complex behavior consisting of irregular breaths that may be taken singly or in bouts that are used to deflate and inflate the lungs. The valves at the two outlets of the buccal cavity (nares and glottis need to be finely controlled throughout the bout for the expression of these complex respiratory behaviors. In this study, we use a technique based on the calculation of the coherence spectra between respiratory variables (buccal pressure; narial airflow; and lung pressure. Coherence was also used to quantify the effects of chemoreceptor and pulmonary mechanoreceptor input on narial and glottal valve behavior on normoxic, hypoxic, and hypercapnic toads with both intact and bilaterally sectioned pulmonary vagi. We found a significant reduction in narial coherence in hypoxic vagotomized toads indicating that pulmonary mechanoreceptor feedback modulates narial opening duration. An unexpectedly high coherence between Pl and Pb during non-respiratory buccal oscillations in hypercapnic toads indicated more forceful use of the buccal pump. We concluded that the coherence function reveals behaviors that are not apparent through visual inspection of ventilatory time series.

  20. Ventilatory behaviors of the toad Bufo marinus revealed by coherence analysis

    Directory of Open Access Journals (Sweden)

    Coelho F. C.

    2003-01-01

    Full Text Available Breathing in amphibians is a remarkably complex behavior consisting of irregular breaths that may be taken singly or in bouts that are used to deflate and inflate the lungs. The valves at the two outlets of the buccal cavity (nares and glottis need to be finely controlled throughout the bout for the expression of these complex respiratory behaviors. In this study, we use a technique based on the calculation of the coherence spectra between respiratory variables (buccal pressure; narial airflow; and lung pressure. Coherence was also used to quantify the effects of chemoreceptor and pulmonary mechanoreceptor input on narial and glottal valve behavior on normoxic, hypoxic, and hypercapnic toads with both intact and bilaterally sectioned pulmonary vagi. We found a significant reduction in narial coherence in hypoxic vagotomized toads indicating that pulmonary mechanoreceptor feedback modulates narial opening duration. An unexpectedly high coherence between Pl and Pb during non-respiratory buccal oscillations in hypercapnic toads indicated more forceful use of the buccal pump. We concluded that the coherence function reveals behaviors that are not apparent through visual inspection of ventilatory time series.

  1. Ventilatory behaviors of the toad Bufo marinus revealed by coherence analysis.

    Science.gov (United States)

    Coelho, F C; Baker, T L; Smatresk, N J

    2003-02-01

    Breathing in amphibians is a remarkably complex behavior consisting of irregular breaths that may be taken singly or in bouts that are used to deflate and inflate the lungs. The valves at the two outlets of the buccal cavity (nares and glottis) need to be finely controlled throughout the bout for the expression of these complex respiratory behaviors. In this study, we use a technique based on the calculation of the coherence spectra between respiratory variables (buccal pressure; narial airflow; and lung pressure). Coherence was also used to quantify the effects of chemoreceptor and pulmonary mechanoreceptor input on narial and glottal valve behavior on normoxic, hypoxic, and hypercapnic toads with both intact and bilaterally sectioned pulmonary vagi. We found a significant reduction in narial coherence in hypoxic vagotomized toads indicating that pulmonary mechanoreceptor feedback modulates narial opening duration. An unexpectedly high coherence between Pl and Pb during non-respiratory buccal oscillations in hypercapnic toads indicated more forceful use of the buccal pump. We concluded that the coherence function reveals behaviors that are not apparent through visual inspection of ventilatory time series.

  2. Ventilatory behaviors of the toad Bufo marinus revealed by coherence analysis

    OpenAIRE

    Coelho, F. C.; Baker, T. L.; Smatresk, N. J.

    2003-01-01

    Breathing in amphibians is a remarkably complex behavior consisting of irregular breaths that may be taken singly or in bouts that are used to deflate and inflate the lungs. The valves at the two outlets of the buccal cavity (nares and glottis) need to be finely controlled throughout the bout for the expression of these complex respiratory behaviors. In this study, we use a technique based on the calculation of the coherence spectra between respiratory variables (buccal pressure; narial airfl...

  3. Breakdown products of heme catabolism as senescence index in sea lamprey (Petromyzon marinus Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Sandra Barca

    2015-11-01

    No significant differences were observed between sexes in the livers of recent migratory individuals. Nevertheless highest values of biliverdin/bilirrubin ratio were reached by females belonging to the group of older upstream migrants (mean: 2.33, sd: 0.53, Kruskal-Wallis test, p<0.05, but the liver weight of males was significantly higher than in females (mean males: 30.36 g, sd: 5.67; mean females: 17.38 g, sd: 5.87; Kruskal-Wallis test, p<0.05.

  4. iso-Petromyroxols: Novel Dihydroxylated Tetrahydrofuran Enantiomers from Sea Lamprey (Petromyzon marinus

    Directory of Open Access Journals (Sweden)

    Ke Li

    2015-03-01

    Full Text Available An enantiomeric pair of new fatty acid-derived hydroxylated tetrahydrofurans, here named iso-petromyroxols, were isolated from sea lamprey larvae-conditioned water. The relative configuration of iso-petromyroxol was elucidated with 1D and 2D NMR spectroscopic analyses. The ratio of enantiomers (er in the natural sample was measured by chiral-HPLC-MS/MS to be ca. 3:1 of (–- to (+-antipodes.

  5. An anti-steroidogenic inhibitory primer pheromone in male sea lamprey (Petromyzon marinus)

    Science.gov (United States)

    Chung-Davidson, Yu-Wen; Wang, Huiyong; Bryan, Mara B.; Wu, Hong; Johnson, Nicholas S.; Li, Weiming

    2013-01-01

    Reproductive functions can be modulated by both stimulatory and inhibitory primer pheromones released by conspecifics. Many stimulatory primer pheromones have been documented, but relatively few inhibitory primer pheromones have been reported in vertebrates. The sea lamprey male sex pheromone system presents an advantageous model to explore the stimulatory and inhibitory primer pheromone functions in vertebrates since several pheromone components have been identified. We hypothesized that a candidate sex pheromone component, 7α, 12α-dihydroxy-5α-cholan-3-one-24-oic acid (3 keto-allocholic acid or 3kACA), exerts priming effects through the hypothalamic-pituitary-gonadal (HPG) axis. To test this hypothesis, we measured the peptide concentrations and gene expressions of lamprey gonadotropin releasing hormones (lGnRH) and the HPG output in immature male sea lamprey exposed to waterborne 3kACA. Exposure to waterborne 3kACA altered neuronal activation markers such as jun and jun N-terminal kinase (JNK), and lGnRH mRNA levels in the brain. Waterborne 3kACA also increased lGnRH-III, but not lGnRH-I or -II, in the forebrain. In the plasma, 3kACA exposure decreased all three lGnRH peptide concentrations after 1 h exposure. After 2 h exposure, 3kACA increased lGnRHI and -III, but decreased lGnRH-II peptide concentrations in the plasma. Plasma lGnRH peptide concentrations showed differential phasic patterns. Group housing condition appeared to increase the averaged plasma lGnRH levels in male sea lamprey compared to isolated males. Interestingly, 15α-hydroxyprogesterone (15α-P) concentrations decreased after prolonged 3kACA exposure (at least 24 h). To our knowledge, this is the only known synthetic vertebrate pheromone component that inhibits steroidogenesis in males.

  6. Etiek en teologie – \\'n aktuele bespreking van Marinus Schoeman se ...

    African Journals Online (AJOL)

    in comparison to a Christian viewpoint. The following topics are discussed: Resentment; Revaluation of all values; Purpose driven universe; Critique of moral values; The aristocrat; Hannah Arendt's view on the publicpolitical realm and private sphere; Plurality and conformity. HTS Theological Studies Vol. 63 (3) 2007: pp.

  7. Diseases and parasites of the sea lamprey, Petromyzon marinus, in the Lake Huron basin

    Science.gov (United States)

    McLain, Alberton L.

    1952-01-01

    Sea lampreys from the Lake Huron basin carried no external parasites and showed a fairly low degree of infection by internal parasites. The material examined represented three life-history stages of the sea lamprey. Recently transformed downstream migrants (215 specimens) harbored only nematodes belonging to the genus Camallanus. The percentage of infection was 2.3. Active feeders from the lake (29 lampreys) revealed the highest degree of parasitism (31.0 percent) with the following parasites present: Echinorhynchus coregoni Linkins; Triaenophorus crassus Forel; and Camallanus sp. Among the 257 sexually mature upstream migrants (14.8 percent infected) Echinorhynchus coregoni and E. leidyi Van Cleave were the most common. Only occasional nematodes and cestodes were found, which fact indicates a failure of the lamprey to carry these parasites to the end of its natural life. Of the parasites observed, only the nematodes gave evidence of serious damage to the host. The study suggests that the role played by parasites in the natural control of the sea lamprey in its new habitat in the upper Great Lakes is of minor importance.

  8. Spatially resolved fish population analysis for designing MPAs

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Mosegaard, Henrik; Jensen, Henrik

    2009-01-01

    habitats for settled sandeels, combined with a life-cycle model for survival, growth, and reproduction, and a three-dimensional hydrodynamic model for describing larval transport between the network of habitats. SPAM couples stock dynamics to ecosystem and anthropogenic forcing via well-defined drivers......The sandeel population analysis model (SPAM) is presented as a simulation tool for exploring the efficiency of Marine Protected Areas (MPAs) for sandeel stocks. SPAM simulates spatially resolved sandeel population distributions, based on a high-resolution map of all fishery-established sandbank...

  9. Towards an integrated forecasting system for pelagic fisheries

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Butenschön, Momme; Gürkan, Zeren

    2012-01-01

    Population Analysis Model describes sandeel stocks in the North Sea, and the Sandeel Larval Analysis Model connects POLCOMS‐ERSEM and SPAM by computing the physical–biological interaction. Our main findings by coupling model subsystems is that well‐defined and generic model interfaces are very important...

  10. Caractérisation de la pêcherie de lamproie marine Petromyzon marinus marinus, Linné (1758) en Loire-aval pour les saisons 1988 et 1989

    OpenAIRE

    Grellier, Patrick

    1996-01-01

    The downstream part of the Loire river is divided into three regulation zones (marine, fluvial and mixed zones) where a traditional fishery for sea lamprey is practised. More than one hundred professional fishermen (either marine or fluvial statute) are interested in this activity during winter and spring to catch lampreys on their trip to the up stream spawning areas. The fluvial contraints (fluvial discharge, tidal current etc...) generate two types of exploitation : the osier trap and the ...

  11. ORF Alignment: NC_005042 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available 8 ... [Prochlorococcus marinus subsp. marinus str. CCMP1375] ... Length = 96 ... Query: 27 ... RPRLAVFRSNNHIYAQVIDDVAQNTLCA...ASTLEKEFLSNSKVNASTCAASTAVGEMLAKR 86 ... RPRLAVFRSNNHIYAQVIDDVAQNTLCA...ASTLEKEFLSNSKVNASTCAASTAVGEMLAKR Sbjct: 1 ... RPRLAVFRSNNHIYAQVIDDVAQNTLCAASTLEKEFLSNSKVNASTCAASTAVGEMLAKR 60 ...

  12. Taxonomy Icon Data: sea lamprey [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available sea lamprey Petromyzon marinus Chordata/Vertebrata/Hyperoartia Petromyzon_marinus_L.png Petromy...zon_marinus_NL.png Petromyzon_marinus_S.png Petromyzon_marinus_NS.png http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Petromyzon+marinus&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Petromyzon+ma...rinus&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Petromyzon+marinus&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Petromyzon+marinus&t=NS ...

  13. Analysis of DNA damage in sea lamprey (Petromyzon marinus) spermatozoa by UV, hydrogen peroxide, and the toxicant bisazir

    Energy Technology Data Exchange (ETDEWEB)

    Ciereszko, Andrzej [School of Natural Resources, Ohio State University, 210 Kottman Hall, 2021 Coffey Rd., Columbus, OH 434210 (United States); Semen Biology Group, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-747 Olsztyn (Poland); Wolfe, Tobie D. [School of Natural Resources, Ohio State University, 210 Kottman Hall, 2021 Coffey Rd., Columbus, OH 434210 (United States); Dabrowski, Konrad [School of Natural Resources, Ohio State University, 210 Kottman Hall, 2021 Coffey Rd., Columbus, OH 434210 (United States)]. E-mail: dabrowski.1@osu.edu

    2005-06-15

    In this study we sought to demonstrate that Comet assay can be applied to sea lamprey sperm DNA fragmentation and used to describe the relationship between sperm DNA damage and sperm fertilizing ability. We show that the assay can be used reliably and accurately, and unlike in the case of mammals, there is no need for additional steps related to improvement of efficacy of lysis and DNA decondensation. This agrees with the presence of histone proteins in lamprey sperm. An increase in DNA fragmentation was noted during short-term storage of milt on ice (0-4 days). We demonstrated genotoxic effects of UV radiation and oxidative stress (exposure to hydrogen peroxide) and found that oxidative damage to sperm DNA was likely repaired after fertilization in the embryo. Repairing capacity of the oocyte toward sperm DNA lesions caused by UV was restricted. Toxic effect of p,p-bis-(1-aziridinyl)-N-methylphosphinothioic acid (p,p-bis(1-aziridinyl)-N-methylphosphinothioic amide), a sea lamprey chemosterilant, could not be linked to DNA fragmentation in the in vitro tests. Its genotoxicity in vivo may possibly be associated with other mechanisms of DNA degradation (oxidation or DNA-protein and DNA-DNA cross-linking). In conclusion, this study demonstrates that Comet assay can be successfully applied to monitor effects of environmental disturbances and imposed injuries in sea lamprey spermatozoa and possibly other species of ancient fish with acrosomal sperm.

  14. COMPARISON OF IN VITRO-CULTURED AND WILD-TYPE PERKINSUS MARINUS. II: DOSING METHODS AND HOST RESPONSE

    Science.gov (United States)

    Endoparasites must breach host barriers to establish infection and then must survive host internal defenses to cause disease. Such barriers may frustrate attempts to experimentally transmit parasites by ?natural' methods. In addition, the host's condition may affect a study's out...

  15. Reduced dermal photosensitivity in juvenile sea lampreys (Petromyzon marinus) reflects life-history-dependent changes in habitat and behaviour

    National Research Council Canada - National Science Library

    Binder, T.R; McDonald, D.G; Wilkie, M.P

    2013-01-01

    ... after metamorphosing from burrow-dwelling, filter-feeding larval sea lampreys (ammocoetes) into open-water, parasitic juvenile phase animals that attach themselves to and feed on the blood of marine and freshwater fishes...

  16. Perfil em ácidos gordos da carne de lampreia marinha (Petromyzon marinus, L.) dos rios Minho e Mondego

    OpenAIRE

    Lança, M.J.; Machado, A.M.; Almeida, Pedro R.

    2012-01-01

    A carne de pescado deve corresponder às expectativas do consumidor no que se refere aos atributos de qualidade sanitária, organolética e nutritiva. Os lípidos são constituintes importantes dos alimentos na medida em que influenciam e determinam o aspeto sensorial do alimento, o sabor, o odor, a maciez, a suculência, a aparência e a sensação de saciedade após a refeição. Estes atributos estão especialmente relacionados com o perfil em ácidos gordos da carne e com a oxidação dos ácidos gordos i...

  17. Albirhodobacter marinus gen. nov., sp. nov., a member of the family Rhodobacteraceae isolated from sea shore water of Visakhapatnam, India

    Digital Repository Service at National Institute of Oceanography (India)

    Nupur; Bhumika, V.; Srinivas, T.N.R.; AnilKumar, P.

    , Sheu SY, Chen CA, Wang JT, Chen WM (2011) Paracoccus isoporae sp. nov., isolated from the reef-building coral Isopora palifera. Int J Syst Evol Microbiol 61:1138–1143 Collins MD, Pirouz T, Goodfellow M, Minnikin DE (1977) Distribution of menaquinones... non-photosynthetic member of the class Alphaproteobacteria isolated from seawater. Int J Syst Evol Microbiol 58:282–285 Liu ZP, Wang BJ, Liu XY, Dai X, Liu YH, Liu SJ (2008) Paracoccus halophilus sp. nov., isolated from marine sediment of the South...

  18. Regulation of a putative corticosteroid, 17, 21-dihydroxypregn-4-ene, 3, 20-one, in sea lamprey, Petromyzon marinus.

    Science.gov (United States)

    Roberts, Brent W.; Didier, Wes; Satbir, Rai; Johnson, Nicholas S.; Libants, Scot V.; Sang-Seon, Yun; Close, David

    2013-01-01

    In higher vertebrates, in response to stress, the hypothalamus produces corticotropin-releasing hormone (CRH), which stimulates cells in the anterior pituitary to produce adrenocorticotropic hormone (ACTH), which in turn stimulates production of either cortisol (F) or corticosterone (B) by the adrenal tissues. In lampreys, however, neither of these steroids is present. Instead, it has been proposed that the stress steroid is actually 17,21-dihydroxypregn-4-ene-3,20-dione (11-deoxycortisol; S). However, there have been no studies yet to determine its mechanism of regulation or site of production. Here we demonstrate that (1) intraperitoneal injections of lamprey-CRH increase plasma S in a dose dependent manner, (2) intraperitoneal injections of four lamprey-specific ACTH peptides at 100 lg/kg, did not induce changes in plasma S concentrations in either males or females; (3) two lamprey-specific gonadotropin-releasing hormones (GnRH I and III) and arginine-vasotocin (AVT), all at single doses, stimulated S production as well as, or to an even greater extent than CRH; (4) sea lamprey mesonephric kidneys, in vitro, converted tritiated 17a-hydroxyprogesterone (17a-P) into a steroid that had the same chromatographic properties (on HPLC and TLC) as S; (5) kidney tissues released significantly more immunoassayable S into the incubation medium than gill, liver or gonad tissues. One interpretation of these results is that the corticosteroid production of the sea lamprey, one of the oldest extant vertebrates, is regulated through multiple pathways rather than the classical HPI-axis. However, the responsiveness of this steroid to the GnRH peptides means that a reproductive rather than a stress role for this steroid cannot yet be ruled out.

  19. The sea lamprey Petromyzon marinus genome reveals the early origin of several chemosensory receptor families in the vertebrate lineage

    Directory of Open Access Journals (Sweden)

    Zhang Ziping

    2009-07-01

    Full Text Available Abstract Background In gnathostomes, chemosensory receptors (CR expressed in olfactory epithelia are encoded by evolutionarily dynamic gene families encoding odorant receptors (OR, trace amine-associated receptors (TAAR, V1Rs and V2Rs. A limited number of OR-like sequences have been found in invertebrate chordate genomes. Whether these gene families arose in basal or advanced vertebrates has not been resolved because these families have not been examined systematically in agnathan genomes. Results Petromyzon is the only extant jawless vertebrate whose genome has been sequenced. Known to be exquisitely sensitive to several classes of odorants, lampreys detect fewer amino acids and steroids than teleosts. This reduced number of detectable odorants is indicative of reduced numbers of CR gene families or a reduced number of genes within CR families, or both, in the sea lamprey. In the lamprey genome we identified a repertoire of 59 intact single-exon CR genes, including 27 OR, 28 TAAR, and four V1R-like genes. These three CR families were expressed in the olfactory organ of both parasitic and adult life stages. Conclusion An extensive search in the lamprey genome failed to identify potential orthologs or pseudogenes of the multi-exon V2R family that is greatly expanded in teleost genomes, but did find intact calcium-sensing receptors (CASR and intact metabotropic glutamate receptors (MGR. We conclude that OR and V1R arose in chordates after the cephalochordate-urochordate split, but before the diversification of jawed and jawless vertebrates. The advent and diversification of V2R genes from glutamate receptor-family G protein-coupled receptors, most likely the CASR, occurred after the agnathan-gnathostome divergence.

  20. Persistence of skin marks on killer whales (Orcinus orca) caused by the parasitic sea lamprey (Petromyzon marinus) in Iceland

    OpenAIRE

    Samarra, Filipa I.P.; Fennell, Alexandra; Aoki, Kagari; Deecke, Volker B.; Miller, Patrick J.O.

    2012-01-01

    Lampreys have long been thought to be a cetacean ectoparasite, due to the observation of round marks on the skin of whales caught during whaling operations. Pike (1951), Nemoto (1955), and van Utrecht (1959) compared such marks on the skin of various cetacean species caught in the Pacific and Atlantic Oceans with the dentition of lampreys and concluded that most round marks had been caused by this parasite. However, lampreys were never collected from captured whales and, due to the lack of di...

  1. Streptomyces tateyamensis sp. nov., Streptomyces marinus sp. nov. and Streptomyces haliclonae sp. nov., isolated from the marine sponge Haliclona sp

    National Research Council Canada - National Science Library

    Khan, Shams Tabrez; Tamura, Tomohiko; Takagi, Motoki; Shin-Ya, Kazuo

    2010-01-01

    ...., collected from the coast of Tateyama City, Japan. Comparison of 16S rRNA gene sequences indicated that these strains represent novel members of the genus Streptomyces, exhibiting low 16S rRNA gene sequence similarities of 98.3-97.4...

  2. Anatomy of the lamprey ear: morphological evidence for occurrence of horizontal semicircular ducts in the labyrinth of Petromyzon marinus

    Science.gov (United States)

    Maklad, Adel; Reed, Caitlyn; Johnson, Nicholas S.; Fritzsch, Bernd

    2014-01-01

    In jawed (gnathostome) vertebrates, the inner ears have three semicircular canals arranged orthogonally in the three Cartesian planes: one horizontal (lateral) and two vertical canals. They function as detectors for angular acceleration in their respective planes. Living jawless craniates, cyclostomes (hagfish and lamprey) and their fossil records seemingly lack a lateral horizontal canal. The jawless vertebrate hagfish inner ear is described as a torus or doughnut, having one vertical canal, and the jawless vertebrate lamprey having two. These observations on the anatomy of the cyclostome (jawless vertebrate) inner ear have been unchallenged for over a century, and the question of how these jawless vertebrates perceive angular acceleration in the yaw (horizontal) planes has remained open. To provide an answer to this open question we reevaluated the anatomy of the inner ear in the lamprey, using stereoscopic dissection and scanning electron microscopy. The present study reveals a novel observation: the lamprey has two horizontal semicircular ducts in each labyrinth. Furthermore, the horizontal ducts in the lamprey, in contrast to those of jawed vertebrates, are located on the medial surface in the labyrinth rather than on the lateral surface. Our data on the lamprey horizontal duct suggest that the appearance of the horizontal canal characteristic of gnathostomes (lateral) and lampreys (medial) are mutually exclusive and indicate a parallel evolution of both systems, one in cyclostomes and one in gnathostome ancestors.

  3. Protein (Cyanobacteria): 11999 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available otein PMT1969 Prochlorococcus marinus str. MIT 9313 MTSTTHPATHHTATDGKGIQITNTAMQQLARLCLEKGNDQVLRVGVRSGGCSGMSYTMDFVPSADIQEGDEVYEYTATDGASFRVICDPKSLLYIYGMQLDFSTEMIGGGFNFTNPNASQTCGCGSSFAV ...

  4. Protein (Cyanobacteria): 341528 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available protein P9301_11511 Prochlorococcus marinus str. MIT 9301 MNSFNILKDNKQILSYLYLFLSILGAVLPMMANFEFAREYGNSFDINNFISLANANPAAQSISRDLLVGASAIFIWIVNESKKLNMKNMWVVYIGTFLIAFAFSAPFFLFLRERRIIELEKIN ...

  5. Protein (Cyanobacteria): 341536 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available rotein P9515_11361 Prochlorococcus marinus str. MIT 9515 MNSLNILKDNKKVLSYIYLCLSILGAILPMMANFDFAMEYGNSFDIKNFISLANANPAAQSISRDLFVGASAVFIWIVNESQKLKIKNMWIVYIGTFLIAFAFSAPFFLFLRERRIMEIENN ...

  6. Protein (Cyanobacteria): 341534 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available otein P9215_11801 Prochlorococcus marinus str. MIT 9215 MNSLNILKDNKKILSYLYLFLSILGAILPMMANFAFAREYGNSFDINNFISLANANPAAQSISRDLLVGASAIFIWIVNESKKLDMKNMWVVYVGTFLIAFAFSAPFFLFLRERRIIELEKIN ...

  7. Protein (Cyanobacteria): 341529 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available in PMT9312_1056 Prochlorococcus marinus str. MIT 9312 MNSFNILKDNKNILSYFYLFLSILGAVLPMMANFEFAREYGNSFDINNFIALANANPAAQSISRDLLVGASSIFIWIVNESKKLNMKNMWVVYIGTFLIAFAFSAPFFLFLRERRIIELEKIN ...

  8. Protein (Cyanobacteria): 341530 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available etical protein Prochlorococcus marinus str. MIT 9202 MNSLNILKDNKQILSYLYLFLSILGAILPMMANFAFAREYGNSFDINNFISLANANPAAQSISRDLLVGASAIFIWIVNESRKLNMKNMWVVYIGTFLIAFAFSAPFFLFLRERRIIELDKIN ...

  9. Protein (Cyanobacteria): 33863823 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available :1282 ... transthyretin precursor Prochlorococcus marinus str. MIT 9313 MIHFTQISTALIVLLGMVFMSKVVMTLVVDFALLSSLKSLMRLMVRGGYVTGRTFGIFYWRYLHGPLRLSLIQLVAINVTLVILAYDACRHIWQHLLKVRPPSVARFTPAH

  10. Protein (Cyanobacteria): 468547 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available hypothetical protein PMM0979 Prochlorococcus marinus subsp. pastoris str. CCMP1986 MSSAYYGIMKFEVKTQNDDLRNSSFSFLLIFALLSLIVILSNVSIKLGTISRYHEINYICRLLTIEKSSLNFKKLSKLTNLNTKQKMWDLCREIVN ...

  11. Protein (Cyanobacteria): 124026251 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 55:1272 ... lipoprotein Prochlorococcus marinus str. NATL1A MKLIPILIIVFFFYIFLTLKKRKKLSNRKTLIERFKKRFKNINVRRERISEEFTNSLLLDPCKNIPLGTWYSEDELREKADIHRSRLSKFGKSKINGEMLYVGPKGGIYKISGDGKKKYV

  12. Protein (Cyanobacteria): 340172 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available al protein PMT0535 Prochlorococcus marinus str. MIT 9313 MLLLLTLFIPYGFLEVEIASAGPVEWKEVPATEAGQQWWDIGSLHYDKDGNLSVLSRFTPALREGEKQQNGSLYLMHVDCDQKLFRDTSVNGLHRFRAEWKPSDGDELIDAVIDEVCTAEVT ...

  13. Protein (Cyanobacteria): 432519 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available mal protein L18 Prochlorococcus marinus str. MIT 9211 MATLSKKQQTQKRHKRLRRHLNGTNHRPRLAVFRSNNHIYAQVIDDEAQSTICSASTLDKDLREKLKASGGSCDASMAVGALLAQRALAKGIEQVVFDRGGNLYHGRVKALAKSAREAGLKF ...

  14. Towards an integrated forecasting system for pelagic fisheries

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Butenschön, Momme; Gürkan, Zeren

    trophic level, in this case the sandeel population, demonstrated here on the basis of hindcast data. The coupled forecasting system has been tested for some typical scientific questions appearing in spatial fish stock management and marine spatial planning, including determination of local‐and basin......First results of a coupled modelling and forecasting system for pelagic fisheries are presented. The system consists of three mathematically fundamentally different model subsystems: POLCOMSERSEM provides the physical–biogeochemical environment in the northwest European shelf, the Sandeel...... Population Analysis Model describes sandeel stocks in the North Sea, and the Sandeel Larval Analysis Model connects POLCOMS‐ERSEM and SPAM by computing the physical–biological interaction. Our main findings by coupling model subsystems is that well‐defined and generic model interfaces are very important...

  15. Towards an integrated forecasting system for pelagic fisheries

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Butenschön, Momme; Gürkan, Zeren

    2012-01-01

    trophic level, in this case the sandeel population, demonstrated here on the basis of hindcast data. The coupled forecasting system has been tested for some typical scientific questions appearing in spatial fish stock management and marine spatial planning, including determination of local‐and basin......First results of a coupled modelling and forecasting system for pelagic fisheries are presented. The system consists of three mathematically fundamentally different model subsystems: POLCOMSERSEM provides the physical–biogeochemical environment in the northwest European shelf, the Sandeel...... Population Analysis Model describes sandeel stocks in the North Sea, and the Sandeel Larval Analysis Model connects POLCOMS‐ERSEM and SPAM by computing the physical–biological interaction. Our main findings by coupling model subsystems is that well‐defined and generic model interfaces are very important...

  16. Die Temperaturabhängigkeit semilunarer und diurnaler Schlüpfrhythmen bei der intertidalen Mücke Clunio marinus (Diptera, Chironomidae)

    Science.gov (United States)

    Krüger, M.; Neumann, D.

    1983-12-01

    On Helgoland (North Sea), the imagines of Clunio emerge during two seasonal periods (late spring and summer) from water temperatures of 8° 18 °C. The temperature dependence of the known semilunar eclosion rhythm of Clunio (correlated in nature with the spring tides every 14 15 days) was tested in the laboratory. Between 15° and 23 °C the semilunar eclosion maxima varied by only one day within the artifical 15-day zeitgebercycle, below 15 °C they were delayed up to 8 days at 8 °C. However, the days of pupation were approximately independent of the temperature level. One can conclude the existence of a temperature-independent physiological switch inducing the pupation only within a few days of the semilunar zeitgeber-cycle. Moreover, a semilunar synchronized differentiation of the imaginal discs already starts in the preceding larval instar, indicating an additional physiological switch. A model is suggested in which the semilunar eclosion rhythm and its relatively slight temperature dependence is explained by the action of two physiological switches which are coupled with the endogenous temperature-compensated lunar timing mechanism on the same days of the 15-day zeitgeber-cycle. In the laboratory, the diurnal eclosion and its underlying circadian timing mechanism (correlated on Helgoland with the time of spring low water in the late afternoon) also proved to be temperature independent between 12° and 20 °C. A comparison of field and laboratory data showed very similar results at temperatures around 18 °C (summer swarming period). In contrast, the midges emerged on all days of the semimonthly cycle of springs and neaps during the spring swarming period. This lack of semilunar synchronization may be the consequence of fluctuating temperatures during the larval and pupal development in spring time due to a general rise in the water temperature (4° 8 °C) and to short temperature rises up to 18 °C during exposure of the intertidal habitat at about low tide. Since some higher parts of the Clunio habitat suitable for egg deposition are exposed on almost every day of the semimonthly cycle, even such animals that undergo lunar unsynchronized metamorphosis can reproduce within the short imaginal life duration (ca 2 h) if they emerge just about the time of low water. In correspondence with the daily delay in the times of low water by about 50 min, the diurnal eclosion rhythm was in fact modified with the tides during the spring period resulting in shifts of the diurnal eclosion time of up to 12 hours within the semimonthly cycle of springs and neaps.

  17. Comparison of the fatty acid profile of muscle neutral lipids and phospholipids of up-river anadromous sea lamprey (Petromyzon marinus L. from three Portuguese river basins

    Directory of Open Access Journals (Sweden)

    Sara Pinela

    2009-12-01

    Full Text Available Composition of fatty acid profile of muscle neutral lipids (NL and phospholipids (PL of sea lamprey that enter the Portuguese rivers Minho, Tagus and Guadiana during their non-trophic spawning migration was analysed. The fatty acid profile exhibited differences in the percentage among NL and PL and between river basins. Similarities were found in the fatty acid profile of NL. Monounsaturated fatty acids (MUFA were the most representative, followed by saturated fatty acids (SFA and finally by polyunsaturated fatty acids (PUFA. Monoenic 16:1 and 18:1ω9 formed a considerable percentage of total fatty acids, followed by SFA 14:0 and 16:0. EPA and DHA were the dominant PUFA fatty acids. In terms of NL, the fatty acid that contributed for the discrimination between the three river basins was 18:1ω7. Individuals from the Minho river basin exhibited a different fatty acid profile of PL characterised by a low PUFA percentage when compared with lampreys from the Tagus and Guadiana river basins. Muscle PL fraction showed that the two monoenes, 16:1 and 18:1ω9, occurred at high percentage, followed by 16:0 and 14:0 (SFA. Among PUFA, DHA was the most representative fatty acid. The fatty acids that contributed to the separation between the three river basins were 16:0, 18:4ω3 and 24:1ω9. Although the results point in the direction of a possible difference between the fatty acid composition of the NL and PL fractions in the muscle samples from the three river basins, further studies, especially in tissues where fatty acid composition will be less sensitive to diet and environmental factors, are necessary to confirm this hypothesis.

  18. Cloning, phylogeny, and regional expression of a Y5 receptor mRNA in the brain of the sea lamprey (Petromyzon marinus).

    Science.gov (United States)

    Pérez-Fernández, Juan; Megías, Manuel; Pombal, Manuel A

    2014-04-01

    The NPY receptors known as Y receptors are classified into three subfamilies, Y1, Y2, and Y5, and are involved in different physiological functions. The Y5 receptor is the only member of the Y5 subfamily, and it is present in all vertebrate groups, except for teleosts. Both molecular and pharmacological studies show that Y5 receptor is highly conserved during vertebrate evolution. Furthermore, this receptor is widely expressed in the mammalian brain, including the hypothalamus, where it is thought to take part in feeding and homeostasis regulation. Lampreys belong to the agnathan lineage, and they are thought to have branched out between the two whole-genome duplications that occurred in vertebrates. Therefore, they are in a key position for studies on the evolution of gene families in vertebrates. Here we report the cloning, phylogeny, and brain expression pattern of the sea lamprey Y5 receptor. In phylogenetic studies, the lamprey Y5 receptor clusters in a basal position, together with Y5 receptors of other vertebrates. The mRNA of this receptor is broadly expressed in the lamprey brain, being especially abundant in hypothalamic areas. Its expression pattern is roughly similar to that reported for other vertebrates and parallels the expression pattern of the Y1 receptor subtype previously described by our group, as it occurs in mammals. Altogether, these results confirm that a Y5 receptor is present in lampreys, thus being highly conserved during the evolution of vertebrates, and suggest that it is involved in many brain functions, the only known exception being teleosts. Copyright © 2013 Wiley Periodicals, Inc.

  19. The effects of fasting and cold exposure on metabolic rate and mitochondrial proton leak in liver and skeletal muscle of an amphibian, the cane toad Bufo marinus.

    Science.gov (United States)

    Trzcionka, M; Withers, K W; Klingenspor, M; Jastroch, M

    2008-06-01

    Futile cycling of protons across the mitochondrial inner membrane contributes significantly to standard metabolic rate in a variety of ectothermic and endothermic animals, but adaptations of the mitochondrial bioenergetics to different environmental conditions have rarely been studied in ectotherms. Changes in ambient temperature and nutritional status have a great effect on the physiological demands of ectothermic amphibians and may require the adjustment of mitochondrial efficiency. In order to investigate the effect of temperature and nutritional status on the mitochondrial level, we exposed male cane toads to either 10 degrees C or 30 degrees C and fasted half of the animals in each group. Cold exposure resulted in a fourfold reduction of the resting metabolic rate whereas nutritional status had only minor effects. The mitochondrial adjustments to each condition were observed by comparing the proton leak kinetics of isolated liver and skeletal muscle mitochondria at 25 degrees C. In response to cold exposure, liver mitochondria showed a decrease in proton conductance while skeletal muscle mitochondria were unchanged. Additional food deprivation had minor effects in skeletal muscle, but in liver we uncovered surprising differences in energy saving mechanisms between the acclimation temperatures: in warm-acclimated toads, fasting resulted in a decrease of the proton conductance whereas in cold-acclimated toads, the activity of the respiratory chain was reduced. To investigate the molecular mechanism underlying mitochondrial proton leakage, we determined the adenine-nucleotide transporter (ANT) content, which explained tissue-specific differences in the basal proton leak, but neither the ANT nor uncoupling protein (UCP) gene expression correlated with alterations of the proton leak in response to physiological stimuli.

  20. Structural lipid changes and NKA activity of gill cells´ basolateral membranes as response to increasing salinity and atrazine stressors in sea lamprey (Petromyzon marinus, L. juveniles

    Directory of Open Access Journals (Sweden)

    Maria João Lança

    2015-12-01

    Modulation of BLM lipids associated with NKA activity seems to be the strategy adopted by gill cells of juveniles to compensate for osmotic and ionic stressors and for contact/resistance to ATZ exposure.

  1. Ultra-performance liquid chromatography tandem mass spectrometry for simultaneous determination of natural steroid hormones in sea lamprey (Petromyzon marinus) plasma and tissues.

    Science.gov (United States)

    Wang, Huiyong; Bussy, Ugo; Chung-Davidson, Yu-Wen; Li, Weiming

    2016-01-15

    This study aims to provide a rapid, sensitive and precise UPLC-MS/MS method for target steroid quantitation in biological matrices. We developed and validated an UPLC-MS/MS method to simultaneously determine 16 steroids in plasma and tissue samples. Ionization sources of Electrospray Ionization (ESI) and Atmospheric Pressure Chemical Ionization (APCI) were compared in this study by testing their spectrometry performances at the same chromatographic conditions, and the ESI source was found up to five times more sensitive than the APCI. Different sample preparation techniques were investigated for an optimal extraction of steroids from the biological matrices. The developed method exhibited excellent linearity for all analytes with regression coefficients higher than 0.99 in broad concentration ranges. The limit of detection (LOD) was from 0.003 to 0.1ng/mL. The method was validated according to FDA guidance and applied to determine steroids in sea lamprey plasma and tissues (fat and testes) by the developed method. Copyright © 2015. Published by Elsevier B.V.

  2. Protein (Cyanobacteria): 317781 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available etical protein NATL1_19671 Prochlorococcus marinus str. NATL1A MQAKTAQANKTAQANKKALAEKKAAADKKAAAEKKALAEKKAAAEKKALADKKAAAEKKALANKKALAD...KKAAAEKKAAAEKKALADKKAAAEKKALANKKALADKKAAAEKKAAAEKKALVDKKAAADKKAAAEKKALADKKAAAEKKAAAD

  3. Protein (Cyanobacteria): 72382929 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available hypothetical protein PMN2A_1091 Prochlorococcus marinus str. NATL2A MQAKTAQAAKKALADKKAAADKKALAEKKAAADKKALADKKAAAAKKALAEKKAAADKKALAD...KKAAAAKKALAEKKAAADKKAAADKKALADKKAAAAKKALAEKKAAADKKAAADKKALADKKAAAAKKALADKKAAADKKAAADKKALAD...KKAAADKKAAADKKALTDKKAAAAKKALAEKKAAADKKAAADKKALADKKAAAAKKALAEKKAAADKKAQARKKVNSPTQVNSQQKRDSRTELLTVSVSLNTGKIVSIASIGILASAILVSAMVFIAG

  4. Protein (Cyanobacteria): 124026672 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 83 ... hypothetical protein NATL1_19671 Prochlorococcus marinus str. NATL1A MQAKTAQANKTAQANKKALAEKKAAADKKAAAEKKALAEKKAAAEKKALAD...KKAAAEKKALANKKALADKKAAAEKKAAAEKKALADKKAAAEKKALANKKALADKKAAAEKKAAAEKKALVDKKAAADKKAAAEKKALADK

  5. Protein (Cyanobacteria): 317782 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available al protein PMN2A_1091 Prochlorococcus marinus str. NATL2A MQAKTAQAAKKALADKKAAADKKALAEKKAAADKKALADKKAAAAKKALAEKKAAADKKALAD...KKAAAAKKALAEKKAAADKKAAADKKALADKKAAAAKKALAEKKAAADKKAAADKKALADKKAAAAKKALADKKAAADKKAAADKKALADKKAAA...DKKAAADKKALTDKKAAAAKKALAEKKAAADKKAAADKKALADKKAAAAKKALAEKKAAADKKAQARKKVNSPTQVNSQQKRDSRTELLTVSVSLNTGKIVSIASIGILASAILVSAMVFIAG ...

  6. Protein (Cyanobacteria): 123968809 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 1:1113 ... metal-binding protein Prochlorococcus marinus str. AS9601 MALNKIFIKRGFLNYLIFSGILFTNIINPYKSIALTQENID...IPKVVSYRSASCGCCKKWINHLRANGLEVVDNIVEDVSVIKNQYQIPNNLRSCHSAQIANYMIEGHVPIESINKLFREKPNINGIAVPGMPLGSPGMEMHSHDSHSHDYENYKVVSFSKTGKTKIFDKISP

  7. Protein (Cyanobacteria): 126696075 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 46:693 ... hypothetical protein P9301_07371 Prochlorococcus marinus str. MIT 9301 MTLGGANVWTNFSYGYRNESPSGWLLSPDRTRLILFIRNKKSPRNSMRIFAHTYYANDLGEPMAIKSSTQMYLDNAWDKWHDLQLEGWTFEELELPESV

  8. Protein (Cyanobacteria): 432001 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available rotein S13p/S18e Prochlorococcus marinus str. MIT 9202 MARIAGIDIPREKRVEIALTYVYGIGLTRSKLILANTGVNPDTRVKDLSDSDVQKLRGATEEFTLEGDLRRKEGMALKRLQDIGCVRGRRHRMSLPVRGQRTRTNARTRRGSRKTVAGRKK ...

  9. Protein (Cyanobacteria): 124024156 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 2:360 ... hypothetical protein P9303_24671 Prochlorococcus marinus str. MIT 9303 MRGADLRDAHLIGVDLRDADLRGARLEGANLEGADLSGARLDDAQLNGAMLTNTELSGTDLRRADLREAVVINAYSPDVRTEGMQFAGADLTGSHLIYGGAP

  10. Forage fish, their fisheries and their predators: who drives whom?

    NARCIS (Netherlands)

    Engelhard, G.H.; Peck, M.A.; Rindorf, A.; Smout, S.C.; Deurs, van M.; Raab, K.E.; Andersen, K.H.; Garthe, S.; Lauerburg, R.A.M.; Scott, F.; Brunel, T.P.A.; Aarts, G.M.; Kooten, van T.; Dickey-Collas, M.

    2014-01-01

    The North Sea has a diverse forage fish assemblage, including herring, targeted for human consumption; sandeel, sprat, and Norway pout, exploited by industrial fisheries; and some sardine and anchovy, supporting small-scale fisheries. All show large abundance fluctuations, impacting on fisheries and

  11. Foraging decisions of sandwich terns in the presence of kleptoparasitising gulls

    NARCIS (Netherlands)

    Stienen, EWM; Brenninkmeijer, A

    We studied prey selection of Sandwich Terns (Sterna sandvicensis) in the presence of kleptoparasitising Black-headed Gulls (Larus ridibundus) on Griend, Dutch Wadden Sea, from 1992 to 1998. Most often, gulls robbed larger sandeels rather than herring from terns. Provided that one parent attends the

  12. Impacts of fisheries on seabird communities

    Directory of Open Access Journals (Sweden)

    Robert W. Furness

    2003-07-01

    Full Text Available Long-line by-catch of albatrosses and petrels may soon lead to species extinctions. Set-net bycatch has caused major reductions in certain seabird populations. Some fisheries may decrease numbers of seabirds by reducing abundance of prey-fish. Other fisheries may increase seabird numbers, by increasing prey-fish abundance through depletion of predatory fish stocks, or by provision of offal and discards. These latter impacts of fisheries on seabirds are often difficult to measure against a background of many and varied environmental and human influences. Depletion of stocks of small lipid-rich fish have reduced numbers of seabirds, in Peru, the Norwegian Sea, and the Barents Sea. However, reductions of predatory fish stocks in the North Sea have more than compensated for quantities of sandeels removed by the sandeel fishery. While piscivorous fish stocks remain low, sandeel fishery and seabirds appear to be able to coexist. However, if piscivorous fish stocks recover in the North Sea, reduced availability of sandeels to seabirds may affect certain species. Provision of discards and offal can stimulate large increases in scavenging seabird numbers. Desirable reductions in discard rates may have an unfortunate side-effect of forcing some scavenging seabirds to turn to killing smaller seabirds, with drastic consequences for community structure.

  13. THE USE OF THE ANTI-VENOM SPECIFIC ANTIBODIES ISOLATED FROM DUCK EGGS FOR INACTIVATION OF THE VIPER VENOM

    Directory of Open Access Journals (Sweden)

    ADRIANA CRISTE

    2008-05-01

    Full Text Available The activity of specific anti-venom can be demonstrated using protection test in laboratory mice. Our study aimed to emphasize the possibility of viper venom inactivation by the antibodies produced and isolated from duck eggs and also to the activation concentration of these antibodies. The venom used for inoculation was harvested from two viper species (Vipera ammodytes and Vipera berus. The immunoglobulin extract had a better activity on the venom from Vipera berus compared to the venom from Vipera ammodytes. This could be the result of a better immunological response, as consequence of the immunization with this type of venom, compared to the response recorded when the Vipera ammodytes venom was used. Besides the advantages of low cost, high productivity and reduced risk of anaphylactic shock, the duck eggs also have high activity up to dilutions of 1/16, 1/32, respectively, with specific activity and 100 surviving in individuals which received 3 x DL50.

  14. Papel de la metilación del ADN en el control del desarrollo y la estabilidad genómica en dos especies de peces anádromas (Petromyzon marinus y Salmo trutta)

    OpenAIRE

    Covelo Soto, Lara

    2015-01-01

    La epigenética es un campo en auge actualmente dentro de la investigación en Genética y Biología Molecular dada su gran importancia en el control de la expresión génica y mantenimiento estructural y funcional del genoma de muchos organismos. La modificación epigenética más estudiada es la metilación de ADN (5mC), consistente en la adicción de un grupo metilo a la posición 5' de un residuo de citosina. En vertebrados la metilación ocurre cuando la citosina está formando el dinucleótido CpG. Di...

  15. Protein (Cyanobacteria): 33861535 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 79:869 59919:869 hypothetical protein PMM0979 Prochlorococcus marinus subsp. pastoris str. CCMP1986 MSSAYYGIMKFEVKTQNDDLRNSSFSFLLIFAL...LSLIVILSNVSIKLGTISRYHEINYICRLLTIEKSSLNFKKLSKLTNLNTKQKMWDLCREIVN

  16. ORF Alignment: NC_005071 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available ... [Prochlorococcus marinus str. MIT 9313] ... Length = 98 ... Query: 25 ... AQRPRLAVFRSNNHIYAQVIDDEAQNTLCA...ASTLDKDLRTSLKADGSSCDASNAVGDLVA 84 ... AQRPRLAVFRSNNHIYAQVIDDEAQNTLCAAS...TLDKDLRTSLKADGSSCDASNAVGDLVA Sbjct: 1 ... AQRPRLAVFRSNNHIYAQVIDDEAQNTLCAASTLDKDLRTSLKADGSSCDASNAVGDLVA 60 ...

  17. Sand lance: a review of biology and predator relations and annotated bibliography.

    Science.gov (United States)

    Martin D. Robards; Mary F. Willson; Robert H. Armstrong; John F. Piatt

    2000-01-01

    Sand lance (Ammodytes) constitute a major prey for at least some populations of over 100 species of consumer, including 40 species of birds, 12 species of marine mammals, 45 species of fishes, and some invertebrates. Variation in the availability of sand lance (and other forage fishes) can have major effects on the breeding success and survival of...

  18. On a meeting between the Horn Viper and a Centipede in the Peloponnese, southern Greece  or the Biter, bit

    DEFF Research Database (Denmark)

    Tan, Kit; Kretzschmar, Horst

    2009-01-01

    Vipera ammodytes L., (the European Horn-Nosed Viper) is a small venomous snake occurring in southern L., (the European Horn-Nosed Viper) is a small venomous snake occurring in southern Europe. It was documented attacking Scolopendra cingulata Latreille (the venomous Mediterranean Banded Centipede...

  19. Habitat selection of juvenile cod (Gadus morhua), whiting (Merlangus merlangius) and some littoral fish in an aquarium. In: Flødevigen rapportserie no 1, 1987

    OpenAIRE

    Gjøsæter, Jakob

    1987-01-01

    Experiments were conducted to study the habit at selection of juvenile cod Gadus morhua, juvenile whiting merlangus merlangius, black goby Gobius niger, great pipefish Syngnathus acus, sand eel Ammodytes tobianus, butterfish Pholis gunnellus, three-spined stickleback Gasterosteus acculeatus, sea stickleback Spinachia spinachia, goldsinny Ctenolabrus rupestris, and flounder Plathichthys flesus. Aquaria with compartments with algae, with sand and with no substratum were us...

  20. Protein (Cyanobacteria): 33241177 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 1430 167539:1430 Recombinational DNA repair ATPase (RecF pathway) Prochlorococcus marinus subsp. marinus str... NP_876119.1 NC_005042 1117:4832 ... 1212:695 ... 1217:1707 1218:1707 1219:760 ... 142554:

  1. Protein (Cyanobacteria): 33239847 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 4:385 167539:385 Recombinational DNA repair protein RecO Prochlorococcus marinus subsp. marinus str. CCMP137... NP_874789.1 NC_005042 1117:2071 ... 1212:1695 ... 1217:2717 1218:2717 1219:1181 ... 14255

  2. Protein (Cyanobacteria): 33240548 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 4:973 167539:973 Recombinational DNA repair protein Prochlorococcus marinus subsp. marinus str. CCMP1375 MHL... NP_875490.1 NC_005042 1117:22466 ... 1212:1219 ... 1217:2078 1218:2078 1219:160 ... 14255

  3. NCBI nr-aa BLAST: CBRC-HSAP-05-0048 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-HSAP-05-0048 ref|YP_001041465.1| hypothetical protein Smar_1468 [Staphylothermus... marinus F1] gb|ABN70557.1| hypothetical protein Smar_1468 [Staphylothermus marinus F1] YP_001041465.1 0.052 24% ...

  4. NCBI nr-aa BLAST: CBRC-PMAR-01-0408 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PMAR-01-0408 ref|YP_001041101.1| alanyl-tRNA synthetase [Staphylothermus marin...us F1] gb|ABN70193.1| alanyl-tRNA synthetase [Staphylothermus marinus F1] YP_001041101.1 1.4 36% ...

  5. NCBI nr-aa BLAST: CBRC-XTRO-01-2187 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-2187 ref|YP_001040194.1| Citrate transporter [Staphylothermus marinus ...F1] gb|ABN69286.1| Citrate transporter [Staphylothermus marinus F1] YP_001040194.1 1.6 29% ...

  6. NCBI nr-aa BLAST: CBRC-DYAK-08-0013 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DYAK-08-0013 ref|YP_001041063.1| NADH/Ubiquinone/plastoquinone (complex I) [St...aphylothermus marinus F1] gb|ABN70155.1| NADH/Ubiquinone/plastoquinone (complex I) [Staphylothermus marinus F1] YP_001041063.1 6.0 30% ...

  7. Zooplankton mortality in 3D ecosystem modelling considering variable spatial–temporal fish consumptions in the North Sea

    DEFF Research Database (Denmark)

    Maar, Marie; Rindorf, Anna; Møller, Eva Friis

    2014-01-01

    . The fish larvae grazing pressure was obtained from a spatial, size-based larval community model. In this model, larvae, herring and sandeel were the most important fish predators on mesozooplankton, but these groups had different spatial and temporal (seasonal) distributions. Fish larvae were particularly...... dominant in the eastern and southern areas in early summer. Herring and sandeel had the highest consumption in the central and north-western areas and were more important in late summer. The fish index changed the perceived annual, seasonal and spatial patterns in modelled mesozooplankton biomass......We tested the feasibility of imposing mesozooplankton mortality into a 3D model based on estimated consumption rates of the dominant planktivorous fish in the North Sea-Kattegat area. The spatial biomass distribution of Atlantic herring (Clupea harengus), horse mackerel (Trachurus trachurus...

  8. Assessing the state of pelagic fish communities within an ecosystem approach and the European Marine Strategy Framework Directive

    DEFF Research Database (Denmark)

    Shephard, Samuel; Rindorf, Anna; Dickey-Collas, Mark

    2014-01-01

    Pelagic fish are key elements in marine foodwebs and thus comprise an important part of overall ecosystem health. We develop a suite of ecological indicators that track pelagic fish community state and evaluate state of specific objectives against Good Environmental Status (GES) criteria. Indicator....... The pelagic fish communities of both subregions currently appear to be close to GES, but each remains vulnerable. In the CS subregion, fishing mortality is close to the precautionary reference point, although the unknown dynamics of sandeel, sprat, and sardine in the subregion may reduce the robustness...... of this evaluation. In the North Sea, sandeel stocks have been in poor state until very recently. Pelagic fish community biomass is slightly below the precautionary reference point in both subregions...

  9. Snapshots of past fish faunas

    DEFF Research Database (Denmark)

    Enghoff, Inge Bødker; Ediger, Vedat

    2016-01-01

    Analyses of fish remains from sediment cores make it possible to detect not only commonly caught fish from prehistoric times, but also species without any economic importance, but with high value of paleaoecological reconstructions. In this study, fish bones from sediment cores reaching several...... thousand years back and taken in the Baltic and Black Seas were analysed. All fish remains dealt with postdate the last glaciations and are from the last marine/brackish stages of both seas. In the Baltic cores, 13+ species were found, the most abundant ones being sand-eel and clupeids (herring and sprat...... sand-eel and several (nearly) complete pipefish which could be identified to the endemic Syngnathus schmidti Popov, 1928. The results from the two seas exhibit common features. Thus, all species found are euryhaline, and species which are commercially important in our days were documented back in time...

  10. Towards an integrated forecasting system for fisheries on habitat-bound stocks

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Butenschön, M.; Gürkan, Z.

    2013-01-01

    First results of a coupled modelling and forecasting system for fisheries on habitat-bound stocks are being presented. The system consists currently of three mathematically, fundamentally different model subsystems coupled offline: POLCOMS providing the physical environment implemented...... and to quantify the impacts on the higher trophic level, in this case the sandeel population, demonstrated here on the basis of hindcast data. The coupled forecasting system is tested for some typical scientific questions appearing in spatial fish stock management and marine spatial planning, including...... in the domain of the north-west European shelf, the SPAM model which describes sandeel stocks in the North Sea, and the third component, the SLAM model, which connects POLCOMS and SPAM by computing the physical– biological interaction. Our major experience by the coupling model subsystems is that well...

  11. Unchanging diet in a stable colony: contemporary and past diet composition of black-legged kittiwakes Rissa tridactyla at Helgoland, south-eastern North Sea

    Science.gov (United States)

    Markones, Nele; Guse, Nils; Hüppop, Ommo; Garthe, Stefan

    2009-09-01

    In contrast to the situation at the west coast of the North Sea, the breeding colony of black-legged kittiwakes Rissa tridactyla at Helgoland in the south-eastern North Sea did not exhibit severe declines since 1990 but instead numbers increased and only lately stabilised. Declines at the west coast of the North Sea were attributed to a lower abundance and lower quality of the key prey, sandeels. We hypothesised that kittiwakes at Helgoland do not rely as heavily on sandeels as their conspecifics. We analysed stomach contents of nestlings and adults of 2001, 2002, 2004 and 2006. In concordance with earlier studies of the 1980s and 1990s, young whiting Merlangius merlangus was the most important prey species in 2001, 2002 and 2004. Clupeids and sandeels were consumed in lower proportions. While earlier studies suggested whiting to originate from fisheries discards, evidence now supports that kittiwakes prey upon whiting in areas of hydrographic fronts. No whiting was recovered in samples of 2006 and the proportion of fish prey was low. Main prey items were polychaete worms (Nereidae), which were presumably consumed as swarming Heteronereis stages. An observed strong rise in water temperature in summer 2006 might have influenced food availability of kittiwakes by inducing swarming of Nereidae. Overall, kittiwakes breeding on Helgoland showed a positive population trend for several decades while mainly feeding on whiting.

  12. Forage fish, their fisheries, and their predators: who drives whom?

    DEFF Research Database (Denmark)

    Engelhard, Georg H.; Peck, Myron A.; Rindorf, Anna

    2014-01-01

    The North Sea has a diverse forage fish assemblage, including herring, targeted for human consumption; sandeel, sprat, and Norway pout, exploited by industrial fisheries; and some sardine and anchovy, supporting small-scale fisheries. All show large abundance fluctuations, impacting on fisheries ...... with forage fish for zooplankton resources. In complex systems, changes in the impact of fisheries on forage fish may have potentially complex (and perhaps unanticipated) consequences on other commercially and/or ecologically important species...... exist, as in the North Sea. Sandeel appears to be the most important prey forage fish. Seabirds are most dependent on forage fish, due to specialized diet and distributional constraints (breeding colonies). Other than fisheries, key predators of forage fish are a few piscivorous fish species including......The North Sea has a diverse forage fish assemblage, including herring, targeted for human consumption; sandeel, sprat, and Norway pout, exploited by industrial fisheries; and some sardine and anchovy, supporting small-scale fisheries. All show large abundance fluctuations, impacting on fisheries...

  13. Species distribution modeling techniques as a tool in preliminary assessment of special nature reserve ,,Goč-Gvozdac’’

    Directory of Open Access Journals (Sweden)

    Čubrić, T.

    2016-09-01

    Full Text Available Effective conservation actions such as defining new nature reserve require accurate estimates of the spatial distributions of the target species. Species distribution models provide habitat suitability maps for studied species. In this paper we used Maxent software to estimate the distribution and extent of potential suitable habitat of five amphibian and reptilian species (Mesotriton alpestris, Bombina variegata, Testudo hermanni, Lacerta viridis and Vipera ammodytes in the special nature reserve “Goč-Gvozdac” (Central Serbia in order to assess how much of the potential habitats is included in this reserve. Comparing produced suitable habitat maps of the species with a map of the special nature reserve “Goč – Gvozdac” we concluded that the reserve boundaries do not coincide with the proposed distribution of suitable habitats for M. alpestris, T. hermanni, L. viridis and V. ammodytes, and therefore this reserve does not contribute much to the protection of local populations of these species.

  14. Snakebites of fingers or toes by viperidae family members: an orthopaedic approach.

    Science.gov (United States)

    Lykissas, Marios G; Koulouvaris, Panayiotis; Kostas-Agnantis, Ioannis; Gkiatas, Ioannis; Milionis, Haralampos J; Mavrodontidis, Alexandros N

    2011-04-01

    The purpose of this study was to review current principles of therapy for affected patients and determine whether an emergent surgical approach or expectant management should be selected in cases of snakebites of fingers or toes by Viperidae family members. Over the past five years (January 2004 to December 2009), 12 patients bitten by Vipera ammodytes were admitted in our department. We retrospectively reviewed their demographic and epidemiological characteristics as well as their symptoms, laboratory findings, and complications. All snake bites occurred at the extremities (fingers and toes). The main complications were oedema, disseminated intravascular coagulation, and decrease in haematocrit. None of the patients developed compartment syndrome or required surgical debridement. The majority of the patients with snakebites of fingers or toes by Vipera ammodytes can be treated conservatively. Surgery is indicated only in case of compartment syndrome, where fasciotomies should be performed without delay after diagnosis.

  15. Lijst van de Nederlandsche visschen aanwezig in 's Rijks Museum van Natuurlijke Historie te Leiden, tevens eene vermelding van de tot nu toe in en bij Nederland waargenomen visschen

    NARCIS (Netherlands)

    Popta, C.M.L.

    1924-01-01

    Afd.: CHORDATA. Groep III: CEPHALOCHORDATA. Fam.: BRANCHIOSTOMATIDAE. Branchiostoma lanceolata (Pallas) — slakprik, niet aanwezig. Groep IV: CRANIATA. Klasse: Marsipobranchii. Fam.: PETROMYZONIDAE. Petromyzon marinus L. — zeeprik. 1 ex. beschadigd, Noordzee, uit het oude kabinet, in spir. no. 4277.

  16. ORF Alignment: NC_005071 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available ... [Prochlorococcus marinus str. MIT 9313] ... Length = 121 ... Query: 1 ... MIQQESFLTVADNSGAKRIQCIRVLGSNRRYAHVGDVIVAAVKDAMP...NMXXXXXXXXXXX 60 ... MIQQESFLTVADNSGAKRIQCIRVLGSNRRYAHVGDVIVAAVKDAMP...NM ... Sbjct: 1 ... MIQQESFLTVADNSGAKRIQCIRVLGSNRRYAHVGDVIVAAVKDAMPNMSVKKSEVVKAV 60 ... Query: 121 I 121 ... I Sbjct: 121 I 121

  17. Mercury in fishes of the J.N. "Ding" Darling National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From June 26 to 30,1990 spotted gar (Lepisosteus oculatus), spotted seatrout (Cynoscion nebulosus), gafftopsail catfish (Bagre marinus), and largemouth bass...

  18. Mercury in fishes of the Chassahowitzka National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From August 24 to 28, 1990, spotted seatrout (Cynoscion nebulosus), hardhead catfish (Arius felis) and gafftopsail catfish (Bagre marinus) were collected from...

  19. Mercury concentrations in gafftopsail catfish and other fishes in waters adjacent to Hobe Sound National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From September 22-26, 1990, 20 gafftopsail catfish (Bagre marinus) and 3 other fish species (n=4) were collected from marine waters adjacent to Hobe Sound National...

  20. Protein (Cyanobacteria): 157414062 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available YP_001484928.1 NC_009840 1117:4682 ... 1212:1747 ... 1217:2782 1218:2782 1219:651 9306...0:1440 ... 7-cyano-7-deazaguanine reductase Prochlorococcus marinus str. MIT 9215 MSTAKLDDSTQRPLYGERIIKESKIICF

  1. Protein (Cyanobacteria): 157413751 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available biotics/polyketide fumonisin biosynthesis protein Prochlorococcus marinus str. MIT ... YP_001484617.1 NC_009840 1117:13736 ... 1212:2458 ... 1217:3581 1218:3581 1219:3751 93060:1222 ... mitomycin anti

  2. Protein (Cyanobacteria): 126696989 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 46:1402 ... 7-cyano-7-deazaguanine reductase Prochlorococcus marinus str. MIT 9301 MSKAKLDDSTQRPLYGERIIEESKIIC... YP_001091875.1 NC_009091 1117:4682 ... 1212:1747 ... 1217:2782 1218:2782 1219:651 1675

  3. Gene : CBRC-PMAR-01-0309 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available tromyzon marinus cDNA, mRNA sequence /gb=CO548425 /gi=51796737 /ug=Pma.8609 /len=962 3e-08 29% MLRVITVHVPCYYCTCSVLLLYTLCYYCTRSV...LLLYTFRVITVHVLLLYTFRVITVQCYYCTRSVLLLYTLRVITVHVLLLYTCYYCTRVITVHAPCYYCTRSVLLLYTLCYYCTRSV...LLLYTFSVITVHVVLLLYTFCVITVHVPCYYCTRSVLLLYTFRGITVHVLCYYCTRVITVHVPCYDCTRSVLLLYTFRVITVHVPCYNCTRSVLLLYTCYYCTRSV...FLLYTFRVITVHVLLLYTFRVITVHVLCCYCTRSVLLLYTCYYCTRSVLLLYTFRVITVXXXXFRVITVHV ...

  4. South African Journal of Geomatics - Vol 5, No 2 (2016)

    African Journals Online (AJOL)

    resolution orthophotos, point clouds and surface models for mapping wetlands · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Marinus Axel Boon, Richard Greenfield, Solomon Tesfamichael ...

  5. Gene : CBRC-PMAR-01-0132 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available Petromyzon marinus cDNA 3', mRNA sequence /clone_end=3' /gb=EE276047 /gi=111173437 /ug=Pma.1199 /len=495 0.004 30% MRPVI...TRPIIATPIITAHILTARVITRPVITRPVIATPIITAHILTARVITRPVITSAVIATPIITAHILTAPVITRPIITSPVI...ATPIITAHILTAPVITRPVITSPVIATPIITAHILTAPVITRPVITSAVIATPIITAHILTAPVITRPVITSAVIATPIITAHILTARVITGSVTTRAVMTCPWRTCLPSGLAVQHVCN ...

  6. Immunological Cross-Reactivity and Neutralisation of European Viper Venoms with the Monospecific Vipera berus Antivenom ViperaTAb

    Directory of Open Access Journals (Sweden)

    Nicholas R. Casewell

    2014-08-01

    Full Text Available Medically important cases of snakebite in Europe are predominately caused by European vipers of the genus Vipera. The mainstay of snakebite therapy is polyclonal antibody therapy, referred to as antivenom. Here we investigate the capability of the monospecific V. berus antivenom, ViperaTAb®, to cross-react with, and neutralise lethality induced by, a variety of European vipers. Using ELISA and immunoblotting, we find that ViperaTAb® antibodies recognise and bind to the majority of toxic components found in the venoms of the Vipera species tested at comparably high levels to those observed with V. berus. Using in vivo pre-clinical efficacy studies, we demonstrate that ViperaTAb® effectively neutralises lethality induced by V. berus, V. aspis, V. ammodytes and V. latastei venoms and at much higher levels than those outlined by regulatory pharmacopoeial guidelines. Notably, venom neutralisation was found to be superior to (V. berus, V. aspis and V. latastei, or as equally effective as (V. ammodytes, the monospecific V. ammodytes “Zagreb antivenom”, which has long been successfully used for treating European snake envenomings. This study suggests that ViperaTAb® may be a valuable therapeutic product for treating snakebite by a variety of European vipers found throughout the continent.

  7. Immunological Cross-Reactivity and Neutralisation of European Viper Venoms with the Monospecific Vipera berus Antivenom ViperaTAb

    Science.gov (United States)

    Casewell, Nicholas R.; Al-Abdulla, Ibrahim; Smith, David; Coxon, Ruth; Landon, John

    2014-01-01

    Medically important cases of snakebite in Europe are predominately caused by European vipers of the genus Vipera. The mainstay of snakebite therapy is polyclonal antibody therapy, referred to as antivenom. Here we investigate the capability of the monospecific V. berus antivenom, ViperaTAb®, to cross-react with, and neutralise lethality induced by, a variety of European vipers. Using ELISA and immunoblotting, we find that ViperaTAb® antibodies recognise and bind to the majority of toxic components found in the venoms of the Vipera species tested at comparably high levels to those observed with V. berus. Using in vivo pre-clinical efficacy studies, we demonstrate that ViperaTAb® effectively neutralises lethality induced by V. berus, V. aspis, V. ammodytes and V. latastei venoms and at much higher levels than those outlined by regulatory pharmacopoeial guidelines. Notably, venom neutralisation was found to be superior to (V. berus, V. aspis and V. latastei), or as equally effective as (V. ammodytes), the monospecific V. ammodytes “Zagreb antivenom”, which has long been successfully used for treating European snake envenomings. This study suggests that ViperaTAb® may be a valuable therapeutic product for treating snakebite by a variety of European vipers found throughout the continent. PMID:25153254

  8. Effects of environmental exposure and diet on levels of persistent organic pollutants (POPs) in eggs of a top predator in the North Atlantic in 1980 and 2008

    Energy Technology Data Exchange (ETDEWEB)

    Leat, Eliza H.K. [College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Bourgeon, Sophie [Norwegian Institute for Nature Research, FRAM Centre, 9296 Tromso (Norway); Borga, Katrine [Norwegian Institute for Water Research, Gaustadalleen 21, 0349 Oslo (Norway); Strom, Hallvard [Norwegian Polar Institute, FRAM Centre, 9296 Tromso (Norway); Hanssen, Sveinn A. [Norwegian Institute for Nature Research, FRAM Centre, 9296 Tromso (Norway); Gabrielsen, Geir W. [Norwegian Polar Institute, FRAM Centre, 9296 Tromso (Norway); Petersen, AEvar [Icelandic Institute of Natural History, IS-105 Reykjavik (Iceland); Olafsdottir, Kristin; Magnusdottir, Ellen [University of Iceland, Department of Pharmacology and Toxicology, IS-107 Reykjavik (Iceland); Fisk, Aaron T.; Ellis, Sandra [Great Lakes Institute of Environmental Research, University of Windsor, Windsor, Ontario, N9B 3P4 (Canada); Bustnes, Jan O. [Norwegian Institute for Nature Research, FRAM Centre, 9296 Tromso (Norway); Furness, Robert W., E-mail: bob.furness@glasgow.ac.uk [College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2011-05-15

    Concentrations of POPs in Great skua eggs from Shetland are among the highest in North Atlantic seabirds, with up to 11,600 {mu}g/kg (ww) DDE and up to 17,900 {mu}g/kg ww {Sigma}PCB. Concentrations of legacy POPs were significantly lower in 2008 than 1980. Decreases were greatest for least persistent compounds. Median {Sigma}PBDEs increased from 99 {mu}g/kg ww in 1980 to 173 {mu}g/kg ww in 2008. There were changes in Great skua breeding season diet, with more adult Herring and Mackerel and less Sandeel. These changes increase exposure to POPs, since Herring and Mackerel accumulate more POPs than Sandeels. In both years, eggs with higher {delta}{sup 15}N had higher POP concentrations. In 1980, birds feeding more on demersal discard fish from trawl fisheries and less on Sandeels, had higher POP levels in eggs. In 2008, individuals feeding more on Herring and Mackerel, and less on discards, had higher POP levels in eggs. - Highlights: > POP levels in Great skua eggs are among the highest in North Atlantic seabirds. > Legacy POPs decreased from 1980 to 2008 but PBDEs increased. > Decreases in legacy POPs were greatest for least persistent compounds. > Levels in eggs varied between nests according to diets of individual females. > Levels of POPs were influenced slightly by changes in diet between decades. - Great skua eggs from Shetland show a decrease in legacy POPs and an increase in PBDEs between 1980 and 2008, and an influence of diet composition.

  9. Towards an integrated forecasting system for fisheries on habitat-bound stocks

    Science.gov (United States)

    Christensen, A.; Butenschön, M.; Gürkan, Z.; Allen, I. J.

    2013-03-01

    First results of a coupled modelling and forecasting system for fisheries on habitat-bound stocks are being presented. The system consists currently of three mathematically, fundamentally different model subsystems coupled offline: POLCOMS providing the physical environment implemented in the domain of the north-west European shelf, the SPAM model which describes sandeel stocks in the North Sea, and the third component, the SLAM model, which connects POLCOMS and SPAM by computing the physical-biological interaction. Our major experience by the coupling model subsystems is that well-defined and generic model interfaces are very important for a successful and extendable coupled model framework. The integrated approach, simulating ecosystem dynamics from physics to fish, allows for analysis of the pathways in the ecosystem to investigate the propagation of changes in the ocean climate and to quantify the impacts on the higher trophic level, in this case the sandeel population, demonstrated here on the basis of hindcast data. The coupled forecasting system is tested for some typical scientific questions appearing in spatial fish stock management and marine spatial planning, including determination of local and basin-scale maximum sustainable yield, stock connectivity and source/sink structure. Our presented simulations indicate that sandeel stocks are currently exploited close to the maximum sustainable yield, even though periodic overfishing seems to have occurred, but large uncertainty is associated with determining stock maximum sustainable yield due to stock inherent dynamics and climatic variability. Our statistical ensemble simulations indicates that the predictive horizon set by climate interannual variability is 2-6 yr, after which only an asymptotic probability distribution of stock properties, like biomass, are predictable.

  10. Towards an integrated forecasting system for fisheries on habitat-bound stocks

    Directory of Open Access Journals (Sweden)

    A. Christensen

    2013-03-01

    Full Text Available First results of a coupled modelling and forecasting system for fisheries on habitat-bound stocks are being presented. The system consists currently of three mathematically, fundamentally different model subsystems coupled offline: POLCOMS providing the physical environment implemented in the domain of the north-west European shelf, the SPAM model which describes sandeel stocks in the North Sea, and the third component, the SLAM model, which connects POLCOMS and SPAM by computing the physical–biological interaction. Our major experience by the coupling model subsystems is that well-defined and generic model interfaces are very important for a successful and extendable coupled model framework. The integrated approach, simulating ecosystem dynamics from physics to fish, allows for analysis of the pathways in the ecosystem to investigate the propagation of changes in the ocean climate and to quantify the impacts on the higher trophic level, in this case the sandeel population, demonstrated here on the basis of hindcast data. The coupled forecasting system is tested for some typical scientific questions appearing in spatial fish stock management and marine spatial planning, including determination of local and basin-scale maximum sustainable yield, stock connectivity and source/sink structure. Our presented simulations indicate that sandeel stocks are currently exploited close to the maximum sustainable yield, even though periodic overfishing seems to have occurred, but large uncertainty is associated with determining stock maximum sustainable yield due to stock inherent dynamics and climatic variability. Our statistical ensemble simulations indicates that the predictive horizon set by climate interannual variability is 2–6 yr, after which only an asymptotic probability distribution of stock properties, like biomass, are predictable.

  11. Diet composition and food consumption rate of harbor porpoises (Phocoena phocoena ) in the western Baltic Sea

    DEFF Research Database (Denmark)

    Andreasen, Heidi; Ross, Stine Dalmann; Siebert, Ursula

    2017-01-01

    prey and in particular otoliths. The bias originating from differential residence time of otoliths in the stomachs was addressed by use of a recently developed approach. Atlantic cod and herring were the main prey of adults, constituting on average 70% of the diet mass. Juvenile porpoises also...... frequently consumed gobies. Here, the mass contribution by gobies was on aver-age 25%, which was as much as cod. Other species such as whiting, sprat, eelpout, and sandeels were of minor importance for both juveniles and adults. The diet compo- sition differed between years, quarters, and porpoise...

  12. Ofidizam i liječenje – povodom nazočnosti novih vrsta otrovnih zmija u Zoološkom vrtu grada Zagreba i privatnim herpetarijima

    OpenAIRE

    Maretić, Tomislav; Cizelj, Ivan; Čivljak, Rok

    2013-01-01

    Među 15 vrsta zmija koje žive u Hrvatskoj tri su vrste otrovne: poskok (Vipera ammodytes), riđovka (Vipera berus) i planinski žutokrug (Vipera ursinii), a sve pripadaju porodici ljutica (Viperidae). Njihov je otrov pretežno hemotoksičan, iako su ustanovljeni elementi neurotoksičnosti i kardiotoksičnosti. Premda njihov ugriz predstavlja veliki zdravstveni problem smrtni slučajevi su razmjerno rijetki. Nedavno uvođenje novih vrsta otrovnica u Zooološki vrt grada Zagreba, kao i izložbe svjetskih...

  13. Assessment of virally vectored autoimmunity as a biocontrol strategy for cane toads.

    Directory of Open Access Journals (Sweden)

    Jackie A Pallister

    Full Text Available BACKGROUND: The cane toad, Bufo (Chaunus marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner. METHODOLOGY/PRINCIPAL FINDINGS: The adult beta globin gene was selected as the model gene for proof of concept of autoimmunity as a biocontrol method for cane toads. A previous report showed injection of bullfrog tadpoles with adult beta globin resulted in an alteration in the form of beta globin expressed in metamorphs as well as reduced survival. In B. marinus we established for the first time that the switch from tadpole to adult globin exists. The effect of injecting B. marinus tadpoles with purified recombinant adult globin protein was then assessed using behavioural (swim speed in tadpoles and jump length in metamorphs, developmental (time to metamorphosis, weight and length at various developmental stages, protein profile of adult globin and genetic (adult globin mRNA levels measures. However, we were unable to detect any differences between treated and control animals. Further, globin delivery using Bohle iridovirus, an Australian ranavirus isolate belonging to the Iridovirus family, did not reduce the survival of metamorphs or alter the form of beta globin expressed in metamorphs. CONCLUSIONS/SIGNIFICANCE: While we were able to show for the first time that the switch from tadpole to adult globin does occur in B. marinus, we were not able to induce autoimmunity and disrupt metamorphosis. The short development time of B. marinus tadpoles may preclude this approach.

  14. Assessment of virally vectored autoimmunity as a biocontrol strategy for cane toads.

    Science.gov (United States)

    Pallister, Jackie A; Halliday, Damien C T; Robinson, Anthony J; Venables, Daryl; Voysey, Rhonda D; Boyle, Donna G; Shanmuganathan, Thayalini; Hardy, Christopher M; Siddon, Nicole A; Hyatt, Alex D

    2011-01-25

    The cane toad, Bufo (Chaunus) marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner. The adult beta globin gene was selected as the model gene for proof of concept of autoimmunity as a biocontrol method for cane toads. A previous report showed injection of bullfrog tadpoles with adult beta globin resulted in an alteration in the form of beta globin expressed in metamorphs as well as reduced survival. In B. marinus we established for the first time that the switch from tadpole to adult globin exists. The effect of injecting B. marinus tadpoles with purified recombinant adult globin protein was then assessed using behavioural (swim speed in tadpoles and jump length in metamorphs), developmental (time to metamorphosis, weight and length at various developmental stages, protein profile of adult globin) and genetic (adult globin mRNA levels) measures. However, we were unable to detect any differences between treated and control animals. Further, globin delivery using Bohle iridovirus, an Australian ranavirus isolate belonging to the Iridovirus family, did not reduce the survival of metamorphs or alter the form of beta globin expressed in metamorphs. While we were able to show for the first time that the switch from tadpole to adult globin does occur in B. marinus, we were not able to induce autoimmunity and disrupt metamorphosis. The short development time of B. marinus tadpoles may preclude this approach.

  15. AcEST: BP920786 [AcEST

    Lifescience Database Archive (English)

    Full Text Available le lymphocyte receptor A diversity region (Fragment) OS=Petromyzon marinus Align length 58 Score (bit) 33.9 ...) Value tr|A5H6P2|A5H6P2_PETMA Variable lymphocyte receptor A diversity ... 34 4.1 >tr|A5H6P2|A5H6P2_PETMA V...ariable lymphocyte receptor A diversity region (Fragment) OS=Petromyzon marinus GN=VLRA PE=2 SV=1 Length = 2

  16. Sand lance: A review of biology and predator relations and annotated bibliography

    Science.gov (United States)

    Robards, Martin D.; Willson, Mary F.; Armstrong, Robert H.; Piatt, John F.

    1999-01-01

    Six species of sand lance (Ammodytes) in temperate and boreal regions are currently recognized. Sand lance can occupy a wide range of environmental conditions, but all appear to be dormant predominantly in winter, and one species is in summer also. They lack a swim bladder and spend much of their time buried in specific substrates. Copepods are the primary food. Spawning usually occurs in fall or winter (although some species also spawn in spring), eggs are demersal, and larvae may hatch at times of low food abundance. Sand lance usually occur in schools and are regarded as a relatively high-quality forage fish.Sand lance constitute a major prey for at least some populations of over 100 species of consumer, including 40 species of birds, 12 species of marine mammals, 45 species of fishes, and some invertebrates. Variation in the availability of sand lance (and other forage fishes) can have major effects on the breeding success and survival of their predators. Commercial fishing and other pressures on sand lance populations potentially have ramifying effects on many species of wildlife.The bibliography contains over 1,700 references on the family Ammodytidae, with an emphasis on the genus Ammodytes. Keywords are provided for each reference and have been further organized into taxonomic, geographic, subject, and predator indexes.

  17. Heterodimeric neurotoxic phospholipases A2--the first proteins from venom of recently established species Vipera nikolskii: implication of venom composition in viper systematics.

    Science.gov (United States)

    Ramazanova, Anna S; Zavada, Larisa L; Starkov, Vladislav G; Kovyazina, Irina V; Subbotina, Tatyana F; Kostyukhina, Ekaterina E; Dementieva, Irina N; Ovchinnikova, Tatiana V; Utkin, Yuri N

    2008-03-15

    For the first time the venom of recently established viper species Vipera nikolskii was fractionated and two heterodimeric phospholipases A(2) (HDP-1 and HDP-2) were isolated. Isolation of HDP-1 and HDP-2 is the first indication of the presence of two heterodimeric phospholipases A(2) in the venom of one viper species. When tested on the frog neuromuscular junction, isolated proteins affected neuromuscular transmission acting presynaptically. Using RP-HPLC, each heterodimer was separated into two monomeric subunits: basic phospholipase A(2) (HDP-1P and HDP-2P) and acidic component without enzymatic activity (HDP-In). The complete primary structures of subunits were deduced from corresponding sequences of cDNAs. The determined amino acid sequences were homologous to those of vipoxin from Vipera ammodytes and vaspin from Vipera aspis. Similar proteins were not found earlier in the well-studied venom of Vipera berus, the species from which V. nikolskii was recently separated. Our finding supports at the biochemical level the correctness of the establishment of V. nikolskii as an independent species. The finding of similar proteins (HDPs and vipoxin) in geographically remote species (V. nikolskii and V. ammodytes) corroborates the hypothesis about the pre-existence of genes encoding these proteins in all true viper species and their expression under certain conditions.

  18. Unusual neurotoxic envenomations by Vipera aspis aspis snakes in France.

    Science.gov (United States)

    de Haro, L; Robbe-Vincent, A; Saliou, B; Valli, M; Bon, C; Choumet, V

    2002-03-01

    Vipera aspis aspis (V.a.a.) is the most dangerous poisonous snake in South-Eastern France. The clinical symptoms observed after V.a.a. envenomations involve mostly local signs (pain, edema) associated in the more severe cases with systemic symptoms (gastro-intestinal and cardiovascular manifestations). Since 1992, several unusual cases of moderate and severe 'neurotoxic' envenomations by V.a.a. snakes have been reported in a very localized area in South-Eastern France. Most of the human patients mainly suffered neurological signs owing to cephalic muscle paralysis. Drowsiness and dyspnea were observed for the most severe cases. Envenomed animals suffered respiratory distress and paralysis. The local signs were never as severe as observed after envenomations by vipers in other French regions. Human patients with moderate or severe clinical features received two intravenous injections of Viperfav antivenom, the first dose inducing the decrease of the neurological signs and the second reducing significantly the edema. Neurotoxic components immunologically cross-reacting with toxins from V. ammodytes ammodytes venom from Eastern Europe were detected in the blood of all patients suffering neurological symptoms after a V.a.a. bite. The protective efficacy of various antivenoms was evaluated in mice. The existence of geographical variations in the composition of V.a.a. venom emphasizes on the use of polyvalent antivenom in the treatment of viper envenomations in France.

  19. Magnet measuring equipment of SC2

    CERN Multimedia

    1974-01-01

    Checking the positioning of the magnet measuring equipment installed between the poles of SC2. The steel structure in front of the magnet is designed to house the rotary condenser and to shield it from the stray magnetic field of the accelerator. On the left, Marinus van Gulik. (See Photo Archive 7402005 and Annual Report 1974, p. 44.)

  20. Mechanical properties of the hindlimb bones of bullfrogs and cane toads in bending and torsion.

    Science.gov (United States)

    Wilson, Megan P; Espinoza, Nora R; Shah, Sagar R; Blob, Richard W

    2009-07-01

    When compared with most vertebrates, frogs use a novel style of jumping locomotion powered by the hindlimbs. Hindlimb bones of frogs must withstand the potentially erratic loads associated with such saltatory locomotion. To evaluate the load bearing capacity of anuran limb bones, we used three-point bending, torsion, and hardness tests to measure the mechanical properties of the femur and tibiofibula from adults of two species that use different jumping styles: explosively jumping bullfrogs (Rana (Lithobates) catesbeiana) and cyclically hopping cane toads (Bufo (Chaunus) marinus). Yield stress and strain values for R. catesbeiana and B. marinus hindlimb bones are within the range of values previously reported for other vertebrates. However, anuran hindlimb bones generally stand out as having higher yield stresses in bending than those of closely related, nonsaltatory salamanders, highlighting the importance of considering phylogenetic context in comparisons of bone functional capacity and adaptation. Stiffness values for both frog species tested were also high, which may facilitate efficient transmission of muscular forces while jumping. Elevated stiffness may also contribute to some discrepancies between determinations of bone properties via hardness versus bending tests. In comparisons between species, B. marinus bones showed significantly higher bending yield stresses than R. catesbeiana, whereas R. catesbeiana bones showed significantly higher torsional yield stresses than B. marinus. These differences may correlate with differences in jumping style and limb anatomy between ranid and bufonid frogs, suggesting that evolutionary changes in bone mechanical properties may help to accommodate new functional demands that emerge in lineages.

  1. Dicty_cDB: Contig-U15561-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Amphidinium carterae Amphidinium carterae c... 42 0.46 3 ( CF067288 ) Ac623 Amphidinium carterae Amphidinium...Amphidinium carterae c... 42 0.48 3 ( FD709253 ) CAAA15312.fwd CAAA Petromyzon marinus Petromyzon ... 36 0.48

  2. Ze Slovníku středověké latiny: sporcia

    Czech Academy of Sciences Publication Activity Database

    Šedinová, Hana

    2017-01-01

    Roč. 140, 1/2 (2017), s. 233-245 ISSN 0024-4457 Institutional support: RVO:67985955 Keywords : porcus marinus * Latin lexicography * ancient and medieval zoology * Latin names of marine animals * Bartholomaeus de Solencia dictus Claretus * Pliny the Elder * Isidorus of Sevilla * Thomas of Cantimpré Subject RIV: AI - Linguistics OBOR OECD: Specific languages

  3. Unigene BLAST: CBRC-PMAR-01-0197 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,666) /gb=EF094725 /gi=126570532 /ug=Pma.9441 /len=666 0.053 30% ... ...CBRC-PMAR-01-0197 gnl|UG|Pma#S38438288 Petromyzon marinus isolate PmVLRA.22 variabl

  4. Unigene BLAST: CBRC-PMAR-01-0342 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,660) /gb=EF094756 /gi=126570624 /ug=Pma.9410 /len=660 2.2 23% ... ...CBRC-PMAR-01-0342 gnl|UG|Pma#S38438257 Petromyzon marinus isolate PmVLRA.C6 variabl

  5. Unigene BLAST: CBRC-PMAR-01-0149 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,681) /gb=EF094735 /gi=126570563 /ug=Pma.9431 /len=681 4.8 43% ... ...CBRC-PMAR-01-0149 gnl|UG|Pma#S38438278 Petromyzon marinus isolate PmVLRA.34 variabl

  6. Apuntes sobre la reproduccion de algunos Bagres marinos

    NARCIS (Netherlands)

    Luengo, José A.

    1973-01-01

    Mouthbreeding in the male, and modifications of the pelvic fins of the female are recorded for the first time in Selenaspis herzbergii. The pelvic girdle of Selenaspis herzbergii is compared with those of Sciadeichthys proops, Arius spixii, and Bagre marinus. Data are given on eggs and fry in the

  7. Does Implicit Learning in Non-Demented Parkinson's Disease depend on the Level of Cognitive Functioning?

    Science.gov (United States)

    Vandenbossche, Jochen; Deroost, Natacha; Soetens, Eric; Kerckhofs, Eric

    2009-01-01

    We investigated the influence of the level of cognitive functioning on sequence-specific learning in Parkinson's disease (PD). This was done by examining the relationship between the scales for outcomes in Parkinson's disease-cognition [SCOPA-COG, Marinus, J., Visser, M., Verwey, N. A., Verhey, F. R. J., Middelkoop, H. A. M.,Stiggelbout, A., et…

  8. Antiproliferative and antibacterial activity evaluation of red ...

    African Journals Online (AJOL)

    Antiproliferative activity of three extracts obtained from red microalgae Rhodosorus marinus was evaluated against cervical (HeLa), colon (HCT 116), lung (A549), prostate (22Rv-1) and breast (HCC38 and MDA-MB-231) cancer cell lines. Antibacterial activity of these extracts was also tested against Salmonella ...

  9. Protein (Cyanobacteria): 33862149 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available NP_893710.1 NC_005072 1117:324 ... 1212:985 ... 1217:1728 1218:1728 1219:776 ... 142479:683 59919:683 dihydrobiliv...erdin:ferredoxin oxidoreductase Prochlorococcus marinus subsp. pastoris str. CCMP19

  10. Paracoccus niistensis sp. nov., isolated from forest soil, India

    Digital Repository Service at National Institute of Oceanography (India)

    Dastager, S.G.; Deepa, C.K.; Li, Wen-Jun; Tang, Shu-Kun; Pandey, A.

    (T) belongs to the subclass alpha-Proteobacteria, being related to the genus Paracoccus, and sharing highest sequence similarity with Paracoccus chinensis NBRC 104937 sup(T) (99.4%), Paracoccus marinus NBRC 100640 sup(T) (97.3%), Paracoccus koreensis Ch05 sup...

  11. Dicty_cDB: Contig-U15713-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available A-FP_179303 WHMH (pink hibiscus mealybug) Maco... 38 1.1 2 ( CP000825 ) Prochlorococcus marinus str. MIT 921...IN... 34 0.98 2 ( AC151817 ) Medicago truncatula clone mth2-10f23, WORKING DRA... 38 0.99 6 ( EH216506 ) USD

  12. Development of a symptoms questionnaire for complex regional pain syndrome and potentially related illnesses: the Trauma Related Neuronal Dysfunction Symptoms Inventory

    NARCIS (Netherlands)

    Collins, S.; van Hilten, J.J.; Marinus, J.J.; Zuurmond, W.W.A.; de Lange, J.J.; Perez, R.S.G.M.

    2008-01-01

    Collins S, van Hilten JJ, Marinus J, Zuurmond WW, de Lange JJ, Perez RS. Development of a symptoms questionnaire for complex regional pain syndrome and potentially related illnesses: the Trauma Related Neuronal Dysfunction Symptoms Inventory. Objective: To develop a questionnaire to evaluate

  13. Unigene BLAST: CBRC-PMAR-01-0149 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,591) /gb=EF094746 /gi=126570596 /ug=Pma.9420 /len=591 4.8 43% ... ...CBRC-PMAR-01-0149 gnl|UG|Pma#S38438267 Petromyzon marinus isolate PmVLRA.B3 variabl

  14. Unigene BLAST: CBRC-PMAR-01-0669 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,660) /gb=EF094732 /gi=126570554 /ug=Pma.9434 /len=660 4.1 50% ... ...CBRC-PMAR-01-0669 gnl|UG|Pma#S38438281 Petromyzon marinus isolate PmVLRA.30 variabl

  15. Unigene BLAST: CBRC-PMAR-01-0149 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,660) /gb=EF094756 /gi=126570624 /ug=Pma.9410 /len=660 4.8 43% ... ...CBRC-PMAR-01-0149 gnl|UG|Pma#S38438257 Petromyzon marinus isolate PmVLRA.C6 variabl

  16. Unigene BLAST: CBRC-PMAR-01-0566 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,741) /gb=EF094755 /gi=126570621 /ug=Pma.9411 /len=741 3e-04 35% ... ...CBRC-PMAR-01-0566 gnl|UG|Pma#S38438258 Petromyzon marinus isolate PmVLRA.C5 variabl

  17. Unigene BLAST: CBRC-PMAR-01-0572 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,660) /gb=EF094807 /gi=126570727 /ug=Pma.9360 /len=660 0.049 27% ... ...CBRC-PMAR-01-0572 gnl|UG|Pma#S38438206 Petromyzon marinus isolate PmVLRA.H7 variabl

  18. Unigene BLAST: CBRC-PMAR-01-0572 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,738) /gb=EF094776 /gi=126570665 /ug=Pma.9391 /len=738 0.049 29% ... ...CBRC-PMAR-01-0572 gnl|UG|Pma#S38438237 Petromyzon marinus isolate PmVLRA.E4 variabl

  19. Unigene BLAST: CBRC-PMAR-01-0572 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,660) /gb=EF094733 /gi=126570557 /ug=Pma.9433 /len=660 7e-04 30% ... ...CBRC-PMAR-01-0572 gnl|UG|Pma#S38438280 Petromyzon marinus isolate PmVLRA.31 variabl

  20. Unigene BLAST: CBRC-PMAR-01-0149 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,663) /gb=EF094740 /gi=126570578 /ug=Pma.9426 /len=663 4.8 43% ... ...CBRC-PMAR-01-0149 gnl|UG|Pma#S38438273 Petromyzon marinus isolate PmVLRA.A5 variabl

  1. Unigene BLAST: CBRC-PMAR-01-0149 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,666) /gb=EF094716 /gi=126570506 /ug=Pma.9450 /len=666 2.2 35% ... ...CBRC-PMAR-01-0149 gnl|UG|Pma#S38438297 Petromyzon marinus isolate PmVLRA.9 variable

  2. Unigene BLAST: CBRC-PMAR-01-0572 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,660) /gb=EF094779 /gi=126570671 /ug=Pma.9388 /len=660 0.037 26% ... ...CBRC-PMAR-01-0572 gnl|UG|Pma#S38438234 Petromyzon marinus isolate PmVLRA.E7 variabl

  3. Unigene BLAST: CBRC-PMAR-01-0203 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,663) /gb=EF094798 /gi=126570709 /ug=Pma.9369 /len=663 0.006 31% ... ...CBRC-PMAR-01-0203 gnl|UG|Pma#S38438215 Petromyzon marinus isolate PmVLRA.G7 variabl

  4. Unigene BLAST: CBRC-PMAR-01-0852 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,666) /gb=EF094721 /gi=126570521 /ug=Pma.9445 /len=666 4e-08 27% ... ...CBRC-PMAR-01-0852 gnl|UG|Pma#S38438292 Petromyzon marinus isolate PmVLRA.17 variabl

  5. Unigene BLAST: CBRC-PMAR-01-0433 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,660) /gb=EF094733 /gi=126570557 /ug=Pma.9433 /len=660 1.2 28% ... ...CBRC-PMAR-01-0433 gnl|UG|Pma#S38438280 Petromyzon marinus isolate PmVLRA.31 variabl

  6. Unigene BLAST: CBRC-PMAR-01-0149 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,669) /gb=EF094780 /gi=126570673 /ug=Pma.9387 /len=669 3.7 43% ... ...CBRC-PMAR-01-0149 gnl|UG|Pma#S38438233 Petromyzon marinus isolate PmVLRA.E8 variabl

  7. Unigene BLAST: CBRC-PMAR-01-0172 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available e lymphocyte receptor A diversity region (VLRA) mRNA, partial cds /cds=p(1,591) /gb=EF094765 /gi=126570643 /ug=Pma.9402 /len=591 8.8 28% ... ...CBRC-PMAR-01-0172 gnl|UG|Pma#S38438248 Petromyzon marinus isolate PmVLRA.D4 variabl

  8. Postmortem proteome degradation profiles of longissimus muscle in Yorkshire and Duroc pigs and their relationship with pork quality traits

    NARCIS (Netherlands)

    te Pas, M.F.W.; Jansen, J; Broekman, K.C.J.A.; Reimert, H.; Heuven, H.C.M.

    2009-01-01

    doi:10.1016/j.meatsci.2009.08.030 Copyright © 2009 Elsevier Ltd All rights reserved. Postmortem proteome degradation profiles of longissimus muscle in Yorkshire and Duroc pigs and their relationship with pork quality traits Marinus F.W. te Pasa, , , Jaap Jansena, Konrad C.J.A. Broekmanb, Henny

  9. Author Details

    African Journals Online (AJOL)

    Boon, Marinus Axel. Vol 5, No 2 (2016) - Articles Unmanned Aerial Vehicle (UAV) photogrammetry produces accurate high-resolution orthophotos, point clouds and surface models for mapping wetlands. Abstract PDF. ISSN: 2225-8531. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

  10. Generositeit en lewenskuns

    African Journals Online (AJOL)

    p1243322

    of moral values; The aristocrat; Hannah Arendt's view on the public- political realm and private sphere; Plurality and conformity. 1. INLEIDING. Marinus Schoeman het 'n lang verbintenis met die Universiteit van Pretoria. In. 1969 skryf hy in as eerstejaarstudent en bly daar aan eers as junior lektor, lektor, senior lektor totdat ...

  11. Selective cutting, rehabilitation, and alternatives for forests of northeastern North America and elsewhere

    Science.gov (United States)

    Laura S. Kenefic

    2014-01-01

    In the 1928 Journal of Forestry, Marinus Westveld commented that logging in the Northeast dating to the mid-1800s had been selective cutting that removed desirable species of large sizes. Later, commercial clearcuts removed progressively smaller trees of merchantable quality and desirable species. Indiscriminate logging damaged young growing stock...

  12. Comparison of stomach contents of haddock (Melanogrammus aeglefinus) from the 1981 and 1991 North Sea International Stomach Sampling Projects

    Science.gov (United States)

    Adlerstein, S.A.; Temming, A.; Mergardt, N.

    2002-01-01

    This study analyses data from over 20 000 haddock stomachs collected during the 1981 and 1991 Stomach Sampling Projects of the North Sea. Sampling was within the framework of the Multispecies Virtual Population Analysis (MSVPA) for fisheries stock assessment. In 1981 stomachs were collected to calculate input feeding parameters from main predators. During 1991 the sampling exercise was repeated to test stability of the parameters in the region. We investigate stability of haddock stomach content weight between years accounting for ontogenic, spatial and temporal variations within the scope of the survey resolution. Analysis using generalized linear and additive models is performed for weight of the stomach content including and excluding empty stomachs and also for proportion of stomachs without food. Results indicate that haddock stomach contents varied significantly between years, quarters and North Sea roundfish areas. Content weights were overall higher in 1981 than in 1991. In 1981 levels were high from spring to fall and in 1991 mostly in spring. During both years levels were lowest in the central North Sea and in winter. Most of the deviance in modelling the stomach weight is explained by the length of the predator. Stomachs sampled in 1981 were most frequently empty in spring and those sampled in 1991 in winter. In both years, proportions decreased with fish length except in winter when levels increased. Proportion of empty stomachs was highest in the central region of the North Sea. Most of the proportion variation is explained by quarterly fluctuation. Variation of content weight can be related to prey composition found in the stomachs. High stomach contents are generally associated with high contribution of fish prey to the total stomach content, mainly sandeels. We propose that sandeels were more vulnerable to predation in 1981 than in 1991 due to colder temperatures. ?? 2002 International Council for the Exploration of the Sea. Published by Elsevier

  13. Maturity, size at age and predator-prey relationships of winter skate Leucoraja ocellata in the southern Gulf of St Lawrence: potentially an undescribed endemic facing extirpation.

    Science.gov (United States)

    Kelly, J T; Hanson, J M

    2013-03-01

    The goals of this study were to document the size and age structure, size at maturity, ovarian fecundity and diet of the endangered population of winter skate Leucoraja ocellata that resides in the southern Gulf of St Lawrence (SGSL). The maximum size observed for SGSL L. ocellata was 68 cm total length (LT ) but >99% of animals caught were 10 mm diameter were ever observed. At 40 cm LT , the diet changed from one dominated by shrimp Crangon septemspinosa and gammarid amphipods to one dominated by fishes (mainly sand lance Ammodytes spp. and rainbow smelt Osmerus mordax) and Atlantic rock crab Cancer irroratus. Sufficient differences were observed between SGSL L. ocellata and other populations in their size-at-maturity pattern and maximum size to propose the taxonomic re-evaluation of the population. © Her Majesty the Queen in Right of Canada 2013. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  14. Crystallographic characterization of functional sites of crotoxin and ammodytoxin, potent β-neurotoxins from Viperidae venom.

    Science.gov (United States)

    Faure, Grazyna; Saul, Frederick

    2012-09-15

    This review will focus on a description of the three-dimensional structures of two β-neurotoxins, the monomeric PLA(2) ammodytoxin from Vipera ammodytes ammodytes, and heterodimeric crotoxin from Crotalus durissus terrificus, and a detailed structural analysis of their multiple functional sites. We have recently determined at high resolution the crystal structures of two natural isoforms of ammodytoxin (AtxA and AtxC) (Saul et al., 2010) which exhibit different toxicity profiles and different anticoagulant properties. Comparative structural analysis of these two PLA(2) isoforms, which differ only by two amino acid residues, allowed us to detect local conformational changes and delineate the role of critical residues in the anticoagulant and neurotoxic functions of these PLA(2) (Saul et al., 2010). We have also determined, at 1.35Å resolution, the crystal structure of heterodimeric crotoxin (Faure et al., 2011). The three-dimensional structure of crotoxin revealed details of the binding interface between its acidic (CA) and basic (CB) subunits and allowed us to identify key residues involved in the stability and toxicity of this potent heterodimeric β-neurotoxin (Faure et al., 2011). The precise spatial orientation of the three covalently linked polypeptide chains in the mature CA subunit complexed with CB helps us to understand the role played by critical residues of the CA subunit in the increased toxicity of the crotoxin complex. Since the CA subunit is a natural inhibitor of the catalytic and anticoagulant activities of CB, identification of the CA-CB binding interface describes residues involved in this inhibition. We propose future research directions based on knowledge of the recently reported 3D structures of crotoxin and ammodytoxin. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Deep ancestry of programmed genome rearrangement in lampreys.

    Science.gov (United States)

    Timoshevskiy, Vladimir A; Lampman, Ralph T; Hess, Jon E; Porter, Laurie L; Smith, Jeramiah J

    2017-09-01

    In most multicellular organisms, the structure and content of the genome is rigorously maintained over the course of development. However some species have evolved genome biologies that permit, or require, developmentally regulated changes in the physical structure and content of the genome (programmed genome rearrangement: PGR). Relatively few vertebrates are known to undergo PGR, although all agnathans surveyed to date (several hagfish and one lamprey: Petromyzon marinus) show evidence of large scale PGR. To further resolve the ancestry of PGR within vertebrates, we developed probes that allow simultaneous tracking of nearly all sequences eliminated by PGR in P. marinus and a second lamprey species (Entosphenus tridentatus). These comparative analyses reveal conserved subcellular structures (lagging chromatin and micronuclei) associated with PGR and provide the first comparative embryological evidence in support of the idea that PGR represents an ancient and evolutionarily stable strategy for regulating inherent developmental/genetic conflicts between germline and soma. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Resting respiratory behavior in minimally instrumented toads - effects of very long apneas on blood gases and pH

    Directory of Open Access Journals (Sweden)

    F. C. Coelho

    Full Text Available Resting respiratory behavior of Bufo marinus in minimally instrumented toads is described for a period of 24 hours in which the animals are left undisturbed. Torpor-related long apneas are described and their implications for blood gas levels are investigated. Results show that the resting ventilation rate of Bufo marinus is much lower than that reported so far. Levels of arterial oxygen, carbon dioxide, and pH are monitored during artificial long apneas induced by anesthesia. The toads showed an unexpected ability to unload carbon dioxide by non-respiratory means, even while being kept on dry plastic box with no access to water. Oxygen arterial partial pressure dropped to very low levels after one hour of apnea. This suggests that these animals may endure very well severe hypoxia for long periods of time while in torpor.

  17. Resting respiratory behavior in minimally instrumented toads - effects of very long apneas on blood gases and pH

    Directory of Open Access Journals (Sweden)

    Coelho F. C.

    2003-01-01

    Full Text Available Resting respiratory behavior of Bufo marinus in minimally instrumented toads is described for a period of 24 hours in which the animals are left undisturbed. Torpor-related long apneas are described and their implications for blood gas levels are investigated. Results show that the resting ventilation rate of Bufo marinus is much lower than that reported so far. Levels of arterial oxygen, carbon dioxide, and pH are monitored during artificial long apneas induced by anesthesia. The toads showed an unexpected ability to unload carbon dioxide by non-respiratory means, even while being kept on dry plastic box with no access to water. Oxygen arterial partial pressure dropped to very low levels after one hour of apnea. This suggests that these animals may endure very well severe hypoxia for long periods of time while in torpor.

  18. Aliphatic hydrocarbons and fatty acids of some marine and freshwater microorganisms.

    Science.gov (United States)

    Oró, J; Tornabene, T G; Nooner, D W; Gelpi, E

    1967-06-01

    Gas chromatography and combined gas chromatography-mass spectrometry have been used to study the fatty acids and hydrocarbons of a bacterium from the Pacific Ocean, Vibrio marinus, a freshwater blue-green alga, Anacystis nidulans, and algal mat communities from the Gulf of Mexico. Both types of microorganisms (bacteria and algae) showed relatively simple hydrocarbon and fatty acid patterns, the hydrocarbons predominating in the region of C-17 and the fatty acids in the range of C-14 to C-18. The patterns of V. marinus were more comparable to those of the algal populations than to patterns reported for other bacteria. An incomplete correlation between fatty acids and hydrocarbons in both types of organisms was observed, making it difficult to accept the concept that the biosynthesis of hydrocarbons follows a simple fatty acid decarboxylation process.

  19. Bufo alvarius: a potent hallucinogen of animal origin.

    Science.gov (United States)

    Weil, A T; Davis, W

    1994-01-01

    Anthropologists have long speculated that ancient peoples of Mesoameria used a toad, Bufo marinus, as a ritual intoxicant. This hypothesis rests on many iconographic and mythological representations of toads and on a number of speculative ethnographic reports. The authors reject B. marinus as a candidate for such use because of the toxicity of its venom. A more likely candidate is the Sonoran desert toad, Bufo alvarius, which secretes large amounts of the potent known hallucinogen, 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). The authors demonstrate that the venom of B. alvarius, although known to be toxic when consumed orally, may be safely smoked and is powerfully psychoactive by that route of administration. These experiments are the first documentation of an hallucinogenic agent from the animal kingdom, and they provide clear evidence of a psychoactive toad that could have been employed by Precolumbian peoples of the New World.

  20. Chromosomes of South American Bufonidae (Amphibia, Anura Chromosomes of South American Bufonidae (Amphibia, Anura

    Directory of Open Access Journals (Sweden)

    Brum Zorrilla N.

    1973-09-01

    Full Text Available Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.

  1. Phylogenetic distribution of a male pheromone that may exploit a nonsexual preference in lampreys

    Science.gov (United States)

    Buchinger, Tyler J.; Bussy, Ugo; Li, Ke; Wang, Huiyong; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas

    2017-01-01

    Pheromones are among the most important sexual signals used by organisms throughout the animal kingdom. However, few are identified in vertebrates, leaving the evolutionary mechanisms underlying vertebrate pheromones poorly understood. Pre-existing biases in receivers’ perceptual systems shape visual and auditory signaling systems, but studies on how receiver biases influence the evolution of pheromone communication remain sparse. The lamprey Petromyzon marinus uses a relatively well-understood suite of pheromones and offers a unique opportunity to study the evolution of vertebrate pheromone communication. Previous studies indicate that male signaling with the mating pheromone 3-keto petromyzonol sulfate (3kPZS) may exploit a nonsexual attraction to juvenile-released 3kPZS that guides migration into productive rearing habitat. Here, we infer the distribution of male signaling with 3kPZS using a phylogenetic comparison comprising six of ten genera and two of three families. Our results indicate that only P. marinus and Ichthyomyzon castaneus release 3kPZS at high rates. Olfactory and behavioral assays with P. marinus, I. castaneus and a subset of three other species that do not use 3kPZS as a sexual signal indicate that male signaling might drive the evolution of female adaptations to detect 3kPZS with specific olfactory mechanisms and respond to 3kPZS with targeted attraction relevant during mate search. We postulate that 3kPZS communication evolved independently in I. castaneus and P. marinus, but cannot eliminate the alternative that other species lost 3kPZS communication. Regardless, our results represent a rare macroevolutionary investigation of a vertebrate pheromone and insight into the evolutionary mechanisms underlying pheromone communication.

  2. Development of Operational Protocols for Electric Barrier Systems on the Chicago Sanitary and Ship Canal: Induction of Passage-Preventing Behaviors in Small Sizes of Silver Carp

    Science.gov (United States)

    2015-07-01

    D. Youngs. 1980. Role of physical barriers in the control of sea lamprey (Petromyzon marinus). Canadian Journal of Fisheries and Aquatic Sciences 37...fishes from invasive exotic fishes. Annual Report to the Division of Fisheries , Illinois Department of Natural Resources, Illinois Natural History...American Journal of Fisheries Management 19: 397-405. NOTE: The contents of this technical note are not to be used for advertising, publication

  3. Unigene BLAST: CBRC-PMAR-01-0699 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available protein UL126 - human cytomegalovirus (strain AD169) >emb|CAA35328.1| HCMVUL126 [Human herpesvirus > /clone_end=5' /gb=DW020928 /gi=83670520 /ug=Pma.6326 /len=870 0.34 57% ... ...romyzon marinus cDNA 5' similar to sp|P16836|ULC6_HCMVA HYPOTHETICAL PROTEIN UL126 >pir||S09875 hypothetical

  4. The ticks (Acari: Ixodida: Argasidae, Ixodidae) of Paraguay

    Science.gov (United States)

    2007-01-01

    de Importancia Veterinaria . São Paulo, Brazil: Pleiade–FAPESP. Hoogstraal, H. (1985). Argasid and nuttalliellid ticks as parasites and vectors...Parasitologı́a Veterinaria . Jakowska, S. (1972). Lesions produced by ticks, Amblyomma dissimile, in Bufo marinus toads from the Dominican Republic. American...A. A. (1990). La distribución geográfica de Amblyomma cajennense Fabricius, 1787 (Acari: Ixodoidea: Ixodidae) en Argentina. Veterinaria Argentina, 7

  5. The complete nucleotide sequence of the mitochondrial DNA of the dogfish, Scyliorhinus canicula.

    OpenAIRE

    Delarbre, C; Spruyt, N; Delmarre, C; Gallut, C.; Barriel, V; Janvier, P.; Laudet, V; Gachelin, G

    1998-01-01

    We have determined the complete nucleotide sequence of the mitochondrial DNA (mtDNA) of the dogfish, Scyliorhinus canicula. The 16,697-bp-long mtDNA possesses a gene organization identical to that of the Osteichthyes, but different from that of the sea lamprey Petromyzon marinus. The main features of the mtDNA of osteichthyans were thus established in the common ancestor to chondrichthyans and osteichthyans. The phylogenetic analysis confirms that the Chondrichthyes are the sister group of th...

  6. A common bottlenose dolphin (Tursiops truncatus) prey handling technique for marine catfish (Ariidae) in the northern Gulf of Mexico

    OpenAIRE

    Ronje, Errol I.; Barry, Kevin P.; Sinclair, Carrie; Grace, Mark A.; Barros, N?lio; Allen, Jason; Balmer, Brian; Panike, Anna; Toms, Christina; Keith D. Mullin; Wells, Randall S.

    2017-01-01

    Few accounts describe predator-prey interactions between common bottlenose dolphins (Tursiops truncatus Montagu 1821) and marine catfish (Ariopsis felis Linnaeus 1766, Bagre marinus Mitchill 1815). Over the course of 50,167 sightings of bottlenose dolphin groups in Mississippi Sound and along the Florida coast of the Gulf of Mexico, severed catfish heads were found floating and exhibiting movements at the surface in close proximity to 13 dolphin groups that demonstrated feeding behavior. Thes...

  7. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

    Directory of Open Access Journals (Sweden)

    Emma R Cold

    Full Text Available The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1 Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2 Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3 Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications.

  8. Combined effects of predator cues and competition define habitat choice and food consumption of amphipod mesograzers.

    Science.gov (United States)

    Beermann, Jan; Boos, Karin; Gutow, Lars; Boersma, Maarten; Peralta, Ana Carolina

    2018-03-01

    Predation has direct impact on prey populations by reducing prey abundance. In addition, predator presence alone can also have non-consumptive effects on prey species, potentially influencing their interspecific interactions and thus the structure of entire assemblages. The performance of potential prey species may, therefore, depend on both the presence of predators and competitors. We studied habitat use and food consumption of a marine mesograzer, the amphipod Echinogammarus marinus, in the presence/absence of a fish mesopredator and/or an amphipod competitor. The presence of the predator affected both habitat choice and food consumption of the grazer, indicating a trade-off between the use of predator-free space and food acquisition. Without the predator, E. marinus were distributed equally over different microhabitats, whereas in the presence of the predator, most individuals chose a sheltered microhabitat and reduced their food consumption. Furthermore, habitat choice of the amphipods changed in the presence of interspecific competitors, also resulting in reduced feeding rates. The performance of E. marinus is apparently driven by trait-mediated direct and indirect effects caused by the interplay of predator avoidance and competition. This highlights the importance of potential non-consumptive impacts of predators on their prey organisms. The flexible responses of small invertebrate consumers to the combined effects of predation and competition potentially lead to changes in the structure of coastal ecosystems and the multiple species interactions therein.

  9. Characterization of Escherichia coli populations from gulls, landfill trash, and wastewater using ribotyping.

    Science.gov (United States)

    Nelson, M; Jones, S H; Edwards, C; Ellis, J C

    2008-08-19

    Due to their opportunistic and gregarious nature, gulls may be important reservoirs and vectors for anthropogenically derived fecal pathogens in coastal areas. We used ribotyping, a genotypic bacterial source tracking method, to compare populations of Escherichia coli among herring gulls Larus argentatus, great black-backed gulls L. marinus, wastewater, and landfill trash in New Hampshire and Maine, USA. Concentrations of E. coli in gull feces varied widely among individuals, but were generally high (6.0 x 10(1) to 2.5 x 10(9) g(-1) wet weight). Of 39 E. coli isolates from L. argentatus, 67% had banding patterns that were > or = 90% similar to those from wastewater and trash, whereas only 39% of 36 L. marinus isolates exhibited > or = 90% similarity to these sources. Strains of E. coli from gulls matched (> or = 90% similarity) more strains from wastewater (39% matching) than from trash (15% matching). E. coli isolates from L. marinus feces exhibited a greater diversity of banding patterns than did isolates from L. argentatus. There were more unique E. coli banding patterns in trash samples than in wastewater, and higher diversity indices in the former compared to the latter. These findings suggest that both species of gulls, especially L. argentatus, obtain fecal bacteria from wastewater and landfill trash, which they may transport to recreational beaches and waters. Our results also indicate that E. coli populations may vary widely between gull species, and between the anthropogenic habitats that they frequent, i.e. landfills and wastewater treatment facilities.

  10. Evidence for partial overlap of male olfactory cues in lampreys

    Science.gov (United States)

    Buchinger, Tyler J.; Li, Ke; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas S.

    2016-01-01

    Animals rely on a mosaic of complex information to find and evaluate mates. Pheromones, often comprised of multiple components, are considered to be particularly important for species-recognition in many species. While the evolution of species-specific pheromone blends is well-described in many insects, very few vertebrate pheromones have been studied in a macro-evolutionary context. Here, we report a phylogenetic comparison of multi-component male odours that guide reproduction in lampreys. Chemical profiling of sexually mature males from eleven species of lamprey, representing six of ten genera and two of three families, indicated the chemical profiles of sexually mature male odours are partially shared among species. Behavioural assays conducted with four species sympatric in the Laurentian Great Lakes indicated asymmetric female responses to heterospecific odours, where Petromyzon marinus were attracted to male odour collected from all species tested but other species generally preferred only the odour of conspecifics. Electro-olfactogram recordings from P. marinusindicated that although P. marinus exhibited behavioural responses to odours from males of all species, at least some of the compounds that elicited olfactory responses were different in conspecific male odours compared to heterospecific male odours. We conclude that some of the compounds released by sexually mature males are shared among species and elicit olfactory and behavioural responses in P. marinus, and suggest that our results provide evidence for partial overlap of male olfactory cues among lampreys. Further characterization of the chemical identities of odour components is needed to confirm shared pheromones among species.

  11. The Nuclear DNA Content and Genetic Diversity of Lampetra morii.

    Directory of Open Access Journals (Sweden)

    Xinyu Yan

    Full Text Available We investigated the nuclear DNA content and genetic diversity of a river lamprey, the Korean lamprey Lampetra morii, which is distributed in the northeast of China. L. morii spends its whole life cycle in fresh water, and its adult size is relatively small (~160 mm long compared with that of other lampreys. The haploid nuclear DNA content of L. morii is 1.618 pg (approximately 1.582 Gb in germline cells, and there is ~15% germline DNA loss in somatic cells. These values are significantly smaller than those of Petromyzon marinus, a lamprey with a published draft genome. The chromosomes of L. morii are small and acrocentric, with a diploid modal number of 2n = 132, lower than some other lampreys. Sequence and AFLP analyses suggest that the allelic polymorphism rate (~0.14% based on examined nuclear and mitochondrial DNA sequences of L. morii is much lower than that (~2% of P. marinus. Phylogenetic analysis based on a mitochondrial DNA fragment confirms that L. morii belongs to the genus Lampetra, which, together with the genus Lethenteron, forms a sister group to P. marinus. These genetic background data are valuable for subsequent genetic and genomic research on L. morii.

  12. Growth, temperature and density relationships of North Sea cod ( Gadus morhua )

    DEFF Research Database (Denmark)

    Rindorf, Anna; Jensen, Henrik; Schrum, Corinna

    2008-01-01

    This study presents an analysis of the relationship between ambient temperature, cod density, fishing mortality, prey fish biomass, and growth of North Sea cod (Gadus morhua) as estimated from survey catches during the period from 1983 to 2006. Growth of young cod was positively related to temper......This study presents an analysis of the relationship between ambient temperature, cod density, fishing mortality, prey fish biomass, and growth of North Sea cod (Gadus morhua) as estimated from survey catches during the period from 1983 to 2006. Growth of young cod was positively related...... to temperature; however, although temperature increased, distribution of 1-year-olds changed concurrently and no increase in length at age 1 occurred. Growth from age 1 to age 2 decreased as ambient biomass of sandeel and density of cod decreased, whereas growth of cod older than 2 years decreased...... with increasing density of cod and increased with increasing biomass of demersal fish prey. Though growth of juveniles was strongly positively correlated to ambient temperature, no indication of direct temperature limitation of growth of older North Sea cod was found....

  13. The influence of feeding behaviour on growth of Atlantic cod (Gadus morhua, Linnaeus, 1758) in the North Sea

    DEFF Research Database (Denmark)

    Hüssy, Karin; Andersen, Niels Gerner; Pedersen, Eva Maria

    2016-01-01

    The objective of this study was to resolve key mechanisms driving individual growth patterns of Atlantic cod (Gadus morhua). Growth dynamics were analysed by linking growth patterns with stomach content composition and environmental temperature. Samples were collected in August/September of the y......The objective of this study was to resolve key mechanisms driving individual growth patterns of Atlantic cod (Gadus morhua). Growth dynamics were analysed by linking growth patterns with stomach content composition and environmental temperature. Samples were collected in August......% by mass), of which six were used for growth analyses: “Sandeel”, “Clupeids”, “Norway pout”, “Flatfishes”, “Crustaceans” and “Brittle stars”. For each group, growth patterns were estimated based on measures of otolith growth increments. The stomach contents showed that cod as a species are opportunistic...... decreased with increasing cod size, whereas that of fish and predominantly herring increased. Prey type had a significant effect on growth, while temperature had no effect. Slowest growth was observed in the cod group preying on sandeel, while cod preying on Norway pout showed the fastest growth...

  14. Vasculature of the parotoid glands of four species of toads (bufonidae: bufo).

    Science.gov (United States)

    Hutchinson, Deborah A; Savitzky, Alan H

    2004-05-01

    The parotoid glands of toads (Bufonidae) consist of large aggregations of granular glands located between the otic region of the skull and the scapular region. To determine the circulatory pattern of these glands, we perfused the vascular systems of Bufo alvarius, B. marinus, B. terrestris, and B. valliceps with either India ink or Microfil, a fine latex. The perfused glands were studied by gross dissection, microscopic examination, and histology. The vascular patterns of the parotoid glands were compared to the arrangement of vessels in the dorsal skin of Rana sphenocephala (Ranidae), a frog that lacks parotoid glands. The parotoid glands of the four species of toads are supplied with blood by the lateral and dorsal cutaneous arteries and are drained by one or more branches of the internal jugular vein. The dorsal cutaneous artery supplies most of the blood to the parotoid glands in B. terrestris and B. valliceps. In B. alvarius and B. marinus, both the lateral and dorsal cutaneous arteries serve major roles in the blood supply of the glands. These patterns of blood flow have not been described previously for parotoid glands and conflict with earlier accounts for B. alvarius and B. marinus. The arteries and veins associated with the parotoid glands of toads are present in R. sphenocephala, but are arranged differently. In R. sphenocephala, the lateral cutaneous artery supplies the dorsal and lateral skin posterior to the shoulder region, whereas the dorsal cutaneous artery supplies the skin of the shoulder region. In toads, both the lateral and dorsal cutaneous arteries supply the skin of the shoulder region and ramify into subcutaneous capillaries that surround the secretory units of the parotoid glands. Extensive vasculature presumably is important for delivering cholesterol and other precursor molecules to the parotoid glands, where those compounds are converted into toxins. Copyright 2004 Wiley-Liss, Inc.

  15. Is Monoglucosyldiacylglycerol a Precursor to Monogalactosyldiacylglycerol in All Cyanobacteria?

    Science.gov (United States)

    Sato, Naoki

    2015-10-01

    Monogalactosyldiacylglycerol (MGDG) is ubiquitous in the photosynthetic membranes of cyanobacteria and chloroplasts. It is synthesized by galactosylation of diacylglycerol (DAG) in the chloroplasts, whereas it is produced by epimerization of monoglucosyldiacylglycerol (GlcDG) in at least several cyanobacteria that have been analyzed such as Synechocystis sp. PCC 6803. A previous study, however, showed that the mgdE gene encoding the epimerase is absent in some cyanobacteria such as Gloeobacter violaceus, Thermosynechococcus elongatus and Acaryochloris marina. In addition, the N-terminal 'fatty acid hydroxylase' domain is lacking in the MgdE protein of Prochlorococcus marinus. These problems may cast doubt upon the general (or exclusive) role of MgdE in the epimerization of GlcDG to MGDG in cyanobacteria. In addition, GlcDG is usually present at a very low level, and the structural determination of endogenous GlcDG has not been accomplished with cyanobacterial samples. In this study, I determined the structure of GlcDG from Anabaena variabilis by (1)H- and (13)C-nuclear magnetic resonance (NMR) spectroscopy. I then showed that G. violaceus, T. elongatus, A. marina and P. marinus contain GlcDG. In all cases, GlcDG consisted of fewer unsaturated molecular species than MGDG, providing further evidence that GlcDG is a precursor to MGDG. The conversion of GlcDG to MGDG was also demonstrated by radiolabeling and chase experiments in G. violaceus and P. marinus. These results demonstrate that all the analyzed cyanobacteria contain GlcDG, which is converted to MGDG, and suggest that an alternative epimerase is required for MGDG synthesis in these cyanobacteria. © 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.

  16. Estimating Burst Swim Speeds and Jumping Characteristics of Silver Carp (Hypophthalmichthys molitrix) Using Video Analyses and Principles of Projectile Physics

    Science.gov (United States)

    2016-09-01

    Applying principles of projectile physics to a subset of those fish (N=4), burst speeds were estimated as 7.78- 9.74 m/s, angle of leap as 44-70º, and...rectilinear and boundary layer flow. Journal of Applied Ichthyology 27:226–230. ERDC/TN ANSRP-16-2 September 2016 11 Hunn, J. B., and W. D. Youngs...1980. Role of physical barriers in the control of sea lamprey (Petromyzon marinus). Canadian Journal of Fisheries and Aquatic Sciences 37(11):2118–2122

  17. Raccoon removal reduces sea turtle nest depredation in the Ten Thousand Islands of Florida

    Science.gov (United States)

    Garmestani, A.S.; Percival, H.F.

    2005-01-01

    Predation by raccoons, Procyon lotor marinus (L.), is the primary cause of sea turtle nest loss in the Ten Thousand Islands archipelago. Four islands within Ten Thousand Islands National Wildlife Refuge were surveyed for sea turtle nesting activity from 1991-95. Raccoons depredated 76-100% of nests on Panther Key from 1991-94, until 14 raccoons were removed in 1995 resulting in 0% depredation and 2 more were removed in 1996 resulting in 0% depredation. Raccoon removal may be an effective management option for increasing sea turtle nest survival on barrier islands.

  18. Mind the Gap: How Some Viruses Infect Their Hosts

    Directory of Open Access Journals (Sweden)

    Peter E. Prevelige

    2010-11-01

    Full Text Available Cryo-electron microscopy (Cryo-EM and cryo-electron tomography (Cryo-ET provide structural insights into complex biological processes. The podoviridae are dsDNA containing phage with short, non-contractile tails which nevertheless translocate their DNA into the cytoplasm of their host cells. Liu et al. [1] used a combination of cryo-EM and cryo-ET to study the structural changes accompanying infection of P. marinus by the phage P-SSP7 and thereby provide unique molecular insight into the process by which the DNA transits from phage to host during infection.

  19. Complete genome sequence of the mitochondrial DNA of the river lamprey, Lethenteron japonicum.

    Science.gov (United States)

    Kawai, Yuri L; Yura, Kei; Shindo, Miyuki; Kusakabe, Rie; Hayashi, Keiko; Hata, Kenichiro; Nakabayashi, Kazuhiko; Okamura, Kohji

    2015-01-01

    Lampreys are eel-like jawless fishes evolutionarily positioned between invertebrates and vertebrates, and have been used as model organisms to explore vertebrate evolution. In this study we determined the complete genome sequence of the mitochondrial DNA of the Japanese river lamprey, Lethenteron japonicum, using next-generation sequencers. The sequence was 16,272 bp in length. The gene content and order were identical to those of the sea lamprey, Petromyzon marinus, which has been the reference among lamprey species. However, the sequence similarity was less than 90%, suggesting the need for the whole-genome sequencing of L. japonicum.

  20. Status Report of the Pacific Lamprey (Lampetra Trzdentata) in the Columbia River Basin.

    Energy Technology Data Exchange (ETDEWEB)

    Close, David A.; Parker, Blaine; James, gary

    1995-07-01

    The widespread decline of Pacific lamprey (Lampetra tridentata) in the Pacific Northwest, especially in the Columbia River system has led to concerns and questions from a number of regional agencies, Native American tribes, and the public. To address these concerns, new research efforts must focus on specific problems associated with this understudied species. The preservation and restoration of this species is critical for a number of reasons, including its importance to the tribes and its importance as an indicator of ecosystem health. Historically lamprey have been labeled a pest species due to the problems associated with the exotic sea lamprey, (Petromyzon marinus), invading the Great Lakes.

  1. Gram-positive bacteria of marine origin: a numerical taxonomic study on Mediterranean isolates.

    Science.gov (United States)

    Ortigosa, M; Garay, E; Pujalte, M J

    1997-12-01

    A numerical taxonomic study was performed on 65 Gram-positive wild strains of heterotrophic, aerobic, marine bacteria, and 9 reference strains. The isolates were obtained from oysters and seawater sampled monthly over one year, by direct plating on Marine Agar. The strains were characterized by 96 morphological, biochemical, physiological and nutritional tests. Clustering yielded 13 phena at 0.62 similarity level (Sl coefficient). Only one of the seven phena containing wild isolates could be identified (Bacillus marinus). A pronounced salt requirement was found in most isolates.

  2. The complete nucleotide sequence of the mitochondrial DNA of the dogfish, Scyliorhinus canicula.

    Science.gov (United States)

    Delarbre, C; Spruyt, N; Delmarre, C; Gallut, C; Barriel, V; Janvier, P; Laudet, V; Gachelin, G

    1998-09-01

    We have determined the complete nucleotide sequence of the mitochondrial DNA (mtDNA) of the dogfish, Scyliorhinus canicula. The 16,697-bp-long mtDNA possesses a gene organization identical to that of the Osteichthyes, but different from that of the sea lamprey Petromyzon marinus. The main features of the mtDNA of osteichthyans were thus established in the common ancestor to chondrichthyans and osteichthyans. The phylogenetic analysis confirms that the Chondrichthyes are the sister group of the Osteichthyes.

  3. Dicty_cDB: Contig-U02482-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available occus marinus MED4 complete genome. 32 5.5 22 ( GO153289 ) CAGA35717.rev CAGA Alvinella pompejana Normalized... 36 6.5 7 ( GO169294 ) CAGA43233.fwd CAGA Alvinella pompejana Normalized... 38 6....5 2 ( GO169293 ) CAGA43233.rev CAGA Alvinella pompejana Normalized... 38 6.5 2 ( AC091149 ) Homo sapiens chr...... 40 6.7 4 ( GO144477 ) CAGA30851.rev CAGA Alvinella pompejana Normalized... 38... 6.7 2 ( GO213214 ) CAGB24659.fwd CAGB Alvinella pompejana Normalized... 38 6.7 2 ( EU028331 ) Glycine max c

  4. Adaptive Evolution of Phosphorus Metabolism in Prochlorococcus

    DEFF Research Database (Denmark)

    Casey, John R; Mardinoglu, Adil; Nielsen, Jens

    2016-01-01

    Inorganic phosphorus is scarce in the eastern Mediterranean Sea, where the high-light-adapted ecotype HLI of the marine picocyanobacterium Prochlorococcus marinus thrives. Physiological and regulatory control of phosphorus acquisition and partitioning has been observed in HLI both in culture and ...... and an extremely high proportion of essential metabolic genes (47%; defined as the percentage of lethal in silico gene knockouts). These strategies are examples of nutrient-controlled adaptive evolution and confer a dramatic growth rate advantage to MED4 in phosphorus-limited regions. ...

  5. Seasonal variation in parasite infection patterns of marine fish species from the Northern Wadden Sea in relation to interannual temperature fluctuations

    Science.gov (United States)

    Schade, Franziska M.; Raupach, Michael J.; Mathias Wegner, K.

    2016-07-01

    Marine environmental conditions are naturally changing throughout the year, affecting life cycles of hosts as well as parasites. In particular, water temperature is positively correlated with the development of many parasites and pathogenic bacteria, increasing the risk of infection and diseases during summer. Interannual temperature fluctuations are likely to alter host-parasite interactions, which may result in profound impacts on sensitive ecosystems. In this context we investigated the parasite and bacterial Vibrionaceae communities of four common small fish species (three-spined stickleback Gasterosteus aculeatus, Atlantic herring Clupea harengus, European sprat Sprattus sprattus and lesser sand eel Ammodytes tobianus) in the Northern Wadden Sea over a period of two years. Overall, we found significantly increased relative diversities of infectious species at higher temperature differentials. On the taxon-specific level some macroparasite species (trematodes, nematodes) showed a shift in infection peaks that followed the water temperatures of preceding months, whereas other parasite groups showed no effects of temperature differentials on infection parameters. Our results show that even subtle changes in seasonal temperatures may shift and modify the phenology of parasites as well as opportunistic pathogens that can have far reaching consequences for sensitive ecosystems.

  6. Testing the junk-food hypothesis on marine birds: Effects of prey type on growth and development

    Science.gov (United States)

    Romano, Marc D.; Piatt, John F.; Roby, D.D.

    2006-01-01

    The junk-food hypothesis attributes declines in productivity of marine birds and mammals to changes in the species of prey they consume and corresponding differences in nutritional quality of those prey. To test this hypothesis nestling Black-legged Kittiwakes (Rissa tridactyla) and Tufted Puffins (Fratercula cirrhata) were raised in captivity under controlled conditions to determine whether the type and quality of fish consumed by young seabirds constrains their growth and development. Some nestlings were fed rations of Capelin (Mallotus villosus), Herring (Clupea pallasi) or Sand Lance (Ammodytes hexapterus) and their growth was compared with nestlings raised on equal biomass rations of Walleye Pollock (Theragra chalcograma). Nestlings fed rations of herring, sand lance, or capelin experienced higher growth increments than nestlings fed pollock. The energy density of forage fish fed to nestlings had a marked effect on growth increments and could be expected to have an effect on pre- and post-fledging survival of nestlings in the wild. These results provide empirical support for the junk-food hypothesis.

  7. Diet and feeding niches of juvenile Gadus morhua, Melanogrammus aeglefinus and Merlangius merlangus during the settlement transition in the northern North Sea.

    Science.gov (United States)

    Demain, D K; Gallego, A; Jaworski, A; Priede, I G; Jones, E G

    2011-07-01

    A study on the feeding ecology of juvenile cod Gadus morhua, haddock Melanogrammus aeglefinus and whiting Merlangius merlangus during the pelagic to demersal transition was carried out on fishes sampled throughout their settlement season at a local nursery ground in the north-western North Sea, off the Scottish east coast. A comprehensive quantitative taxonomic analysis of the diets, as described in the paper, showed the emergence of distinctive feeding niches, minimizing the potential for competition between species and size categories. The diet of the juveniles changed with fish size, water depth, time of year and distance offshore. Small G. morhua were present in the study area earlier in the season, settled further inshore and ate a higher proportion of pelagic prey (copepods) and as size increased they moved into deeper waters and targeted larger, more benthic prey. As M. aeglefinus grew larger and moved into deeper waters, a diet of largely copepods, amphipods, pelagic Ammodytes spp., cyprids and pelagic gastropods evolved to one dominated predominantly by fishes and benthic invertebrates. In the case of M. merlangus, widespread ages and sizes throughout the sampling season, a consequence of their more protracted spawning season, resulted in dietary changes which were more likely to be influenced by seasonal changes in the prey field, in addition to developmental (size) changes, than the diets of the other two species. © 2011 Marine Scotland. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  8. Deciphering the social structure of Marbled Murrelets from behavioral observations at sea

    Science.gov (United States)

    Speckman, Suzann G.; Piatt, John F.; Springer, Alan M.

    2003-01-01

    We surveyed Marbled Murrelets (Brachyramphus marmoratus) daily from small boats in Auke Bay and Fritz Cove, Alaska, from May through August 1992 and 1993. Differences in numbers of juveniles and in the timing of their presence in the study area between the two years indicated that breeding phenology was late and productivity was low in 1992 compared to 1993. This difference was consistent with variability in the physical environment. Of 99 fish identified in the bills of fish-holding adult murrelets, 81 (82%) were Pacific Sand Lance (Ammodytes hexapterus). Counts of fish-holding adult murrelets were significantly higher in the evening than at any other time of day. Time of day had no significant effects on counts of fledglings, indicating that juveniles were moving into and out of the study area during the day. Murrelets were predominantly found in groups of two or more, even during incubation, suggesting that murrelets incur an appreciable benefit, such as increased foraging efficiency, from foraging in groups. For both summers, there was no correlation between counts of murrelets on the water and numbers of murrelet detections in the adjacent forest. We suggest that many behavior patterns of the Marbled Murrelet (displaying, choosing of mates, and pair-bonding, finding of nest sites and successful foraging of juveniles) may be socially facilitated.

  9. Parasite communities of four fish species in the Wadden Sea and the role of fish discarded by the shrimp fisheries in parasite transmission

    Science.gov (United States)

    Groenewold, S.; Berghahn, R.; Zander, C.-D.

    1996-03-01

    Parasites were observed in medium- and small-sized fish taken from the discards of a commercial shrimper during seven different cruises in the tidal channels of the North Frisian Wadden Sea (Süderaue, North Sea) from April to September 1991. In total, 442 fish comprising four species ( Sprattus sprattus, Hyperoplus lanceolatus, Ammodytes tobianus, Pomatoschistus minutus) were investigated. The parasite fauna consisted of 22 species. The parasite community structure of the 4 hosts was compared. The diet of the hosts seemed to be the main factor determining the structure of the parasite community. Other factors could not be assessed. Eight species of parasites occurred as larval stages. This indicated that fish were intermediate or paratenic hosts in their life cycle. The nematode Hysterothylacium sp. (Anisakidae) and the digenean Cryptocotyle lingua (Heterophyidea) were the dominant parasites, reaching their highest prevalence and density in sprat and sand eel. Sprat and sand eel play a very important role in parasite transmission to predacious fish and seabirds.

  10. Foraging Habitat and Chick Diets of Roseate Tern, Sterna dougallii, Breeding on Country Island, Nova Scotia

    Directory of Open Access Journals (Sweden)

    Jennifer C. Rock

    2007-06-01

    Full Text Available Breeding seabirds are threatened by human activities that affect nesting and foraging habitat. In Canada, one of the seabirds most at risk of extirpation is the Roseate Tern, Sterna dougallii. Although critical nesting habitat has been identified for the Roseate Tern in Canada, its foraging locations and the diet of its chicks are unknown. Therefore, our goal was to determine the foraging locations and diet of chicks of Roseate Tern breeding on Country Island, Nova Scotia, which is one of Canada's two main breeding colonies. In 2003 and 2004, we radio-tracked the Roseate Tern by plane to locate foraging areas and conducted feeding watches to determine the diet of chicks. Roseate Tern foraged approximately 7 km from the breeding colony over shallow water < 5 m deep. In both years, sand lance, Ammodytes spp., was the most common prey item delivered to chicks, followed by hake, Urophycis spp. Our results are consistent with previous work at colonies in the northeastern United States, suggesting that throughout its range, this species may be restricted in both habitat use and prey selection. The reliance on a specific habitat type and narrow range of prey species makes the Roseate Tern generally susceptible to habitat perturbations and reductions in the availability of prey.

  11. Ecological conversion efficiency and its influencers in twelve species of fish in the Yellow Sea Ecosystem

    Science.gov (United States)

    Tang, Qisheng; Guo, Xuewu; Sun, Yao; Zhang, Bo

    2007-09-01

    The ecological conversion efficiencies in twelve species of fish in the Yellow Sea Ecosystem, i.e., anchovy ( Engraulis japonicus), rednose anchovy ( Thrissa kammalensis), chub mackerel ( Scomber japonicus), halfbeak ( Hyporhamphus sajori), gizzard shad ( Konosirus punctatus), sand lance ( Ammodytes personatus), red seabream ( Pagrus major), black porgy ( Acanthopagrus schlegeli), black rockfish ( Sebastes schlegeli), finespot goby ( Chaeturichthys stigmatias), tiger puffer ( Takifugu rubripes), and fat greenling ( Hexagrammos otakii), were estimated through experiments conducted either in situ or in a laboratory. The ecological conversion efficiencies were significantly different among these species. As indicated, the food conversion efficiencies and the energy conversion efficiencies varied from 12.9% to 42.1% and from 12.7% to 43.0%, respectively. Water temperature and ration level are the main factors influencing the ecological conversion efficiencies of marine fish. The higher conversion efficiency of a given species in a natural ecosystem is acquired only under the moderate environment conditions. A negative relationship between ecological conversion efficiency and trophic level among ten species was observed. Such a relationship indicates that the ecological efficiency in the upper trophic levels would increase after fishing down marine food web in the Yellow Sea ecosystem.

  12. Estimated food consumption of minke whales Balaenoptera acutorostrata in Northeast Atlantic waters in 1992-1995

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    Lars P Folkow

    2000-05-01

    Uncertainties in stock estimates suggest a 95% confidence range of 1.4 - 2.1 million tonnes. The point estimate was composed of 602,000 tonnes of krill Thysanoessa spp., 633,000 tonnes of herring Clupea harengus, 142,000 tonnes of capelin Mallotus villosus, 256,000 tonnes of cod Gadus morhua, 128,000 tonnes of haddock Melanogrammus aeglefinus and 54,500 tonnes of other fish species, including saithe Pollaehius virens and sand eel Ammodytes sp. Consumption of various prey items by minke whales may represent an important mortality factor for some of the species. For example, the estimated annual consumption of herring corresponds to about 70% of the herring fisheries in the Northeast Atlantic in 1995. Minke whale diets are subject to year-to-year variations due to changes in the resource base in different feeding areas. Thus, the regional distribution of consumption of different prey items is highly dynamic.

  13. Seasonal and interannual variability in grey seal diets on Sable Island, eastern Scotian Shelf

    Directory of Open Access Journals (Sweden)

    W D Bowen

    2007-01-01

    Full Text Available We studied seasonal and interannual variability in the diet of grey seals (Halichoerus grypus using faecal samples collected from Sable Island, Nova Scotia between 1991 and 1998. More than 28,000 prey from at least 28 taxa were identified from 1,245 faecal samples collect mainly in spring, fall and winter. Sand lance (Ammodytes dubius dominated the diet in all seasons and years, but the importance of this and other species varied over time. There was also evidence of seasonal and interannual variation in the size of prey consumed both within and among species. We compared diet composition with estimates of prey numbers and biomass from annual researchtrawl surveys conducted in March and July. Species-specific numerical corrections were applied to otolith counts to account for the complete digestion of otoliths, and fish catchability correction factors applied to trawl survey catches to account for trawl selectivity. Based on an odds ratio index of prey selectivity, grey seals positively selected sand lance in both seasons. Other species were either relatively avoided or eaten roughly in proportion to their estimated abundance.

  14. Primary structure and conformational analysis of peptide methionine-tyrosine, a peptide related to neuropeptide Y and peptide YY isolated from lamprey intestine

    DEFF Research Database (Denmark)

    Conlon, J M; Bjørnholm, B; Jørgensen, Flemming Steen

    1991-01-01

    A peptide belonging to the pancreatic-polypeptide-fold family of regulatory peptides has been isolated from the intestine of an Agnathan, the sea lamprey (Petromyzon marinus). The primary structure of the peptide (termed peptide methionine-tyrosine) was established as Met-Pro-Pro-Lys-Pro-Asp-Asn-......A peptide belonging to the pancreatic-polypeptide-fold family of regulatory peptides has been isolated from the intestine of an Agnathan, the sea lamprey (Petromyzon marinus). The primary structure of the peptide (termed peptide methionine-tyrosine) was established as Met......%) or with pig pancreatic polypeptide (42%). Molecular modelling and dynamic simulation, based upon sequence similarity with turkey pancreatic polypeptide, indicates that the conformations of the polyproline-helix-like region (residues 1-8) and the alpha-helical region (residues 15-30) in turkey pancreatic...... polypeptide are conserved in peptide methionine-tyrosine, and that non-bonded interactions between these domains have preserved the overall polypeptide fold in the molecule. The substitution of the otherwise totally conserved Gly9 residue by serine in lamprey peptide methionine-tyrosine, however, results...

  15. Expresión heteróloga de ARN mensajeros de Leishmania en ovocitos de anfibios

    Directory of Open Access Journals (Sweden)

    Arroyo Olarte Rubén Darío

    2006-06-01

    Full Text Available La técnica de expresión heteróloga en ovocitos de Xenopus laevis ha sido ampliamente utilizada para la caracterización funcional de canales iónicos. En este estudio se reporta el uso del modelo nativo de ovocitos de Bufo marinus para la expresión heteróloga de ARN poliadenilado (ARNm poli(A+ de Leishmania amazonensis y la posterior identificación de canales iónicos mediante registros electrofisiológicos utilizando la técnica de voltaje controlado (voltage-clamp. Se logró realizar la maduración, extracción y cultivo de ovocitos de B. marinus bajo condiciones similares a las estandarizadas para X. laevis. El potencial de reposo promedio así como las corrientes endógenas mostraron ser definidas por canales de cloruro dependientes de calcio y rectificadores de salida, de manera similar a lo reportado en X. laevis. La inyección de ARNm poli(A+ de L. amazonensis generó la expresión de corrientes de cloruro de  amplitud, cinética y características farmacológicas diferentes a las corrientes endógenas, reportadas en estudios previos con X. laevis como posible resultado de la expresión heteróloga de canales iónicos de L. amazonensis.

  16. Specialized Hydrocarbonoclastic Bacteria Prevailing in Seawater around a Port in the Strait of Malacca.

    Science.gov (United States)

    Teramoto, Maki; Queck, Shu Yeong; Ohnishi, Kouhei

    2013-01-01

    Major degraders of petroleum hydrocarbons in tropical seas have been indicated only by laboratory culturing and never through observing the bacterial community structure in actual environments. To demonstrate the major degraders of petroleum hydrocarbons spilt in actual tropical seas, indigenous bacterial community in seawater at Sentosa (close to a port) and East Coast Park (far from a port) in Singapore was analyzed. Bacterial species was more diverse at Sentosa than at the Park, and the composition was different: γ-Proteobacteria (57.3%) dominated at Sentosa, while they did not at the Park. Specialized hydrocarbonoclastic bacteria (SHCB), which use limited carbon sources with a preference for petroleum hydrocarbons, were found as abundant species at Sentosa, indicating petroleum contamination. On the other hand, SHCB were not the abundant species at the Park. The abundant species of SHCB at Sentosa were Oleibacter marinus and Alcanivorax species (strain 2A75 type), which have previously been indicated by laboratory culturing as important petroleum-aliphatic-hydrocarbon degraders in tropical seas. Together with the fact that SHCB have been identified as major degraders of petroleum hydrocarbons in marine environments, these results demonstrate that the O. marinus and Alcanivorax species (strain 2A75 type) would be major degraders of petroleum aliphatic hydrocarbons spilt in actual tropical seas.

  17. Expresión heteróloga de ARN mensajeros de Leishmania en ovocitos de anfibios

    Directory of Open Access Journals (Sweden)

    Rubén Darío Arroyo Olarte

    2006-01-01

    Full Text Available La técnica de expresión heteróloga en ovocitos de Xenopus laevis ha sido ampliamente utilizada para la caracterización funcional de canales iónicos. En este estudio se reporta el uso del modelo nativo de ovocitos de Bufo marinus para la expresión heteróloga de ARN poliadenilado (ARNm poli(A+ de Leishmania amazonensis y la posterior identificación de canales iónicos mediante registros electrofisiológicos utilizando la técnica de voltaje controlado (voltage-clamp. Se logró realizar la maduración, extracción y cultivo de ovocitos de B. marinus bajo condiciones similares a las estandarizadas para X. laevis. El potencial de reposo promedio así como las corrientes endógenas mostraron ser definidas por canales de cloruro dependientes de calcio y rectificadores de salida, de manera similar a lo reportado en X. laevis. La inyección de ARNm poli(A+ de L. amazonensis generó la expresión de corrientes de cloruro de  amplitud, cinética y características farmacológicas diferentes a las corrientes endógenas, reportadas en estudios previos con X. laevis como posible resultado de la expresión heteróloga de canales iónicos de L. amazonensis.

  18. Parasites of the pleasure oyster Crassostrea corteziensis cultured in Nayarit, Mexico.

    Science.gov (United States)

    Cáceres-Martínez, Jorge; Vasquez-Yeomans, Rebeca; Padilla-Lardizábal, Gloria

    2010-09-01

    The pleasure oyster Crassostrea corteziensis is collected and cultured in Nayarit on the Pacific coast of Mexico, and the improvement and promotion of its culture are seen as a possible source for the economic development of coastal populations. However, information about the parasite fauna of the pleasure oyster is almost completely lacking. A histopathological survey carried out in two estuaries, Boca del Camichín and Pozo Chino, revealed the presence of hypertrophied gametes, rickettsiales-like prokaryotes (RLPs), the protozoan Perkinsus marinus, a protozoan Nematopsis sp., Ancistrocoma-like ciliates (ALCs), Sphenophrya-like ciliates, a turbellarian Urastoma sp., and encysted crustaceans. In general, prevalence and intensity of parasites were similar in both localities except that ALCs and encysted crustaceans were more prevalent in Pozo Chino than in Boca del Camichín. Perkinsus marinus and RLPs seem to represent a more significant risk for the health of pleasure oysters than do the other parasites, and surveillance and control of these parasites are needed for the development of pleasure oyster culture.

  19. Specialized Hydrocarbonoclastic Bacteria Prevailing in Seawater around a Port in the Strait of Malacca.

    Directory of Open Access Journals (Sweden)

    Maki Teramoto

    Full Text Available Major degraders of petroleum hydrocarbons in tropical seas have been indicated only by laboratory culturing and never through observing the bacterial community structure in actual environments. To demonstrate the major degraders of petroleum hydrocarbons spilt in actual tropical seas, indigenous bacterial community in seawater at Sentosa (close to a port and East Coast Park (far from a port in Singapore was analyzed. Bacterial species was more diverse at Sentosa than at the Park, and the composition was different: γ-Proteobacteria (57.3% dominated at Sentosa, while they did not at the Park. Specialized hydrocarbonoclastic bacteria (SHCB, which use limited carbon sources with a preference for petroleum hydrocarbons, were found as abundant species at Sentosa, indicating petroleum contamination. On the other hand, SHCB were not the abundant species at the Park. The abundant species of SHCB at Sentosa were Oleibacter marinus and Alcanivorax species (strain 2A75 type, which have previously been indicated by laboratory culturing as important petroleum-aliphatic-hydrocarbon degraders in tropical seas. Together with the fact that SHCB have been identified as major degraders of petroleum hydrocarbons in marine environments, these results demonstrate that the O. marinus and Alcanivorax species (strain 2A75 type would be major degraders of petroleum aliphatic hydrocarbons spilt in actual tropical seas.

  20. The chimeric nature of the genomes of marine magnetotactic coccoid-ovoid bacteria defines a novel group of Proteobacteria.

    Science.gov (United States)

    Ji, Boyang; Zhang, Sheng-Da; Zhang, Wei-Jia; Rouy, Zoe; Alberto, François; Santini, Claire-Lise; Mangenot, Sophie; Gagnot, Séverine; Philippe, Nadège; Pradel, Nathalie; Zhang, Lichen; Tempel, Sébastien; Li, Ying; Médigue, Claudine; Henrissat, Bernard; Coutinho, Pedro M; Barbe, Valérie; Talla, Emmanuel; Wu, Long-Fei

    2017-03-01

    Magnetotactic bacteria (MTB) are a group of phylogenetically and physiologically diverse Gram-negative bacteria that synthesize intracellular magnetic crystals named magnetosomes. MTB are affiliated with three classes of Proteobacteria phylum, Nitrospirae phylum, Omnitrophica phylum and probably with the candidate phylum Latescibacteria. The evolutionary origin and physiological diversity of MTB compared with other bacterial taxonomic groups remain to be illustrated. Here, we analysed the genome of the marine magneto-ovoid strain MO-1 and found that it is closely related to Magnetococcus marinus MC-1. Detailed analyses of the ribosomal proteins and whole proteomes of 390 genomes reveal that, among the Proteobacteria analysed, only MO-1 and MC-1 have coding sequences (CDSs) with a similarly high proportion of origins from Alphaproteobacteria, Betaproteobacteria, Deltaproteobacteria and Gammaproteobacteria. Interestingly, a comparative metabolic network analysis with anoxic network enzymes from sequenced MTB and non-MTB successfully allows the eventual prediction of an organism with a metabolic profile compatible for magnetosome production. Altogether, our genomic analysis reveals multiple origins of MO-1 and M. marinus MC-1 genomes and suggests a metabolism-restriction model for explaining whether a bacterium could become an MTB upon acquisition of magnetosome encoding genes. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  1. Isolation, cultivation and genomic analysis of magnetosome biomineralization genes of a new genus of South-seeking magnetotactic cocci within the Alphaproteobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Morillo, Viviana [Universidade Federal do Rio de Janeiro; Abreu, Fernanda [Universidade Federal do Rio de Janeiro; Araujo, Ana C [Universidade Federal do Rio de Janeiro; de Almeida, Luiz G [Laboratorio Nacional de Computacao Cientifica; Enrich-Prast, Alex [Universidade Federal do Rio de Janeiro; Farina, Marcos [Universidade Federal do Rio de Janeiro; de Vasconcelos, Ana T [Laboratorio Nacional de Computacao Cientifica; Bazylinski, Dennis A [Ames Laboratory; Lins, Ulysses [Universidade Federal do Rio de Janeiro

    2014-01-01

    Although magnetotactic bacteria (MTB) are ubiquitous in aquatic habitats, they are still considered fastidious microorganisms with regard to growth and cultivation with only a relatively low number of axenic cultures available to date. Here, we report the first axenic culture of an MTB isolated in the Southern Hemisphere (Itaipu Lagoon in Rio de Janeiro, Brazil). Cells of this new isolate are coccoid to ovoid in morphology and grow microaerophilically in semi-solid medium containing an oxygen concentration ([O2]) gradient either under chemoorganoheterotrophic or chemolithoautotrophic conditions. Each cell contains a single chain of approximately 10 elongated cuboctahedral magnetite (Fe3O4) magnetosomes. Phylogenetic analysis based on the 16S rRNA gene sequence shows that the coccoid MTB isolated in this study represents a new genus in the Alphaproteobacteria; the name Magnetofaba australis strain IT-1 is proposed. Preliminary genomic data obtained by pyrosequencing shows that M. australis strain IT-1 contains a genomic region with genes involved in biomineralization similar to those found in the most closely related magnetotactic cocci Magnetococcus marinus strain MC-1. However, organization of the magnetosome genes differs from M. marinus.

  2. Redescrição de Pterobothrium crassicolle Diesing, 1850 (Cestoda: Trypanorhyncha e revalidação da espécie Redescription of Pterobothrium crassicole Diesing, 1850 (Cestoda: Trypanorhyncha and revalidation of the species

    Directory of Open Access Journals (Sweden)

    A. Arandas Rego

    1987-03-01

    Full Text Available É feito um estudo dos plerocercos, larvas de Trypanorhyncha, coletados de peixes estuarinos (Bagrus marinus e de peixes fluviais, da região de Belém, Pará; os peixes fluviais foram a dourada (Brachyplatystoma flavicans e a piramutaba (Brachyplatystoma vaillanti. Estes plerocercos foram comparados com outros coletados de pescadas (Cynoscion e corvinas (Micropogonias, do litoral do Rio de Janeiro. Foram identificados à espécie Pterobothrium crassicolle Diesing, 1850; é dada uma redescrição, uma vez que se considerava como espécie imperfeitamente conhecida.The author studies some plerocercus specimens collected from freshwater and estuarine fishes from Pará, Amazonian Region: Brachyplatystoma flavicans, B. vaillanti and Bagrus marinus. These larvae were compared with plerocercur collected from Cynoscion and Micropogonias, marine fishes from Rio de Janeiro and they were identified to Pterobothrium crassicolle Diesing, 1850. A redescription of P. crassicolle is given since most of the species described in the last century are poorly known.

  3. Review on utilization and research on harbour seal (Phoca vitulina in Iceland

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    Erlingur Hauksson

    2010-09-01

    Full Text Available Harbour seals (Phoca vitulina have been harvested in Iceland since the first settlers arrived in the 9th century. Pups were generally netted, clubbed and harpooned until 1875 when general use of guns for hunting began. Seal-hunting has been traditional amongst the farms legal rights. Seal hunting was an important supplement to other economic resources. Harbour seal skins, salted ordried, were exported and large dataset of catch statistics is available from trading logbooks since the late 19th century. In the early 20th century catch was about 6,000. In the ‘bounty’ period 1982 – 1989, maximum catches were of 4,000 animals with about 350 hunters participated; in 2006 catches were only about 100 animals with 18 hunters. After 1989 the population continued to decline even though catches decreased markedly. Unreported by-catch in fishing gear, hunt for local consumption and shooting of seals swimming in salmon rivers estuaries may have kept the total removal from the stock above sustainable levels. A considerable Icelandic knowledge base had been compiled about the biology of the harbour seal since the late 16th century, with the first written reference in 1588-1589. In the last decades, research on various aspects of its biology and monitoring have been intensified, with focus on abundance, distribution, diet and nematode infestation. The main results show that the Icelandic harbour seal population - has declined annually about 5% in the period 1980-2006, - was most abundant on the NW-coast, - feeds mainly on sand-eels and gadoids, - and was less infected with anisakid nematodes than grey seals. Seal watching, as a low-consumptive indirect utilization, may represent a new economical opportunity if properly regulated.

  4. Fishes and humankind III. Editorial.

    Directory of Open Access Journals (Sweden)

    Andrew K. G. Jones

    1999-12-01

    Full Text Available The publication of this group of three papers form part of the 1987 meeting of the International Council for Archaeozoologists Fish Remains Working Group which took place at the University of York, U. K. The papers illustrate an increased awareness of the significance of ichthyological research to archaeology and cover three areas of research: taphonomy; fishing artefacts; and fish remains recovered from an excavation. Jones sheds some light on the relative robustness of the bewildering array of elements in a fish skeleton by recording damage to a skeleton when it is trampled. His paper suggests an index of robustness which might be used to assess the degree of fragmentation in archaeological assemblages. Kemp reports on the excavation of a small medieval building located adjacent to medieval fish ponds created by Cistercian monks in North Yorkshire, England. In addition to the structural evidence, an impressive assemblage of weights, presumably net weights, found on or near the site is published. Perhaps most significant is a large lead weight which may have been used to weight catches of fish from the ponds. Fish remains recovered from two excavations at the quayside at Newcastle-upon-Tyne, England are discussed by Nicholson. Around 6000 identified bones form the basis for the study, the majority of which were identified as Gadid (cod family or herring. While the main food fishes typify fish bone assemblages from most post-Roman urban archaeological sites, the identification of small fishes such as sandeels, smelt, gobies and buttefish may indicate the utilisation of fish not nowadays considered as food at all. Given the diversity of species (30 individual species identified it is suggested that the remains from the main bone-producing organic horizons, dated to the late twelfth to thirteenth centuries, may include discard from a nearby fishmarket.

  5. A review of neogene and quaternary snakes of Central and Eastern Europe. Part 11: natricinae, elapidae, viperidae

    Directory of Open Access Journals (Sweden)

    Szyndlar, Z.

    1991-08-01

    Full Text Available Remains of Neogene and Quaternary "natricine" colubrids, elapids and viperids, including snakes previously described and those undescribed yet, coming from Poland, Ukraine, Moldavia, Czechoslovakia, Austria, Hungary, Romania, Bulgaria, and Greece are discussed. The following taxa, including 11 extinct species, were recognized: "Natricinae": Neonatrix nova, Neonatrix sp., Palaeonatrix silesiaca, Palaeonatrix lehmani, Natrix longivertebrata, Natrix cf. N. longivertebrata, Natrix natrix, Natrix tesselata, Natrix cf. N. tesselata, Natrix sp., "Natricinae" indet.; Elapidae: Naja romani, Naja sp., cf. Naja sp.; Viperidae: Vipera platyspondyla, Vipera sarmatica, Vipera burgenlandica, Vipera gedulyi, Vipera kuchurganica, Vipera antiqua, Vipera cf. V. ammodytes, Vipera berus, Vipera sp ('Oriental vipers' group, Vipera sp. ('aspis' group, Vipera sp. ('berus' group, Vipera sp. . (status unknown. Taxonomic status of two other extinct species, Natrix parva and Laophis crotaloides, is uncertain. Modern species appeared fírst in Central and East Europe in the middle Pliocene (MN 15. Older snakes belonged to extinct species of either extinct or extant genera; taxonomic distinction of most extinct genera is, however, not fully demonstrated. Best recognized oldest snakes from the area (Elapidae, Viperidae, and sorne Colubridae are clearly referable to modern genera and intrageneric subdivisions occurring today are observed in oldest (Iower Miocene remains; closest living relatives of these fossils are presently distributed in the Oriental Realm.Se revisan y estudian los restos neógenos y cuaternarios de colúbridos «natricinos», elápidos y vipéridos, incluyendo tanto serpientes previamente descritas como- otras inéditas. Los materiales analizados proceden de Polonia, Ukrania, Moldavia, Checoslovaquia, Austria, Hungría, Rumania, Bulgaria y Grecia. Se reconocen los siguientes taxones, incluyendo 11 especies extinguidas: Natricinae: Neonatrix nova

  6. Puffins reveal contrasting relationships between forage fish and ocean climate in the North Pacific

    Science.gov (United States)

    Sydeman, William J.; Piatt, John F.; Thompson, Sarah Ann; Garcia-Reyes, Marisol; Hatch, Scott A.; Arimitsu, Mayumi; Slater, Leslie; Williams, Jeffrey C.; Rojek, Nora A.; Zador, Stephani G.; Renner, Heather M.

    2017-01-01

    Long-term studies of predator food habits (i.e., ‘predator-based sampling’) are useful for identifying patterns of spatial and temporal variability of forage nekton in marine ecosystems. We investigated temporal changes in forage fish availability and relationships to ocean climate by analyzing diet composition of three puffin species (horned puffin Fratercula corniculata, tufted puffin Fratercula cirrhata, and rhinoceros auklet Cerorhinca monocerata) from five sites in the North Pacific from 1978–2012. Dominant forage species included squids and hexagrammids in the western Aleutians, gadids and Pacific sand lance (Ammodytes personatus) in the eastern Aleutians and western Gulf of Alaska (GoA), and sand lance and capelin (Mallotus villosus) in the northern and eastern GoA. Interannual fluctuations in forage availability dominated variability in the western Aleutians, whereas lower-frequency shifts in forage fish availability dominated elsewhere. We produced regional multivariate indicators of sand lance, capelin, and age-0 gadid availability by combining data across species and sites using Principal Component Analysis, and related these indices to environmental factors including sea level pressure (SPL), winds, and sea surface temperature (SST). There was coherence in the availability of sand lance and capelin across the study area. Sand lance availability increased linearly with environmental conditions leading to warmer ocean temperatures, whereas capelin availability increased in a non-linear manner when environmental changes led to lower ocean temperatures. Long-term studies of puffin diet composition appear to be a promising tool for understanding the availability of these difficult-to-survey forage nekton in remote regions of the North Pacific.

  7. Seasonal variation of assemblage and feeding guild structure of fish species in a boreal tidal basin

    Science.gov (United States)

    Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald

    2012-08-01

    Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas.

  8. Inter-season and interannual variations in fish and macrocrustacean community structure on a eastern English Channel sandy beach: Influence of environmental factors

    Science.gov (United States)

    Selleslagh, Jonathan; Amara, Rachid

    2008-05-01

    The intertidal zone of an exposed sandy beach on the French coast of the English Channel was sampled with a 1.5 m beam-trawl over five years (2000 and 2003-2006) at weekly intervals. The fish and macrocrustacean catches were analysed to determine the inter-season and interannual variation in community structure and relate these variations to changes in the major environmental variables. Only six species (plaice Pleuronectes platessa, common goby Pomatoschistus microps, sprat Sprattus sprattus, sand eel Ammodytes tobianus, brown shrimp Crangon crangon and shore crab Carcinus maenas) from the 27 species captured can be considered as dominant species of the intertidal zone, and they accounted for >90% of total numbers. Most individuals caught were young-of-the-year or juvenile. Analysis of similarities (ANOSIM) and similarities percentage (SIMPER) indicated that inter-season variability of community structure (mean average similarity = 47%) was more pronounced than interannual variability (mean average similarity = 65%). Canonical correspondence analysis (CCA) indicates that a substantial component (32.2%) of the measured inter-season variation in community structure can be explained by environmental factors (mainly water temperature). The main inter-season changes in the abundance and community structure were due to the variation of the six key species and reflect the different times of their recruitment. During the five years of the study, the structure of the fish and macrocrustacean spring community persisted from year to year, with the dominant species reappearing consistently even though their abundances fluctuated from year to year. This interannual variation probably reflects variable recruitment success influenced by physico-chemical conditions. In spite of the considerable interannual variation (40 times) in the spring bloom of the prymnesiophyte alga Phaeocystis globosa we found no effect of this bloom on either fish and macrocrustacean species densities or

  9. Assessing the nutritional stress hypothesis: Relative influence of diet quantity and quality on seabird productivity

    Science.gov (United States)

    Jodice, Patrick G.R.; Roby, Daniel D.; Turco, K.R.; Suryan, Robert M.; Irons, David B.; Piatt, John F.; Shultz, Michael T.; Roseneau, David G.; Kettle, Arthur B.; Anthony, Jill A.

    2006-01-01

    Food availability comprises a complex interaction of factors that integrates abundance, taxonomic composition, accessibility, and quality of the prey base. The relationship between food availability and reproductive performance can be assessed via the nutritional stress (NSH) and junk-food (JFH) hypotheses. With respect to reproductive success, NSH posits that a deficiency in any of the aforementioned metrics can have a deleterious effect on a population via poor reproductive success. JFH, a component of NSH, posits specifically that it is a decline in the quality of food (i.e. energy density and lipid content) that leads to poor reproductive success. We assessed each in relation to reproductive success in a piscivorous seabird, the black-legged kittiwake Rissa tridactyla. We measured productivity, taxonomic composition, frequency, size, and quality of meals delivered to nestlings from 1996 to 1999 at 6 colonies in Alaska, USA, 3 each in Prince William Sound and Lower Cook Inlet. Productivity varied widely among colony-years. Pacific herring Clupea pallasi, sand lance Ammodytes hexapterus, and capelin Mallotus villosus comprised ca. 80% of the diet among colony-years, and each was characterized by relatively high energy density. Diet quality for kittiwakes in this region therefore remained uniformly high during this study. Meal delivery rate and meal size were quite variable among colony-years, however, and best explained the variability in productivity. Parent kittiwakes appeared to select prey that were energy dense and that maximized the biomass provisioned to broods. While these results fail to support JFH, they do provide substantial support for NSH.

  10. Individual-based energetic model suggests bottom up mechanisms for the impact of coastal hypoxia on Pacific harbor seal (Phoca vitulina richardii) foraging behavior.

    Science.gov (United States)

    Steingass, Sheanna; Horning, Markus

    2017-03-07

    Wind-driven coastal hypoxia represents an environmental stressor that has the potential to drive redistribution of gilled marine organisms, and thereby indirectly affect the foraging characteristics of air-breathing upper trophic-level predators. We used a conceptual individual-based model to simulate effects of coastal hypoxia on the spatial foraging behavior and efficiency of a marine mammal, the Pacific harbor seal (Phoca vitulina richardii) on the Oregon coast. Habitat compression of fish was simulated at varying intensities of hypoxia. Modeled hypoxia affected up to 80% of the water column and half of prey species' horizontal habitat. Pacific sand lance (Ammodytes hexapterus), Pacific herring (Clupea pallasii), and English sole (Parophrys vetulus) were selected as representative harbor seal prey species. Model outputs most affected by coastal hypoxia were seal travel distance to foraging sites, time spent at depth during foraging dives, and daily energy balance. For larger seals, English sole was the most optimal prey during normoxia, however during moderate to severe hypoxia Pacific sand lance was the most beneficial prey. For smaller seals, Pacific herring was the most efficient prey species during normoxia, but sand lance became more efficient as hypoxia increased. Sand lance represented the highest increase in foraging efficiency during severe hypoxic events for all seals. Results suggest that during increasing hypoxia, smaller adult harbor seals could benefit by shifting from foraging on larger neritic schooling fishes to foraging closer inshore on less energetically-dense forage fish. Larger adult seals may benefit by shifting from foraging on groundfish to smaller, schooling neritic fishes as hypoxia increases. The model suggests a mechanism by which hypoxia may result in increased foraging efficiency of Pacific harbor seals, and therefore increased rates of predation on coastal fishes on the continental shelf during hypoxic events. Copyright © 2017

  11. Kittiwake diets and chick production signal a 2008 regime shift in the Northeast Pacific

    Science.gov (United States)

    Hatch, Scott A.

    2013-01-01

    I examined ~2700 food samples collected from adult and nestling black-legged kittiwakes Rissa tridactyla from 1978 through 2011 on Middleton Island in the Gulf of Alaska. The kittiwake diet was composed chiefly of fish, but invertebrates were taken in appreciable quantities in April and May. Upon spring arrival at the colony, adult kittiwakes foraged regularly at night on vertically migrating mesopelagic prey—lanternfishes (Myctophidae), squids, crustaceans, and polychaetes—a behavior they largely discontinued by egg-laying. During incubation and chick-rearing, food samples contained mostly (~85% by weight) Pacific sand lance Ammodytes hexapterus, capelin Mallotus villosus, Pacific herring Clupea pallasii, sablefish Anopoploma fimbria, krill (Euphausiidae), and juvenile salmon Onchorynchus gorboscha and O. keta. A salient finding over the longitudinal study was the emergence, twice, of capelin as a dominant forage species—once in 2000 to 2003, and again in 2008 through 2011. Kittiwakes responded to capelin availability by producing markedly higher numbers of fledged young. The 2000 to 2003 event corresponded to a previously documented shift to cooler conditions in the NE Pacific, which apparently was relatively limited in magnitude or duration. The more recent transition appears stronger and may be more lasting. I submit that 2008 was an important turning point, marking a substantive reversal of warm conditions that began with the well-documented regime shift of 1977. That interpretation is consistent with the existence of a ~60 yr cycle in ocean and atmospheric conditions in the North Pacific. All else being equal, it predicts the next 20 to 30 yr will be favorable for species such as kittiwakes and Steller sea lions, which seemed to respond negatively to the 1977 to 2007 warm phase of the Pacific Decadal Oscillation.

  12. Dicty_cDB: Contig-U15688-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 34 AX647129_1( AX647129 |pid:none) Sequence 1321 from Patent EP1270724. 134 2e-29 S27869( S27869 )GTPase-activating protein - mouse...1( AK122371 |pid:none) Mus musculus mRNA for mKIAA0799 pr... 41 0.23 A59297( A59297 ) myosin X - mouse &AJ24...A, clone:MSMg01-079C24.... 38 4.8 3 ( DW471640 ) SGP285757 Atlantic salmon Spleen cDNA library Sal... 36 4.8... Sus scrofa EST, clone C0007736b17, 5' direction. 36 0.030 3 ( EY311941 ) CAWX23745.fwd CAWX Helobdella robusta Primary Ear...... 44 0.18 7 ( CO544386 ) LyEST12150 Sea lamprey LyEST Petromyzon marinus c... 3

  13. The nature of the lamprey visual pigment.

    Science.gov (United States)

    CRESCITELLI, F

    1956-01-20

    From the retina of the land-locked population of the sea lamprey, Petromyzon marinus, a photolabile pigment was extracted which was identified spectrophotometrically as a member of the rhodopsin group of pigments. Using the absorption spectrum of a relatively pure solution and analysis by means of difference spectra, the peak of this pigment was placed at about 497 mmicro. The method of selective bleaching by light of different wave lengths revealed no significant amounts of any other pigment in the extracts. A similar pigment was also detected in retinal extracts of the Pacific Coast lamprey, Entospenus tridentatus. These results are significant for two reasons: (a) the lamprey is shown to be an example of an animal which spawns in fresh water but which is characterized by the presence of rhodopsin, rather than porphyropsin, in the retina; (b) the primitive phylogenetic position of the lamprey suggests that rhodopsin was the visual pigment of the original vertebrates.

  14. Lake Superior revisited 1984

    Science.gov (United States)

    MacCallum, Wayne R.; Selgeby, James H.

    1987-01-01

    The Lake Superior fish community has changed substantially since the early 1960s, when control of the sea lamprey (Petromyzon marinus) became effective. Self-reproducing stocks of lake trout (Salvelinus namaycush) have been reestablished in many inshore areas, although they have not yet reached pre-sea lamprey abundance; offshore lake trout are probably at or near pre-sea lamprey abundance. Stocks of lake whitefish (Coregonus clupeaformis) appear to have fully recovered; commercial catches are at or above historical levels. Lake herring (Coregonus artedii) are recovering rapidly in U.S. waters and are abundant in western Canadian waters. The population of rainbow smelt (Osmerus mordax), which declined in the 1970s, is recovering. Pacific salmon (Oncorhynchus) are becoming more abundant as a result of increased stocking in U.S. waters and are reproducing in most suitable tributaries; they have become significant in anglers' creels.

  15. Neither philopatric nor panmictic: microsatellite and mtDNA evidence suggests lack of natal homing but limits to dispersal in Pacific lamprey.

    Science.gov (United States)

    Spice, Erin K; Goodman, Damon H; Reid, Stewart B; Docker, Margaret F

    2012-06-01

    Most species with lengthy migrations display some degree of natal homing; some (e.g. migratory birds and anadromous salmonids) show spectacular feats of homing. However, studies of the sea lamprey (Petromyzon marinus) indicate that this anadromous species locates spawning habitat based on pheromonal cues from larvae rather than through philopatry. Previous genetic studies in the anadromous Pacific lamprey (Entosphenus tridentatus) have both supported and rejected the hypothesis of natal homing. To resolve this, we used nine microsatellite loci to examine the population structure in 965 Pacific lamprey from 20 locations from central British Columbia to southern California and supplemented this analysis with mitochondrial DNA restriction fragment length polymorphism analysis on a subset of 530 lamprey. Microsatellite analysis revealed (i) relatively low but often statistically significant genetic differentiation among locations (97% pairwise F(ST) values were lampreys are unusual among species with long migrations, but suggest that limited dispersal at sea precludes panmixia in this species. © 2012 Blackwell Publishing Ltd.

  16. The sea lamprey germline genome provides insights into programmed genome rearrangement and vertebrate evolution.

    Science.gov (United States)

    Smith, Jeramiah J; Timoshevskaya, Nataliya; Ye, Chengxi; Holt, Carson; Keinath, Melissa C; Parker, Hugo J; Cook, Malcolm E; Hess, Jon E; Narum, Shawn R; Lamanna, Francesco; Kaessmann, Henrik; Timoshevskiy, Vladimir A; Waterbury, Courtney K M; Saraceno, Cody; Wiedemann, Leanne M; Robb, Sofia M C; Baker, Carl; Eichler, Evan E; Hockman, Dorit; Sauka-Spengler, Tatjana; Yandell, Mark; Krumlauf, Robb; Elgar, Greg; Amemiya, Chris T

    2018-02-01

    The sea lamprey (Petromyzon marinus) serves as a comparative model for reconstructing vertebrate evolution. To enable more informed analyses, we developed a new assembly of the lamprey germline genome that integrates several complementary data sets. Analysis of this highly contiguous (chromosome-scale) assembly shows that both chromosomal and whole-genome duplications have played significant roles in the evolution of ancestral vertebrate and lamprey genomes, including chromosomes that carry the six lamprey HOX clusters. The assembly also contains several hundred genes that are reproducibly eliminated from somatic cells during early development in lamprey. Comparative analyses show that gnathostome (mouse) homologs of these genes are frequently marked by polycomb repressive complexes (PRCs) in embryonic stem cells, suggesting overlaps in the regulatory logic of somatic DNA elimination and bivalent states that are regulated by early embryonic PRCs. This new assembly will enhance diverse studies that are informed by lampreys' unique biology and evolutionary/comparative perspective.

  17. Kinematics and flow fields in 3D around swimming lamprey using light field PIV

    Science.gov (United States)

    Lehn, Andrea M.; Techet, Alexandra H.

    2016-11-01

    The fully time-resolved 3D kinematics and flow field velocities around freely swimming sea lamprey are derived using 3D light field imaging PIV. Lighthill's Elongated Body Theory (EBT) predicts that swimmers with anguilliform kinematics likened to lamprey, and similarly eels, will exhibit relatively poor propulsive efficiency. However, previous experimental studies of eel locomotion utilizing 2D PIV suggest disagreement with EBT estimates of wake properties; although, the thrust force generated by such swimmers has yet to be fully resolved using 3D measurements. A light field imaging array of multiple high-speed cameras is used to perform 3D synthetic aperture PIV around ammocoete sea lamprey (Petromyzon marinus). Fluid mechanics equations are used to determine thrust force generation, leading experimental studies closer to underpinning the physical mechanisms that enable aquatic locomotion of long, slender undulatory swimmers.

  18. The blood parasites of anurans from Costa Rica with reflections on the taxonomy of their trypanosomes.

    Science.gov (United States)

    Desser, S S

    2001-02-01

    During May 1997, specimens of 7 species of anurans, that included 5 Phrynohyas venulosa Laurenti, 5 Rana forreri Boulenger, 7 Rana vaillanti Brucchi, 6 Eleutherodactylus fitzingeri Schimdt, 4 Smilisca baudinii Duméril and Bibron, 1 Leptodactylus melanonotus, and 3 Bufo marinus Linneaus, from the Guanacaste Conservation Area, Costa Rica were examined for blood parasites. Their hematozoan fauna included intraerythrocytic and intraleukocytic icosahedral viruses, a rickettsia (Aegyptianella sp.), 2 species of Hepatozoon, Lankesterella minima, 2 unknown species of apicomplexans, 9 morphologically distinct types of trypanosomes, and 2 species of microfilariae. Rana vaillanti, the most aquatic species of frog, harbored the most species of parasites. Recent evidence indicates that morphological changes in the highly pleomorphic trypanosomes of anurans from different geographical regions have not kept pace with biochemical (isozyme) and molecular (DNA sequence) changes. Describing new species based solely on bloodstream trypomastigotes is discouraged. Additional criteria described herein should be applied when naming new species of anuran trypanosomes.

  19. Host-parasite interactions: Marine bivalve molluscs and protozoan parasites, Perkinsus species.

    Science.gov (United States)

    Soudant, Philippe; E Chu, Fu-Lin; Volety, Aswani

    2013-10-01

    This review assesses and examines the work conducted to date concerning host and parasite interactions between marine bivalve molluscs and protozoan parasites, belonging to Perkinsus species. The review focuses on two well-studied host-parasite interaction models: the two clam species, Ruditapes philippinarum and R. decussatus, and the parasite Perkinsus olseni, and the eastern oyster, Crassostrea virginica, and the parasite Perkinsus marinus. Cellular and humoral defense responses of the host in combating parasitic infection, the mechanisms (e.g., antioxidant enzymes, extracellular products) employed by the parasite in evading host defenses as well as the role of environmental factors in modulating the host-parasite interactions are described. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Disproportionate distribution of field potentials across the toad's tectal visual map in response to diffuse light ON and OFF stimulations.

    Science.gov (United States)

    Schwippert, W W; Beneke, T W; Ewert, J P

    1996-01-01

    In toads Bufo marinus and Bufo bufo spinosus, field potentials (FPs) were recorded from the surface of the optic tectum at different sites of the visual map in response to a sudden diffuse darkening (OFF) and lightening (ON) of the visual field of the contralateral eye. The OFF and ON responses were differently pronounced or even failed to occur. The latency of the former was significantly less than the one of the latter. FP amplitudes of the OFF and ON responses were strongest in the representation of a horizonto-superior anterio-lateral portion of the visual field and weakest toward the posterior field of vision. This phenomenon suggests various interpretations for subsequent experiments.

  1. New Mediterranean Biodiversity Records (December 2012

    Directory of Open Access Journals (Sweden)

    M. THESSALOU-LEGAKI

    2012-12-01

    Isl., Aegean Sea and the bryozoan Electra tenella (Livorno harbour and Messina Straits area. The alien fish Siganus luridus, Siganus rivulatus, Fistularia commersonii, Sphyraena chrysotaenia and Sargocentron rubrum are also reported from the islands of Karpathos and Chalki, and Pteragogus pelycus from Heraklion Bay, Crete. In addition, new localities for four rare Mediterranean inhabitants are given: the cephalopod Thysanoteuthis rhombus (NW Sardinia and the fish: Lampris guttatus (Calabria, S Italy, Petromyzon marinus (Gokova Bay and Remora australis (Saronikos Gulf, while the opisthobranch gastropod Cerberilla bernadettae is reported for the first time from the E Mediterranean (Cyprus. Finally, three species of the Aegean ascidiofauna are recorded for the first time: Lissoclinum perforatum, Ciona roulei and Ecteinascidia turbinata. Furthermore, it was established that Phallusia nigra has extended its distributional range to the north of the Aegean Sea.

  2. The Greenland shark (Somniosus microcephalus)

    DEFF Research Database (Denmark)

    Nielsen, Julius

    This PhD project has aimed at investigating longevity of the Greenland shark. The largest Greenland sharks measure at least 550 cm, and ever since Poul Marinus Hansen in 1963 presented that a recaptured medium-sized Greenland shark had grown 8 cm in 16 year, longevity of the species has been...... subject for speculation. Conventional age determination techniques for teleost or elasmobranchs are not applicable on the Greenland shark and its longevity has thus remained a mystery for decades. Inspired by alternative age estimation techniques applied on other sharks and whales, I have used bomb...... radiocarbon dating and a Bayesian calibration model to estimate longevity of the Greenland shark. The analyzed tissue stems from the eye lens nucleus – unique material which presumably reflects age 0 of the shark, as it has not undergone metabolic changes during the animal’s life. By studying 28 Greenland...

  3. An invasive species induces rapid adaptive change in a native predator: cane toads and black snakes in Australia.

    Science.gov (United States)

    Phillips, Ben L; Shine, Richard

    2006-06-22

    Rapid environmental change due to human activities has increased rates of extinction, but some species may be able to adapt rapidly enough to deal with such changes. Our studies of feeding behaviour and physiological resistance to toxins reveal surprisingly rapid adaptive responses in Australian black snakes (Pseudechis porphyriacus) following the invasion of a lethally toxic prey item, the cane toad (Bufo marinus). Snakes from toad-exposed localities showed increased resistance to toad toxin and a decreased preference for toads as prey. Separate laboratory experiments suggest that these changes are not attributable to learning (we were unable to teach naive snakes to avoid toxic prey) or to acquired resistance (repeated sub-lethal doses did not enhance resistance). These results strongly suggest that black snake behaviour and physiology have evolved in response to the presence of toads, and have done so rapidly. Toads were brought to Australia in 1935, so these evolved responses have occurred in fewer than 23 snake generations.

  4. Miniaturized Bioaffinity Assessment Coupled to Mass Spectrometry for Guided Purification of Bioactives from Toad and Cone Snail

    Directory of Open Access Journals (Sweden)

    Ferry Heus

    2014-02-01

    Full Text Available A nano-flow high-resolution screening platform, featuring a parallel chip-based microfluidic bioassay and mass spectrometry coupled to nano-liquid chromatography, was applied to screen animal venoms for nicotinic acetylcholine receptor like (nAChR affinity by using the acetylcholine binding protein, a mimic of the nAChR. The potential of this microfluidic platform is demonstrated by profiling the Conus textile venom proteome, consisting of over 1,000 peptides. Within one analysis (<90 min, 500 ng venom injected, ligands are detected and identified. To show applicability for non-peptides, small molecular ligands such as steroidal ligands were identified in skin secretions from two toad species (Bufo alvarius and Bufo marinus. Bioactives from the toad samples were subsequently isolated by MS-guided fractionation. The fractions analyzed by NMR and a radioligand binding assay with α7-nAChR confirmed the identity and bioactivity of several new ligands.

  5. Active urea transport by the skin of Bufo viridis: Amiloride- and phloretin-sensitive transport sites

    Energy Technology Data Exchange (ETDEWEB)

    Rapoport, J.; Abuful, A.; Chaimovitz, C.; Noeh, Z.; Hays, R.M. (Soroka Medical Center, Beersheva (Israel) Albert Einstein College of Medicine, New York, NY (USA))

    1988-09-01

    Urea is actively transported inwardly (J{sub i}) across the skin of the green toad Bufo viridis. J{sub i} is markedly enhanced in toads adapted to hypertonic saline. The authors studied urea transport across the skin of Bufo viridis under a variety of experimental conditions, including treatment with amiloride and phloretin, agents that inhibit urea permeability in the bladder of Bufo marinus. Amiloride (10{sup {minus}4} M) significantly inhibited J{sub i} in both adapted and unadapted animals and was unaffected by removal of sodium from the external medium. Phloretin (10{sup {minus}4} M) significantly inhibited J{sub i} in adapted animals by 23-46%; there was also a reduction in J{sub i} in unadapted toads at 10{sup {minus}4} and 5 {times} 10{sup {minus}4} M phloretin. A dose-response study revealed that the concentration of phloretin causing half-maximal inhibition (K{sub {1/2}}) was 5 {times} 10{sup {minus}4} M for adapted animals. J{sub i} was unaffected by the substitution of sucrose for Ringer solution or by ouabain. They conclude (1) the process of adaptation appears to involve an increase in the number of amiloride- and phloretin-inhibitable urea transport sites in the skin, with a possible increase in the affinity of the sites for phloretin; (2) the adapted skin resembles the Bufo marinus urinary bladder with respect to amiloride and phloretin-inhibitable sites; (3) they confirm earlier observations that J{sub i} is independent of sodium transport.

  6. Vertebrate phylogeny of hydrogen sulfide vasoactivity.

    Science.gov (United States)

    Dombkowski, Ryan A; Russell, Michael J; Schulman, Alexis A; Doellman, Meredith M; Olson, Kenneth R

    2005-01-01

    Hydrogen sulfide (H(2)S) is a recently identified endogenous vasodilator in mammals. In steelhead/rainbow trout (Oncorhynchus mykiss, Osteichthyes), H(2)S produces both dose-dependent dilation and a unique dose-dependent constriction. In this study, we examined H(2)S vasoactivity in all vertebrate classes to determine whether H(2)S is universally vasoactive and to identify phylogenetic and/or environmental trends. H(2)S was generated from NaHS and examined in unstimulated and precontracted systemic and, when applicable, pulmonary arteries (PA) from Pacific hagfish (Eptatretus stouti, Agnatha), sea lamprey (Petromyzon marinus, Agnatha), sandbar shark (Carcharhinus milberti, Chondrichthyes), marine toad (Bufo marinus, Amphibia), American alligator (Alligator mississippiensis, Reptilia), Pekin duck (Anas platyrhynchos domesticus, Aves), and white rat (Rattus rattus, Mammalia). In otherwise unstimulated vessels, NaHS produced 1) a dose-dependent relaxation in Pacific hagfish dorsal aorta; 2) a dose-dependent contraction in sea lamprey dorsal aorta, marine toad aorta, alligator aorta and PA, duck aorta, and rat thoracic aorta; 3) a threshold relaxation in shark ventral aorta, dorsal aorta, and afferent branchial artery; and 4) a multiphasic contraction-relaxation-contraction in the marine toad PA, duck PA, and rat PA. Precontraction of these vessels with another agonist did not affect the general pattern of NaHS vasoactivity with the exception of the rat aorta, where relaxation was now dominant. These results show that H(2)S is a phylogenetically ancient and versatile vasoregulatory molecule that appears to have been opportunistically engaged to suit both organ-specific and species-specific homeostatic requirements.

  7. Kittlitz's and Marbled Murrelets in Kenai Fjords National Park, South-Central Alaska: At-Sea Distribution, Abundance, and Foraging Habitat, 2006-08

    Science.gov (United States)

    Arimitsu, M.L.; Piatt, John F.; Romano, Marc D.; Madison, E.N.; Conaway, J.S.

    2010-01-01

    (Ammodytes hexapterus) were important forage species for murrelets in Kenai Fjords. Euphausiids also may have been an important forage resource for Kittlitz's murrelets in turbid glacial outflows in shallow waters during daytime. Marbled murrelets generally were more tolerant to a wider range of foraging habitat conditions although they tended to avoid the ice-covered silty waters close to glaciers. In contrast, Kittlitz's murrelets preferred areas where the influence of tidewater glaciers was the greatest and where their distribution was determined largely by prey availability. This work highlights an important link between interannual variability in murrelet counts at sea and mesoscale oceanographic conditions that influence marine productivity and prey distribution.

  8. Development and application of DNA techniques for validating and improving pinniped diet estimates.

    Science.gov (United States)

    Tollit, Dominic J; Schulze, Angela D; Trites, Andrew W; Olesiuk, Peter F; Crockford, Susan J; Gelatt, Thomas S; Ream, Rolf R; Miller, Kristina M

    2009-06-01

    Polymerase chain reaction techniques were developed and applied to identify DNA from >40 species of prey contained in fecal (scat) soft-part matrix collected at terrestrial sites used by Steller sea lions (Eumetopias jubatus) in British Columbia and the eastern Aleutian Islands, Alaska. Sixty percent more fish and cephalopod prey were identified by morphological analyses of hard parts compared with DNA analysis of soft parts (hard parts identified higher relative proportions of Ammodytes sp., Cottidae, and certain Gadidae). DNA identified 213 prey occurrences, of which 75 (35%) were undetected by hard parts (mainly Salmonidae, Pleuronectidae, Elasmobranchii, and Cephalopoda), and thereby increased species occurrences by 22% overall and species richness in 44% of cases (when comparing 110 scats that amplified prey DNA). Prey composition was identical within only 20% of scats. Overall, diet composition derived from both identification techniques combined did not differ significantly from hard-part identification alone, suggesting that past scat-based diet studies have not missed major dietary components. However, significant differences in relative diet contributions across scats (as identified using the two techniques separately) reflect passage rate differences between hard and soft digesta material and highlight certain hypothesized limitations in conventional morphological-based methods (e.g., differences in resistance to digestion, hard part regurgitation, partial and secondary prey consumption), as well as potential technical issues (e.g., resolution of primer efficiency and sensitivity and scat subsampling protocols). DNA analysis of salmon occurrence (from scat soft-part matrix and 238 archived salmon hard parts) provided species-level taxonomic resolution that could not be obtained by morphological identification and showed that Steller sea lions were primarily consuming pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon. Notably, DNA from

  9. Prochlorococcus as a Possible Source for Transparent Exopolymer Particles (TEP)

    KAUST Repository

    Agusti, Susana

    2017-04-26

    Transparent exopolymer particles (TEP), usually associated with phytoplankton blooms, promote the formation of marine aggregates. Their exportation to deep waters is considered a key component of the biological carbon pump. Here, we explored the role of solar radiation and picocyanobacteria in the formation of TEP in oligotrophic surface waters of the Atlantic and Pacific Oceans in ten on-deck incubation experiments during the Malaspina 2010 Expedition. TEP concentrations were low on the ocean’s surface although these concentrations were significantly higher on the surface of the Pacific (24.45 ± 2.3 μg XG Eq. L-1) than on the surface of the Atlantic Ocean (8.18 ± 4.56 μg XG Eq. L-1). Solar radiation induced a significant production of TEP in the on-deck experiments from the surface water of the Pacific Ocean, reaching values up to 187.3 μg XG Eq. L-1 compared with the low production observed in the dark controls. By contrast, TEP production in the Atlantic Ocean experiments was lower, and its formation was not related to the light treatments. Prochlorococcus sp. from the surface ocean was very sensitive to solar radiation and experienced a high cell decay in the Pacific Ocean experiments. TEP production in the on-deck incubation experiments was closely related to the observed cell decay rates of Prochlorococcus sp., suggesting that this picocyanobacteria genus is a potential source of TEP. The evidence to propose such potential role was derived experimentally, using natural communities including the presence of several species and a variety of processes. Laboratory experiments with cultures of a non-axenic strain of Prochlorococcus marinus were then used to test TEP production by this genus. TEP concentrations in the culture increased with increasing cell abundance during the exponential phase, reaching the highest TEP concentration at the beginning of the stationary phase. The average TEP concentration of 1474 ± 226 μg XG Eq. L-1 (mean ± SE) observed at

  10. Prochlorococcus as a Possible Source for Transparent Exopolymer Particles (TEP).

    Science.gov (United States)

    Iuculano, Francesca; Mazuecos, Ignacio P; Reche, Isabel; Agustí, Susana

    2017-01-01

    Transparent exopolymer particles (TEP), usually associated with phytoplankton blooms, promote the formation of marine aggregates. Their exportation to deep waters is considered a key component of the biological carbon pump. Here, we explored the role of solar radiation and picocyanobacteria in the formation of TEP in oligotrophic surface waters of the Atlantic and Pacific Oceans in ten on-deck incubation experiments during the Malaspina 2010 Expedition. TEP concentrations were low on the ocean's surface although these concentrations were significantly higher on the surface of the Pacific (24.45 ± 2.3 μg XG Eq. L-1) than on the surface of the Atlantic Ocean (8.18 ± 4.56 μg XG Eq. L-1). Solar radiation induced a significant production of TEP in the on-deck experiments from the surface water of the Pacific Ocean, reaching values up to 187.3 μg XG Eq. L-1 compared with the low production observed in the dark controls. By contrast, TEP production in the Atlantic Ocean experiments was lower, and its formation was not related to the light treatments. Prochlorococcus sp. from the surface ocean was very sensitive to solar radiation and experienced a high cell decay in the Pacific Ocean experiments. TEP production in the on-deck incubation experiments was closely related to the observed cell decay rates of Prochlorococcus sp., suggesting that this picocyanobacteria genus is a potential source of TEP. The evidence to propose such potential role was derived experimentally, using natural communities including the presence of several species and a variety of processes. Laboratory experiments with cultures of a non-axenic strain of Prochlorococcus marinus were then used to test TEP production by this genus. TEP concentrations in the culture increased with increasing cell abundance during the exponential phase, reaching the highest TEP concentration at the beginning of the stationary phase. The average TEP concentration of 1474 ± 226 μg XG Eq. L-1 (mean ± SE) observed at

  11. Substanzuntersuchungen an präkambrischen Favososphaeren/Silicobacteria

    Directory of Open Access Journals (Sweden)

    G. Burmann

    1998-01-01

    Full Text Available Aus der präkambrischen Lausitzer Grauwackeneinheit wurden in mineralischer Substanz überlieferte Mikrofossilien — Favososphaeren — mit Hilfe von EDS (energiedispersives Spektrum untersucht. Die Ergebnisse der Substanzanalysen belegen für die Kugeln eine Zusammensetzung aus SiO2 als Hauptsubstanz und eine sulfidische Zusammensetzung für die opaken Einschlüsse (Sulfidkörner. Die Favososphaeren sind morphologisch annähernd vergleichbar mit dem rezenten marinen Archaebacterium Staphylothermus marinus. Auf der Grundlage der Substanzdaten und der morphologischen Vergleichsmöglichkeit werden die Favososphaeren als eine spezielle Gruppe fossiler Archaebacteria angesehen, bezeichnet als Silicobacteria. Sie sind gekennzeichnet durch einen schwefelabhängigen Metabolismus, den Einbau kieseliger Substanz und eine Lebensweise als Mikrobenthos. Die Silicobacteria (Favososphaeren sensu lato werden unterschieden in die Familie Concentrisphaeridae mit konzentrisch-schaligem Aufbau und die Familie Favososphaeridae (Favososphaeren sensu stricto mit Wabenstruktur. Neue Taxa sind: Tenuisphaera faveolata, Crassosphaera brandenburgensis, Concentrisphaera crassogranulata, C. duplicata, C. triplicata, C. associata, Favososphaera magna, F. intermedia, F. circumpolaris, F. bipolaris, F. aequatorialis, F. coronata. Substance investigations of Precambrian Favosospheres/Silicobacteria. Part 1: Primary composition of Favosospheres. Favosospheres (microfossils in mineral preservation from the Precambrian Lusatian greywacke unit were investigated by EDS (energy dispersive spectrum. EDS-data indicate a SiO2-composition of the spheres and a sulfidic composition of opaque inclusions (sulfidic grains. The favosospheres are morphologically comparable with the living marine archaebacterium Staphylothermus marinus. On the base of chemical and morphological data, the favosospheres are interpreted as a special group of fossil archaebacteria, for which is proposed the name

  12. Signature proteins for the major clades of Cyanobacteria

    Science.gov (United States)

    2010-01-01

    Background The phylogeny and taxonomy of cyanobacteria is currently poorly understood due to paucity of reliable markers for identification and circumscription of its major clades. Results A combination of phylogenomic and protein signature based approaches was used to characterize the major clades of cyanobacteria. Phylogenetic trees were constructed for 44 cyanobacteria based on 44 conserved proteins. In parallel, Blastp searches were carried out on each ORF in the genomes of Synechococcus WH8102, Synechocystis PCC6803, Nostoc PCC7120, Synechococcus JA-3-3Ab, Prochlorococcus MIT9215 and Prochlor. marinus subsp. marinus CCMP1375 to identify proteins that are specific for various main clades of cyanobacteria. These studies have identified 39 proteins that are specific for all (or most) cyanobacteria and large numbers of proteins for other cyanobacterial clades. The identified signature proteins include: (i) 14 proteins for a deep branching clade (Clade A) of Gloebacter violaceus and two diazotrophic Synechococcus strains (JA-3-3Ab and JA2-3-B'a); (ii) 5 proteins that are present in all other cyanobacteria except those from Clade A; (iii) 60 proteins that are specific for a clade (Clade C) consisting of various marine unicellular cyanobacteria (viz. Synechococcus and Prochlorococcus); (iv) 14 and 19 signature proteins that are specific for the Clade C Synechococcus and Prochlorococcus strains, respectively; (v) 67 proteins that are specific for the Low B/A ecotype Prochlorococcus strains, containing lower ratio of chl b/a2 and adapted to growth at high light intensities; (vi) 65 and 8 proteins that are specific for the Nostocales and Chroococcales orders, respectively; and (vii) 22 and 9 proteins that are uniquely shared by various Nostocales and Oscillatoriales orders, or by these two orders and the Chroococcales, respectively. We also describe 3 conserved indels in flavoprotein, heme oxygenase and protochlorophyllide oxidoreductase proteins that are specific for

  13. Excrement examination with blood detection tests as a novel method to study the postmetamorphic feeding in lampreys

    Directory of Open Access Journals (Sweden)

    Sergio Silva

    2015-11-01

    Full Text Available After several years in freshwater, sea lamprey Petromyzon marinus L. 1758 ammocoetes undergo metamorphosis that allows postmetamorphic individuals to migrate to the sea and start the haematophagous feeding. Very little and fragmented information, based on scarce captures of lampreys or wounded preys, is available concerning the postmetamorphic phase of the life cycle. For example, although it was previously considered that postmetamorphics do not start feeding until they reach the estuary or the sea, recent studies have shown that in European populations some individuals start feeding in freshwater. Therefore, it is necessary to develop, calibrate and standardize new methods to advance in the knowledge of the trophic ecology of postmetamorphic lampreys. According to that, the aim of this study is to investigate the usefulness of a commercial test for blood detection based on an advanced modification of the Kastle-Meyer test (Hemastix, Siemens® as a non invasive method to notice active haematophagous feeding in postmetamorphic lampreys (analysing excrements, and in our particular case to study the onset of feeding in newly transformed P. marinus. For this purpose, 170 postmetamorphic sea lampreys were captured in a fixed trap located in the River Ulla (NW Spain since December 2014 until June 2015. Thirty six individuals presented excrements (21%, which were analyzed. Positive blood tests were obtained in March (1 of 84 individuals; 1.2%, April (5 of 23 individuals; 22%, May (1 individual, 100% and June (1 individual, 100%. Excrements with positive results were characterized by being abundant, usually of dense consistency and white, red, orange or dark green. Less abundant light green faeces of liquid consistency (and dark green faeces in some cases provided negative results. Thus, this study reveals the test for blood detection as a suitable tool to notice active feeding in postmetamorphic lampreys. The presence and visual analysis of excrements

  14. EFL GTPase in cryptomonads and the distribution of EFL and EF-1alpha in chromalveolates.

    Science.gov (United States)

    Gile, Gillian H; Patron, Nicola J; Keeling, Patrick J

    2006-10-01

    EFL (EF-like protein) is a member of the GTPase superfamily that includes several translation factors. Because it has only been found in a few eukaryotic lineages and its presence correlates with the absence of the related core translation factor EF-1alpha, its distribution is hypothesized to be the result of lateral gene transfer and replacement of EF-1alpha. In one supergroup of eukaryotes, the chromalveolates, two major lineages were found to contain EFL (dinoflagellates and haptophytes), while the others encode EF-1alpha (apicomplexans, ciliates, heterokonts and cryptomonads). For each of these groups, this distribution was deduced from whole genome sequence or expressed sequence tag (EST) data from several species, with the exception of cryptomonads from which only a single EF-1alpha PCR product from one species was known. By sequencing ESTs from two cryptomonads, Guillardia theta and Rhodomonas salina, and searching for all GTPase translation factors, we revealed that EFL is present in both species, but, contrary to expectations, we found EF-1alpha in neither. On balance, we suggest the previously reported EF-1alpha from Rhodomonas salina is likely an artefact of contamination. We also identified EFL in EST data from two members of the dinoflagellate lineage, Karlodinium micrum and Oxyrrhis marina, and from an ongoing genomic sequence project from a third, Perkinsus marinus. Karlodinium micrum is a symbiotic pairing of two lineages that would have both had EFL (a dinoflagellate and a haptophyte), but only the dinoflagellate gene remains. Oxyrrhis marina and Perkinsus marinus are early diverging sister-groups to dinoflagellates, and together show that EFL originated early in this lineage. Phylogenetic analysis confirmed that these genes are all EFL homologues, and showed that cryptomonad genes are not detectably related to EFL from other chromalveolates, which collectively form several distinct groups. The known distribution of EFL now includes a third group

  15. Prochlorococcus as a Possible Source for Transparent Exopolymer Particles (TEP

    Directory of Open Access Journals (Sweden)

    Susana Agustí

    2017-04-01

    Full Text Available Transparent exopolymer particles (TEP, usually associated with phytoplankton blooms, promote the formation of marine aggregates. Their exportation to deep waters is considered a key component of the biological carbon pump. Here, we explored the role of solar radiation and picocyanobacteria in the formation of TEP in oligotrophic surface waters of the Atlantic and Pacific Oceans in ten on-deck incubation experiments during the Malaspina 2010 Expedition. TEP concentrations were low on the ocean’s surface although these concentrations were significantly higher on the surface of the Pacific (24.45 ± 2.3 μg XG Eq. L-1 than on the surface of the Atlantic Ocean (8.18 ± 4.56 μg XG Eq. L-1. Solar radiation induced a significant production of TEP in the on-deck experiments from the surface water of the Pacific Ocean, reaching values up to 187.3 μg XG Eq. L-1 compared with the low production observed in the dark controls. By contrast, TEP production in the Atlantic Ocean experiments was lower, and its formation was not related to the light treatments. Prochlorococcus sp. from the surface ocean was very sensitive to solar radiation and experienced a high cell decay in the Pacific Ocean experiments. TEP production in the on-deck incubation experiments was closely related to the observed cell decay rates of Prochlorococcus sp., suggesting that this picocyanobacteria genus is a potential source of TEP. The evidence to propose such potential role was derived experimentally, using natural communities including the presence of several species and a variety of processes. Laboratory experiments with cultures of a non-axenic strain of Prochlorococcus marinus were then used to test TEP production by this genus. TEP concentrations in the culture increased with increasing cell abundance during the exponential phase, reaching the highest TEP concentration at the beginning of the stationary phase. The average TEP concentration of 1474 ± 226 μg XG Eq. L-1 (mean

  16. Signature proteins for the major clades of Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Mathews Divya W

    2010-01-01

    Full Text Available Abstract Background The phylogeny and taxonomy of cyanobacteria is currently poorly understood due to paucity of reliable markers for identification and circumscription of its major clades. Results A combination of phylogenomic and protein signature based approaches was used to characterize the major clades of cyanobacteria. Phylogenetic trees were constructed for 44 cyanobacteria based on 44 conserved proteins. In parallel, Blastp searches were carried out on each ORF in the genomes of Synechococcus WH8102, Synechocystis PCC6803, Nostoc PCC7120, Synechococcus JA-3-3Ab, Prochlorococcus MIT9215 and Prochlor. marinus subsp. marinus CCMP1375 to identify proteins that are specific for various main clades of cyanobacteria. These studies have identified 39 proteins that are specific for all (or most cyanobacteria and large numbers of proteins for other cyanobacterial clades. The identified signature proteins include: (i 14 proteins for a deep branching clade (Clade A of Gloebacter violaceus and two diazotrophic Synechococcus strains (JA-3-3Ab and JA2-3-B'a; (ii 5 proteins that are present in all other cyanobacteria except those from Clade A; (iii 60 proteins that are specific for a clade (Clade C consisting of various marine unicellular cyanobacteria (viz. Synechococcus and Prochlorococcus; (iv 14 and 19 signature proteins that are specific for the Clade C Synechococcus and Prochlorococcus strains, respectively; (v 67 proteins that are specific for the Low B/A ecotype Prochlorococcus strains, containing lower ratio of chl b/a2 and adapted to growth at high light intensities; (vi 65 and 8 proteins that are specific for the Nostocales and Chroococcales orders, respectively; and (vii 22 and 9 proteins that are uniquely shared by various Nostocales and Oscillatoriales orders, or by these two orders and the Chroococcales, respectively. We also describe 3 conserved indels in flavoprotein, heme oxygenase and protochlorophyllide oxidoreductase proteins that

  17. Olfactory sensitivity of Pacific Lampreys to lamprey bile acids

    Science.gov (United States)

    Robinson, T. Craig; Sorensen, Peter W.; Bayer, Jennifer M.; Seelye, James G.

    2009-01-01

    Pacific lampreys Lampetra tridentata are in decline throughout much of their historical range in the Columbia River basin. In support of restoration efforts, we tested whether larval and adult lamprey bile acids serve as migratory and spawning pheromones in adult Pacific lampreys, as they do in sea lampreys Petromyzon marinus. The olfactory sensitivity of adult Pacific lampreys to lamprey bile acids was measured by electro-olfactogram recording from the time of their capture in the spring until their spawning in June of the following year. As controls, we tested L-arginine and a non-lamprey bile acid, taurolithocholic acid 3-sulfate (TLS). Migrating adult Pacific lampreys were highly sensitive to petromyzonol sulfate (a component of the sea lamprey migratory pheromone) and 3-keto petromyzonol sulfate (a component of the sea lamprey sex pheromone) when first captured. This sensitivity persisted throughout their long migratory and overwinter holding period before declining to nearly unmeasurable levels by the time of spawning. The absolute magnitudes of adult Pacific lamprey responses to lamprey bile acids were smaller than those of the sea lamprey, and unlike the sea lamprey, the Pacific lamprey did not appear to detect TLS. No sexual dimorphism was noted in olfactory sensitivity. Thus, Pacific lampreys are broadly similar to sea lampreys in showing sensitivity to the major lamprey bile acids but apparently differ in having a longer period of sensitivity to those acids. The potential utility of bile acid-like pheromones in the restoration of Pacific lampreys warrants their further investigation in this species.

  18. Ecology of the Lake Huron fish community, 1970-1999

    Science.gov (United States)

    Dobiesz, Norine E.; McLeish, David A.; Eshenroder, Randy L.; Bence, James R.; Mohr, Lloyd C.; Ebener, Mark P.; Nalepa, Thomas F.; Woldt, Aaron P.; Johnson, James E.; Argyle, Ray L.; Makarewicz, Joseph C.

    2005-01-01

    We review the status of the Lake Huron fish community between 1970 and 1999 and explore the effects of key stressors. Offshore waters changed little in terms of nutrient enrichment, while phosphorus levels declined in inner Saginaw Bay. Introduced mussels (Dreissena spp.) proliferated and may have caused a decline in Diporeia spp. This introduction could have caused a decline in lake whitefish (Coregonus clupeaformis) growth and condition, with serious repercussions for commercial fisheries. Bythotrephes, an exotic predatory cladoceran, and other new exotics may be influencing the fish community. Sea lampreys (Petromyzon marinus) remained prevalent, but intensive control efforts on the St. Mary's River may reduce their predation on salmonines. Overfishing was less of a problem than in the past, although fishing continued to reduce the amount of lake trout (Salvelinus namaycush) spawning biomass resulting from hatchery-reared fish planted to rehabilitate this species. Massive stocking programs have increased the abundance of top predators, but lake trout were rehabilitated in only one area. Successful lake trout rehabilitation may require lower densities of introduced pelagic prey fish than were seen in the 1990s, along with continued stocking of hatchery-reared lake trout and control of sea lamprey. Such reductions in prey fish could limit Pacific salmon (Oncorhynchus spp.) fisheries.

  19. HPLC and ELISA analyses of larval bile acids from Pacific and western brook lampreys.

    Science.gov (United States)

    Yun, Sang-Seon; Scott, Alexander P; Bayer, Jennifer M; Seelye, James G; Close, David A; Li, Weiming

    2003-08-01

    Comparative studies were performed on two native lamprey species, Pacific lamprey (Lampetra tridentata) and western brook lamprey (Lampetra richardsoni) from the Pacific coast along with sea lamprey (Petromyzon marinus) from the Great Lakes, to investigate their bile acid production and release. HPLC and ELISA analyses of the gall bladders and liver extract revealed that the major bile acid compound from Pacific and western brook larval lampreys was petromyzonol sulfate (PZS), previously identified as a migratory pheromone in larval sea lamprey. An ELISA for PZS has been developed in a working range of 20 pg-10 ng per well. The tissue concentrations of PZS in gall bladder were 127.40, 145.86, and 276.96 micro g/g body mass in sea lamprey, Pacific lamprey, and western brook lamprey, respectively. Releasing rates for PZS in the three species were measured using ELISA to find that western brook and sea lamprey released PZS 20 times higher than Pacific lamprey did. Further studies are required to determine whether PZS is a chemical cue in Pacific and western brook lampreys.

  20. Origins of the descending spinal projections in petromyzontid and myxinoid agnathans.

    Science.gov (United States)

    Ronan, M

    1989-03-01

    The origins of the descending spinal pathways in sea lampreys (Petromyzon marinus), silver lampreys (Ichthyomyzon unicuspis), and Pacific hagfish (Eptatretus stouti) were identified by the retrograde transport of horseradish peroxidase (HRP) placed in the rostral spinal cord. In lampreys, the majority of HRP-labeled cells were located along the length of the brainstem reticular formation in the inferior, middle, and superior reticular nuclei of the medulla, mesencephalic tegmentum, and nucleus of the medial longitudinal fasciculus. Labeled reticular cells included the Mauthner and Müller cells. Horseradish-peroxidase-filled cells were also present in the descending trigeminal tract, intermediate and posterior octavomotor nuclei, and a diencephalic cell group, the nucleus of the posterior tubercle. As in lampreys, the reticular formation of the Pacific hagfish was the largest source of descending afferents to the spinal cord. Labeled cells were found in the dorsolateral and ventromedial reticular nuclei, the dorsal tegmentum at the juncture of the medulla and midbrain, and the nucleus of the medial longitudinal fasciculus. Additional medullary cells projecting to the cord were located in the perivagal nucleus, the central gray, and the anterior and posterior magnocellular octavolateralis nuclei. The existence of reticulospinal and possible vestibulo-, trigemino-, and solitary spinal projections in lampreys and hagfishes and the wide distribution of these pathways in jawed vertebrates suggest that they evolved in the common ancestor of gnathostomes and both groups of jawless fishes. However, descending spinal pathways from the cerebellum, red nucleus, and telencephalon appear to be gnathostome characters.

  1. Diversity of extracellular proteins during the transition from the ‘proto-apicomplexan’ alveolates to the apicomplexan obligate parasites

    KAUST Repository

    Templeton, Thomas J.

    2015-11-20

    The recent completion of high-coverage draft genome sequences for several alveolate protozoans – namely, the chromerids, Chromera velia and Vitrella brassicaformis ; the perkinsid Perkinsus marinus ; the apicomplexan, Gregarina niphandrodes , as well as high coverage transcriptome sequence information for several colpodellids, allows for new genome-scale comparisons across a rich landscape of apicomplexans and other alveolates. Genome annotations can now be used to help interpret fine ultrastructure and cell biology, and guide new studies to describe a variety of alveolate life strategies, such as symbiosis or free living, predation, and obligate intracellular parasitism, as well to provide foundations to dissect the evolutionary transitions between these niches. This review focuses on the attempt to identify extracellular proteins which might mediate the physical interface of cell–cell interactions within the above life strategies, aided by annotation of the repertoires of predicted surface and secreted proteins encoded within alveolate genomes. In particular, we discuss what descriptions of the predicted extracellular proteomes reveal regarding a hypothetical last common ancestor of a pre-apicomplexan alveolate – guided by ultrastructure, life strategies and phylogenetic relationships – in an attempt to understand the evolution of obligate parasitism in apicomplexans.

  2. DNA methylation in a sea lamprey vasotocin receptor gene promoter correlates with tissue- and life-stage-specific mRNA expression.

    Science.gov (United States)

    Mayasich, Sally A; Bemis, Lynne T; Clarke, Benjamin L

    2016-12-01

    The jawless vertebrate sea lamprey (Petromyzon marinus) genome has a different structure from both invertebrates and jawed vertebrates featuring high guanine-cytosine (GC) content. This raises the question of whether DNA methylation of cytosine-guanine (CpG) dinucleotides could function to regulate lamprey gene transcription. We previously characterized a lamprey arginine vasotocin (AVT) receptor gene (Pm807) possessing characteristics of both arginine vasopressin (AVP) V1A and oxytocin (OXT) receptor genes of jawed vertebrates. Lamprey Pm807 mRNA is highly expressed in adult heart and larval liver but not expressed in adult liver. Using high-resolution melt (HRM) PCR on bisulfite-converted DNA, we pinpointed a region with tissue-specific differences in DNA melt characteristics, indicating differences in methylation level. Sequencing revealed a pattern of methylation at specific CpGs at consistently higher levels in adult heart and larval liver than adult liver. These CpGs are associated with putative transcription factor binding sequences organized similarly to functional OXTR promoters in mammals, suggesting functional similarity in lamprey gene transcription regulation. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Effects of temperature, pH-values and sodium chloride concentrations on the glucose-6-phosphate dehydrogenase activity by thermotolerant Bacillus strains

    Directory of Open Access Journals (Sweden)

    HAZEM AQEL

    2012-01-01

    Full Text Available Thirteen new isolated thermotolerant Bacillus strains and four known Bacillus species were used to evaluate the effect of growth temperature, pH-values and NaCl concentrations on the intracellular glucose-6-phosphate dehydrogenase (G6PDH activity. Results had shown a significant difference in G6PDH production among all species at all used temperatures (p<0.05. The response of individual new isolates and controls for production of G6PDH under growth conditions was variable. The optimal growth conditions did not correspond to the optimal cultivation conditions for maximum G6PDH production. The growth temperature showed the most significant effect on G6PDH activity. The combined effect of temperature and NaCl on the G6PDH activity was strongly pronounced in comparison with the combined effect of temperature and pH or pH and NaCl. Thermal stability at 53ºC and electrophoretic mobility were also investigated. G6PDH from HUTB41 was the most thermostable G6PDH enzyme with T50% of more than 360 minutes. Electrophoretic study demonstrated that G6PDH was composed of two isoenzymes for all strains except B. marinus and B. schlegelii that had three isoenzymes.

  4. Diversity of KaiC-based timing systems in marine Cyanobacteria.

    Science.gov (United States)

    Axmann, Ilka M; Hertel, Stefanie; Wiegard, Anika; Dörrich, Anja K; Wilde, Annegret

    2014-04-01

    The coordination of biological activities into daily cycles provides an important advantage for the fitness of diverse organisms. Most eukaryotes possess an internal clock ticking with a periodicity of about one day to anticipate sunrise and sunset. The 24-hour period of the free-running rhythm is highly robust against many changes in the natural environment. Among prokaryotes, only Cyanobacteria are known to harbor such a circadian clock. Its core oscillator consists of just three proteins, KaiA, KaiB, and KaiC that produce 24-hour oscillations of KaiC phosphorylation, even in vitro. This unique three-protein oscillator is well documented for the freshwater cyanobacterium Synechococcus elongatus PCC 7942. Several physiological studies demonstrate a circadian clock also for other Cyanobacteria including marine species. Genes for the core clock components are present in nearly all marine cyanobacterial species, though there are large differences in the specific composition of these genes. In the first section of this review we summarize data on the model circadian clock from S. elongatus PCC 7942 and compare it to the reduced clock system of the marine cyanobacterium Prochlorococcus marinus MED4. In the second part we discuss the diversity of timing mechanisms in other marine Cyanobacteria with regard to the presence or absence of different components of the clock. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Huschke's anterior external auditory canal foramen: art before medicine?

    Science.gov (United States)

    Pirsig, Wolfgang; Mudry, Albert

    2015-03-01

    During the Renaissance, several anatomic details were described with a degree of exactness, which would stand the test of time. One example is the foramen in the anteroinferior wall of the external auditory canal, eponymously named after the German anatomist, Emil Huschke, who described it in 1844. However, the first clearly medical observation of this foramen was published by the French physician Jean Riolan the Younger in 1648. After a short excursion into some paleopathologic findings of this foramen in skulls of the Early Bronze Age and of pre-Columbian Peruvian populations, this article follows the traces of the early medical descriptions and depictions of the foramen up until the 19th century. They are connected with the names of Duverney (1683), Cassebohm (1734), Lincke (1837), Huschke (1844); Humphry (1858), von Troeltsch (1860), and especially Buerkner (1878). Surprisingly, the earliest exact depiction of the foramen in the auditory canal of a skull was found in the oil painting Saint Jerome in his study by the Flemish artist Marinus Claeszon van Reymerswaele. He depicted the foramen in the period between 1521 and 1541, a hundred years before Riolan the Younger.

  6. Increasing temperature decreases the predatory effect of the intertidal shanny Lipophrys pholis on an amphipod prey

    KAUST Repository

    South, J.

    2017-11-15

    Interactions between Lipophrys pholis and its amphipod prey Echinogammarus marinus were used to investigate the effect of changing water temperatures, comparing current and predicted mean summer temperatures. Contrary to expectations, predator attack rates significantly decreased with increasing temperature. Handling times were significantly longer at 19° C than at 17 and 15° C and the maximum feeding estimate was significantly lower at 19° C than at 17° C. Functional-response type changed from a destabilizing type II to the more stabilizing type III with a temperature increase to 19° C. This suggests that a temperature increase can mediate refuge for prey at low densities. Predatory pressure by teleosts may be dampened by a large increase in temperature (here from 15 to 19° C), but a short-term and smaller temperature increase (to 17° C) may increase destabilizing resource consumption due to high maximum feeding rates; this has implications for the stability of important intertidal ecosystems during warming events.

  7. Understanding behavioral responses of fish to pheromones in natural freshwater environments

    Science.gov (United States)

    Johnson, Nicholas S.; Li, Weiming

    2010-01-01

    There is an abundance of experimental studies and reviews that describe odorant-mediated behaviors of fish in laboratory microcosms, but research in natural field conditions has received considerably less attention. Fish pheromone studies in laboratory settings can be highly productive and allow for controlled experimental designs; however, laboratory tanks and flumes often cannot replicate all the physical, physiological and social contexts associated with natural environments. Field experiments can be a critical step in affirming and enhancing understanding of laboratory discoveries and often implicate the ecological significance of pheromones employed by fishes. When findings from laboratory experiments have been further tested in field environments, often different and sometimes contradictory conclusions are found. Examples include studies of sea lamprey (Petromyzon marinus) mating pheromones and fish alarm substances. Here, we review field research conducted on fish pheromones and alarm substances, highlighting the following topics: (1) contradictory results obtained in laboratory and field experiments, (2) how environmental context and physiological status influences behavior, (3) challenges and constraints of aquatic field research and (4) innovative techniques and experimental designs that advance understanding of fish chemical ecology through field research.

  8. Blocking and guiding adult sea lamprey with pulsed direct current from vertical electrodes

    Science.gov (United States)

    Johnson, Nicholas S.; Thompson, Henry T.; Holbrook, Christopher M.; Tix, John A.

    2014-01-01

    Controlling the invasion front of aquatic nuisance species is of high importance to resource managers. We tested the hypothesis that adult sea lamprey (Petromyzon marinus), a destructive invasive species in the Laurentian Great Lakes, would exhibit behavioral avoidance to dual-frequency pulsed direct current generated by vertical electrodes and that the electric field would not injure or kill sea lamprey or non-target fish. Laboratory and in-stream experiments demonstrated that the electric field blocked sea lamprey migration and directed sea lamprey into traps. Rainbow trout (Oncorhynchus mykiss) and white sucker (Catostomus commersoni), species that migrate sympatrically with sea lamprey, avoided the electric field and had minimal injuries when subjected to it. Vertical electrodes are advantageous for fish guidance because (1) the electric field produced varies minimally with depth, (2) the electric field is not grounded, reducing power consumption to where portable and remote deployments powered by solar, wind, hydro, or a small generator are feasible, and (3) vertical electrodes can be quickly deployed without significant stream modification allowing rapid responses to new invasions. Similar dual-frequency pulsed direct current fields produced from vertical electrodes may be advantageous for blocking or trapping other invasive fish or for guiding valued fish around dams.

  9. Physiological activity of docosahexaenoic acid and its production by microbial culture; DHA no seiri sayo to sono biseibutsu seisan

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, T. [National Institute of Bioscience an Human Technology, Tsukuba (Japan)

    1995-10-20

    Docosahexaenoic acid (DHA) has recently attracted nutritional attentions through its specific function in brain/retina as well as beneficial effects of (n-3) polyunsaturated fatty acids. Firstly, the physiological activity of DHA is reviewed from recent publications, and compared to the activity of icosapentaenoic acid (IPA), with respect to its incorporation into plasma/tissues, its anticoagulant/anti-inflammatory effect, its effect on brain/retina, its anticancer effect, and adverse effects of excess intake, if any. Secondly, reports on microbial lipid (single cell oil, SCO) production including DHA are reviewed, which include Crythecodinium cohnii, Thraustochytrium aureum, Vibrio marinus etc. Two trials for DHA-SCO using C. cohnii has revealed high cell/DHA productivities in a semicontinuous culture (50 g/L of cell mass) and a continuous culture (120 mg/L.h of DHA). A new strain, SR 21, isolated from the coral sea water in Yap Islands and identified as Thraustochytrium sp., showed tolerance to high concentration of glucose and to mechanical mixing and resulted in the highest DHA productivity at 4000 mg/L in a fermented culture for 7 day. 105 refs., 1 fig.

  10. Anselm Citron (1923 - 2014)

    CERN Multimedia

    2015-01-01

    Anselm Citron, one of CERN’s pioneers, an enthusiastic scholar and internationally renowned researcher, passed away on 8 December at the age of 91.   Anselm Citron, front, looks at a quadrupole for the muon beam at the SC with, left to right, Bengt Hedin, Marinus van Gulik and Pierre Lapostolle. Born in Germany, Citron went to high school in the Netherlands, where he had been sent to escape the persecution of people with Jewish roots. After abitur and a short period at a technical high school, he took part in the last stages of the Second World War before returning to Freiburg in 1945. There, he studied physics under Wolfgang Gentner, and obtained his PhD. Citron then joined the Cavendish Laboratory, Cambridge, in 1952, to take part in research on accelerator physics. A year later, he came to the newly founded CERN as one of its first 12 staff physicists and contributed to the construction of the Proton Synchrotron, for which he was responsible for the high-frequency powe...

  11. An immune-enriched oligo-microarray analysis of gene expression in Manila clam (Venerupis philippinarum) haemocytes after a Perkinsus olseni challenge.

    Science.gov (United States)

    Romero, Alejandro; Forn-Cuní, Gabriel; Moreira, Rebeca; Milan, Massimo; Bargelloni, Luca; Figueras, Antonio; Novoa, Beatriz

    2015-03-01

    Parasites of the genus Perkinsus cause high mortality and economic losses in bivalves commonly produced in global aquaculture. Although the immune responses of oysters and clams naturally infected with Perkinsus marinus or Perkinsus olseni have been extensively studied, there is not much information on host response at the early stages of infection. In this study, we analysed how P. olseni influences the gene expression profiles of haemocytes from the Manila clam (Venerupis philippinarum) using temporal experimental infections and an immune-enriched microarray. We identified an early phase of infection that was characterised by no mortality and by the increased expression of genes associated with pathogen recognition, production of nitrogen radicals and antimicrobial activity. Cellular processes such as inhibition of serine proteases and proliferation were also involved in this early response. This phase was followed by an intermediate stage, when the pathogen was most likely multiplying and infecting new areas of the body, and animals began to die. In this stage, many genes related to cell movement were over-expressed. Thirty days after infection metabolic pathway genes were the most affected. Apoptosis appears to be important during pathogenesis. Our results provide novel observations of the broader innate immune response triggered by P. olseni at different infection stages. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Thermogladius shockii gen. nov., sp. nov., a hyperthermophilic crenarchaeote from Yellowstone National Park, USA.

    Science.gov (United States)

    Osburn, Magdalena R; Amend, Jan P

    2011-01-01

    A hyperthermophilic heterotrophic archaeon (strain WB1) was isolated from a thermal pool in the Washburn hot spring group of Yellowstone National Park, USA. WB1 is a coccus, 0.6-1.2 μm in diameter, with a tetragonal S-layer, vacuoles, and occasional stalk-like protrusions. Growth is optimal at 84°C (range 64-93°C), pH 5-6 (range 3.5-8.5), and <1 g/l NaCl (range 0-4.6 g/l NaCl). Tests of metabolic properties show the isolate to be a strict anaerobe that ferments complex organic substrates. Phylogenetic analysis of the 16S rRNA gene sequence places WB1 in a clade of previously uncultured Desulfurococcaceae and shows it to have ≤ 96% 16S rRNA sequence identity to Desulfurococcus mobilis, Staphylothermus marinus, Staphylothermus hellenicus, and Sulfophobococcus zilligii. The 16S rRNA gene contains a large insertion similar to homing endonuclease introns reported in Thermoproteus and Pyrobaculum species. Growth is unaffected by the presence of S(0) or SO(4)(2-), thereby differentiating the isolate from its closest relatives. Based on phylogenetic and physiological differences, it is proposed that isolate WB1 represents the type strain of a novel genus and species within the Desulfurococcaceae, Thermogladius shockii gen. nov., sp. nov. (RIKEN = JCM-16579, ATCC = BAA-1607, Genbank 16S rRNA gene = EU183120).

  13. Restoration of oyster reefs in an estuarine lake: population dynamics and shell accretion

    Science.gov (United States)

    Casas, Sandra M.; La Peyre, Jerome F.; La Peyre, Megan K.

    2015-01-01

    Restoration activities inherently depend on understanding the spatial and temporal variation in basic demographic rates of the species of interest. For species that modify and maintain their own habitat such as the eastern oyster Crassostrea virginica, understanding demographic rates and their impacts on population and habitat success are crucial to ensuring restoration success. We measured oyster recruitment, density, size distribution, biomass, mortality and Perkinsus marinus infection intensity quarterly for 3 yr on shallow intertidal reefs created with shell cultch in March 2009. All reefs were located within Sister Lake, LA. Reefs were placed in pairs at 3 different locations within the lake; pairs were placed in low and medium energy sites within each location. Restored reefs placed within close proximity (14.6 kg m-2) at the end of 3 yr. Shell accretion, on average, exceeded estimated rates required to keep pace with local subsidence and shell loss. Variation in recruitment, growth and survival drives local site-specific population success, which highlights the need to understand local water quality, hydrodynamics, and metapopulation dynamics when planning restoration.

  14. Contribution of manipulable and non-manipulable environmental factors to trapping efficiency of invasive sea lamprey

    Science.gov (United States)

    Dawson, Heather A.; Bravener, Gale; Beaulaurier, Joshua; Johnson, Nicholas S.; Twohey, Michael; McLaughlin, Robert L.; Brenden, Travis O.

    2017-01-01

    We identified aspects of the trapping process that afforded opportunities for improving trap efficiency of invasive sea lamprey (Petromyzon marinus) in a Great Lake's tributary. Capturing a sea lamprey requires it to encounter the trap, enter, and be retained until removed. Probabilities of these events depend on the interplay between sea lamprey behavior, environmental conditions, and trap design. We first tested how strongly seasonal patterns in daily trap catches (a measure of trapping success) were related to nightly rates of trap encounter, entry, and retention (outcomes of sea lamprey behavior). We then tested the degree to which variation in rates of trap encounter, entry, and retention were related to environmental features that control agents can manipulate (attractant pheromone addition, discharge) and features agents cannot manipulate (water temperature, season), but could be used as indicators for when to increase trapping effort. Daily trap catch was most strongly associated with rate of encounter. Relative and absolute measures of predictive strength for environmental factors that managers could potentially manipulate were low, suggesting that opportunities to improve trapping success by manipulating factors that affect rates of encounter, entry, and retention are limited. According to results at this trap, more sea lamprey would be captured by increasing trapping effort early in the season when sea lamprey encounter rates with traps are high. The approach used in this study could be applied to trapping of other invasive or valued species.

  15. The sea lamprey has a primordial accessory olfactory system

    Science.gov (United States)

    2013-01-01

    Background A dual olfactory system, represented by two anatomically distinct but spatially proximate chemosensory epithelia that project to separate areas of the forebrain, is known in several classes of tetrapods. Lungfish are the earliest evolving vertebrates known to have this dual system, comprising a main olfactory and a vomeronasal system (VNO). Lampreys, a group of jawless vertebrates, have a single nasal capsule containing two anatomically distinct epithelia, the main (MOE) and the accessory olfactory epithelia (AOE). We speculated that lamprey AOE projects to specific telencephalic regions as a precursor to the tetrapod vomeronasal system. Results To test this hypothesis, we characterized the neural circuits and molecular profiles of the accessory olfactory epithelium in the sea lamprey (Petromyzon marinus). Neural tract-tracing revealed direct and reciprocal connections with the dorsomedial telencephalic neuropil (DTN) which in turn projects directly to the dorsal pallium and the rostral hypothalamus. High-throughput sequencing demonstrated that the main and the accessory olfactory epithelia have virtually identical profiles of expressed genes. Real time quantitative PCR confirmed expression of representatives of all 3 chemoreceptor gene families identified in the sea lamprey genome. Conclusion Anatomical and molecular evidence shows that the sea lamprey has a primordial accessory olfactory system that may serve a chemosensory function. PMID:23957559

  16. Investigations of novel unsaturated bile salts of male sea lamprey as potential chemical cues

    Science.gov (United States)

    Johnson, Nicholas S.; Yun, Sang-Seon; Li, Weiming

    2014-01-01

    Sulfated bile salts function as chemical cues that coordinate reproduction in sea lamprey, Petromyzon marinus. 7α, 12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) is the most abundant known bile salt released by sexually mature male sea lampreys and attracts ovulated females. However, previous studies showed that the male-produced pheromone consists of unidentified components in addition to 3kPZS. Here, analysis of water conditioned with mature male sea lampreys indicated the presence of 4 oxidized, unsaturated compounds with molecular weights of 466 Da, 468 Da, and 2 of 470 Da. These compounds were not detectable in water conditioned with immature male sea lampreys. By using mass spectrometry, 4 A-ring unsaturated sulfated bile salts were tentatively identified from male washings as 2 4-ene, a 1-ene, and a 1,4-diene analogs. These were synthesized to determine if they attracted ovulated female sea lampreys to spawning nests in natural streams. One of the novel synthetic bile salts, 3 keto-1-ene PZS, attracted ovulated females to the point of application at a concentration of 10-12 M. This study reveals the structural diversity of bile salts in sea lamprey, some of which have been demonstrated to be pheromonal cues.

  17. Two Lamprey Hedgehog Genes Share Non-Coding Regulatory Sequences and Expression Patterns with Gnathostome Hedgehogs

    Science.gov (United States)

    Ekker, Marc; Hadzhiev, Yavor; Müller, Ferenc; Casane, Didier; Magdelenat, Ghislaine; Rétaux, Sylvie

    2010-01-01

    Hedgehog (Hh) genes play major roles in animal development and studies of their evolution, expression and function point to major differences among chordates. Here we focused on Hh genes in lampreys in order to characterize the evolution of Hh signalling at the emergence of vertebrates. Screening of a cosmid library of the river lamprey Lampetra fluviatilis and searching the preliminary genome assembly of the sea lamprey Petromyzon marinus indicate that lampreys have two Hh genes, named Hha and Hhb. Phylogenetic analyses suggest that Hha and Hhb are lamprey-specific paralogs closely related to Sonic/Indian Hh genes. Expression analysis indicates that Hha and Hhb are expressed in a Sonic Hh-like pattern. The two transcripts are expressed in largely overlapping but not identical domains in the lamprey embryonic brain, including a newly-described expression domain in the nasohypophyseal placode. Global alignments of genomic sequences and local alignment with known gnathostome regulatory motifs show that lamprey Hhs share conserved non-coding elements (CNE) with gnathostome Hhs albeit with sequences that have significantly diverged and dispersed. Functional assays using zebrafish embryos demonstrate gnathostome-like midline enhancer activity for CNEs contained in intron2. We conclude that lamprey Hh genes are gnathostome Shh-like in terms of expression and regulation. In addition, they show some lamprey-specific features, including duplication and structural (but not functional) changes in the intronic/regulatory sequences. PMID:20967201

  18. Effects of coded-wire-tagging on stream-dwelling Sea Lamprey larvae

    Science.gov (United States)

    Johnson, Nicholas; Swink, William D.; Dawson, Heather A.; Jones, Michael L.

    2016-01-01

    The effects of coded wire tagging Sea Lamprey Petromyzon marinus larvae from a known-aged stream-dwelling population were assessed. Tagged larvae were significantly shorter on average than untagged larvae from 3 to 18 months after tagging. However, 30 months after tagging, the length distribution of tagged and untagged larvae did not differ and tagged Sea Lampreys were in better condition (i.e., higher condition factor) and more likely to have undergone metamorphosis than the untagged population. The reason why tagged larvae were more likely to metamorphose is not clear, but the increased likelihood of metamorphosis could have been a compensatory response to the period of slower growth after tagging. Slower growth after tagging was consistent across larval size-classes, so handling and displacement from quality habitat during the early part of the growing season was likely the cause rather than the tag burden. The tag effects observed in this study, if caused by displacement and handling, may be minimized in future studies if tagging is conducted during autumn after growth has concluded for the year.

  19. Assessment of PIT tag retention and post-tagging survival in metamorphosing juvenile Sea Lamprey

    Science.gov (United States)

    Simard, Lee G; Sotola, V Alex; Marsden, J Ellen; Miehls, Scott M.

    2017-01-01

    Background: Passive integrated transponder (PIT) tags have been used to document and monitor the movement or behavior of numerous species of fishes. Data on short-term and long-term survival and tag retention are needed before initiating studies using PIT tags on a new species or life stage. We evaluated the survival and tag retention of 153 metamorphosing juvenile Sea Lamprey Petromyzon marinus tagged with 12 mm PIT tags on three occasions using a simple surgical procedure. Results: Tag retention was 100% and 98.6% at 24 h and 28-105 d post-tagging. Of the lamprey that retained their tags, 87.3% had incisions sufficiently healed to prevent further loss. Survival was 100% and 92.7% at 24 h and 41-118 d post-tagging with no significant difference in survival between tagged and untagged control lamprey. Of the 11 lamprey that died, four had symptoms that indicated their death was directly related to tagging. Survival was positively correlated with Sea Lamprey length. Conclusions: Given the overall high level of survival and tag retention in this study, future studies can utilize 12 mm PIT tags to monitor metamorphosing juvenile Sea Lamprey movement and migration patterns.

  20. Feeding strategy assessment through fatty acid profiles in muscles of adult sea lampreys from the western Iberian coast

    Directory of Open Access Journals (Sweden)

    Maria João Lança

    2013-06-01

    Full Text Available The fatty acid signature of sea lamprey Petromyzon marinus (L. muscle was used as a tool to detect feeding strategies used during the parasitic marine trophic phase of the species. Adult sea lampreys were collected near the mouth of six Portuguese rivers (Minho, Lima, Douro, Vouga, Mondego and Tagus and muscle fatty acid profile was characterized. The analysis of fatty acid composition of muscle neutral lipids showed the formation of two groups, indicating that two feeding strategies may have been used by sea lampreys during the parasitic phase, based on the availability of ω-3 and ω-6 PUFA and on evidence of phytoplankton/zooplankton and bacterial detritus contribution in the sea lamprey host preferences. Two distinct lipid profiles were observed, probably related to two different trophic approaches, one typical of a top predator of a marine food web with a planktonic support, and the other much more diverse, including the same planktonic markers, together with biochemical clues that probably resulted from a parasitic phase that directly targeted fish that consumed detritus and benthic algae and/or fish from a food web with a detritivorous base.

  1. Increased pheromone signaling by small male sea lamprey has distinct effects on female mate search and courtship

    Science.gov (United States)

    Buchinger, Tyler J.; Bussy, Ugo; Buchinger, Ethan G.; Fissette, Skye D.; Li, Weiming; Johnson, Nicholas

    2017-01-01

    Male body size affects access to mates in many animals. Attributes of sexual signals often correlate with body size due to physiological constraints on signal production. Larger males generally produce larger signals, but costs of being large or compensation by small males can result in smaller males producing signals of equal or greater magnitude. Female choice following multiple male traits with different relationships to size might further complicate the effect of male body size on access to mates. We report the relationship between male body size and pheromone signaling, and the effects on female mate search and courtship in the sea lamprey (Petromyzon marinus). We predicted that pheromone production in the liver and the liver mass to body mass ratio would remain constant across sizes, resulting in similar mass-adjusted pheromone release rates across sizes but a positive relationship between absolute pheromone release and body mass. Our results confirmed positive relationships between body mass and liver mass, and liver mass and the magnitude of the pheromone signal. Surprisingly, decreasing body mass was correlated with higher pheromone concentrations in the liver, liver mass to body mass ratios, and mass-adjusted pheromone release rates. In a natural stream, females more often entered nests treated with small versus large male odors. However, close-proximity courtship behaviors were similar in nests treated with small or large male odors. We conclude that small males exhibit increased release of the main pheromone component, but female discrimination of male pheromones follows several axes of variation with different relationships to size.

  2. Lethal and sub-lethal responses of native freshwater mussels exposed to granular Bayluscide®, a sea lamprey larvicide

    Science.gov (United States)

    Newton, Teresa; Boogaard, Michael A.; Gray, Brian R.; Hubert, Terrance D.; Schloesser, Nicholas

    2017-01-01

    The invasive sea lamprey (Petromyzon marinus) poses a substantial threat to fish communities in the Great Lakes. Efforts to control sea lamprey populations typically involve treating tributary streams with lampricides on a recurring cycle. The presence of a substantial population of larval sea lampreys in the aquatic corridor between Lakes Huron and Erie prompted managers to propose a treatment using the granular formulation of Bayluscide® that targets larval sea lampreys that reside in sediments. However, these treatments could cause adverse effects on native freshwater mussels—imperiled animals that also reside in sediments. We estimated the risk of mortality and sub-lethal effects among eight species of adult and sub-adult mussels exposed to Bayluscide® for durations up to 8 h to mimic field applications. Mortality was appreciable in some species, especially in sub-adults (range, 23–51%). The lethal and sub-lethal effects were positively associated with the duration of exposure in most species and life stage combinations. Estimates of the median time of exposure that resulted in lethal and sub-lethal effects suggest that sub-adults were often affected by Bayluscide® earlier than adults. Siphoning activity and burrowing position of mussels during exposure may have moderated the uptake of Bayluscide® and may have influenced lethal and sub-lethal responses. Given that the various species and life stages were differentially affected, it will be difficult to predict the effects of Bayluscide® treatments on mussels.

  3. Tradeoff between assessment and control of aquatic invasive species: A case study of sea lamprey management in the St. Marys River

    Science.gov (United States)

    Robinson, Jason M.; Wilberg, Michael J.; Adams, Jean V.; Jones, Michael L.

    2016-01-01

    Allocating resources between the gathering of information to guide management actions and implementing those actions presents an inherent tradeoff. This tradeoff is evident for control of the Sea Lamprey Petromyzon marinus in the St. Marys River, connecting Lakes Huron and Superior and a major source of parasitic Sea Lampreys to Lake Huron and northern Lake Michigan. Larval Sea Lampreys in the St. Marys River are controlled through the application of Bayluscide, which is applied to areas of high larval density. Bayluscide applications are guided with an annual deepwater electrofishing survey to estimate larval Sea Lamprey density at relatively fine spatial scales. We took a resampling approach to describe the effect of sampling intensity on the success of the larval Sea Lamprey management program and explicitly incorporated the economic tradeoff between assessment and control efforts to maximize numbers of larvae killed in the St. Marys River. When no tradeoff between assessment and control was incorporated, increasing assessment always led to more larvae killed for the same treatment budget. When the tradeoff was incorporated, the sampling intensity that maximized the number of larvae killed depended on the overall budget available. Increased sampling intensities maximized effectiveness under medium to large budgets (US \\$0.4 to \\$2.0 million), and intermediate sampling intensities maximized effectiveness under low budgets. Sea Lamprey control actions based on assessment information outperformed those that were implemented with no assessment under all budget scenarios.

  4. Sea lamprey avoid areas scented with conspecific tissue extract in Michigan streams

    Science.gov (United States)

    Di Rocco, Richard; Johnson, Nicholas; Brege, Linnea; Imre, I.; Brown, G.E.

    2016-01-01

    Three in-stream experiments were conducted to determine whether sea lamprey, Petromyzon marinus L., tissue extract (alarm cue) and 2-phenylethylamine hydrochloride (PEA HCl, a putative predator cue) influenced the distribution of migrating adult sea lamprey. Experiments evaluated sea lamprey movement when an odour was applied to (1) a tributary of a larger stream; and (2) half of a stream channel. Fewer sea lamprey entered the tributary and side of the river scented with sea lamprey tissue extract compared to the control treatment. Sea lamprey did not avoid the tributary and side of the river scented with PEA HCl. A final laboratory experiment found no difference in the avoidance response of sea lamprey to PEA HCl mixed with river water vs PEA HCl mixed with water from Lake Huron. As such, the lack of sea lamprey response to PEA HCl in the stream was unlikely to have been caused by the presence of the river water. Rather, the difference between laboratory and field results may be attributed to the complexity of the physical environment.

  5. Horizontal Transfers of Tc1 Elements between Teleost Fishes and Their Vertebrate Parasites, Lampreys

    Science.gov (United States)

    Kuraku, Shigehiro; Qiu, Huan; Meyer, Axel

    2012-01-01

    Horizontal gene transfer (HGT) has been recognized to be an important mechanism that shaped the evolution and genomes of prokaryotes and unicellular eukaryotes. However, HGT is regarded to be exceedingly rare among eukaryotes. We discovered massive transfers of a DNA transposon, a Tc1 element encoding a transposase, between multiple teleost fishes and lampreys that last shared a common ancestor over 500 Ma. Members of this group of Tc1 elements were found to exhibit a mosaic phylogenetic distribution, yet their sequences were highly similar even between distantly related lineages (95%–99% identity). Our molecular phylogenetic analyses suggested that horizontal transfers of this element happened repeatedly, involving multiple teleost fishes that are phylogenetically only distantly related. Interestingly, almost all the affected teleost lineages are also known to be subject to lamprey parasitism, suggesting that the horizontal transfers between vertebrates might have occurred through parasite–host interaction. The genomes of several northern hemisphere lamprey species, including that of the sea lamprey (Petromyzon marinus), were found to contain thousands of copies of the foreign elements. Impact of this event is discussed in relation to other peculiar genomic features of lampreys. PMID:22887124

  6. Test of a non-physical barrier consisting of light, sound, and bubble screen to block upstream movement of sea lamprey in an experimental raceway

    Science.gov (United States)

    Miehls, Scott M.; Johnson, Nicholas S.; Hrodey, Pete J.

    2017-01-01

    Control of the invasive Sea Lamprey Petromyzon marinus is critical for management of commercial and recreational fisheries in the Laurentian Great Lakes. Use of physical barriers to block Sea Lampreys from spawning habitat is a major component of the control program. However, the resulting interruption of natural streamflow and blockage of nontarget species present substantial challenges. Development of an effective nonphysical barrier would aid the control of Sea Lampreys by eliminating their access to spawning locations while maintaining natural streamflow. We tested the effect of a nonphysical barrier consisting of strobe lights, low-frequency sound, and a bubble screen on the movement of Sea Lampreys in an experimental raceway designed as a two-choice maze with a single main channel fed by two identical inflow channels (one control and one blocked). Sea Lampreys were more likely to move upstream during trials when the strobe light and low-frequency sound were active compared with control trials and trials using the bubble screen alone. For those Sea Lampreys that did move upstream to the confluence of inflow channels, no combination of stimuli or any individual stimulus significantly influenced the likelihood that Sea Lampreys would enter the blocked inflow channel, enter the control channel, or return downstream.

  7. Sea lamprey carcasses exert local and variable food web effects in a nutrient-limited Atlantic coastal stream

    Science.gov (United States)

    Weaver, Daniel M.; Coghlan, Stephen M.; Zydlewski, Joseph D.

    2016-01-01

    Resource flows from adjacent ecosystems are critical in maintaining structure and function of freshwater food webs. Migrating sea lamprey (Petromyzon marinus) deliver a pulsed marine-derived nutrient subsidy to rivers in spring when the metabolic demand of producers and consumers are increasing. However, the spatial and temporal dynamics of these nutrient subsidies are not well characterized. We used sea lamprey carcass additions in a small stream to examine changes in nutrients, primary productivity, and nutrient assimilation among consumers. Algal biomass increased 57%–71% immediately adjacent to carcasses; however, broader spatial changes from multiple-site carcass addition may have been influenced by canopy cover. We detected assimilation of nutrients (via δ13C and δ15N) among several macroinvertebrate families including Heptageniidae, Hydropsychidae, and Perlidae. Our research suggests that subsidies may evoke localized patch-scale effects on food webs, and the pathways of assimilation in streams are likely coupled to adjacent terrestrial systems. This research underscores the importance of connectivity in streams, which may influence sea lamprey spawning and elicit varying food web responses from carcass subsidies due to fine-scale habitat variables.

  8. A cytosolic carbonic anhydrase molecular switch occurs in the gills of metamorphic sea lamprey

    Science.gov (United States)

    Ferreira-Martins, D.; McCormick, Stephen; Campos, A.; Lopes-Marques, M.; Osorio, H.; Coimbra, J.; Castro, L.F.C.; Wilson, Jonthan M

    2016-01-01

    Carbonic anhydrase plays a key role in CO2 transport, acid-base and ion regulation and metabolic processes in vertebrates. While several carbonic anhydrase isoforms have been identified in numerous vertebrate species, basal lineages such as the cyclostomes have remained largely unexamined. Here we investigate the repertoire of cytoplasmic carbonic anhydrases in the sea lamprey (Petromyzon marinus), that has a complex life history marked by a dramatic metamorphosis from a benthic filter-feeding ammocoete larvae into a parasitic juvenile which migrates from freshwater to seawater. We have identified a novel carbonic anhydrase gene (ca19) beyond the single carbonic anhydrase gene (ca18) that was known previously. Phylogenetic analysis and synteny studies suggest that both carbonic anhydrase genes form one or two independent gene lineages and are most likely duplicates retained uniquely in cyclostomes. Quantitative PCR of ca19 and ca18 and protein expression in gill across metamorphosis show that the ca19 levels are highest in ammocoetes and decrease during metamorphosis while ca18 shows the opposite pattern with the highest levels in post-metamorphic juveniles. We propose that a unique molecular switch occurs during lamprey metamorphosis resulting in distinct gill carbonic anhydrases reflecting the contrasting life modes and habitats of these life-history stages.

  9. Monitoring sea lamprey pheromones and their degradation using rapid stream-side extraction coupled with UPLC-MS/MS

    Science.gov (United States)

    Wang, Huiyong; Johnson, Nicholas; Bernardy, Jeffrey; Hubert, Terry; Li, Weiming

    2013-01-01

    Pheromones guide adult sea lamprey (Petromyzon marinus) to suitable spawning streams and mates, and therefore, when quantified, can be used to assess population size and guide management. Here, we present an efficient sample preparation method where 100 mL of river water was spiked with deuterated pheromone as an internal standard and underwent rapid field-based SPE and elution in the field. The combination of field extraction with laboratory UPLC-MS/MS reduced the sample consumption from 1 to 0.1 L, decreased the sample process time from more than 1 h to 10 min, and increased the precision and accuracy. The sensitivity was improved more than one order of magnitude compared with the previous method. The influences of experimental conditions were assessed to optimize the separation and peak shapes. The analytical method has been validated by studies of stability, selectivity, precision, and linearity and by the determination of the limits of detection and quantification. The method was used to quantify pheromone concentration from five streams tributary to Lake Ontario and to estimate that the environmental half-life of 3kPZS is about 26 h.

  10. Re-examination of sea lamprey control policies for the St. Marys River: Completion of an adaptive management cycle

    Science.gov (United States)

    Jones, Michael L.; Brenden, Travis O.; Irwin, Brian J.

    2015-01-01

    The St. Marys River (SMR) historically has been a major producer of sea lampreys (Petromyzon marinus) in the Laurentian Great Lakes. In the early 2000s, a decision analysis (DA) project was conducted to evaluate sea lamprey control policies for the SMR; this project suggested that an integrated policy of trapping, sterile male releases, and Bayluscide treatment was the most cost-effective policy. Further, it concluded that formal assessment of larval sea lamprey abundance and distribution in the SMR would be valuable for future evaluation of control strategies. We updated this earlier analysis, adding information from annual larval assessments conducted since 1999 and evaluating additional control policies. Bayluscide treatments continued to be critical for sea lamprey control, but high recruitment compensation minimized the effectiveness of trapping and sterile male release under current feasible ranges. Because Bayluscide control is costly, development of strategies to enhance trapping success remains a priority. This study illustrates benefits of an adaptive management cycle, wherein models inform decisions, are updated based on learning achieved from those decisions, and ultimately inform future decisions.

  11. Migratory behavior of adult sea lamprey and cumulative passage performance through four fishways

    Science.gov (United States)

    Castro-Santos, Theodore R.; Shi, Xiaotao; Haro, Alexander

    2017-01-01

    This article describes a study of PIT-tagged sea lamprey (Petromyzon marinus) ascending four fishways comprising three designs at two dams on the Connecticut River, USA. Migration between dams was rapid (median migration rate = 23 km·day−1). Movement through the fishways was much slower, however (median = 0.02–0.33 km·day−1). Overall delay at dams was substantial (median = 13.6–14.6 days); many fish failed to pass (percent passage ranged from 29% to 55%, depending on fishway), and repeated passage attempts compounded delay for both passers and failers. Cox regression revealed that fishway entry rates were influenced by flow, temperature, and diel cycle, with most lampreys entering at night and at elevated flows, but with no apparent effect of sex or length. Overall delay was influenced by slow movement through the fishways, but repeated failures were the primary factor determining delay. These data suggest that although some lamprey were able to pass fishways, they did so with difficulty, and delays incurred as they attempted to pass may act to limit their distribution within their native range.

  12. A thermogenic secondary sexual character in male sea lamprey

    Science.gov (United States)

    Chung-Davidson, Yu-Wen; Priess, M. Cody; Yeh, Chu-Yin; Brant, Cory O.; Johnson, Nicholas S.; Li, Ke; Nanlohy, Kaben G.; Bryan, Mara B.; Brown, C. Titus; Choi, Jongeun; Li, Weiming

    2013-01-01

    Secondary sexual characters in animals are exaggerated ornaments or weapons for intrasexual competition. Unexpectedly, we found that a male secondary sexual character in sea lamprey (Petromyzon marinus ) is a thermogenic adipose tissue that instantly increases its heat production during sexual encounters. This secondary sexual character, developed in front of the anterior dorsal fin of mature males, is a swollen dorsal ridge known as the ‘rope’ tissue. It contains nerve bundles, multivacuolar adipocytes and interstitial cells packed with small lipid droplets and mitochondria with dense and highly organized cristae. The fatty acid composition of the rope tissue is rich in unsaturated fatty acids. The cytochrome c oxidase activity is high but the ATP concentration is very low in the mitochondria of the rope tissue compared with those of the gill and muscle tissues. The rope tissue temperature immediately rose up to 0.3°C when the male encountered a conspecific. Mature males generated more heat in the rope and muscle tissues when presented with a mature female than when presented with a male (paired t-test, P-3 more heat than the muscle in 10 min. Transcriptome analyses revealed that genes involved in fat cell differentiation are upregulated whereas those involved in oxidative-phosphorylation-coupled ATP synthesis are downregulated in the rope tissue compared with the gill and muscle tissues. Sexually mature male sea lamprey possess the only known thermogenic secondary sexual character that shows differential heat generation toward individual conspecifics.

  13. Proteogenomic Analysis of a Thermophilic Bacterial Consortium Adapted to Deconstruct Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    D' haeseleer, Patrik; Gladden, John M.; Allgaier, Martin; Chain, Patrick; Tringe, Susannah G.; Malfatti, Stephanie; Aldrich, Joshua T.; Nicora, Carrie D.; Robinson, Errol W.; Pasa-Tolic, Ljiljana; Hugenholtz, Philip; Simmons, Blake A.; Singer, Steven W.

    2013-07-19

    Thermophilic bacteria are a potential source of enzymes for the deconstruction of lignocellulosic biomass. However, the complement of proteins used to deconstruct biomass and the specific roles of different microbial groups in thermophilic biomass deconstruction are not well-explored. Here we report on the metagenomic and proteogenomic analyses of a compost-derived bacterial consortium adapted to switchgrass at elevated temperature with high levels of glycoside hydrolase activities. Near-complete genomes were reconstructed for the most abundant populations, which included composite genomes for populations closely related to sequenced strains of Thermus thermophilus and Rhodothermus marinus, and for novel populations that are related to thermophilic Paenibacilli and an uncultivated subdivision of the littlestudied Gemmatimonadetes phylum. Partial genomes were also reconstructed for a number of lower abundance thermophilic Chloroflexi populations. Identification of genes for lignocellulose processing and metabolic reconstructions suggested Rhodothermus, Paenibacillus and Gemmatimonadetes as key groups for deconstructing biomass, and Thermus as a group that may primarily metabolize low molecular weight compounds. Mass spectrometry-based proteomic analysis of the consortium was used to identify .3000 proteins in fractionated samples from the cultures, and confirmed the importance of Paenibacillus and Gemmatimonadetes to biomass deconstruction. These studies also indicate that there are unexplored proteins with important roles in bacterial lignocellulose deconstruction.

  14. Plastic and Non-plastic Debris Ingestion in Three Gull Species Feeding in an Urban Landfill Environment.

    Science.gov (United States)

    Seif, S; Provencher, J F; Avery-Gomm, S; Daoust, P-Y; Mallory, M L; Smith, P A

    2017-12-27

    Plastic debris is recognized as a widespread, common and problematic environmental pollutant. An important consequence of this pollution is the ingestion of plastic debris by wildlife. Assessing the degree to which different species ingest plastics, and the potential effects of these plastics on their health are important research needs for understanding the impacts of plastic pollution. We examined debris (plastic and other types) ingestion in three sympatric overwintering gull species (Herring gulls Larus smithsonianus, Great Black-backed Gulls Larus marinus, and Iceland Gulls Larus glaucoides) to understand how debris ingestion differs among species, age classes and sexes in gulls. We also assessed how plastic burdens were associated with body condition to investigate how gulls may be affected by debris ingestion. There were no differences among the species, age classes or sexes in the incidence of debris ingestion (plastic or otherwise), the mass or number of debris pieces ingested. We found no correlation between ingested plastics burdens and individual condition. Gulls ingested plastic debris, but also showed high levels of other debris types as well, including metal, glass and building materials, including a metal piece of debris found within an abscess in the stomach. Thus, when the health effects of debris ingestion on gulls, and other species that ingest debris, is of interest, either from a physical or chemical perspective, it may be necessary to consider all debris types and not just plastic burdens as is often currently done for seabirds.

  15. Naturally occurring cardiac glycosides.

    Science.gov (United States)

    Radford, D J; Gillies, A D; Hinds, J A; Duffy, P

    1986-05-12

    Cardiac glycoside poisoning from the ingestion of plants, particularly of oleanders, occurs with reasonable frequency in tropical and subtropical areas. We have assessed a variety of plant specimens for their cardiac glycoside content by means of radioimmunoassays with antibodies that differ in their specificity for cardiac glycosides. Significant amounts of immunoreactive cardiac glycoside were found to be present in the ornamental shrubs: yellow oleander (Thevetia peruviana); oleander (Nerium oleander); wintersweet (Carissa spectabilis); bushman's poison (Carissa acokanthera); sea-mango (Cerbera manghas); and frangipani (Plumeria rubra); and in the milkweeds: redheaded cotton-bush (Asclepias curassavica); balloon cotton (Asclepias fruiticosa); king's crown (Calotropis procera); and rubber vine (Cryptostegia grandifolia). The venom gland of the cane toad (Bufo marinus) also contained large quantities of cardiac glycosides. The competitive immunoassay method permits the rapid screening of specimens that are suspected to contain cardiac glycosides. Awareness of the existence of these plant and animal toxins and their dangers allows them to be avoided and poisoning prevented. The method is also useful for the confirmation of the presence of cardiac glycosides in serum in cases of poisoning.

  16. Ups and Downs of Burbot and their predator Lake Trout in Lake Superior, 1953-2011

    Science.gov (United States)

    Gorman, Owen T.; Sitar, Shawn P.

    2013-01-01

    The fish community of Lake Superior has undergone a spectacular cycle of decline and recovery over the past 60 years. A combination of Sea Lamprey Petromyzon marinus depredation and commercial overfishing resulted in severe declines in Lake Trout Salvelinus namaycush, which served as the primary top predator of the community. Burbot Lota lota populations also declined as a result of Sea Lamprey depredation, largely owing to the loss of adult fish. After Sea Lamprey control measures were instituted in the early 1960s, Burbot populations rebounded rapidly but Lake Trout populations recovered more slowly and recovery was not fully evident until the mid-1980s. As Lake Trout populations recovered, Burbot populations began to decline, and predation on small Burbot was identified as the most likely cause. By 2000, Burbot densities had dropped below their nadir in the early 1960s and have continued to decline, with the densities of juveniles and small adults falling below that of large adults. Although Burbot populations are at record lows in Lake Superior, the density of large reproductive adults remains stable and a large reserve of adult Burbot is present in deep offshore waters. The combination of the Burbot's early maturation, long life span, and high fecundity provides the species with the resiliency to remain a viable member of the Lake Superior fish community into the foreseeable future.

  17. Impacts of aquatic nonindigenous invasive species on the Lake Erie ecosystem

    Science.gov (United States)

    Austen, Madeline J.W.; Ciborowski, Jan J.H.; Corkum, Lynda D.; Johnson, Tim B.; MacIsaac, Hugh J.; Metcalfe-Smith, Janice L.; Schloesser, Donald W.; George, Sandra E.

    2002-01-01

    Lake Erie is particularly vulnerable to the introduction and establishment of aquatic nonindigenous invasive species (NIS) populations. A minimum of 144 aquatic NIS have been recorded in the Lake Erie basin including several species [e.g., Eurasian watermilfoil (Myriophyllum spicatum); zebra mussel (Dreissena polymorpha); quagga mussel (Dreissena bugensis); an amphipod (Echinogammarus ischnus); round goby (Neogobius melanostomus); and sea lamprey (Petromyzon marinus)] that have had discernible impacts on the lake's ecology. NIS pose threats to the Lake Erie ecosystem for a variety of reasons including their ability to proliferate quickly, compete with native species, and transfer contaminants (e.g., PCBs) and disease through the food web. Six of the 14 beneficial use impairments listed in Annex 2 of the Great Lakes Water Quality Agreement are impaired in Lake Erie, in part as a result of the introduction of NIS. The Lake Erie Lakewide Management Plan (LaMP) has adopted an ecosystem approach to restore beneficial use impairments in the lake. Furthermore, a research consortium, known as the Lake Erie Millennium Network, is working alongside the LaMP, to address research problems regarding NIS, the loss of habitat, and the role of contaminants in the Lake Erie ecosystem.

  18. Methanol Production by a Broad Phylogenetic Array of Marine Phytoplankton.

    Science.gov (United States)

    Mincer, Tracy J; Aicher, Athena C

    2016-01-01

    Methanol is a major volatile organic compound on Earth and serves as an important carbon and energy substrate for abundant methylotrophic microbes. Previous geochemical surveys coupled with predictive models suggest that the marine contributions are exceedingly large, rivaling terrestrial sources. Although well studied in terrestrial ecosystems, methanol sources are poorly understood in the marine environment and warrant further investigation. To this end, we adapted a Purge and Trap Gas Chromatography/Mass Spectrometry (P&T-GC/MS) method which allowed reliable measurements of methanol in seawater and marine phytoplankton cultures with a method detection limit of 120 nanomolar. All phytoplankton tested (cyanobacteria: Synechococcus spp. 8102 and 8103, Trichodesmium erythraeum, and Prochlorococcus marinus), and Eukarya (heterokont diatom: Phaeodactylum tricornutum, coccolithophore: Emiliania huxleyi, cryptophyte: Rhodomonas salina, and non-diatom heterokont: Nannochloropsis oculata) produced methanol, ranging from 0.8-13.7 micromolar in culture and methanol per total cellular carbon were measured in the ranges of 0.09-0.3%. Phytoplankton culture time-course measurements displayed a punctuated production pattern with maxima near early stationary phase. Stabile isotope labeled bicarbonate incorporation experiments confirmed that methanol was produced from phytoplankton biomass. Overall, our findings suggest that phytoplankton are a major source of methanol in the upper water column of the world's oceans.

  19. A pheromone outweighs temperature in influencing migration of sea lamprey

    Science.gov (United States)

    Brant, Cory O.; Li, Ke; Johnson, Nicholas S.; Li, Weiming

    2015-01-01

    Organisms continuously acquire and process information from surrounding cues. While some cues complement one another in delivering more reliable information, others may provide conflicting information. How organisms extract and use reliable information from a multitude of cues is largely unknown. We examined movement decisions of sea lampreys (Petromyzon marinus L.) exposed to a conspecific and an environmental cue during pre-spawning migration. Specifically, we predicted that the mature male-released sex pheromone 3-keto petromyzonol sulfate (3kPZS) will outweigh the locomotor inhibiting effects of cold stream temperature (less than 15°C). Using large-scale stream bioassays, we found that 3kPZS elicits an increase (more than 40%) in upstream movement of pre-spawning lampreys when the water temperatures were below 15°C. Both warming temperatures and conspecific cues increase upstream movement when the water temperature rose above 15°C. These patterns define an interaction between abiotic and conspecific cues in modulating animal decision-making, providing an example of the hierarchy of contradictory information.

  20. Lankesterella poeppigii n. sp. (Apicomplexa, Lankesterellidae from Bufo poeppigii (Tschudi, 1845 from Peru

    Directory of Open Access Journals (Sweden)

    Ilan Paperna

    2011-07-01

    Full Text Available Lankesterella poeppigii n. sp. is described from Bufo poeppigii (Tschudi, 1845 from Peru. Merogony and oogony occur in the capillary endothelium and the macrophages in the liver, spleen and kidneys. Meronts are oval, 25,2–29,4 x 15,7–16,8 μm in size and yield 35–46 merozoites. Oocysts are 26,3–29,4 x 15,1–17,6 μm in size; sporozoites 9,2-9,8 x 4,2–5,0 μm in size, assemble in macrophages. Released 8,7–9,8 x 2,8–3,1 μm sporozoites enter erythrocytes. L. poeppigii is compared with Lankesterella petiti Lainson & Paperna, 1995 infecting Bufo marinus (Linnaeus, 1758 in Brazil. The above mentioned specific characters, added to differences in hosts and geographical location warrant the description of Lankesterella poeppigii from B. poeppigii as a new species.

  1. [Genetics in methylotrophic bacteria]. Progress report, July 1, 1992--June 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The focus of this project has been to identify and characterize mox genes and other methylotrophy genes in both methane- and methanol-utilizing bacteria, and study expression of those genes. In the last three years of support, the project has focused on identifying methylotrophy genes and the regions involved in their expression for comparative purposes, and has begun the process of analyzing the genes involved in transcriptional regulation of the mox system in the strain for which the authors have the most information, M. extorquens AM1. In order to carry out comparative studies of the transcription of methylotrophy genes, they have cloned and characterized genes involved in methanol oxidation (mox genes) from two Type I methanotrophs, Methylobacter marinus A45 (formerly Methylomonas sp A45) and Methylobacter albus BG8 (formerly Methylomonas albus BG8). In both cases, the organization of the genes was found to be identical, and the transcriptional start sites upstream of the mxaF genes were mapped. Other methylotrophy genes have been cloned and characterized from these methanotrophs, including mxaAKL and fdh. The rest of this project has focused on the regulatory network for the mox system in M. extorquens AM1. The authors have sequenced two mox regulatory genes, mxbD and mxbM and they show identify with a specific group of sensor-kinase/response regulator pair systems.

  2. Lunnoe zatmenie -330, sept. 20 i problema izmereniya dolgoty v antichnoj geografii %t The -330, Sept. 20 lunar eclipse and the problem of the determination of longitude in ancient geography

    Science.gov (United States)

    Shcheglov, D. A.

    The attempt to reconstruct the Hipparchus system of is proposed. The offered analysis of certain passages in the treatises of Ptolemy, Pliny, and Strabo allows to trace the latent semantic connection between them and to advance a hypothesis to clarify it. Ptolemy's passage (sect. 3) states Hipparchus to propose in his geography a certain system of meridians and to use the -330, Sept. 20 eclipse to determine the relative longitudes of Arbela and Carthage. Pliny's evidence (4) shows that Hipparchus must have known about the observation of this eclipse from Sicily, which demands to situate this island far eastward of Carthage. Strabo's data (5) confirm that Hipparchus, while criticising Eratosthenes, suggested situating Sicily far eastward of Carthage. Ptolemy's data (6) show that Marinus, whose work Ptolemy's geography was based on, in his early redaction, must situate Sicily farther eastward than in the final variant. Posidonius' passage (7) demonstrates the latitude of Sicily in Ptolemy's geography to go back to Hipparchus. In "Almagest" (9) the longitude of Babylon (relative to Alexandria) is directly ascribed to Hipparchus and the longitude of Rome agrees with that of Sicily in Pliny's evidence. The data of Ptolemy's geography (9.3-9.5) permit that Arbela and Babylon were situated on the same meridian initially. All these enable us to suggest that Hipparchus determined the longitudes not only of Arbela and Babylon, but also of Babylon and Sicily, Alexandria and Rome.

  3. Corresponding long-term shifts in stream temperature and invasive fish migration

    Science.gov (United States)

    McCann, Erin L.; Johnson, Nicholas; Pangle, Kevin

    2017-01-01

    By investigating historic trapping records of invasive sea lamprey (Petromyzon marinus) throughout tributaries to the Laurentian Great Lakes, we found that upstream spawning migration timing was highly correlated with stream temperatures over large spatial and temporal scales. Furthermore, several streams in our study exceeded a critical spring thermal threshold (i.e., 15°C) and experienced peak spawning migration up to 30 days earlier since the 1980s, whereas others were relatively unchanged. Streams exhibiting warming trends and earlier migration were spatially clustered and generally found on the leeward side of the Great Lakes where the lakes most affect local climate. These findings highlight that all streams are not equally impacted by climate change and represent, to our knowledge, the first observation linking long-term changes in stream temperatures to shifts in migration timing of an invasive fish. Earlier sea lamprey migration in Great Lakes tributaries may improve young of the year growth and survival, but not limit their spatial distribution, making sea lamprey control more challenging.

  4. Galen. On my own books

    Directory of Open Access Journals (Sweden)

    Irina Prolygina

    2017-07-01

    Full Text Available In the treatise On my own books (De libris propriis Galen explains why there have been circulating many forgeries, entitled by his name, in the book market of Roman Empire, and gives a list of his authentic works with a short description of each of them. In his notes to his books Galen discusses the content of each book, and describes historical circumstances of its appearance, specificity of its genre and its addressee. This work contains a unique historical information on Galen’s childhood, on the two periods of his life in Rome, on the fire which took place in the Temple of Peace in Rome in 192 A.D., on the plague which burst out during the reign of Antonius Pius, and on the agonistic nature of the medical profession in Rome in the 2nd–3rd cent. C.E. Moreover this work is an important source for the history of ancient philosophy and medicine, because Galen mentions the titles and even summaries of many lost works of his own as well as of his famous predecessors and contemporaries — philosophers and physicians. In particular, he mentions two great anatomists of antiquity — Marinus and Likus. The treatise «On my own books» is one of the most frequently cited works of Galen and may serve as an introduction to his thought. The first Russian translation of this work is provided with a short introduction and detailed commentary.

  5. Foraging success, kleptoparasitism and feeding techniques in scavenging seabirds: does crime pay?

    Science.gov (United States)

    Garthe, Stefan; Hüppop, Ommo

    1998-06-01

    Scavenging seabirds in the North Sea exploit discards with different success and by different feeding techniques. Northern gannet ( Sula bassana) had the highest foraging success index, followed by lesser black-backed gull ( Larus fuscus) and black-legged kittiwake ( Rissa tridactyla). Northern fulmar ( Fulmarus glacialis), mew gull ( Larus canus) and black-headed gull ( Larus ridibundus) were the least successful species. Ranking species according to the ratio of fish stolen from vs. lost to other species (=robbery index), northern gannet, great black-backed gull ( Larus marinus) and great skua ( Catharacta skua) were at the top, northern fulmar and black-legged kittiwake at the bottom. Varying compositions of the feeding flocks influenced the foraging success of the species significantly. Both body length and body mass of the birds can well explain species order in the robbery index but not in the foraging success index. Our hypothesis that the most successful species employ particular feeding techniques and/or exhibit the strongest kleptoparasitic abilities could be confirmed to a large extent but not totally. During reduced overall feeding rates, some less successful species and/or species with weaker kleptoparasitic capabilities fared better than during intense feeding rates as predicted, some others did not.

  6. Comparative embryology of five species of lampreys of the upper Great Lakes

    Science.gov (United States)

    Smith, Allen J.; Howell, John H.; Piavis, George W.

    1968-01-01

    The four species of lampreys native to the upper Great Lakes (American brook lamprey, Lampetra lamotteni; chestnut lamprey, Ichthyomyzon castaneus; northern brook lamprey, I. fossor; and silver lamprey, I. unicuspis) were collected in various stages of their life cycle and maintained in the laboratory until sexually mature. Secondary sex characters of the four native species are compared. Several batches of eggs of each species were reared at 18.4A?C and their development was compared to that of the exotic sea lamprey, Petromyzon marinus. The temperature of 18.4A?C was previously determined to be optimum for development of the sea lamprey. The high percentage survival of many batches of eggs of native species to prolarvae indicated that 18.4A?C was near the optimum for them. Survival to the burrowing stage varied considerably among different batches of eggs from the same species; some batches failed to produce prolarvae. The staging characteristics used for the sea lamprey were applicable to the native species, except for the end point of the burrowing stage. Embryos of the native species in each stage of development appeared according to the time sequence established for the sea lamprey.

  7. Sea lamprey orient toward a source of a synthesized pheromone using odor-conditioned rheotaxis

    Science.gov (United States)

    Johnson, Nicholas S.; Muhammad, Azizah; Thompson, Henry; Choi, Jongeun; Li, Weiming

    2012-01-01

    Characterization of vertebrate chemo-orientation strategies over long distances is difficult because it is often not feasible to conduct highly controlled hypothesis-based experiments in natural environments. To overcome the challenge, we couple in-stream behavioral observations of female sea lampreys (Petromyzon marinus) orienting to plumes of a synthesized mating pheromone, 7a,12a,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS), and engineering algorithms to systematically test chemo-orientation hypotheses. In-stream field observations and simulated movements of female sea lampreys according to control algorithms support that odor-conditioned rheotaxis is a component of the mechanism used to track plumes of 3kPZS over hundreds of meters in flowing water. Simulated movements of female sea lampreys do not support that rheotaxis or klinotaxis alone is sufficient to enable the movement patterns displayed by females in locating 3kPZS sources in the experimental stream. Odor-conditioned rheotaxis may not only be effective at small spatial scales as previous described in crustaceans, but may also be effectively used by fishes over hundreds of meters. These results may prove useful for developing management strategies for the control of invasive species that exploit the odor-conditioned tracking behavior and for developing biologically inspired navigation strategies for robotic fish.

  8. HPLC and ELISA analyses of larval bile acids from Pacific and western brook lampreys

    Science.gov (United States)

    Yun, S.-S.; Scott, A.P.; Bayer, J.M.; Seelye, J.G.; Close, D.A.; Li, W.

    2003-01-01

    Comparative studies were performed on two native lamprey species, Pacific lamprey (Lampetra tridentata) and western brook lamprey (Lampetra richardsoni) from the Pacific coast along with sea lamprey (Petromyzon marinus) from the Great Lakes, to investigate their bile acid production and release. HPLC and ELISA analyses of the gall bladders and liver extract revealed that the major bile acid compound from Pacific and western brook larval lampreys was petromyzonol sulfate (PZS), previously identified as a migratory pheromone in larval sea lamprey. An ELISA for PZS has been developed in a working range of 20pg-10ng per well. The tissue concentrations of PZS in gall bladder were 127.40, 145.86, and 276.96??g/g body mass in sea lamprey, Pacific lamprey, and western brook lamprey, respectively. Releasing rates for PZS in the three species were measured using ELISA to find that western brook and sea lamprey released PZS 20 times higher than Pacific lamprey did. Further studies are required to determine whether PZS is a chemical cue in Pacific and western brook lampreys. ?? 2003 Elsevier Inc. All rights reserved.

  9. The Structure of a BamA-BamD Fusion Illuminates the Architecture of the β-Barrel Assembly Machine Core.

    Science.gov (United States)

    Bergal, Hans Thor; Hopkins, Alex Hunt; Metzner, Sandra Ines; Sousa, Marcelo Carlos

    2016-02-02

    The β-barrel assembly machine (BAM) mediates folding and insertion of integral β-barrel outer membrane proteins (OMPs) in Gram-negative bacteria. Of the five BAM subunits, only BamA and BamD are essential for cell viability. Here we present the crystal structure of a fusion between BamA POTRA4-5 and BamD from Rhodothermus marinus. The POTRA5 domain binds BamD between its tetratricopeptide repeats 3 and 4. The interface structural elements are conserved in the Escherichia coli proteins, which allowed structure validation by mutagenesis and disulfide crosslinking in E. coli. Furthermore, the interface is consistent with previously reported mutations that impair BamA-BamD binding. The structure serves as a linchpin to generate a BAM model where POTRA domains and BamD form an elongated periplasmic ring adjacent to the membrane with a central cavity approximately 30 × 60 Å wide. We propose that nascent OMPs bind this periplasmic ring prior to insertion and folding by BAM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Rapid evolution meets invasive species control: The potential for pesticide resistance in sea lamprey

    Science.gov (United States)

    Dunlop, Erin S.; McLaughlin, Robert L.; Adams, Jean V.; Jones, Michael L.; Birceanu, Oana; Christie, Mark R.; Criger, Lori A.; Hinderer, Julia L.M.; Hollingworth, Robert M.; Johnson, Nicholas; Lantz, Stephen R.; Li, Weiming; Miller, James R.; Morrison, Bruce J.; Mota-Sanchez, David; Muir, Andrew M.; Sepulveda, Maria S.; Steeves, Todd B.; Walter, Lisa; Westman, Erin; Wirgin, Isaac; Wilkie, Michael P.

    2018-01-01

    Rapid evolution of pest, pathogen and wildlife populations can have undesirable effects; for example, when insects evolve resistance to pesticides or fishes evolve smaller body size in response to harvest. A destructive invasive species in the Laurentian Great Lakes, the sea lamprey (Petromyzon marinus) has been controlled with the pesticide 3-trifluoromethyl-4-nitrophenol (TFM) since the 1950s. We evaluated the likelihood of sea lamprey evolving resistance to TFM by (1) reviewing sea lamprey life history and control; (2) identifying physiological and behavioural resistance strategies; (3) estimating the strength of selection from TFM; (4) assessing the timeline for evolution; and (5) analyzing historical toxicity data for evidence of resistance. The number of sea lamprey generations exposed to TFM was within the range observed for fish populations where rapid evolution has occurred. Mortality from TFM was estimated as 82-90%, suggesting significant selective pressure. However, 57 years of toxicity data revealed no increase in lethal concentrations of TFM. Vigilance and the development of alternative controls are required to prevent this aquatic invasive species from evolving strategies to evade control.

  11. Field study suggests that sex determination in sea lamprey is directly influenced by larval growth rate

    Science.gov (United States)

    Johnson, Nicholas; Swink, William D.; Brenden, Travis O.

    2017-01-01

    Sex determination mechanisms in fishes lie along a genetic-environmental continuum and thereby offer opportunities to understand how physiology and environment interact to determine sex. Mechanisms and ecological consequences of sex determination in fishes are primarily garnered from teleosts, with little investigation into basal fishes. We tagged and released larval sea lamprey (Petromyzon marinus) into unproductive lake and productive stream environments. Sex ratios produced from these environments were quantified by recapturing tagged individuals as adults. Sex ratios from unproductive and productive environments were initially similar. However, sex ratios soon diverged, with unproductive environments becoming increasingly male-skewed and productive environments becoming less male-skewed with time. We hypothesize that slower growth in unproductive environments contributed to the sex ratio differences by directly influencing sex determination. To the best of our knowledge, this is the first study suggesting that growth rate in a fish species directly influences sex determination; other studies have suggested that the environmental variables to which sex determination is sensitive (e.g. density, temperature) act as cues for favourable or unfavourable growth conditions. Understanding mechanisms of sex determination in lampreys may provide unique insight into the underlying principles of sex determination in other vertebrates and provide innovative approaches for their management where valued and invasive.

  12. Review of fish species introduced into the Great Lakes, 1819-1974

    Science.gov (United States)

    Emery, Lee

    1985-01-01

    This review is based on an extensive literature search, combined with updated information obtained from biologists, and unpublished reports from private, state, and federal organizations throughout the Great Lakes basin. The chronological review lists 34 species of fishes in 13 families that were introduced into the basin from 1819 to 1974. The Salmonidae and Cyprinidae are best represented, contributing 14 and 5 of the species, respectively. The list is divided into successful and unsuccessful introductions; each species is briefly described and information about its entry into the basin and present status is given. About half of the introductions have been successful (i.e., the fish have reproduced and created viable, self-sustaining populations). Some of the successful introductions were disastrous in terms of damage inflicted on native populations (e.g., the effect of the sea lamprey, Petromyzon marinus, on populations of lake trout, Salvelinus namaycush, and lake whitefish, Coregonus clupeaformis), but others yielded highly favorable results (e.g., the extraordinary sport fisheries created by introductions of coho salmon, Oncorhynchus kisutch, and chinook salmon, Oncorhynchus tshawytscha).

  13. Multiple evolutionary origins of prochlorophytes within the cyanobacterial radiation.

    Science.gov (United States)

    Urbach, E; Robertson, D L; Chisholm, S W

    1992-01-16

    The taxonomic group Prochlorales (Lewin 1977) Burger-Wiersma, Stal and Mur 1989 was established to accommodate a set of prokaryotic oxygenic phototrophs which, like plant, green algal and euglenoid chloroplasts, contain chlorophyll b instead of phycobiliproteins. Prochlorophytes were originally proposed (with concomitant scepticism) to be a monophyletic group sharing a common ancestry with these 'green' chloroplasts. Results from molecular sequence phylogenies, however, have suggested that Prochlorothrix hollandica is not on a lineage that leads to plastids. Our results from 16S ribosomal RNA sequence comparisons, which include new sequences from the marine picoplankter Prochlorococcus marinus and the Lissoclinum patella symbiont Prochloron sp., indicate that prochlorophytes are polyphyletic within the cyanobacterial radiation, and suggest that none of the known species is specifically related to chloroplasts. This implies that the three prochlorophytes and the green chloroplast ancestor acquired chlorophyll b and its associated structural proteins in convergent evolutionary events. We report further that the 16S rRNA gene sequence from Prochlorococcus is very similar to those of open ocean Synechococcus strains (marine cluster A), and to a family of 16S rRNA genes shotgun-cloned from plankton in the north Atlantic and Pacific Oceans.

  14. Lake Ontario: Food web dynamics in a changing ecosystem (1970-2000)

    Science.gov (United States)

    Mills, E.L.; Casselman, J.M.; Dermott, R.; Fitzsimons, J.D.; Gal, G.; Holeck, K. T.; Hoyle, J.A.; Johannsson, O.E.; Lantry, B.F.; Makarewicz, J.C.; Millard, E.S.; Munawar, I.F.; Munawar, M.; O'Gorman, R.; Owens, R.W.; Rudstam, L. G.; Schaner, T.; Stewart, T.J.

    2003-01-01

    We examined stressors that have led to profound ecological changes in the Lake Ontario ecosystem and its fish community since 1970. The most notable changes have been reductions in phosphorus loading, invasion by Dreissena spp., fisheries management through stocking of exotic salmonids and control of sea lamprey (Petromyzon marinus), and fish harvest by anglers and double-crested cormorants (Phalacrocorax auritus). The response to these stressors has led to (i) declines in both algal photosynthesis and epilimnetic zooplankton production, (ii) decreases in alewife (Alosa pseudoharengus) abundance, (iii) declines in native Diporeia and lake whitefish (Coregonus clupeaformis), (iv) behavioral shifts in alewife spatial distribution benefitting native lake trout (Salvelinus namaycush), threespine stickleback (Gasterosteus aculeatus), and emerald shiner (Notropis atherinoides) populations, (v) dramatic increases in water clarity, (vi) predation impacts by cormorants on select fish species, and (vii) lake trout recruitment bottlenecks associated with alewife-induced thiamine deficiency. We expect stressor responses associated with anthropogenic forces like exotic species invasions and global climate warming to continue to impact the Lake Ontario ecosystem in the future and recommend continuous long-term ecological studies to enhance scientific understanding and management of this important resource.

  15. Cambrian origin of the CYP27C1-mediated vitamin A1-to-A2 switch, a key mechanism of vertebrate sensory plasticity

    Science.gov (United States)

    Morshedian, Ala; Toomery, Matthew B.; Pollock, Gabriel E.; Frederiksen, Rikard; Enright, Jennifer; McCormick, Stephen; Cornwall, M. Carter; Fain, Gordon L.; Corbo, Joseph C.

    2017-01-01

    The spectral composition of ambient light varies across both space and time. Many species of jawed vertebrates adapt to this variation by tuning the sensitivity of their photoreceptors via the expression of CYP27C1, an enzyme that converts vitamin A1 into vitamin A2, thereby shifting the ratio of vitamin A1-based rhodopsin to red-shifted vitamin A2-based porphyropsin in the eye. Here, we show that the sea lamprey (Petromyzon marinus), a jawless vertebrate that diverged from jawed vertebrates during the Cambrian period (approx. 500 Ma), dynamically shifts its photoreceptor spectral sensitivity via vitamin A1-to-A2 chromophore exchange as it transitions between photically divergent aquatic habitats. We further show that this shift correlates with high-level expression of the lamprey orthologue of CYP27C1, specifically in the retinal pigment epithelium as in jawed vertebrates. Our results suggest that the CYP27C1-mediated vitamin A1-to-A2 switch is an evolutionarily ancient mechanism of sensory plasticity that appeared not long after the origin of vertebrates.

  16. Methanol Production by a Broad Phylogenetic Array of Marine Phytoplankton.

    Directory of Open Access Journals (Sweden)

    Tracy J Mincer

    Full Text Available Methanol is a major volatile organic compound on Earth and serves as an important carbon and energy substrate for abundant methylotrophic microbes. Previous geochemical surveys coupled with predictive models suggest that the marine contributions are exceedingly large, rivaling terrestrial sources. Although well studied in terrestrial ecosystems, methanol sources are poorly understood in the marine environment and warrant further investigation. To this end, we adapted a Purge and Trap Gas Chromatography/Mass Spectrometry (P&T-GC/MS method which allowed reliable measurements of methanol in seawater and marine phytoplankton cultures with a method detection limit of 120 nanomolar. All phytoplankton tested (cyanobacteria: Synechococcus spp. 8102 and 8103, Trichodesmium erythraeum, and Prochlorococcus marinus, and Eukarya (heterokont diatom: Phaeodactylum tricornutum, coccolithophore: Emiliania huxleyi, cryptophyte: Rhodomonas salina, and non-diatom heterokont: Nannochloropsis oculata produced methanol, ranging from 0.8-13.7 micromolar in culture and methanol per total cellular carbon were measured in the ranges of 0.09-0.3%. Phytoplankton culture time-course measurements displayed a punctuated production pattern with maxima near early stationary phase. Stabile isotope labeled bicarbonate incorporation experiments confirmed that methanol was produced from phytoplankton biomass. Overall, our findings suggest that phytoplankton are a major source of methanol in the upper water column of the world's oceans.

  17. Determination of intracellular pH and PCO2 after metabolic inhibition by fluoride and nitrilotriacetic acid.

    Science.gov (United States)

    Pörtner, H O; Boutilier, R G; Tang, Y; Toews, D P

    1990-08-01

    Mean intracellular pH (pHi) and PCO2 (PiCO2) have been analysed based on pH and total CO2 measurements in tissue homogenates. Tissues were sampled from undisturbed worms (Sipunculus nudus), squid (Illex illecebrosus), trout (Salmo gairdneri), toads (Bufo marinus), and rats. Homogenate metabolism was inhibited by the addition of potassium fluoride and nitrilotriacetic acid (NTA). Model calculations revealed that the influence of dilution, medium buffers, and contamination by extracellular fluids was negligible. In white muscle tissue the resulting pHi values were virtually the same as found in studies using DMO (dimethyloxazolidinedione). If large fractions of mitochondria were present (e.g. in heart muscle), DMO derived pHi values were considerably higher, probably representing overestimates. Homogenate derived pHi values are concluded to represent the effective mean pHi by taking into account pH gradients, and the volumes and buffering of cellular compartments. High time resolution and small variability make this method especially useful to assess rapid changes in pHi, e.g. in exercising animals.

  18. Using visible implant elastomer to study ammocoete populations with Cormack-Jolly-Seber models.

    Science.gov (United States)

    Evans, T M

    2017-12-01

    This study examined the efficacy of marking wild populations of lampreys with visible implant elastomer (VIE) for 6-18 months to examine ammocoete movements using Cormack-Jolly-Seber (CJS) open-population models. These methods were tested on two lamprey populations in different river systems. American brook lamprey Lethenteron appendix at Dyke Creek apparent survival (φ) was high in the summer and winter (c. 0·7), but declined after flow events in the spring and autumn. Sea lamprey Petromyzon marinus at Oquaga Creek φ in the top-ranked models varied with stream location and time. Estimates of φ were similar to Dyke Creek during the summer (c. 0·7), but declined after flow events and remained low (c. 0·1) in winter. Open-population models support current understanding of ammocoete movement, i.e. dispersal is driven by high-flow events at certain times of the year. The present study provides a framework to study ammocoetes with VIE. © 2017 The Fisheries Society of the British Isles.

  19. Methanol Production by a Broad Phylogenetic Array of Marine Phytoplankton

    Science.gov (United States)

    Mincer, Tracy J.; Aicher, Athena C.

    2016-01-01

    Methanol is a major volatile organic compound on Earth and serves as an important carbon and energy substrate for abundant methylotrophic microbes. Previous geochemical surveys coupled with predictive models suggest that the marine contributions are exceedingly large, rivaling terrestrial sources. Although well studied in terrestrial ecosystems, methanol sources are poorly understood in the marine environment and warrant further investigation. To this end, we adapted a Purge and Trap Gas Chromatography/Mass Spectrometry (P&T-GC/MS) method which allowed reliable measurements of methanol in seawater and marine phytoplankton cultures with a method detection limit of 120 nanomolar. All phytoplankton tested (cyanobacteria: Synechococcus spp. 8102 and 8103, Trichodesmium erythraeum, and Prochlorococcus marinus), and Eukarya (heterokont diatom: Phaeodactylum tricornutum, coccolithophore: Emiliania huxleyi, cryptophyte: Rhodomonas salina, and non-diatom heterokont: Nannochloropsis oculata) produced methanol, ranging from 0.8–13.7 micromolar in culture and methanol per total cellular carbon were measured in the ranges of 0.09–0.3%. Phytoplankton culture time-course measurements displayed a punctuated production pattern with maxima near early stationary phase. Stabile isotope labeled bicarbonate incorporation experiments confirmed that methanol was produced from phytoplankton biomass. Overall, our findings suggest that phytoplankton are a major source of methanol in the upper water column of the world’s oceans. PMID:26963515

  20. [Distribution and characteristics of Bacillus bacteria associated with hydrobionts and the waters of the Peter the Great Bay, Sea of Japan].

    Science.gov (United States)

    Beleneva, I A

    2008-01-01

    Bacilli of the species Bacillus subtilis, B. pumilus, B. mycoides, B. marinus and B. licheniformis (a total of 53 strains) were isolated from 15 invertebrate species and the water of the Vostok Bay, Peter the Great Bay, Sea of Japan. Bacilli were most often isolated from bivalves (22.7%) and sea cucumbers (18.9%); they occurred less frequently in sea urchins and starfish (13.2 and 7.5%, respectively). Most of bacilli strains were isolated from invertebrates inhabiting silted sediments. No Bacillus spp. strains were isolated from invertebrates inhabiting stony and sandy environments. The species diversity of bacilli isolated from marine objects under study was low. Almost all bacterial isolates were resistant to lincomycin. Unlike B. pumilus, B. subtilis isolates were mostly resistant to benzylpenicillin and ampicillin. Antibiotic sensitivity of B. licheniformis strains was variable (two strains were resistant to benzylpenicillin and oxacillin, while one was sensitive). A significant fraction of isolated bacilli contained pigments. Pigmented strains were more often isolated from seawater samples, while colorless ones predominated within hydrobionts. B. subtilis colonies had the broadest range of colors. In the Bacillus strains obtained, DNase, RNase, phosphatase, elastolytic, chitinase, and agarolytic activity was detected. Bacilli strains with hydrolytic activity occurred in invertebrates more often than in seawater.

  1. Nonparenchymal liver cells and granulomas during lamprey biliary atresia.

    Science.gov (United States)

    Youson, J H; Sargent, P A; Yamamoto, K; Ogilvie, D; Fisher, M M

    1987-06-01

    Transmission (thin sections and freeze-fracture replicas) and scanning electron microscopy were used to describe the nonparenchymal liver cells during the seven (1-7) stages of metamorphosis in the sea lamprey, Petromyzon marinus L., when bile ducts and canaliculi degenerate. The biliary atresia is accompanied by an increased diameter of fenestrae in the endothelium, an active phagocytosis by Kupffer cells in the sinusoids, and large lipid inclusions in perisinusoidal lipocytes (fat-storing or Ito cells). Plasma-like cells and foci of nonparenchymal cells (granulomas) are present in the liver interstitium during at least four stages of metamorphosis. The fenestrae in the sinusoidal wall are wider (up to 2.8-micron diameter) than normally reported for vertebrate livers but are likely a reflection of the morphogenetic and physiological events and consequences of the biliary atresia. Kupffer cells are involved in an extensive erythrophagocytosis, the storage of iron, and perhaps the incorporation of cellular components from hepatocytes. Lipocytes are the vitamin A-storing cells of the transforming liver and may be responsible for some perisinusoidal fibrosis. Granulomas are present during stages 3-6 and are focal areas where mononuclear leukocytes (lymphocytes and plasmalike cells), macrophages, and neutrophils have infiltrated the hepatic parenchyma. The function of the granulomas is not known; but their presence may be related to the porous nature of the sinusoidal wall, the tissue degeneration, and/or the physiological change (e.g., bile stasis) during biliary atresia.

  2. Characterization and Extracellular Enzyme Activity of Predominant Marine Bacillus spp. Isolated From Sea Water of Orissa Coast, India

    Directory of Open Access Journals (Sweden)

    Bal, S.

    2009-01-01

    Full Text Available Bacillus species are ubiquitous and diverse both in the terrestrial and marine ecosystems. In this investigation, predominant Bacillus species from sea water of three different sites of Orissa Coast were isolated and identified. In total, 16 Bacillus species were identified using morpho-physiological and biochemical characterisation. These identified bacterial strains include B. fastidiosus (CMB1, B. alvei (CMB2, B. coagulans (CMB3, B. marinus (CMB5, B. mycoides (CMB8, B. coagulans (PMB1, B. circulans (PMB2, B. cereus (PMB3, B. subtilis (PMB4, B. alcalophilus (GMB1, B. licheniformics (GMB2, B. polymyxa (GMB3 and B. pumilus (GMB4. The isolates CMB4, CMB6 and CMB7 were identified only up to genus level. These isolates were further screened for their salt tolerance and growth under varied temperature and pH conditions. Ability of these strains to produce extracellular enzymes such as protease, amylase, lipase, gelatinase, casein hydrolase, lecithinase, chitinase and pectinase were also screened and found that most of the Bacillus spp. possess extracellular enzymes.

  3. Evolutionarily conserved role for SoxC genes in neural crest specification and neuronal differentiation.

    Science.gov (United States)

    Uy, Benjamin R; Simoes-Costa, Marcos; Koo, Daniel E S; Sauka-Spengler, Tatjana; Bronner, Marianne E

    2015-01-15

    Members of the Sox family of transcription factors play a variety of critical developmental roles in both vertebrates and invertebrates. Whereas SoxBs and SoxEs are involved in neural and neural crest development, respectively, far less is known about members of the SoxC subfamily. To address this from an evolutionary perspective, we compare expression and function of SoxC genes in neural crest cells and their derivatives in lamprey (Petromyzon marinus), a basal vertebrate, to frog (Xenopus laevis). Analysis of transcript distribution reveals conservation of lamprey and X. laevis SoxC expression in premigratory neural crest, branchial arches, and cranial ganglia. Moreover, morpholino-mediated loss-of-function of selected SoxC family members demonstrates essential roles in aspects of neural crest development in both organisms. The results suggest important and conserved functions of SoxC genes during vertebrate evolution and a particularly critical, previously unrecognized role in early neural crest specification. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Electrical guidance efficiency of downstream-migrating juvenile Sea Lamprey decreases with increasing water velocity

    Science.gov (United States)

    Miehls, Scott M.; Johnson, Nicholas; Haro, Alexander

    2017-01-01

    We tested the efficacy of a vertically oriented field of pulsed direct current (VEPDC) created by an array of vertical electrodes for guiding downstream-moving juvenile Sea Lampreys Petromyzon marinus to a bypass channel in an artificial flume at water velocities of 10–50 cm/s. Sea Lampreys were more likely to be captured in the bypass channel than in other sections of the flume regardless of electric field status (on or off) or water velocity. Additionally, Sea Lampreys were more likely to be captured in the bypass channel when the VEPDC was active; however, an interaction between the effects of VEPDC and water velocity was observed, as the likelihood of capture decreased with increases in water velocity. The distribution of Sea Lampreys shifted from right to left across the width of the flume toward the bypass channel when the VEPDC was active at water velocities less than 25 cm/s. The VEPDC appeared to have no effect on Sea Lamprey distribution in the flume at water velocities greater than 25 cm/s. We also conducted separate tests to determine the threshold at which Sea Lampreys would become paralyzed. Individuals were paralyzed at a mean power density of 37.0 µW/cm3. Future research should investigate the ability of juvenile Sea Lampreys to detect electric fields and their specific behavioral responses to electric field characteristics so as to optimize the use of this technology as a nonphysical guidance tool across variable water velocities.

  5. Using experimental de-worming to measure the immunological and pathological impacts of lungworm infection in cane toads

    Directory of Open Access Journals (Sweden)

    Patrick B. Finnerty

    2017-12-01

    Full Text Available The immunological and pathological consequences of parasite infection can be more rigorously assessed from experimental manipulation than from correlational studies of natural infections. We used anthelmintic treatment to experimentally decrease intensities of lungworm infection in captive and free-ranging wild cane toads to assess parasite impacts on host immune responses. First, we administered the anthelmintic drug Ivermectin to both infected and uninfected toads, to distinguish drug effects per se from the impacts of killing lungworms. Worms began dying and decomposing <48 h after injection. The only immunological variables that were affected by anthelmintic treatment were bactericidal capacity of the blood which increased in parasitized toads (presumably triggered by decomposing worms in the lungs, and the phagocytic capacity of blood (which increased in both infected and uninfected toads; the latter effect presumably was caused by the injection of Ivermectin per se rather than removal of parasites. Second, we looked at correlates of variation in the infection intensity induced by de-worming (in both captive and free-ranging toads over an eight-week period. Heavier lungworm infection was associated with increased phagocytic ability of the host's blood, and a reduction in the host's liver mass (and hence, energy stores. Experimental de-worming thus revealed pathological and immunological costs of the presence of lungworms, and of their removal by anthelmintic injection. Keywords: Rhinella marina, Bufo marinus, Host, Parasite, Nematode

  6. Community dynamics and glycoside hydrolase activities of thermophilic bacterial consortia adapted to switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Gladden, J.M.; Allgaier, M.; Miller, C.S.; Hazen, T.C.; VanderGheynst, J.S.; Hugenholtz, P.; Simmons, B.A.; Singer, S.W.

    2011-05-01

    Industrial-scale biofuel production requires robust enzymatic cocktails to produce fermentable sugars from lignocellulosic biomass. Thermophilic bacterial consortia are a potential source of cellulases and hemicellulases adapted to harsher reaction conditions than commercial fungal enzymes. Compost-derived microbial consortia were adapted to switchgrass at 60 C to develop thermophilic biomass-degrading consortia for detailed studies. Microbial community analysis using small-subunit rRNA gene amplicon pyrosequencing and short-read metagenomic sequencing demonstrated that thermophilic adaptation to switchgrass resulted in low-diversity bacterial consortia with a high abundance of bacteria related to thermophilic paenibacilli, Rhodothermus marinus, and Thermus thermophilus. At lower abundance, thermophilic Chloroflexi and an uncultivated lineage of the Gemmatimonadetes phylum were observed. Supernatants isolated from these consortia had high levels of xylanase and endoglucanase activities. Compared to commercial enzyme preparations, the endoglucanase enzymes had a higher thermotolerance and were more stable in the presence of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), an ionic liquid used for biomass pretreatment. The supernatants were used to saccharify [C2mim][OAc]-pretreated switchgrass at elevated temperatures (up to 80 C), demonstrating that these consortia are an excellent source of enzymes for the development of enzymatic cocktails tailored to more extreme reaction conditions.

  7. Structure of ADP-aluminium fluoride-stabilized protochlorophyllide oxidoreductase complex.

    Science.gov (United States)

    Moser, Jürgen; Lange, Christiane; Krausze, Joern; Rebelein, Johannes; Schubert, Wolf-Dieter; Ribbe, Markus W; Heinz, Dirk W; Jahn, Dieter

    2013-02-05

    Photosynthesis uses chlorophylls for the conversion of light into chemical energy, the driving force of life on Earth. During chlorophyll biosynthesis in photosynthetic bacteria, cyanobacteria, green algae and gymnosperms, dark-operative protochlorophyllide oxidoreductase (DPOR), a nitrogenase-like metalloenzyme, catalyzes the chemically challenging two-electron reduction of the fully conjugated ring system of protochlorophyllide a. The reduction of the C-17=C-18 double bond results in the characteristic ring architecture of all chlorophylls, thereby altering the absorption properties of the molecule and providing the basis for light-capturing and energy-transduction processes of photosynthesis. We report the X-ray crystallographic structure of the substrate-bound, ADP-aluminium fluoride-stabilized (ADP·AlF(3)-stabilized) transition state complex between the DPOR components L(2) and (NB)(2) from the marine cyanobacterium Prochlorococcus marinus. Our analysis permits a thorough investigation of the dynamic interplay between L(2) and (NB)(2). Upon complex formation, substantial ATP-dependent conformational rearrangements of L(2) trigger the protein-protein interactions with (NB)(2) as well as the electron transduction via redox-active [4Fe-4S] clusters. We also present the identification of artificial "small-molecule substrates" of DPOR in correlation with those of nitrogenase. The catalytic differences and similarities between DPOR and nitrogenase have broad implications for the energy transduction mechanism of related multiprotein complexes that are involved in the reduction of chemically stable double and/or triple bonds.

  8. The effects of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) on fuel stores and ion balance in a non-target fish, the rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Birceanu, Oana; Sorensen, Lisa A; Henry, Matthew; McClelland, Grant B; Wang, Yuxiang S; Wilkie, Michael P

    2014-03-01

    The pesticide 3-trifluoromethyl-4-nitrophenol (TFM) is used to control sea lamprey (Petromyzon marinus) populations in the Great Lakes through its application to nursery streams containing larval sea lampreys. TFM uncouples oxidative phosphorylation, impairing mitochondrial ATP production in sea lampreys and rainbow trout (Oncorhynchus mykiss). However, little else is known about its sub-lethal effects on non-target aquatic species. The present study tested the hypotheses that TFM exposure in hard water leads to (i) marked depletion of energy stores in metabolically active tissues (brain, muscle, kidney, liver) and (ii) disruption of active ion transport across the gill, adversely affecting electrolyte homeostasis in trout. Exposure of trout to 11.0mgl(-1) TFM (12-h LC50) led to increases in muscle TFM and TFM-glucuronide concentrations, peaking at 9h and 12h, respectively. Muscle and brain glycogen was reduced by 50%, while kidney and muscle lactate increased with TFM exposure. Kidney ATP and phosphocreatine decreased by 50% and 70%, respectively. TFM exposure caused no changes in whole body ion (Na(+), Cl(-), Ca(2+), K(+)) concentrations, gill Na(+)/K(+) ATPase activity, or unidirectional Na(+) movements across the gills. We conclude that TFM causes a mismatch between ATP supply and demand in trout, leading to increased reliance on glycolysis, but it does not have physiologically relevant effects on ion balance in hard water. © 2013.

  9. Estimating reach-specific fish movement probabilities in rivers with a Bayesian state-space model: application to sea lamprey passage and capture at dams

    Science.gov (United States)

    Holbrook, Christopher M.; Johnson, Nicholas S.; Steibel, Juan P.; Twohey, Michael B.; Binder, Thomas R.; Krueger, Charles C.; Jones, Michael L.

    2014-01-01

    Improved methods are needed to evaluate barriers and traps for control and assessment of invasive sea lamprey (Petromyzon marinus) in the Great Lakes. A Bayesian state-space model provided reach-specific probabilities of movement, including trap capture and dam passage, for 148 acoustic tagged invasive sea lamprey in the lower Cheboygan River, Michigan, a tributary to Lake Huron. Reach-specific movement probabilities were combined to obtain estimates of spatial distribution and abundance needed to evaluate a barrier and trap complex for sea lamprey control and assessment. Of an estimated 21 828 – 29 300 adult sea lampreys in the river, 0%–2%, or 0–514 untagged lampreys, could have passed upstream of the dam, and 46%–61% were caught in the trap. Although no tagged lampreys passed above the dam (0/148), our sample size was not sufficient to consider the lock and dam a complete barrier to sea lamprey. Results also showed that existing traps are in good locations because 83%–96% of the population was vulnerable to existing traps. However, only 52%–69% of lampreys vulnerable to traps were caught, suggesting that traps can be improved. The approach used in this study was a novel use of Bayesian state-space models that may have broader applications, including evaluation of barriers for other invasive species (e.g., Asian carp (Hypophthalmichthys spp.)) and fish passage structures for other diadromous fishes.

  10. Metabolism of a sea lamprey pesticide by fish liver enzymes part A: identification and synthesis of TFM metabolites.

    Science.gov (United States)

    Bussy, Ugo; Chung-Davidson, Yu-Wen; Buchinger, Tyler; Li, Ke; Smith, Scott A; Jones, A Daniel; Li, Weiming

    2018-02-01

    The sea lamprey (Petromyzon marinus) is a destructive invasive species in the Great Lakes that contributed to the collapse of native fish populations in the mid-1900s. 3-Trifluoromethyl-4-nitrophenol (TFM) is a selective pesticide that has been applied to sea lamprey infested tributaries of the Great Lakes to kill larvae since the 1960s and has reduced the populations by as much as 90%. However, the metabolism of TFM by sea lamprey and non-target species is not fully illuminated. Elucidation of TFM metabolism is critical for understanding its mode of action and possible environmental impact. Here, we describe the screening, identification, synthesis and structural characterization of TFM metabolites in livers from sea lamprey and three non-target species that differ in their ability to survive TFM exposure. We identified glucuronidation, sulfation, N-acetylation, glutathione conjugation, and aromatic nitro group reduction as potential detoxification mechanisms. Seven metabolites were synthesized for use as markers of TFM metabolism in fish. Quantitative 1 H NMR was used to assay synthesized metabolite stock solutions that were then used as standard material to develop a quantitative LC-MS/MS method for TFM metabolites.

  11. Elsam. Offshore Wind Turbines. Horns Rev. Annual status report for the environmental monitoring programme 1. January 2004 - 31. December 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-15

    demonstrate any potential impacts resulting from the construction of the wind farm. This report presents results from 2004, in the second year of monitoring after the construction of the wind farm. For the Horns Rev offshore wind farm, the monitoring comprises: bottom flora and fauna; hard substrate habitat; fish; sandeel; birds; marine mammals (seals and harbour porpoises); socioeconomic and environmental economic effects. Monitoring programmes in 2004: Due to problems with the turbines, Vestas and Elsam decided to dismantle the turbines and bring them to shore to make the necessary adjustments and replacements. Thus, extensive boat traffic and work took place in the wind farm area between June and October 2004. Since these conditions did not resemble what could be considered a normal operational phase the Environmental Group decided to temporarily suspend the bird and harbour porpoise monitoring programmes planned for the second half of 2004. The biological and marine environments have been monitored continuously since the very first EIA survey and throughout the construction period. The monitoring was expected to continue until the end of 2004 in order to cover the post-construction period. This period has been extended until the end of 2005 in order to provide sufficient data from the operational phase, since some 2004 programmes were cut short by the replacement activities. The present report describes the results of the surveys conducted in 2004. (au)

  12. Patterns in prey use among fur seals and seabirds in the Pribilof Islands

    Science.gov (United States)

    Sinclair, E. H.; Vlietstra, L. S.; Johnson, D. S.; Zeppelin, T. K.; Byrd, G. V.; Springer, A. M.; Ream, R. R.; Hunt, G. L., Jr.

    2008-08-01

    We explored correlation in diet trends for five piscivorous predators that reproduce on the Pribilof Islands as illustrative of the shifting structure of the Bering Sea ecosystem. We evaluated the size and species of prey consumed by adult female and juvenile northern fur seals ( Callorhinus ursinus) and adults and chicks of black-legged kittiwakes ( Rissa tridactyla), red-legged kittiwakes ( Rissa brevirostris), thick-billed murres ( Uria lomvia), and common murres ( Uria aalge) from data collected between July and October 1960-2000. Sample sources included stomachs from seals and seabirds collected on pelagic foraging grounds in the eastern Bering Sea, seal scats from rookeries and seabird regurgitations and whole prey from nest sites on St. Paul and St. George Islands of the Pribilof Island archipelago. Typical prey included small fish and invertebrates (⩽20 cm for seals and ⩽12 cm for seabirds) that concentrate along frontal boundaries of the continental shelf/slope and in the epi-pelagic zone. Squids and fishes including walleye pollock ( Theragra chalcogramma), capelin ( Mallotus villosus), and sand lance ( Ammodytes hexapterus) were variably important in the diet of all five predators. Some prey, such as capelin, were principal in predator diets during the 1960s (seals) and into the early 1980s (seabirds), but declined or disappeared from all predator diets thereafter while others, such as walleye pollock, occurred with increasing frequency from the 1970s forward. As the number of individuals consuming walleye pollock increased, the overall volume of pollock in seabird diets declined. This decline was coincident with a decrease in the age and body size of pollock consumed by both seabirds and fur seals. Squid and pollock were negatively correlated in the diets of their primary consumers, northern fur seals (Pearson's coefficient -0.71, p=0.016) and thick-billed murres (Pearson's coefficient=-0.74, p=0.015) from the 1970s forward. Inter-island variation

  13. Notes on the Bull shark Carcharhinus leucas in the lagoon region of Cananéia, Brazil

    Directory of Open Access Journals (Sweden)

    V Sadowsky

    1971-12-01

    Full Text Available Ninety one young specimens and 3 adult females of BulI shark ("cação cabeça chata" caught in the lagoon region of Cananéia were examined, their tooth formula being 27/25 and the number of pre-caudal vertebrae ranging from 109 to 115. The proportion between the 1st and 2nd dorsal fins were found to be 2.3 and 2.8 for the young,and 2.9 to 3.1 for the adults. These data confirm that the studied form belongs to C. leuoas. Young occur regularly but in limited numbers.As regards the adults, however, females only appear during the short parturition period, i.e., from November to February. The number of embryos in the litters were from 7 to 9, their sizes ranging between 768-812 mm. The length of the smallest free young found was 697 mm, but young presumably 9 to 12 months old had 98 to 112 cm; between 21 and 24 months they were reaching 124 to 128 cm, that is, the same size they have when they start migrating to the open sea. The feeding inhibition phenomenon during the period of parturition was not observed in the female specimens caught in the lagoon. The more abundant species found in the stomach contents were: Arius spixii; Chloroscombrus chrysurus; A. grandicassus; A. barbus; Felichtys marinus; Genidens genidens; Chanophorus tajacica and Carcharhinus porosus.Noventa e um espécimes jovens e 3 fêmeas adultas de "cação cabeça chata" capturados na região lagunar de Cananeia foram examinados, constatando-se a fórmula dental 27/25 e número de vértebras pré-caudais entre 109 e 115.Verificouse que as proporções entre a la. nadadeira dorsal e a 2a. foram de 2.3 e 2.8 para os jovens e de 2.9 até 3.1 para os adultos.Ficou assim confirmado que a forma es tudada pertence a C. leuaas. É comum a ocorrência de jovens dentro da região estudada~ no entanto,quanto aos adultos,as fêmeas só são encontradas durante o período de parição, i.é, de novembro a fevereiro. Constatou-se que o número de embriões nas ninhadas foi de 7 a 9 e seus

  14. Development and implementation of an integrated program for control of sea lampreys in the St. Marys River

    Science.gov (United States)

    Schleen, Larry P.; Christie, Gavin C.; Heinrich, John W.; Bergstedt, Roger A.; Young, Robert J.; Morse, Terry J.; Lavis, Dennis S.; Bills, Terry D.; Johnson, James E.; Ebener, Mark P.

    2003-01-01

    The development and implementation of a strategy for control of sea lampreys (Petromyzon marinus) in the St. Marys River formed the basis for rehabilitation of lake trout (Salvelinus namaycush) and other fish in Lakes Huron and Michigan. The control strategy was implemented by the Great Lakes Fishery Commission (GLFC) upon recommendations by the interagency Sea Lamprey Integration Committee, and many managers and scientists from United States and Canada federal, state, provincial, tribal, and private institutions. Analyses of benefits vs. costs of control options and modeling of the cumulative effects on abundance of parasitic-phase sea lampreys and lake trout produced a strategy that involved an integration of control technologies that included long- and short-term measures. The longterm measures included interference with sea lamprey reproduction by the trapping and removal of spawning-phase sea lampreys from the river and the sterilization and release of the trapped male sea lampreys. The theoretical reduction of larvae produced in the river from these two combined techniques averaged almost 90% during 1997 to 1999. Lampricide treatment with granular Bayluscide of 880 ha of plots densely populated with larvae occurred during 1998, 1999, and 2001 because modeling showed the sooner parasitic-phase sea lamprey populations declined in Lake Huron the greater the improvement for restoration of lake trout during 1995 to 2015. Post-treatment assessments showed about 55% of the larvae had been removed from the river. An adaptive assessment plan predicted high probability of detection of control effects because of many available indicators. The GLFC will face several critical decisions beyond 2001, and initiated a decision analysis project to aid in those decisions.

  15. Side-of-onset of Parkinson's disease in relation to neuropsychological measures.

    Science.gov (United States)

    Modestino, Edward J; Amenechi, Chioma; Reinhofer, AnnaMarie; O'Toole, Patrick

    2017-01-01

    Parkinson's disease (PD) usually emerges with a unilateral side-of-onset (left-onset: LOPD; right-onset: ROPD; Marinus & van Hilten, 2015) due to an asymmetrical degeneration of striatal dopaminergic neurons (Donnemiller et al., Brain, 135, 2012, 3348). This has led to a body of research exploring the cognitive, neuropsychological, and clinical differences between LOPD and ROPD (e.g., Verreyt et al., Neuropsychology Review, 21, 2011, 405). Thirty ROPD and 14 LOPD cases were drawn from a Boston clinic specializing in PD. Various cognitive and neuropsychological measures were used in an attempt to discover if there were indeed any differences between LOPD and ROPD in this cohort. For LOPD, duration of illness was found to be significantly greater than that of ROPD. However, further testing was able to confirm that despite this difference, it was not the cause of the other significant differences found. Furthermore, this increased duration was consistent with a previous study (Munhoz et al., Parkinsonism and Related Disorders, 19, 2013, 77). Performance on the Digit Span Backward (DSB) was found to be significantly poorer in LOPD than ROPD, suggesting compromised executive function in LOPD. Additionally, LOPD had significantly greater anxiety on the DASS Anxiety scales than ROPD. However, unlike Foster et al (Cognitive and Behavioral Neurology, 23, 2010, 4), this increased anxiety could not account for the poorer performance on the DSB for LOPD. Finally, ROPD had significantly greater magical ideation than LOPD, which can be explained by the theory put forth by Brugger and Graves (European Archives of Psychiatry, 247, 1997, 55). Clear and significant differences between LOPD and ROPD were found within our cohort. LOPD showed greater impairment of working memory, greater anxiety, and greater duration of illness-all independent of one another; whereas, those with ROPD had greater magical ideation, also independent of any other variables.

  16. Comparison of toad venoms from different Bufo species by HPLC and LC-DAD-MS/MS.

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    Gao, Huimin; Zehl, Martin; Leitner, Alexander; Wu, Xiyan; Wang, Zhimin; Kopp, Brigitte

    2010-09-15

    Toad venom, called Chansu in China, has been widely used for the treatment of heart failure, sores, pains, and various cancers for a long time in clinic. The aim of the study is to investigate the chemical differences among a variety of toad venoms from different geographic locations and related Bufo species. Ten batches of commercial toad venom collected from different regions in China, one batch of fresh toad venom obtained from Bufo bufo gargarizans, and six batches of related Bufo species were analyzed by HPLC and LC-DAD-MS/MS. Individual components were identified by comparison of retention times, UV spectra, and mass spectra with authentic compounds, standard addition, as well as summarized MS fragmentation rules. Based on the profile of identified constituents and the content of cinobufagin and resibufogenin, the chemical differences observed among different samples are discussed. Overall, 43 compounds were identified in the methanolic extracts of the different samples of toad venom. Besides of suberoyl arginine, several free bufadienolides, bufadienolide sulfates, and suberoyl esters of bufadienolides were found. The total amounts of cinobufagin and resibufogenin, which are the only two control markers according to the current Chinese Pharmacopoeia, varied widely from 0.7% to 10.9% in the commercial Chansu samples collected in the different locations in China. Low levels of resibufogenin, but no cinobufagin was observed in the samples from Bufo melanosticus and Bufo marinus, and even neither of both compounds was found in the sample from Bufo viridis. The chemical profiles of the different commercial and collected toad venoms from related Bufo species differed significantly, not only in the absolute and relative contents, but also in the number and type of the constituents. The main reason for this variation are species-specific differences, but additional factors, such as the harvest and post-harvest processing, and adaption to environmental factors in

  17. Comparison of synthesis of 15 alpha-hydroxylated steroids in males of four North American lamprey species.

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    Bryan, Mara B; Young, Bradley A; Close, David A; Semeyn, Jesse; Robinson, T Craig; Bayer, Jennifer; Li, Weiming

    2006-04-01

    Recent studies have provided evidence that 15 alpha-hydroxytestosterone (15 alpha-T) and 15 alpha-hydroxyprogesterone (15 alpha-P) are produced in vitro and in vivo in adult male sea lampreys (Petromyzon marinus), and that circulatory levels increase in response to injections with gonadotropin-releasing hormone (GnRH). We examined four species from the Petromyzontidae family including silver lampreys (Ichthyomyzon unicuspis), chestnut lampreys (I. castaneus), American brook lampreys (Lethenteron appendix), and Pacific lampreys (Entosphenus tridentatus) to determine if these unusual steroids were unique to sea lampreys or a common feature in lamprey species. In vitro production was examined through incubations of testis with tritiated precursors, and 15 alpha-T and 15 alpha-P production was confirmed in all species through co-elution with standards on both high performance liquid chromatography (HPLC) and thin layer chromatography. In vivo production was proven by demonstrating that HPLC-fractionated plasma had peaks of immunoreactive 15 alpha-T and 15 alpha-P that co-eluted with standards through using previously developed radioimmunoassays for 15 alpha-T and 15 alpha-P. The possible functionality of 15 alpha-T and 15 alpha-P was further examined in silver and Pacific lampreys by investigating the effect of injection of either type of lamprey GnRH on plasma concentrations of 15 alpha-T and 15 alpha-P. Injections with exogenous GnRH did not affect circulatory levels of either steroid in silver lampreys, and only GnRH III elicited higher levels of both steroids in Pacific lampreys. The 15 alpha-hydroxylase enzyme(s) for steroids appeared to present in adult males of all species examined, but the question of whether 15 alpha-hydroxylated steroids are functional in these lamprey species, and the significance of the 15-hydroxyl group, requires further research.

  18. A fate-map for cranial sensory ganglia in the sea lamprey.

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    Modrell, Melinda S; Hockman, Dorit; Uy, Benjamin; Buckley, David; Sauka-Spengler, Tatjana; Bronner, Marianne E; Baker, Clare V H

    2014-01-15

    Cranial neurogenic placodes and the neural crest make essential contributions to key adult characteristics of all vertebrates, including the paired peripheral sense organs and craniofacial skeleton. Neurogenic placode development has been extensively characterized in representative jawed vertebrates (gnathostomes) but not in jawless fishes (agnathans). Here, we use in vivo lineage tracing with DiI, together with neuronal differentiation markers, to establish the first detailed fate-map for placode-derived sensory neurons in a jawless fish, the sea lamprey Petromyzon marinus, and to confirm that neural crest cells in the lamprey contribute to the cranial sensory ganglia. We also show that a pan-Pax3/7 antibody labels ophthalmic trigeminal (opV, profundal) placode-derived but not maxillomandibular trigeminal (mmV) placode-derived neurons, mirroring the expression of gnathostome Pax3 and suggesting that Pax3 (and its single Pax3/7 lamprey ortholog) is a pan-vertebrate marker for opV placode-derived neurons. Unexpectedly, however, our data reveal that mmV neuron precursors are located in two separate domains at neurula stages, with opV neuron precursors sandwiched between them. The different branches of the mmV nerve are not comparable between lampreys and gnatho-stomes, and spatial segregation of mmV neuron precursor territories may be a derived feature of lampreys. Nevertheless, maxillary and mandibular neurons are spatially segregated within gnathostome mmV ganglia, suggesting that a more detailed investigation of gnathostome mmV placode development would be worthwhile. Overall, however, our results highlight the conservation of cranial peripheral sensory nervous system development across vertebrates, yielding insight into ancestral vertebrate traits.

  19. Synthetic xylan-binding modules for mapping of pulp fibres and wood sections

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    Daniel Geoffrey

    2007-10-01

    Full Text Available Abstract Background The complex carbohydrate composition of natural and refined plant material is not known in detail but a matter that is of both basic and applied importance. Qualitative assessment of complex samples like plant and wood tissues requires the availability of a range of specific probes. Monoclonal antibodies and naturally existing carbohydrate binding modules (CBMs have been used in the past to assess the presence of certain carbohydrates in plant tissues. However, the number of natural CBMs is limited and development of carbohydrate-specific antibodies is not always straightforward. We envisage the use of sets of very similar proteins specific for defined targets, like those developed by molecular evolution of a single CBM scaffold, as a suitable strategy to assess carbohydrate composition. An advantage of using synthetic CBMs lies in the possibility to study fine details of carbohydrate composition within non-uniform substrates like plant cell walls as made possible through minor differences in CBM specificity of the variety of binders that can be developed by genetic engineering. Results A panel of synthetic xylan-binding CBMs, previously selected from a molecular library based on the scaffold of CBM4-2 from xylanase Xyn10A of Rhodothermus marinus, was used in this study. The wild type CBM4-2 and evolved modules both showed binding to wood sections. However, differences were observed in the staining patterns suggesting that these modules have different xylan-binding properties. Also the staining stability varied between the CBMs, the most stable staining being obtained with one (X-2 of the synthetic modules. Treatment of wood materials resulted in altered signal intensities, thereby also demonstrating the potential application of engineered CBMs as analytical tools for quality assessment of diverse plant material processes. Conclusion In this study we have demonstrated the usefulness of synthetic xylan-binding modules as

  20. Horizontal gene transfer of epigenetic machinery and evolution of parasitism in the malaria parasite Plasmodium falciparum and other apicomplexans.

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    Kishore, Sandeep P; Stiller, John W; Deitsch, Kirk W

    2013-02-11

    The acquisition of complex transcriptional regulatory abilities and epigenetic machinery facilitated the transition of the ancestor of apicomplexans from a free-living organism to an obligate parasite. The ability to control sophisticated gene expression patterns enabled these ancient organisms to evolve several differentiated forms, invade multiple hosts and evade host immunity. How these abilities were acquired remains an outstanding question in protistan biology. In this work, we study SET domain bearing genes that are implicated in mediating immune evasion, invasion and cytoadhesion pathways of modern apicomplexans, including malaria parasites. We provide the first conclusive evidence of a horizontal gene transfer of a Histone H4 Lysine 20 (H4K20) modifier, Set8, from an animal host to the ancestor of apicomplexans. Set8 is known to contribute to the coordinated expression of genes involved in immune evasion in modern apicomplexans. We also show the likely transfer of a H3K36 methyltransferase (Ashr3 from plants), possibly derived from algal endosymbionts. These transfers appear to date to the transition from free-living organisms to parasitism and coincide with the proposed horizontal acquisition of cytoadhesion domains, the O-glycosyltransferase that modifies these domains, and the primary family of transcription factors found in apicomplexan parasites. Notably, phylogenetic support for these conclusions is robust and the genes clearly are dissimilar to SET sequences found in the closely related parasite Perkinsus marinus, and in ciliates, the nearest free-living organisms with complete genome sequences available. Animal and plant sources of epigenetic machinery provide new insights into the evolution of parasitism in apicomplexans. Along with the horizontal transfer of cytoadhesive domains, O-linked glycosylation and key transcription factors, the acquisition of SET domain methyltransferases marks a key transitional event in the evolution to parasitism in

  1. A restoration suitability index model for the eastern oyster (Crassostrea virginica in the Mission-Aransas Estuary, TX, USA.

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    Jennifer Beseres Pollack

    Full Text Available Oyster reefs are one of the most threatened marine habitats on earth, with habitat loss resulting from water quality degradation, coastal development, destructive fishing practices, overfishing, and storm impacts. For successful and sustainable oyster reef restoration efforts, it is necessary to choose sites that support long-term growth and survival of oysters. Selection of suitable sites is critically important as it can greatly influence mortality factors and may largely determine the ultimate success of the restoration project. The application of Geographic Information Systems (GIS provides an effective methodology for identifying suitable sites for oyster reef restoration and removes much of the uncertainty involved in the sometimes trial and error selection process. This approach also provides an objective and quantitative tool for planning future oyster reef restoration efforts. The aim of this study was to develop a restoration suitability index model and reef quality index model to characterize locations based on their potential for successful reef restoration within the Mission-Aransas Estuary, Texas, USA. The restoration suitability index model focuses on salinity, temperature, turbidity, dissolved oxygen, and depth, while the reef quality index model focuses on abundance of live oysters, dead shell, and spat. Size-specific Perkinsus marinus infection levels were mapped to illustrate general disease trends. This application was effective in identifying suitable sites for oyster reef restoration, is flexible in its use, and provides a mechanism for considering alternative approaches. The end product is a practical decision-support tool that can be used by coastal resource managers to improve oyster restoration efforts. As oyster reef restoration activities continue at small and large-scales, site selection criteria are critical for assisting stakeholders and managers and for maximizing long-term sustainability of oyster resources.

  2. Impact of increasing market access on a tropical small-scale fishery

    Science.gov (United States)

    Stevens, Kara; Irwin, Brian J.; Kramer, Daniel; Urquhart, Gerald

    2014-01-01

    Small-scale fisheries have historically been marginalized in management and policy investments, and they often remain under-reported in national economic and fisheries statistics. Even so, small-scale fisheries are not entirely buffered from the impacts of globalization, such as the introduction and expansion of markets. This study measures the long-term impact of market-access on a coastal fishery on Nicaragua׳s remote Atlantic Coast from approximately the time when fishermen had access to stable and predictable local markets until the present, when the region has been transformed by road connection. In the last four years, fisheries trade has expanded as road connection has facilitated export to distant markets. Fishery-independent surveys were used to measure changes in indicators of fish-community status such as length-frequency, mean trophic level, and relative biomass. Species-level changes in relative biomass of common snook Centropomus undecimalis and gafftopsail catfish Bagre marinus were also evaluated since these species are the most economically valuable and likely account for the most fish biomass in the system. Using historical records, reports, current observations and interviews, changes in indicators of fishing intensity and market access over the past 17 years were assessed. From 1994 to 2011, community and species-specific metrics of the lagoon fishery declined significantly across all indicators examined. The potential social and economic outcomes of the decline in the fishery are far-reaching for the region, because this tropical fishery comprises the main source of protein and income for residents of twelve indigenous and Afro-descendent communities.

  3. A common bottlenose dolphin (Tursiops truncatus) prey handling technique for marine catfish (Ariidae) in the northern Gulf of Mexico.

    Science.gov (United States)

    Ronje, Errol I; Barry, Kevin P; Sinclair, Carrie; Grace, Mark A; Barros, Nélio; Allen, Jason; Balmer, Brian; Panike, Anna; Toms, Christina; Mullin, Keith D; Wells, Randall S

    2017-01-01

    Few accounts describe predator-prey interactions between common bottlenose dolphins (Tursiops truncatus Montagu 1821) and marine catfish (Ariopsis felis Linnaeus 1766, Bagre marinus Mitchill 1815). Over the course of 50,167 sightings of bottlenose dolphin groups in Mississippi Sound and along the Florida coast of the Gulf of Mexico, severed catfish heads were found floating and exhibiting movements at the surface in close proximity to 13 dolphin groups that demonstrated feeding behavior. These observations prompted a multi-disciplinary approach to study the predator-prey relationship between bottlenose dolphins and marine catfish. A review was conducted of bottlenose dolphin visual survey data and dorsal fin photographs from sightings where severed catfish heads were observed. Recovered severed catfish heads were preserved and studied, whole marine catfish were collected and examined, and stranding network pathology reports were reviewed for references to injuries related to fish spines. Photographic identification analysis confirms eight dolphins associated with severed catfish heads were present in three such sightings across an approximately 350 km expanse of coast between the Mississippi Sound and Saint Joseph Bay, FL. An examination of the severed catfish heads indicated interaction with dolphins, and fresh-caught whole hardhead catfish (A. felis) were examined to estimate the presumed total length of the catfish before decapitation. Thirty-eight instances of significant trauma or death in dolphins attributed to ingesting whole marine catfish were documented in stranding records collected from the southeastern United States of America. Bottlenose dolphins typically adhere to a ram-feeding strategy for prey capture followed by whole prey ingestion; however, marine catfish skull morphology may pose a consumption hazard due to rigid spines that can puncture and migrate through soft tissue, prompting a prey handling technique for certain dolphins, facilitating

  4. Molecular cloning, functional characterization, and evolutionary analysis of vitamin D receptors isolated from basal vertebrates.

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    Erin M Kollitz

    Full Text Available The vertebrate genome is a result of two rapid and successive rounds of whole genome duplication, referred to as 1R and 2R. Furthermore, teleost fish have undergone a third whole genome duplication (3R specific to their lineage, resulting in the retention of multiple gene paralogs. The more recent 3R event in teleosts provides a unique opportunity to gain insight into how genes evolve through specific evolutionary processes. In this study we compare molecular activities of vitamin D receptors (VDR from basal species that diverged at key points in vertebrate evolution in order to infer derived and ancestral VDR functions of teleost paralogs. Species include the sea lamprey (Petromyzon marinus, a 1R jawless fish; the little skate (Leucoraja erinacea, a cartilaginous fish that diverged after the 2R event; and the Senegal bichir (Polypterus senegalus, a primitive 2R ray-finned fish. Saturation binding assays and gel mobility shift assays demonstrate high affinity ligand binding and classic DNA binding characteristics of VDR has been conserved across vertebrate evolution. Concentration response curves in transient transfection assays reveal EC50 values in the low nanomolar range, however maximum transactivational efficacy varies significantly between receptor orthologs. Protein-protein interactions were investigated using co-transfection, mammalian 2-hybrid assays, and mutations of coregulator activation domains. We then combined these results with our previous study of VDR paralogs from 3R teleosts into a bioinformatics analysis. Our results suggest that 1, 25D3 acts as a partial agonist in basal species. Furthermore, our bioinformatics analysis suggests that functional differences between VDR orthologs and paralogs are influenced by differential protein interactions with essential coregulator proteins. We speculate that we may be observing a change in the pharmacodynamics relationship between VDR and 1, 25D3 throughout vertebrate evolution that may

  5. Comparative genomic analysis of multi-subunit tethering complexes demonstrates an ancient pan-eukaryotic complement and sculpting in Apicomplexa.

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    Christen M Klinger

    Full Text Available Apicomplexa are obligate intracellular parasites that cause tremendous disease burden world-wide. They utilize a set of specialized secretory organelles in their invasive process that require delivery of components for their biogenesis and function, yet the precise mechanisms underpinning such processes remain unclear. One set of potentially important components is the multi-subunit tethering complexes (MTCs, factors increasingly implicated in all aspects of vesicle-target interactions. Prompted by the results of previous studies indicating a loss of membrane trafficking factors in Apicomplexa, we undertook a bioinformatic analysis of MTC conservation. Building on knowledge of the ancient presence of most MTC proteins, we demonstrate the near complete retention of MTCs in the newly available genomes for Guillardiatheta and Bigelowiellanatans. The latter is a key taxonomic sampling point as a basal sister taxa to the group including Apicomplexa. We also demonstrate an ancient origin of the CORVET complex subunits Vps8 and Vps3, as well as the TRAPPII subunit Tca17. Having established that the lineage leading to Apicomplexa did at one point possess the complete eukaryotic complement of MTC components, we undertook a deeper taxonomic investigation in twelve apicomplexan genomes. We observed excellent conservation of the VpsC core of the HOPS and CORVET complexes, as well as the core TRAPP subunits, but sparse conservation of TRAPPII, COG, Dsl1, and HOPS/CORVET-specific subunits. However, those subunits that we did identify appear to be expressed with similar patterns to the fully conserved MTC proteins, suggesting that they may function as minimal complexes or with analogous partners. Strikingly, we failed to identify any subunits of the exocyst complex in all twelve apicomplexan genomes, as well as the dinoflagellate Perkinsus marinus. Overall, we demonstrate reduction of MTCs in Apicomplexa and their ancestors, consistent with modification during

  6. A generic system for the expression and purification of soluble and stable influenza neuraminidase.

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    Peter M Schmidt

    Full Text Available The influenza surface glycoprotein neuraminidase (NA is essential for the efficient spread of the virus. Antiviral drugs such as Tamiflu (oseltamivir and Relenza (zanamivir that inhibit NA enzyme activity have been shown to be effective in the treatment of influenza infections. The recent 'swine flu' pandemic and world-wide emergence of Tamiflu-resistant seasonal human influenza A(H1N1 H(274Y have highlighted the need for the ongoing development of new anti-virals, efficient production of vaccine proteins and novel diagnostic tools. Each of these goals could benefit from the production of large quantities of highly pure and stable NA. This publication describes a generic expression system for NAs in a baculovirus Expression Vector System (BEVS that is capable of expressing milligram amounts of recombinant NA. To construct NAs with increased stability, the natural influenza NA stalk was replaced by two different artificial tetramerization domains that drive the formation of catalytically active NA homotetramers: GCN4-pLI from yeast or the Tetrabrachion tetramerization domain from Staphylothermus marinus. Both recombinant NAs are secreted as FLAG-tagged proteins to allow for rapid and simple purification. The Tetrabrachion-based NA showed good solubility, increased stability and biochemical properties closer to the original viral NA than the GCN4-pLI based construct. The expressed quantities and high quality of the purified recombinant NA suggest that this expression system is capable of producing recombinant NA for a broad range of applications including high-throughput drug screening, protein crystallisation, or vaccine development.

  7. A Prochlorococcus proving ground for constraint-based metabolic modeling and multi-`omics data integration

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    Casey, J.; Ji, B.; Shaoie, S.; Mardinoglu, A.; Sarathi Sen, P.; Jahn, O.; Reda, K.; Leigh, J.; Follows, M. J.; Nielsen, J.; Karl, D. M.

    2016-02-01

    Representatives of the oligotrophic marine cyanobacterium Prochlorococcus marinus are the smallest free-living photosynthetic organisms, both in terms of physical size and genome size, yet are the most abundant photoautotrophic microbes in the oceans and profoundly influence global biogeochemical cycles. Physiological and regulatory control of nutrient and light stress has been observed in MED4 in culture and in its closely related `ecotype' eMED4 in the field, however its metabolism has not been investigated in detail. We present a genome-scale metabolic network reconstruction of the high-light adapted axenic strain MED4ax ("iJCMED4") for the quantitative analysis of a range of its metabolic phenotypes. The resulting structure is a proving ground for the incorporation of enzyme kinetics, biochemical and elemental compositional data, transcriptomic, proteomic, metabolomic, and fluxomic datasets which can be implemented within a constraint-based metabolic modeling environment. The iJCMED4 stoichiometric model consists of 523 metabolic genes encoding 787 reactions with 673 unique metabolites distributed in 5 sub-cellular compartments and is mass, charge, and thermodynamically balanced. Several variants of flux balance analysis were used to simulate growth and metabolic fluxes over the diel cycle, under various stress conditions (e.g., nitrogen, phosphorus, light), and within the framework of a global biogeochemical model (DARWIN). Model simulations accurately predicted growth rates in culture under a variety of defined medium compositions and there was close agreement of photosynthetic performance, biomass and energy yields and efficiencies, and transporter fluxes for iJCMED4 and culture experiments. In addition to a nearly optimal photosynthetic quotient and central carbon metabolism efficiency, MED4 has made dramatic alterations to redox and phosphorus metabolism across biosynthetic and intermediate pathways. We propose that reductions in phosphate reaction

  8. Recovery and decline of lake whitefish in U.S. waters of eastern Lake Ontario, 1980-2001

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    Owens, Randall W.; O'Gorman, Robert; Eckert, Thomas H.; Lantry, Brian F.; Dittman, Dawn E.

    2005-01-01

    The lake whitefish (Coregonus clupeaformis) was an important member of the native fish community and a valued commercial species in Lake Ontario. Lake whitefish were common in U.S. waters of the lake until 1965 and very abundant in Canadian waters through the early 1970s, although their numbers declined shortly thereafter. During 1975-1985, lake whitefish stocks remained depressed throughout the lake as a result of the combined effects of degraded water quality, overfishing, and predation. Rainbow smelt (Osmerus mordax) probably preyed on whitefish fry, and sea lamprey (Petromyzon marinus) preyed on adults. During 1985-1987, lake whitefish stocks began to recover in eastern Lake Ontario, and their buildup continued into the mid-1990s. Reasons for the recovery likely included control of the sea lamprey population and a reduction in the number of piscivorous rainbow smelt. By 1997, lake whitefish abundance had declined severely again; some fish appeared to have dispersed from the northeastern to the southeastern regions of the lake, and the depth of capture increased. We believe that the collapse of Diporeia spp. populations during 1992-1999 was responsible for the decline in the lake whitefish populations and the shifts in geographic and bathymetric distribution because lake whitefish fed primarily on Diporeia spp. After the collapse of Diporeia spp. populations, lake whitefish in southeastern Lake Ontario fed on Mysis relicta and quagga mussels (Dreissena bugensis). Changing from a diet of high-lipid Diporeia spp to low-lipid dreissenids and foraging on Mysis relicta at lower temperatures are apparently hampering the rebuilding of lake whitefish stocks.

  9. Development of a pH/alkalinity treatment model for applications of the lampricide TFM to streams tributary to the Great Lakes

    Science.gov (United States)

    Bills, Terry D.; Boogaard, Michael A.; Johnson, David A.; Brege, Dorance C.; Scholefield, Ronald J.; Westman, R. Wayne; Stephens, Brian E.

    2003-01-01

    It has long been known that the toxicity of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) is influenced by chemical and physical properties of water. As the pH, conductivity, and alkalinity of water increase, greater concentrations of TFM are required to kill sea lamprey (Petromyzon marinus) larvae. Consequently, the concentration of TFM required for effective treatment varies among streams. Brown trout (Salmo trutta) and sea lamprey larvae were exposed to a series of TFM concentrations in a continuous-flow diluter for 12 h. Twenty five exposures were conducted at various water alkalinities and pHs that treatment personnel encounter during lampricide treatments. Survival/mortality data were analyzed for lampricide concentrations that produced 50 and 99.9% mortality (LC50 and LC99.9) for sea lamprey larvae and 25 and 50% mortality (LC25 and LC50) for brown trout. Linear regression analyses were performed for each set of tests for each selected alkalinity by comparing the 12-h post exposure LC99.9 sea lamprey data and LC25 brown trout data at each pH. Mortality data from on-site toxicity tests conducted by lampricide control personnel were compared to predicted values from the pH/alkalinity prediction model. Of the 31 tests examined, 27 resulted in the LC100s (lowest TFM concentration where 100% mortality of sea lamprey was observed after 12 h of exposure) falling within 0.2 mg/L of the predicted sea lamprey minimum lethal (LC99.9) range. The pH/alkalinity prediction model provides managers with an operational tool that reduces the amount of TFM required for effective treatment while minimizing the impact on non-target organisms.

  10. Paracoccus aestuarii sp. nov., isolated from tidal flat sediment.

    Science.gov (United States)

    Roh, Seong Woon; Nam, Young-Do; Chang, Ho-Won; Kim, Kyoung-Ho; Kim, Min-Soo; Shin, Kee-Sun; Yoon, Jung-Hoon; Oh, Hee-Mock; Bae, Jin-Woo

    2009-04-01

    A Gram-negative micro-organism, designated strain B7(T), was isolated from tidal flat sediment and subjected to a polyphasic taxonomic study involving morphological, physiological, biochemical and 16S rRNA gene sequence analyses. A phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain B7(T) belonged to the genus Paracoccus and was closely related phylogenetically to Paracoccus marcusii MH1(T) (97.5 % sequence similarity), Paracoccus marinus KKL-A5(T) (97.5 %), Paracoccus haeundaensis BC74171(T) (97.3 %), Paracoccus carotinifaciens E-396(T) (97.3 %), Paracoccus homiensis DD-R11(T) (97.2 %), Paracoccus seriniphilus MBT-A4(T) (96.9 %) and other type strains of the genus Paracoccus (95.2-96.7 %). The G+C content of the genomic DNA and the major isoprenoid quinone of the type strain were 62.0 mol% and ubiquinone-10, respectively. The major fatty acid components were C(18 : 1)omega7c (68.9 %) and C(18 : 0) (18.1 %); this profile, with C(18 : 1)omega7c as the predominant fatty acid, was characteristic of members of the genus Paracoccus. The 16S rRNA gene sequence analysis, DNA-DNA hybridization studies and physiological and biochemical tests identified genotypic and phenotypic differences between strain B7(T) and recognized Paracoccus species. On the basis of these data, therefore, strain B7(T) represents a novel species of the genus Paracoccus, for which the name Paracoccus aestuarii sp. nov. is proposed. The type strain is B7(T) (=KCTC 22049(T)=DSM 19484(T)=JCM 15119(T)).

  11. Evolutionary Origin of the Proepicardium

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    Elena Cano

    2013-05-01

    Full Text Available The embryonic epicardium and the cardiac mesenchyme derived from it are critical to heart development. The embryonic epicardium arises from an extracardiac progenitor tissue called the proepicardium, a proliferation of coelomic cells located at the limit between the liver and the sinus venosus. A proepicardium has not been described in invertebrates, and the evolutionary origin of this structure in vertebrates is unknown. We herein suggest that the proepicardium might be regarded as an evolutionary derivative from an ancient pronephric external glomerulus that has lost its excretory role. In fact, we previously described that the epicardium arises by cell migration from the primordia of the right pronephric external glomerulus in a representative of the most primitive vertebrate lineage, the lamprey Petromyzon marinus. In this review, we emphasize the striking similarities between the gene expression profiles of the proepicardium and the developing kidneys, as well as the parallelisms in the signaling mechanisms involved in both cases. We show some preliminary evidence about the existence of an inhibitory mechanism blocking glomerular differentiation in the proepicardium. We speculate as to the possibility that this developmental link between heart and kidney can be revealing a phylogenetically deeper association, supported by the existence of a heart-kidney complex in Hemichordates. Finally, we suggest that primitive hematopoiesis could be related with this heart-kidney complex, thus accounting for the current anatomical association of the hematopoietic stem cells with an aorta-gonad-mesonephros area. In summary, we think that our hypothesis can provide new perspectives on the evolutionary origin of the vertebrate heart.

  12. Infection of sea lamprey with an unusual strain of Aeromonas salmonicida

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    Diamanka, Arfang; Loch, Thomas P.; Cipriano, Rocco C.; Winters, Andrew D.; Faisal, Mohamed

    2014-01-01

    The invasion of the Laurentian Great Lakes by the fish-parasitic sea lamprey has led to catastrophic consequences, including the potential introduction of fish pathogens. Aeromonas salmonicida is a bacterial fish pathogen that causes devastating losses worldwide. Currently, there are five accepted subspecies of Aeromonas salmonicida: A. salmonicida subsp. salmonicida, masoucida, smithia, achromogenes, and pectinolytica. We discuss the discovery of an isolate of A. salmonicida that is pathogenic to rainbow trout (Oncorhynchus mykiss) and exhibits unique phenotypic and molecular characteristics. We examined 181 adult sea lamprey (Petromyzon marinus) from the Humber River (Lake Ontario watershed) and 162 adult sea lamprey from Duffins Creek (Lake Ontario watershed) during the spring seasons of 2005–11. Among those, 4/343 (1.2%) sea lamprey were culture positive for A. salmonicida, whereby biochemical and molecular studies identified three of the isolates as A. salmonicida subsp. salmonicida. The remaining isolate (As-SL1) recovered from Humber River sea lamprey was phenotypically more similar to A. salmonicida subsp. salmonicida than to the four other A. salmonicida subspecies. However, unlike A. salmonicida subsp. salmonicida, As-SL1 was sucrose positive, produced an acid-over-acid reaction on triple-sugar iron medium and did not amplify with A. salmonicida subsp. salmonicida specific primers. Phylogenetic analysis based on partial stretches of the 16S rRNA and DNA gyrase subunit B genes further confirmed that the As-SL1 isolate was not A. salmonicida subsp. masoucida, smithia, achromogenes, or pectinolytica. Based on our analyses, the As-SL1 isolate is either an unusual strain of A. salmonicida subsp. salmonicida or a novel A. salmonicida subspecies. The four A. salmonicida isolates that were recovered from sea lamprey were pathogenic to rainbow trout in experimental challenge studies. Our study also underscores the potential role of sea lamprey in the ecology of

  13. Origin and evolution of retinoid isomerization machinery in vertebrate visual cycle: hint from jawless vertebrates.

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    Eugenia Poliakov

    Full Text Available In order to maintain visual sensitivity at all light levels, the vertebrate eye possesses a mechanism to regenerate the visual pigment chromophore 11-cis retinal in the dark enzymatically, unlike in all other taxa, which rely on photoisomerization. This mechanism is termed the visual cycle and is localized to the retinal pigment epithelium (RPE, a support layer of the neural retina. Speculation has long revolved around whether more primitive chordates, such as tunicates and cephalochordates, anticipated this feature. The two key enzymes of the visual cycle are RPE65, the visual cycle all-trans retinyl ester isomerohydrolase, and lecithin:retinol acyltransferase (LRAT, which generates RPE65's substrate. We hypothesized that the origin of the vertebrate visual cycle is directly connected to an ancestral carotenoid oxygenase acquiring a new retinyl ester isomerohydrolase function. Our phylogenetic analyses of the RPE65/BCMO and N1pC/P60 (LRAT superfamilies show that neither RPE65 nor LRAT orthologs occur in tunicates (Ciona or cephalochordates (Branchiostoma, but occur in Petromyzon marinus (Sea Lamprey, a jawless vertebrate. The closest homologs to RPE65 in Ciona and Branchiostoma lacked predicted functionally diverged residues found in all authentic RPE65s, but lamprey RPE65 contained all of them. We cloned RPE65 and LRATb cDNAs from lamprey RPE and demonstrated appropriate enzymatic activities. We show that Ciona ß-carotene monooxygenase a (BCMOa (previously annotated as an RPE65 has carotenoid oxygenase cleavage activity but not RPE65 activity. We verified the presence of RPE65 in lamprey RPE by immunofluorescence microscopy, immunoblot and mass spectrometry. On the basis of these data we conclude that the crucial transition from the typical carotenoid double bond cleavage functionality (BCMO to the isomerohydrolase functionality (RPE65, coupled with the origin of LRAT, occurred subsequent to divergence of the more primitive chordates

  14. Adult sea lamprey tolerates biliary atresia by altering bile salt composition and renal excretion

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    Cai, Shi-Ying; Lionarons, Daniël A.; Hagey, Lee; Soroka, Carol J.; Mennone, Albert; Boyer, James L.

    2012-01-01

    The sea lamprey (Petromyzon marinus) is a genetically programmed animal model for biliary atresia as it loses its bile ducts and gallbladder during metamorphosis. However, in contrast to patients with biliary atresia or other forms of cholestasis who develop progressive disease, the post-metamorphosis lampreys grow normally to adult size. To understand how the adult lamprey thrives without the ability to secrete bile, we examined bile salt homeostasis in larval and adult lampreys. Adult livers were severely cholestatic with levels of bile salts >1 mM, but no evidence of necrosis, fibrosis, or inflammation. Interestingly, both larvae and adults had normal plasma levels (~10 μM) of bile salts. In larvae, petromyzonol sulfate (PZS) was the predominant bile salt, whereas the major bile salts in adult liver were sulfated C27 bile alcohols. Cytotoxicity assays revealed that PZS was highly toxic. Pharmacokinetic studies in free-swimming adults revealed that ~35% of intravenously injected bromosulfophthalein (BSP) was eliminated over a 72 hr period. Collection of urine and feces demonstrated that both endogenous and exogenous organic anions, including biliverdin, bile salts and BSP, were predominantly excreted via the kidney with minor amounts also detected in feces. Gene expression analysis detected marked up-regulation of orthologs of known organic anion and bile salt transporters in the kidney with lesser effects in the intestine and gills in adults compared to larvae. These findings indicate that adult lampreys tolerate cholestasis by altering hepatic bile salt composition, while maintaining normal plasma bile salt levels predominantly through renal excretion of bile products. Therefore, we conclude that strategies to accelerate renal excretion of bile salt and other toxins should be beneficial for patients with cholestasis. PMID:23175353

  15. Evaluating harvest-based control of invasive fish with telemetry: Performance of sea lamprey traps in the Great Lakes

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    Holbrook, Christopher; Bergstedt, Roger A.; Barber, Jessica M.; Bravener, Gale A; Jones, Michael L.; Krueger, Charles C.

    2016-01-01

    Physical removal (e.g., harvest via traps or nets) of mature individuals may be a cost-effective or socially acceptable alternative to chemical control strategies for invasive species, but requires knowledge of the spatial distribution of a population over time. We used acoustic telemetry to determine the current and possible future role of traps to control and assess invasive sea lampreys, Petromyzon marinus, in the St. Marys River, the connecting channel between Lake Superior and Lake Huron. Exploitation rates (i.e., fractions of an adult sea lamprey population removed by traps) at two upstream locations were compared among three years and two points of entry to the system. Telemetry receivers throughout the drainage allowed trap performance (exploitation rate) to be partitioned into two components: proportion of migrating sea lampreys that visited trap sites (availability) and proportion of available sea lampreys that were caught by traps (local trap efficiency). Estimated exploitation rates were well below those needed to provide population control in the absence of lampricides and were limited by availability and local trap efficiency. Local trap efficiency estimates for acoustic-tagged sea lampreys were lower than analogous estimates regularly obtained using traditional mark–recapture methods, suggesting that abundance had been previously underestimated. Results suggested major changes would be required to substantially increase catch, including improvements to existing traps, installation of new traps, or other modifications to attract and retain more sea lampreys. This case study also shows how bias associated with telemetry tags can be estimated and incorporated in models to improve inferences about parameters that are directly relevant to fishery management.

  16. Habituation of adult sea lamprey repeatedly exposed to damage-released alarm and predator cues

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    Imre, Istvan; Di Rocco, Richard T.; Brown, Grant E.; Johnson, Nicholas

    2016-01-01

    Predation is an unforgiving selective pressure affecting the life history, morphology and behaviour of prey organisms. Selection should favour organisms that have the ability to correctly assess the information content of alarm cues. This study investigated whether adult sea lamprey Petromyzon marinus habituate to conspecific damage-released alarm cues (fresh and decayed sea lamprey extract), a heterospecific damage-released alarm cue (white sucker Catostomus commersoniiextract), predator cues (Northern water snake Nerodia sipedon washing, human saliva and 2-phenylethylamine hydrochloride (PEA HCl)) and a conspecific damage-released alarm cue and predator cue combination (fresh sea lamprey extract and human saliva) after they were pre-exposed 4 times or 8 times, respectively, to a given stimulus the previous night. Consistent with our prediction, adult sea lamprey maintained an avoidance response to conspecific damage-released alarm cues (fresh and decayed sea lamprey extract), a predator cue presented at high relative concentration (PEA HCl) and a conspecific damage-released alarm cue and predator cue combination (fresh sea lamprey extract plus human saliva), irrespective of previous exposure level. As expected, adult sea lamprey habituated to a sympatric heterospecific damage-released alarm cue (white sucker extract) and a predator cue presented at lower relative concentration (human saliva). Adult sea lamprey did not show any avoidance of the Northern water snake washing and the Amazon sailfin catfish extract (heterospecific control). This study suggests that conspecific damage-released alarm cues and PEA HCl present the best options as natural repellents in an integrated management program aimed at controlling the abundance of sea lamprey in the Laurentian Great Lakes.

  17. Chemical Characterization of Lipophilic Constituents in the Skin of Migratory Adult Sea Lamprey from the Great Lakes Region

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    Dissanayake, Amila A.; Wagner, C. Michael; Nair, Muraleedharan G.

    2016-01-01

    The sea lamprey (Petromzons marinus) is an invasive ectoparasite of large-bodied fishes that adversely affects the fishing industry and ecology of the Laurentian Great Lakes. Lipid content in the whole sea lamprey and muscles, liver and kidney of metamorphosing larval stages has been reported. Similarly, the fatty acid profile of the rope tissues of sexually-mature male sea lampreys has also been reported. The average body weight of a sub-adult migratory sea lamprey is 250 g, which includes 14.4% skin (36 g). Our preliminary extraction data of an adult sea lamprey skin revealed that it contained approximately 8.5% of lipophilic compounds. Lamprey skin is home to a naturally aversive compound (an alarm cue) that is being developed into a repellent for use in pest management. As part of an ongoing investigation to identify the chemical structure of the sea lamprey alarm cue, we extracted the skin with water and methanol, respectively. The methanolic extract (1.55%) contained exclusively lipophilic compounds and did not include the alarm cue. We chemically characterized all compounds present in the methanolic extract as cholesterol esters (CE), tri- and di-glycerides (TG and DG), cholesterol, free fatty acids (FFA) and minor amounts of plasticizers. The free fatty acids fraction was composed of saturated (41.8%), monounsaturated (40.7%) and polyunsaturated (17.4%) fatty acids, respectively. The plasticizers characterized were phthalate and benzoate and found to be 0.95 mg and 2.54 mg, respectively, per adult sea lamprey skin. This is the first report of the chemical characterization of all the lipophilic constituents in the skin of sub-adult migratory sea lamprey. The CEs isolated and characterized from sea lamprey skin are also for the first time. PMID:27992570

  18. Evidence for a receiver bias underlying female preference for a male mating pheromone in sea lamprey

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    Buchinger, Tyler J.; Wang, Huiyong; Li, Weiming; Johnson, Nicholas S.

    2013-01-01

    Receiver bias models suggest that a male sexual signal became exaggerated to match a pre-existing sensory, perceptual or cognitive disposition of the female. Accordingly, these models predict that females of related taxa possessing the ancestral state of signalling evolved preference for the male trait in a non-sexual context. We postulated that female preference for the male-released bile alcohol mating pheromone, 3 keto petromyzonol sulfate (3kPZS), of the sea lamprey (Petromyzon marinus) evolved as a result of a receiver bias. In particular, we propose that migratory silver lamprey (Ichthyomyzon unicuspis), a basal member of the Petromyzontidae, evolved a preference for 3kPZS released by stream-resident larvae as a means of identifying productive habitat for offspring. Larval silver lamprey released 3kPZS at rates sufficient to be detected by migratory lampreys. Females responded to 3kPZS by exhibiting upstream movement behaviours relevant in a migratory context, but did not exhibit proximate behaviours important to mate search and spawning. Male silver lamprey did not release 3kPZS at rates sufficient to be detected by females in natural high-volume stream environments. We infer that female silver lamprey cue onto 3kPZS excreted by stream-resident larvae as a mechanism to locate habitat conducive to offspring survival and that males do not signal with 3kPZS. We suggest that this female preference for a male signal in a non-sexual context represents a bias leading to the sexual signalling observed in sea lamprey.

  19. Chemical Characterization of Lipophilic Constituents in the Skin of Migratory Adult Sea Lamprey from the Great Lakes Region.

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    Amila A Dissanayake

    Full Text Available The sea lamprey (Petromzons marinus is an invasive ectoparasite of large-bodied fishes that adversely affects the fishing industry and ecology of the Laurentian Great Lakes. Lipid content in the whole sea lamprey and muscles, liver and kidney of metamorphosing larval stages has been reported. Similarly, the fatty acid profile of the rope tissues of sexually-mature male sea lampreys has also been reported. The average body weight of a sub-adult migratory sea lamprey is 250 g, which includes 14.4% skin (36 g. Our preliminary extraction data of an adult sea lamprey skin revealed that it contained approximately 8.5% of lipophilic compounds. Lamprey skin is home to a naturally aversive compound (an alarm cue that is being developed into a repellent for use in pest management. As part of an ongoing investigation to identify the chemical structure of the sea lamprey alarm cue, we extracted the skin with water and methanol, respectively. The methanolic extract (1.55% contained exclusively lipophilic compounds and did not include the alarm cue. We chemically characterized all compounds present in the methanolic extract as cholesterol esters (CE, tri- and di-glycerides (TG and DG, cholesterol, free fatty acids (FFA and minor amounts of plasticizers. The free fatty acids fraction was composed of saturated (41.8%, monounsaturated (40.7% and polyunsaturated (17.4% fatty acids, respectively. The plasticizers characterized were phthalate and benzoate and found to be 0.95 mg and 2.54 mg, respectively, per adult sea lamprey skin. This is the first report of the chemical characterization of all the lipophilic constituents in the skin of sub-adult migratory sea lamprey. The CEs isolated and characterized from sea lamprey skin are also for the first time.

  20. Factors influencing capture of invasive sea lamprey in traps baited with a synthesized sex pheromone component

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    Johnson, Nicholas; Siefkes, Michael J.; Wagner, C. Michael; Bravener, Gale; Steeves, Todd; Twohey, Michael; Li, Weiming

    2015-01-01

    The sea lamprey, Petromyzon marinus, is emerging as a model organism for understanding how pheromones can be used for manipulating vertebrate behavior in an integrated pest management program. In a previous study, a synthetic sex pheromone component 7α,12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) was applied to sea lamprey traps in eight streams at a final in-stream concentration of 10−12 M. Application of 3kPZS increased sea lamprey catch, but where and when 3kPZS had the greatest impact was not determined. Here, by applying 3kPZS to additional streams, we determined that overall increases in yearly exploitation rate (proportion of sea lampreys that were marked, released, and subsequently recaptured) were highest (20–40 %) in wide streams (~40 m) with low adult sea lamprey abundance (lamprey and, in the absence of other attractants (larval odor, sex pheromone), sea lamprey may have been more responsive to a partial sex pheromone blend emitted from traps. Furthermore, we found that the largest and most consistent responses to 3kPZS were during nights early in the trapping season, when water temperatures were increasing. This may have occurred because, during periods of increasing water temperatures, sea lamprey become more active and males at large may not have begun to release sex pheromone. In general, our results are consistent with those for pheromones of invertebrates, which are most effective when pest density is low and when pheromone competition is low.

  1. Telemetry narrows the search for sea lamprey spawning locations in the St. Clair-Detroit River System

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    Holbrook, Christopher; Jubar, Aaron K.; Barber, Jessica M.; Tallon, Kevin; Hondorp, Darryl W.

    2016-01-01

    Adult sea lamprey (Petromyzon marinus) abundance in Lake Erie has remained above targets set by fishery managers since 2005, possibly due to increased recruitment in the St. Clair-Detroit River System (SCDRS). Sea lamprey recruitment in the SCDRS poses an enormous challenge to sea lamprey control and assessment in Lake Erie because the SCDRS contains no dams to facilitate capture and discharge is at least an order of magnitude larger in the SCDRS than most other sea lamprey-producing tributaries in the Great Lakes. As a first step toward understanding population size, spatial distribution, and spawning habitat of adult sea lampreys in the SCDRS, we used acoustic telemetry to determine where sea lampreys ceased migration (due to spawning, death, or both) among major regions of the SCDRS. All tagged sea lampreys released in the lower Detroit River (N = 27) moved upstream through the Detroit River and entered Lake St. Clair. After entering Lake St. Clair, sea lampreys entered the St. Clair River (N = 22), Thames River (N = 1), or were not detected again (N = 4). Many sea lampreys (10 of 27) were last observed moving downstream (“fallback”) but we were unable to determine if those movements occurred before or after spawning, or while sea lampreys were dead or alive. Regardless of whether estimates of locations where sea lampreys ceased migration were based on the most upstream region occupied or final region occupied, most sea lampreys ceased migration in the St. Clair River or Lake St. Clair. Results suggest that spawning and rearing in the St. Clair River could be an important determinant of sea lamprey recruitment in the SCDRS and may direct future assessment and control activities in that system.

  2. Early evolution of conserved regulatory sequences associated with development in vertebrates.

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    Gayle K McEwen

    2009-12-01

    Full Text Available Comparisons between diverse vertebrate genomes have uncovered thousands of highly conserved non-coding sequences, an increasing number of which have been shown to function as enhancers during early development. Despite their extreme conservation over 500 million years from humans to cartilaginous fish, these elements appear to be largely absent in invertebrates, and, to date, there has been little understanding of their mode of action or the evolutionary processes that have modelled them. We have now exploited emerging genomic sequence data for the sea lamprey, Petromyzon marinus, to explore the depth of conservation of this type of element in the earliest diverging extant vertebrate lineage, the jawless fish (agnathans. We searched for conserved non-coding elements (CNEs at 13 human gene loci and identified lamprey elements associated with all but two of these gene regions. Although markedly shorter and less well conserved than within jawed vertebrates, identified lamprey CNEs are able to drive specific patterns of expression in zebrafish embryos, which are almost identical to those driven by the equivalent human elements. These CNEs are therefore a unique and defining characteristic of all vertebrates. Furthermore, alignment of lamprey and other vertebrate CNEs should permit the identification of persistent sequence signatures that are responsible for common patterns of expression and contribute to the elucidation of the regulatory language in CNEs. Identifying the core regulatory code for development, common to all vertebrates, provides a foundation upon which regulatory networks can be constructed and might also illuminate how large conserved regulatory sequence blocks evolve and become fixed in genomic DNA.

  3. 13

    Science.gov (United States)

    Cordova, Lauren T; Cipolla, Robert M; Swarup, Adti; Long, Christopher P; Antoniewicz, Maciek R

    2017-11-01

    Thermophilic organisms are being increasingly investigated and applied in metabolic engineering and biotechnology. The distinct metabolic and physiological characteristics of thermophiles, including broad substrate range and high uptake rates, coupled with recent advances in genetic tool development, present unique opportunities for strain engineering. However, poor understanding of the cellular physiology and metabolism of thermophiles has limited the application of systems biology and metabolic engineering tools to these organisms. To address this concern, we applied high resolution 13 C metabolic flux analysis to quantify fluxes for three divergent extremely thermophilic bacteria from separate phyla: Geobacillus sp. LC300, Thermus thermophilus HB8, and Rhodothermus marinus DSM 4252. We performed 18 parallel labeling experiments, using all singly labeled glucose tracers for each strain, reconstructed and validated metabolic network models, measured biomass composition, and quantified precise metabolic fluxes for each organism. In the process, we resolved many uncertainties regarding gaps in pathway reconstructions and elucidated how these organisms maintain redox balance and generate energy. Overall, we found that the metabolisms of the three thermophiles were highly distinct, suggesting that adaptation to growth at high temperatures did not favor any particular set of metabolic pathways. All three strains relied heavily on glycolysis and TCA cycle to generate key cellular precursors and cofactors. None of the investigated organisms utilized the Entner-Doudoroff pathway and only one strain had an active oxidative pentose phosphate pathway. Taken together, the results from this study provide a solid foundation for future model building and engineering efforts with these and related thermophiles. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  4. Female sea lamprey shift orientation toward a conspecific chemical cue to escape a sensory trap

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    Brant, Cory O.; Johnson, Nicholas; Li, Ke; Buchinger, Tyler J.; Li, Weiming

    2016-01-01

    The sensory trap model of signal evolution hypothesizes that signalers adapt to exploit a cue used by the receiver in another context. Although exploitation of receiver biases can result in conflict between the sexes, deceptive signaling systems that are mutually beneficial drive the evolution of stable communication systems. However, female responses in the nonsexual and sexual contexts may become uncoupled if costs are associated with exhibiting a similar response to a trait in both contexts. Male sea lamprey (Petromyzon marinus) signal with a mating pheromone, 3-keto petromyzonol sulfate (3kPZS), which may be a match to a juvenile cue used by females during migration. Upstream movement of migratory lampreys is partially guided by 3kPZS, but females only move toward 3kPZS with proximal accuracy during spawning. Here, we use in-stream behavioral assays paired with gonad histology to document the transition of female preference for juvenile- and male-released 3kPZS that coincides with the functional shift of 3kPZS as a migratory cue to a mating pheromone. Females became increasingly biased toward the source of synthesized 3kPZS as their maturation progressed into the reproductive phase, at which point, a preference for juvenile odor (also containing 3kPZS naturally) ceased to exist. Uncoupling of female responses during migration and spawning makes the 3kPZS communication system a reliable means of synchronizing mate search. The present study offers a rare example of a transition in female responses to a chemical cue between nonsexual and sexual contexts, provides insights into the origins of stable communication signaling systems.

  5. A semelparous fish continues upstream migration when exposed to alarm cue, but adjusts movement speed and timing

    Science.gov (United States)

    Luhring, Thomas M; Meckley, Trevor D.; Johnson, Nicholas S.; Siefkes, Michael J.; Hume, John B.; Wagner, C. Michael

    2016-01-01

    Animals make trade-offs between predation risk and pursuit of opportunities such as foraging and reproduction. Trade-offs between antipredator behaviours and foraging are well suited to manipulation in laboratory and field settings and have generated a vast compendium of knowledge. However, much less is known about how animals manage trade-offs between predation risk and pursuit of reproductive opportunities in the absence of the confounding effects of foraging. In the present study, we investigated how the nonfeeding migratory life stage of sea lamprey, Petromyzon marinus, responds to odour from dead conspecifics (a cue that induces avoidance behaviours in laboratory and field studies). We released groups of PIT-tagged sea lamprey 65 m from the shore of Lake Michigan or 287 m upstream in Carp Lake River and used antennas to detect their movements in the river. As the breeding season progressed, sea lamprey initiated upstream movement earlier and were more likely to enter the river. Sea lamprey that began the night in Lake Michigan entered Carp Lake River at higher rates and accelerated upstream when exposed to high concentrations of alarm cue, consistent with animals attempting to minimize time spent in risky areas. Sea lampreys that began the night in the river delayed upstream movement when exposed to alarm cue, consistent with animals sheltering and gathering information about a source of risk. We attribute this context-specific reaction to alarm cue to differences in perceived vulnerability to predation in sheltered positions in the river versus exposed positions in the lake. Once in the river, the vast majority of sea lamprey moved upstream independent of alarm cue or Julian date. Although life-history-induced time and energy budgets place rigid constraints on the direction of migration, sea lamprey attend to predation risk by modifying movement timing and speed.

  6. Optimizing larval assessment to support sea lamprey control in the Great Lakes

    Science.gov (United States)

    Hansen, Michael J.; Adams, Jean V.; Cuddy, Douglas W.; Richards, Jessica M.; Fodale, Michael F.; Larson, Geraldine L.; Ollila, Dale J.; Slade, Jeffrey W.; Steeves, Todd B.; Young, Robert J.; Zerrenner, Adam

    2003-01-01

    Elements of the larval sea lamprey (Petromyzon marinus) assessment program that most strongly influence the chemical treatment program were analyzed, including selection of streams for larval surveys, allocation of sampling effort among stream reaches, allocation of sampling effort among habitat types, estimation of daily growth rates, and estimation of metamorphosis rates, to determine how uncertainty in each element influenced the stream selection program. First, the stream selection model based on current larval assessment sampling protocol significantly underestimated transforming sea lam-prey abundance, transforming sea lampreys killed, and marginal costs per sea lamprey killed, compared to a protocol that included more years of data (especially for large streams). Second, larval density in streams varied significantly with Type-I habitat area, but not with total area or reach length. Third, the ratio of larval density between Type-I and Type-II habitat varied significantly among streams, and that the optimal allocation of sampling effort varied with the proportion of habitat types and variability of larval density within each habitat. Fourth, mean length varied significantly among streams and years. Last, size at metamorphosis varied more among years than within or among regions and that metamorphosis varied significantly among streams within regions. Study results indicate that: (1) the stream selection model should be used to identify streams with potentially high residual populations of larval sea lampreys; (2) larval sampling in Type-II habitat should be initiated in all streams by increasing sampling in Type-II habitat to 50% of the sampling effort in Type-I habitat; and (3) methods should be investigated to reduce uncertainty in estimates of sea lamprey production, with emphasis on those that reduce the uncertainty associated with larval length at the end of the growing season and those used to predict metamorphosis.

  7. Central angiotensin II stimulates cutaneous water intake behavior via an angiotensin II type-1 receptor pathway in the Japanese tree frog Hyla japonica.

    Science.gov (United States)

    Maejima, Sho; Konno, Norifumi; Matsuda, Kouhei; Uchiyama, Minoru

    2010-08-01

    Angiotensin II (Ang II) stimulates oral water intake by causing thirst in all terrestrial vertebrates except anurans. Anuran amphibians do not drink orally but absorb water osmotically through ventral skin. In this study, we examined the role of Ang II on the regulation of water-absorption behavior in the Japanese tree frog (Hyla japonica). In fully hydrated frogs, intracerebroventricular (ICV) and intralymphatic sac (ILS) injection of Ang II significantly extended the residence time of water in a dose-dependent manner. Ang II-dependent water uptake was inhibited by ICV pretreatment with an angiotensin II type-1 (AT(1)) receptor antagonist but not a type-2 (AT(2)) receptor antagonist. These results suggest that Ang II stimulates water-absorption behavior in the tree frog via an AT(1)-like but not AT(2)-like receptor. We then cloned and characterized cDNA of the tree frog AT(1) receptor from the brain. The tree frog AT(1) receptor cDNA encodes a 361 amino acid residue protein, which is 87% identical to the toad (Bufo marinus) AT(1) receptor and exhibits the functional characteristics of an Ang II receptor. AT(1) receptor mRNAs were found to be present in a number of tissues including brain (especially in the diencephalon), lung, large intestine, kidney and ventral pelvic skin. When tree frogs were exposed to dehydrating conditions, AT(1) receptor mRNA significantly increased in the diencephalon and the rhombencephalon. These data suggest that central Ang II may control water intake behavior via an AT(1) receptor on the diencephalon and rhombencephalon in anuran amphibians and may have implications for water consumption in vertebrates. Copyright 2010 Elsevier Inc. All rights reserved.

  8. Genetic models reveal historical patterns of sea lamprey population fluctuations within Lake Champlain

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    Cassidy C. D’Aloia

    2015-10-01

    Full Text Available The origin of sea lamprey (Petromyzon marinus in Lake Champlain has been heavily debated over the past decade. Given the lack of historical documentation, two competing hypotheses have emerged in the literature. First, it has been argued that the relatively recent population size increase and concomitant rise in wounding rates on prey populations are indicative of an invasive population that entered the lake through the Champlain Canal. Second, recent genetic evidence suggests a post-glacial colonization at the end of the Pleistocene, approximately 11,000 years ago. One limitation to resolving the origin of sea lamprey in Lake Champlain is a lack of historical and current measures of population size. In this study, the issue of population size was explicitly addressed using nuclear (nDNA and mitochondrial DNA (mtDNA markers to estimate historical demography with genetic models. Haplotype network analysis, mismatch analysis, and summary statistics based on mtDNA noncoding sequences for NCI (479 bp and NCII (173 bp all indicate a recent population expansion. Coalescent models based on mtDNA and nDNA identified two potential demographic events: a population decline followed by a very recent population expansion. The decline in effective population size may correlate with land-use and fishing pressure changes post-European settlement, while the recent expansion may be associated with the implementation of the salmonid stocking program in the 1970s. These results are most consistent with the hypothesis that sea lamprey are native to Lake Champlain; however, the credibility intervals around parameter estimates demonstrate that there is uncertainty regarding the magnitude and timing of past demographic events.

  9. Thyroglobulin Represents a Novel Molecular Architecture of Vertebrates.

    Science.gov (United States)

    Holzer, Guillaume; Morishita, Yoshiaki; Fini, Jean-Baptiste; Lorin, Thibault; Gillet, Benjamin; Hughes, Sandrine; Tohmé, Marie; Deléage, Gilbert; Demeneix, Barbara; Arvan, Peter; Laudet, Vincent

    2016-08-05

    Thyroid hormones modulate not only multiple functions in vertebrates (energy metabolism, central nervous system function, seasonal changes in physiology, and behavior) but also in some non-vertebrates where they control critical post-embryonic developmental transitions such as metamorphosis. Despite their obvious biological importance, the thyroid hormone precursor protein, thyroglobulin (Tg), has been experimentally investigated only in mammals. This may bias our view of how thyroid hormones are produced in other organisms. In this study we searched genomic databases and found Tg orthologs in all vertebrates including the sea lamprey (Petromyzon marinus). We cloned a full-size Tg coding sequence from western clawed frog (Xenopus tropicalis) and zebrafish (Danio rerio). Comparisons between the representative mammal, amphibian, teleost fish, and basal vertebrate indicate that all of the different domains of Tg, as well as Tg regional structure, are conserved throughout the vertebrates. Indeed, in Xenopus, zebrafish, and lamprey Tgs, key residues, including the hormonogenic tyrosines and the disulfide bond-forming cysteines critical for Tg function, are well conserved despite overall divergence of amino acid sequences. We uncovered upstream sequences that include start codons of zebrafish and Xenopus Tgs and experimentally proved that these are full-length secreted proteins, which are specifically recognized by antibodies against rat Tg. By contrast, we have not been able to find any orthologs of Tg among non-vertebrate species. Thus, Tg appears to be a novel protein elaborated as a single event at the base of vertebrates and virtually unchanged thereafter. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Keystone predators (eastern newts, Notophthalmus viridescens) reduce the impacts of an aquatic invasive species

    Science.gov (United States)

    Smith, Kimberly G.

    2006-01-01

    Predation, competition, and their interaction are known to be important factors that influence the structure of ecological communities. In particular, in those cases where a competitive hierarchy exists among prey species, the presence of certain keystone predators can result in enhanced diversity in the prey community. However, little is known regarding the influence of keystone predator presence on invaded prey communities. Given the widespread occurrence of invasive species and substantial concern regarding their ecological impacts, studies on this topic are needed. In this study I used naturalistic replications of an experimental tadpole assemblage to assess the influence of predatory eastern newts, Notophthalmus viridescens, on the outcome of interspecific competition among native and nonindigenous tadpoles. When newts were absent, the presence of the tadpoles of one invasive species, the Cuban treefrog, Osteopilus septentrionalis, resulted in decreased survival and growth rate of the dominant native species, Bufo terrestris, and dominance of the tadpole assemblage by O. septentrionalis. However, the presence of one adult newt generally reduced or eliminated the negative impacts of O. septentrionalis tadpoles, resulting in comparable survival and performance of native species in invaded and noninvaded treatments. Differential mortality among the tadpole species suggests that newts preyed selectively on O. septentrionalis tadpoles, supporting the hypothesis that newts acted as keystone predators in the invaded assemblage. The presence of nonindigenous larval cane toads, Bufo marinus, did not significantly affect native species, and this species was not negatively affected by the presence of newts. Collectively, these results suggest that eastern newts significantly modified the competitive hierarchy of the invaded tadpole assemblage and reduced the impacts of a competitively superior invasive species. If general, these results suggest that the presence of

  11. Combined genomic and structural analyses of a cultured magnetotactic bacterium reveals its niche adaptation to a dynamic environment

    Directory of Open Access Journals (Sweden)

    Ana Carolina Vieira Araujo

    2016-10-01

    Full Text Available Abstract Background Magnetotactic bacteria (MTB are a unique group of prokaryotes that have a potentially high impact on global geochemical cycling of significant primary elements because of their metabolic plasticity and the ability to biomineralize iron-rich magnetic particles called magnetosomes. Understanding the genetic composition of the few cultivated MTB along with the unique morphological features of this group of bacteria may provide an important framework for discerning their potential biogeochemical roles in natural environments. Results Genomic and ultrastructural analyses were combined to characterize the cultivated magnetotactic coccus Magnetofaba australis strain IT-1. Cells of this species synthesize a single chain of elongated, cuboctahedral magnetite (Fe3O4 magnetosomes that cause them to align along magnetic field lines while they swim being propelled by two bundles of flagella at velocities up to 300 μm s−1. High-speed microscopy imaging showed the cells move in a straight line rather than in the helical trajectory described for other magnetotactic cocci. Specific genes within the genome of Mf. australis strain IT-1 suggest the strain is capable of nitrogen fixation, sulfur reduction and oxidation, synthesis of intracellular polyphosphate granules and transporting iron with low and high affinity. Mf. australis strain IT-1 and Magnetococcus marinus strain MC-1 are closely related phylogenetically although similarity values between their homologous proteins are not very high. Conclusion Mf. australis strain IT-1 inhabits a constantly changing environment and its complete genome sequence reveals a great metabolic plasticity to deal with these changes. Aside from its chemoautotrophic and chemoheterotrophic metabolism, genomic data indicate the cells are capable of nitrogen fixation, possess high and low affinity iron transporters, and might be capable of reducing and oxidizing a number of sulfur compounds. The relatively

  12. Development and applications of Ray's fluid thioglycollate media for detection and manipulation of Perkinsus spp. pathogens of marine molluscs.

    Science.gov (United States)

    Dungan, Christopher F; Bushek, David

    2015-10-01

    During the early 1950s, Sammy M. Ray discovered that his high-salt modification of fluid thioglycollate sterility test medium caused dramatic in vitro enlargement of Perkinsus marinus (=Dermocystidium marinum) cells that coincidentally infected several experimentally cultured oyster gill tissue explants. Subsequent testing confirmed that the enlarged cells among some oyster tissues incubated in Ray's fluid thioglycollate medium (RFTM) were those of that newly described oyster pathogen. Non-proliferative in vitro enlargement, cell wall thickening, and subsequent blue-black iodine-staining of hypertrophied trophozoites (=hypnospores=prezoosporangia) following incubation in RFTM are unique characteristics of confirmed members of the protistan genus Perkinsus. A number of in vitro assays and manipulations with RFTM have been developed for selective detection and enumeration of Perkinsus sp. cells in tissues of infected molluscs, and in environmental samples. RFTM-enlarged Perkinsus sp. cells from tissues of infected molluscs also serve as useful inocula for initiating in vitro isolate cultures, and cells of several Perkinsus spp. from both in vitro cultures and infected mollusc tissues may be induced to zoosporulate by brief incubations in RFTM. DNAs from RFTM-enlarged Perkinsus sp. cells provide useful templates for PCR amplifications, and for sequencing and other assays to differentiate and identify the detected Perkinsus species. We review the history and components of fluid thioglycollate and RFTM media, and the characteristics of numerous RFTM-based diagnostic assays that have been developed and used worldwide since 1952 for detection and identification of Perkinsus spp. in host mollusc tissues and environmental samples. We also review applications of RFTM for in vitro manipulations and purifications of Perkinsus sp. pathogen cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Involvement of the β Clamp in Methyl-directed Mismatch Repair in Vitro*

    Science.gov (United States)

    Pluciennik, Anna; Burdett, Vickers; Lukianova, Olga; O'Donnell, Mike; Modrich, Paul

    2009-01-01

    We have examined function of the bacterial β replication clamp in the different steps of methyl-directed DNA mismatch repair. The mismatch-, MutS-, and MutL-dependent activation of MutH is unaffected by the presence or orientation of loaded β clamp on either 3′ or 5′ heteroduplexes. Similarly, β is not required for 3′ or 5′ mismatch-provoked excision when scored in the presence of γ complex or in the presence of γ complex and DNA polymerase III core components. However, mismatch repair does not occur in the absence of β, an effect we attribute to a requirement for the clamp in the repair DNA synthesis step of the reaction. We have confirmed previous findings that β clamp interacts specifically with MutS and MutL (López de Saro, F. J., Marinus, M. G., Modrich, P., and O'Donnell, M. (2006) J. Biol. Chem. 281, 14340–14349) and show that the mutator phenotype conferred by amino acid substitution within the MutS N-terminal β-interaction motif is the probable result of instability coupled with reduced activity in multiple steps of the repair reaction. In addition, we have found that the DNA polymerase III α catalytic subunit interacts strongly and specifically with both MutS and MutL. Because interactions of polymerase III holoenzyme components with MutS and MutL appear to be of limited import during the initiation and excision steps of mismatch correction, we suggest that their significance might lie in the control of replication fork events in response to the sensing of DNA lesions by the repair system. PMID:19783657

  14. Molecular cytogenetic characterization of chromosome site-specific repetitive sequences in the Arctic lamprey (Lethenteron camtschaticum, Petromyzontidae)

    Science.gov (United States)

    Ishijima, Junko; Uno, Yoshinobu; Nunome, Mitsuo; Nishida, Chizuko; Kuraku, Shigehiro

    2017-01-01

    Abstract All extant lamprey karyotypes are characterized by almost all dot-shaped microchromosomes. To understand the molecular basis of chromosome structure in lampreys, we performed chromosome C-banding and silver staining and chromosome mapping of the 18S–28S and 5S ribosomal RNA (rRNA) genes and telomeric TTAGGG repeats in the Arctic lamprey (Lethenteron camtschaticum). In addition, we cloned chromosome site-specific repetitive DNA sequences and characterized them by nucleotide sequencing, chromosome in situ hybridization, and filter hybridization. Three types of repetitive sequences were detected; a 200-bp AT-rich repetitive sequence, LCA-EcoRIa that co-localized with the 18S–28S rRNA gene clusters of 3 chromosomal pairs; a 364-bp AT-rich LCA-EcoRIb sequence that showed homology to the EcoRI sequence family from the sea lamprey (Petromyzon marinus), which contains short repeats as centromeric motifs; and a GC-rich 702-bp LCA-ApaI sequence that was distributed on nearly all chromosomes and showed significant homology with the integrase-coding region of a Ty3/Gypsy family long terminal repeat (LTR) retrotransposon. All three repetitive sequences are highly conserved within the Petromyzontidae or within Petromyzontidae and Mordaciidae. Molecular cytogenetic characterization of these site-specific repeats showed that they may be correlated with programed genome rearrangement (LCA-EcoRIa), centromere structure and function (LCA-EcoRIb), and site-specific amplification of LTR retroelements through homogenization between non-homologous chromosomes (LCA-ApaI). PMID:28025319

  15. ADPase activity of recombinantly expressed thermotolerant ATPases may be caused by copurification of adenylate kinase of Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baoyu; Sysoeva, Tatyana A.; Chowdhury, Saikat; Guo, Liang; Nixon, B.Tracy; (IIT); (Penn)

    2009-10-06

    Except for apyrases, ATPases generally target only the {gamma}-phosphate of a nucleotide. Some non-apyrase ATPases from thermophilic microorganisms are reported to hydrolyze ADP as well as ATP, which has been described as a novel property of the ATPases from extreme thermophiles. Here, we describe an apparent ADP hydrolysis by highly purified preparations of the AAA+ ATPase NtrC1 from an extremely thermophilic bacterium, Aquifex aeolicus. This activity is actually a combination of the activities of the ATPase and contaminating adenylate kinase (AK) from Escherichia coli, which is present at 1/10 000 of the level of the ATPase. AK catalyzes conversion of two molecules of ADP into AMP and ATP, the latter being a substrate for the ATPase. We raise concern that the observed thermotolerance of E. coli AK and its copurification with thermostable proteins by commonly used methods may confound studies of enzymes that specifically catalyze hydrolysis of nucleoside diphosphates or triphosphates. For example, contamination with E. coli AK may be responsible for reported ADPase activities of the ATPase chaperonins from Pyrococcus furiosus, Pyrococcus horikoshii, Methanococcus jannaschii and Thermoplasma acidophilum; the ATP/ADP-dependent DNA ligases from Aeropyrum pernix K1 and Staphylothermus marinus; or the reported ATP-dependent activities of ADP-dependent phosphofructokinase of P. furiosus. Purification methods developed to separate NtrC1 ATPase from AK also revealed two distinct forms of the ATPase. One is tightly bound to ADP or GDP and able to bind to Q but not S ion exchange matrixes. The other is nucleotide-free and binds to both Q and S ion exchange matrixes.

  16. Discovery of permuted and recently split transfer RNAs in Archaea

    Science.gov (United States)

    2011-01-01

    Background As in eukaryotes, precursor transfer RNAs in Archaea often contain introns that are removed in tRNA maturation. Two unrelated archaeal species display unique pre-tRNA processing complexity in the form of split tRNA genes, in which two to three segments of tRNAs are transcribed from different loci, then trans-spliced to form a mature tRNA. Another rare type of pre-tRNA, found only in eukaryotic algae, is permuted, where the 3' half is encoded upstream of the 5' half, and must be processed to be functional. Results Using an improved version of the gene-finding program tRNAscan-SE, comparative analyses and experimental verifications, we have now identified four novel trans-spliced tRNA genes, each in a different species of the Desulfurococcales branch of the Archaea: tRNAAsp(GUC) in Aeropyrum pernix and Thermosphaera aggregans, and tRNALys(CUU) in Staphylothermus hellenicus and Staphylothermus marinus. Each of these includes features surprisingly similar to previously studied split tRNAs, yet comparative genomic context analysis and phylogenetic distribution suggest several independent, relatively recent splitting events. Additionally, we identified the first examples of permuted tRNA genes in Archaea: tRNAiMet(CAU) and tRNATyr(GUA) in Thermofilum pendens, which appear to be permuted in the same arrangement seen previously in red alga. Conclusions Our findings illustrate that split tRNAs are sporadically spread across a major branch of the Archaea, and that permuted tRNAs are a new shared characteristic between archaeal and eukaryotic species. The split tRNA discoveries also provide new clues to their evolutionary history, supporting hypotheses for recent acquisition via viral or other mobile elements. PMID:21489296

  17. A common bottlenose dolphin (Tursiops truncatus prey handling technique for marine catfish (Ariidae in the northern Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    Errol I Ronje

    Full Text Available Few accounts describe predator-prey interactions between common bottlenose dolphins (Tursiops truncatus Montagu 1821 and marine catfish (Ariopsis felis Linnaeus 1766, Bagre marinus Mitchill 1815. Over the course of 50,167 sightings of bottlenose dolphin groups in Mississippi Sound and along the Florida coast of the Gulf of Mexico, severed catfish heads were found floating and exhibiting movements at the surface in close proximity to 13 dolphin groups that demonstrated feeding behavior. These observations prompted a multi-disciplinary approach to study the predator-prey relationship between bottlenose dolphins and marine catfish. A review was conducted of bottlenose dolphin visual survey data and dorsal fin photographs from sightings where severed catfish heads were observed. Recovered severed catfish heads were preserved and studied, whole marine catfish were collected and examined, and stranding network pathology reports were reviewed for references to injuries related to fish spines. Photographic identification analysis confirms eight dolphins associated with severed catfish heads were present in three such sightings across an approximately 350 km expanse of coast between the Mississippi Sound and Saint Joseph Bay, FL. An examination of the severed catfish heads indicated interaction with dolphins, and fresh-caught whole hardhead catfish (A. felis were examined to estimate the presumed total length of the catfish before decapitation. Thirty-eight instances of significant trauma or death in dolphins attributed to ingesting whole marine catfish were documented in stranding records collected from the southeastern United States of America. Bottlenose dolphins typically adhere to a ram-feeding strategy for prey capture followed by whole prey ingestion; however, marine catfish skull morphology may pose a consumption hazard due to rigid spines that can puncture and migrate through soft tissue, prompting a prey handling technique for certain dolphins

  18. A common bottlenose dolphin (Tursiops truncatus) prey handling technique for marine catfish (Ariidae) in the northern Gulf of Mexico

    Science.gov (United States)

    Barry, Kevin P.; Sinclair, Carrie; Grace, Mark A.; Allen, Jason; Balmer, Brian; Panike, Anna; Toms, Christina; Mullin, Keith D.; Wells, Randall S.

    2017-01-01

    Few accounts describe predator-prey interactions between common bottlenose dolphins (Tursiops truncatus Montagu 1821) and marine catfish (Ariopsis felis Linnaeus 1766, Bagre marinus Mitchill 1815). Over the course of 50,167 sightings of bottlenose dolphin groups in Mississippi Sound and along the Florida coast of the Gulf of Mexico, severed catfish heads were found floating and exhibiting movements at the surface in close proximity to 13 dolphin groups that demonstrated feeding behavior. These observations prompted a multi-disciplinary approach to study the predator-prey relationship between bottlenose dolphins and marine catfish. A review was conducted of bottlenose dolphin visual survey data and dorsal fin photographs from sightings where severed catfish heads were observed. Recovered severed catfish heads were preserved and studied, whole marine catfish were collected and examined, and stranding network pathology reports were reviewed for references to injuries related to fish spines. Photographic identification analysis confirms eight dolphins associated with severed catfish heads were present in three such sightings across an approximately 350 km expanse of coast between the Mississippi Sound and Saint Joseph Bay, FL. An examination of the severed catfish heads indicated interaction with dolphins, and fresh-caught whole hardhead catfish (A. felis) were examined to estimate the presumed total length of the catfish before decapitation. Thirty-eight instances of significant trauma or death in dolphins attributed to ingesting whole marine catfish were documented in stranding records collected from the southeastern United States of America. Bottlenose dolphins typically adhere to a ram-feeding strategy for prey capture followed by whole prey ingestion; however, marine catfish skull morphology may pose a consumption hazard due to rigid spines that can puncture and migrate through soft tissue, prompting a prey handling technique for certain dolphins, facilitating

  19. Structural, functional, and evolutionary aspects of galectins in aquatic mollusks: From a sweet tooth to the Trojan horse.

    Science.gov (United States)

    Vasta, G R; Feng, C; Bianchet, M A; Bachvaroff, T R; Tasumi, S

    2015-09-01

    Galectins constitute a conserved and widely distributed lectin family characterized by their binding affinity for β-galactosides and a unique binding site sequence motif in the carbohydrate recognition domain (CRD). In spite of their structural conservation, galectins display a remarkable functional diversity, by participating in developmental processes, cell adhesion and motility, regulation of immune homeostasis, and recognition of glycans on the surface of viruses, bacteria and protozoan parasites. In contrast with mammals, and other vertebrate and invertebrate taxa, the identification and characterization of bona fide galectins in aquatic mollusks has been relatively recent. Most of the studies have focused on the identification and domain organization of galectin-like transcripts or proteins in diverse tissues and cell types, including hemocytes, and their expression upon environmental or infectious challenge. Lectins from the eastern oyster Crassostrea virginica, however, have been characterized in their molecular, structural and functional aspects and some notable features have become apparent in the galectin repertoire of aquatic mollusks. These including less diversified galectin repertoires and different domain organizations relative to those observed in vertebrates, carbohydrate specificity for blood group oligosaccharides, and up regulation of galectin expression by infectious challenge, a feature that supports their proposed role(s) in innate immune responses. Although galectins from some aquatic mollusks have been shown to recognize microbial pathogens and parasites and promote their phagocytosis, they can also selectively bind to phytoplankton components, suggesting that they also participate in uptake and intracellular digestion of microalgae. In addition, the experimental evidence suggests that the protozoan parasite Perkinsus marinus has co-evolved with the oyster host to be selectively recognized by the oyster hemocyte galectins over algal food

  20. Quantification of a male sea lamprey pheromone in tributaries of Laurentian Great Lakes by liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Xi, X.; Johnson, N.S.; Brant, C.O.; Yun, S.-S.; Chambers, K.L.; Jones, A.D.; Li, W.

    2011-01-01

    We developed an assay for measuring 7α,12α,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS), a mating pheromone released by male sea lampreys (Petromyzon marinus), at low picomolar concentrations in natural waters to assess the presence of invasive populations. 3kPZS was extracted from streamwater at a rate of recovery up to 90% using a single cation-exchange and reversed-phase mixed-mode cartridge, along with [2H5]3kPZS as an internal standard, and quantified using ultrahigh performance liquid chromatography-tandem mass spectrometry. The limit of detection was below 0.1 ng L–1 (210 fM), which was the lowest concentration tested. Intra- and interday coefficients of variation were between 0.3–11.6% and 4.8–9.8%, respectively, at 1 ng 3kPZS L–1 and 5 ng 3kPZS L–1. This assay was validated by repeat measurements of water samples from a stream spiked with synthesized 3kPZS to reach 4.74 ng L–1 or 0.24 ng L–1. We further verified the utility of this assay to detect spawning populations of lampreys; in the seven tributaries to the Laurentian Great Lakes sampled, 3kPZS concentrations were found to range between 0.15 and 2.85 ng L–1 during the spawning season in known sea lamprey infested segments and were not detectable in uninfested segments. The 3kPZS assay may be useful for the integrated management of sea lamprey, an invasive species in the Great Lakes where pheromone-based control and assessment techniques are desired.

  1. Growth and seasonal behavior of Anguilla anguilla in the River Minho tidal freshwater wetlands

    Directory of Open Access Journals (Sweden)

    Helena Correia

    2015-11-01

    Full Text Available The River Minho estuary, located on the northwest coast of the Iberian Peninsula, is a mesotidal estuary, partially mixed that during the period of high floods it tends to evolve towards a salt wedge estuary. The influence of spring tides extends approximately 40 km upstream and the tidal freshwater wetlands (TFWs are located in the upper 30 km. The Minho estuary is part of a Natura 2000 site, which includes the entire international section of the river being considered a very important river concerning migratory fish species. In the River Minho TFWs several fish species have ecological and economic value (Salmo trutta, Alosa fallax, Platichthys flesus, Anguilla anguilla, Salmo salar, Alosa alosa and Petromyzon marinus. European eel, A. anguilla, is in Appendix II of CITES list, that includes species not necessarily threatened with extinction, but in which trade must be controlled in order to avoid utilization incompatible with their survival. Between January 2007 and December 2014, in a selected semi-enclosed area of TFW and using 5 fyke-nets, were captured 1303 eels. All eels were measured and weighted, ocular index was determined and also marked with pit-tags and released in the same area. During these 8 years of work, around 15% of the total captured eels were recaptured once, less than 3% were recapture twice, less than 1% three times and 3 eels were recaptured 4 times. Eels marked in 2009 are until now the ones that were recaptured more times. Biological data as eel growth, seaward migration state, seasonal differences of by-catch will be crossed with abiotic data namely river flow, precipitation and water temperature.

  2. Estimating Mudpuppy (Necturus maculosus) abundance in the Lamoille River, Vermont, USA

    Science.gov (United States)

    Chellman, Isaac C.; Parrish, Donna; Donovan, Therese M.

    2017-01-01

    The Mudpuppy (Necturus maculosus) is classified as a Species of Greatest Conservation Need by the state of Vermont. There is concern regarding status of populations in the Lake Champlain basin because of habitat alteration and potential effects of 3-trifluromethyl-4-nitrophenol (TFM), a chemical used to control Sea Lamprey (Petromyzon marinus). The purpose of our research was to assess Mudpuppy capture methods and abundance in the Lamoille River, Vermont, USA. We sampled Mudpuppies under a mark-recapture framework, using modified, baited minnow traps set during two winter-spring periods. We marked each Mudpuppy with a passive integrated transponder (PIT) tag and released individuals after collecting morphological measurements. We collected 80 individuals during 2,581 trap days in 2008–2009 (year 1), and 81 individuals during 3,072 trap days in 2009–2010 (year 2). We estimated abundance from spring trapping periods in 2009 and 2010, during which capture rates were sufficient for analysis. Capture probability was low (events in spring, during periods of higher river flow, when water temperatures were approximately 3 to 6° C. During October 2009, management agencies treated the Lamoille River with TFM. Surveyors recovered more than 500 dead Mudpuppies during the post-treatment assessment. Overall, Mudpuppy captures did not change between sampling periods; however, we captured fewer females during year 2 compared to year 1, and the sex ratio changed from 0.79:1 (M:F) during year 1 to 3:1 (M:F) during year 2. Our data may help wildlife managers assess population status of Mudpuppies in conjunction with fisheries management techniques.

  3. A suspected parasite spill-back of two novel Myxidium spp. (Myxosporea causing disease in Australian endemic frogs found in the invasive Cane toad.

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    Ashlie Hartigan

    Full Text Available Infectious diseases are contributing to the decline of endangered amphibians. We identified myxosporean parasites, Myxidium spp. (Myxosporea: Myxozoa, in the brain and liver of declining native frogs, the Green and Golden Bell frog (Litoria aurea and the Southern Bell frog (Litoria raniformis. We unequivocally identified two Myxidium spp. (both generalist affecting Australian native frogs and the invasive Cane toad (Bufo marinus, syn. Rhinella marina and demonstrated their association with disease. Our study tested the identity of Myxidium spp. within native frogs and the invasive Cane toad (brought to Australia in 1935, via Hawaii to resolve the question whether the Cane toad introduced them to Australia. We showed that the Australian brain and liver Myxidium spp. differed 9%, 7%, 34% and 37% at the small subunit rDNA, large subunit rDNA, internal transcribed spacers 1 and 2, but were distinct from Myxidium cf. immersum from Cane toads in Brazil. Plotting minimum within-group distance against maximum intra-group distance confirmed their independent evolutionary trajectory. Transmission electron microscopy revealed that the brain stages localize inside axons. Myxospores were morphologically indistinguishable, therefore genetic characterisation was necessary to recognise these cryptic species. It is unlikely that the Cane toad brought the myxosporean parasites to Australia, because the parasites were not found in 261 Hawaiian Cane toads. Instead, these data support the enemy-release hypothesis predicting that not all parasites are translocated with their hosts and suggest that the Cane toad may have played an important spill-back role in their emergence and facilitated their dissemination. This work emphasizes the importance of accurate species identification of pathogens relevant to wildlife management and disease control. In our case it is paving the road for the spill-back role of the Cane toad and the parasite emergence.

  4. Genetically programmed chiral organoborane synthesis

    Science.gov (United States)

    Kan, S. B. Jennifer; Huang, Xiongyi; Gumulya, Yosephine; Chen, Kai; Arnold, Frances H.

    2017-12-01

    Recent advances in enzyme engineering and design have expanded nature’s catalytic repertoire to functions that are new to biology. However, only a subset of these engineered enzymes can function in living systems. Finding enzymatic pathways that form chemical bonds that are not found in biology is particularly difficult in the cellular environment, as this depends on the discovery not only of new enzyme activities, but also of reagents that are both sufficiently reactive for the desired transformation and stable in vivo. Here we report the discovery, evolution and generalization of a fully genetically encoded platform for producing chiral organoboranes in bacteria. Escherichia coli cells harbouring wild-type cytochrome c from Rhodothermus marinus (Rma cyt c) were found to form carbon–boron bonds in the presence of borane–Lewis base complexes, through carbene insertion into boron–hydrogen bonds. Directed evolution of Rma cyt c in the bacterial catalyst provided access to 16 novel chiral organoboranes. The catalyst is suitable for gram-scale biosynthesis, providing up to 15,300 turnovers, a turnover frequency of 6,100 h–1, a 99:1 enantiomeric ratio and 100% chemoselectivity. The enantiopreference of the biocatalyst could also be tuned to provide either enantiomer of the organoborane products. Evolved in the context of whole-cell catalysts, the proteins were more active in the whole-cell system than in purified forms. This study establishes a DNA-encoded and readily engineered bacterial platform for borylation; engineering can be accomplished at a pace that rivals the development of chemical synthetic methods, with the ability to achieve turnovers that are two orders of magnitude (over 400-fold) greater than those of known chiral catalysts for the same class of transformation. This tunable method for manipulating boron in cells could expand the scope of boron chemistry in living systems.

  5. A fate-map for cranial sensory ganglia in the sea lamprey☆

    Science.gov (United States)

    Modrell, Melinda S.; Hockman, Dorit; Uy, Benjamin; Buckley, David; Sauka-Spengler, Tatjana; Bronner, Marianne E.; Baker, Clare V.H.

    2014-01-01

    Cranial neurogenic placodes and the neural crest make essential contributions to key adult characteristics of all vertebrates, including the paired peripheral sense organs and craniofacial skeleton. Neurogenic placode development has been extensively characterized in representative jawed vertebrates (gnathostomes) but not in jawless fishes (agnathans). Here, we use in vivo lineage tracing with DiI, together with neuronal differentiation markers, to establish the first detailed fate-map for placode-derived sensory neurons in a jawless fish, the sea lamprey Petromyzon marinus, and to confirm that neural crest cells in the lamprey contribute to the cranial sensory ganglia. We also show that a pan-Pax3/7 antibody labels ophthalmic trigeminal (opV, profundal) placode-derived but not maxillomandibular trigeminal (mmV) placode-derived neurons, mirroring the expression of gnathostome Pax3 and suggesting that Pax3 (and its single Pax3/7 lamprey ortholog) is a pan-vertebrate marker for opV placode-derived neurons. Unexpectedly, however, our data reveal that mmV neuron precursors are located in two separate domains at neurula stages, with opV neuron precursors sandwiched between them. The different branches of the mmV nerve are not comparable between lampreys and gnatho-stomes, and spatial segregation of mmV neuron precursor territories may be a derived feature of lampreys. Nevertheless, maxillary and mandibular neurons are spatially segregated within gnathostome mmV ganglia, suggesting that a more detailed investigation of gnathostome mmV placode development would be worthwhile. Overall, however, our results highlight the conservation of cranial peripheral sensory nervous system development across vertebrates, yielding insight into ancestral vertebrate traits. PMID:24513489

  6. Fine-scale pathways used by adult sea lampreys during riverine spawning migrations

    Science.gov (United States)

    Holbrook, Christopher; Bergstedt, Roger A.; Adams, Noah S.; Hatton, Tyson; McLaughlin, Robert L.

    2015-01-01

    Better knowledge of upstream migratory patterns of spawning Sea Lampreys Petromyzon marinus, an invasive species in the Great Lakes, is needed to improve trapping for population control and assessment. Although trapping of adult Sea Lampreys provides the basis for estimates of lake-wide abundance that are used to evaluate the Sea Lamprey control program, traps have only been operated at dams due to insufficient knowledge of Sea Lamprey behavior in unobstructed channels. Acoustic telemetry and radiotelemetry were used to obtain movement tracks for 23 Sea Lampreys in 2008 and 18 Sea Lampreys in 2009 at two locations in the Mississagi River, Ontario. Cabled hydrophone arrays provided two-dimensional geographic positions from acoustic transmitters at 3-s intervals; depth-encoded radio tag detections provided depths. Upstream movements occurred at dusk or during the night (2015–0318 hours). Sea Lampreys were closely associated with the river bottom and showed some preference to move near banks in shallow glide habitats, suggesting that bottom-oriented gears could selectively target adult Sea Lampreys in some habitats. However, Sea Lampreys were broadly distributed across the river channel, suggesting that the capture efficiency of nets and traps in open channels would depend heavily on the proportion of the channel width covered. Lack of vertical movements into the water column may have reflected lamprey preference for low water velocities, suggesting that energy conservation was more beneficial for lampreys than was vertical searching in rivers. Improved understanding of Sea Lamprey movement will assist in the development of improved capture strategies for their assessment and control in the Great Lakes.

  7. Quantification of a male sea lamprey pheromone in tributaries of Laurentian Great Lakes by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Xi, Xiaodan; Johnson, Nicholas S; Brant, Cory O; Yun, Sang-Seon; Chambers, Keali L; Jones, A Daniel; Li, Weiming

    2011-08-01

    We developed an assay for measuring 7α,12α,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS), a mating pheromone released by male sea lampreys (Petromyzon marinus), at low picomolar concentrations in natural waters to assess the presence of invasive populations. 3kPZS was extracted from streamwater at a rate of recovery up to 90% using a single cation-exchange and reversed-phase mixed-mode cartridge, along with [(2)H(5)]3kPZS as an internal standard, and quantified using ultrahigh performance liquid chromatography-tandem mass spectrometry. The limit of detection was below 0.1 ng L(-1) (210 fM), which was the lowest concentration tested. Intra- and interday coefficients of variation were between 0.3-11.6% and 4.8-9.8%, respectively, at 1 ng 3kPZS L(-1) and 5 ng 3kPZS L(-1). This assay was validated by repeat measurements of water samples from a stream spiked with synthesized 3kPZS to reach 4.74 ng L(-1) or 0.24 ng L(-1). We further verified the utility of this assay to detect spawning populations of lampreys; in the seven tributaries to the Laurentian Great Lakes sampled, 3kPZS concentrations were found to range between 0.15 and 2.85 ng L(-1) during the spawning season in known sea lamprey infested segments and were not detectable in uninfested segments. The 3kPZS assay may be useful for the integrated management of sea lamprey, an invasive species in the Great Lakes where pheromone-based control and assessment techniques are desired.

  8. Comparative bioenergetics modeling of two Lake Trout morphotypes

    Science.gov (United States)

    Kepler, Megan V.; Wagner, Tyler; Sweka, John A.

    2014-01-01

    Efforts to restore Lake Trout Salvelinus namaycush in the Laurentian Great Lakes have been hampered for decades by several factors, including overfishing and invasive species (e.g., parasitism by Sea Lampreys Petromyzon marinus and reproductive deficiencies associated with consumption of Alewives Alosa pseudoharengus). Restoration efforts are complicated by the presence of multiple body forms (i.e., morphotypes) of Lake Trout that differ in habitat utilization, prey consumption, lipid storage, and spawning preferences. Bioenergetics models constitute one tool that is used to help inform management and restoration decisions; however, bioenergetic differences among morphotypes have not been evaluated. The goal of this research was to investigate bioenergetic differences between two actively stocked morphotypes: lean and humper Lake Trout. We measured consumption and respiration rates across a wide range of temperatures (4–22°C) and size-classes (5–100 g) to develop bioenergetics models for juvenile Lake Trout. Bayesian estimation was used so that uncertainty could be propagated through final growth predictions. Differences between morphotypes were minimal, but when present, the differences were temperature and weight dependent. Basal respiration did not differ between morphotypes at any temperature or size-class. When growth and consumption differed between morphotypes, the differences were not consistent across the size ranges tested. Management scenarios utilizing the temperatures presently found in the Great Lakes (e.g., predicted growth at an average temperature of 11.7°C and 14.4°C during a 30-d period) demonstrated no difference in growth between the two morphotypes. Due to a lack of consistent differences between lean and humper Lake Trout, we developed a model that combined data from both morphotypes. The combined model yielded results similar to those of the morphotype-specific models, suggesting that accounting for morphotype differences may

  9. Effects of water pH on the uptake and elimination of the piscicide, 3-trifluoromethyl-4-nitrophenol (TFM), by larval sea lamprey.

    Science.gov (United States)

    Hlina, Benjamin L; Tessier, Laura R; Wilkie, Michael P

    2017-10-01

    Invasive sea lamprey (Petromyzon marinus) populations in the Great Lakes are controlled by applying the piscicide, 3-trifluoromethyl-4-nitrophenol (TFM), to infested streams with larval sea lamprey (ammocoetes). While treatment mortality is >90%, surviving lamprey, called residuals, can undermine control efforts. A key determinant of TFM effectiveness is water pH, which can fluctuate daily and seasonally in surface waters. The objectives of this research were to evaluate the influence of pH on the uptake, elimination, and accumulation of TFM by larval sea lamprey using radio-labeled TFM ( 14 C-TFM), when exposed to a nominal concentration of 4.6mgTFML -1 or 7.6mgTFML -1 , 3h or 1h, respectively. TFM uptake rates were approximately 5.5-fold greater at low pH (6.86) compared to the high pH (8.78), most likely due to the unionized, lipophilic form of TFM existing in greater amounts at a lower pH. In contrast, elimination rates following the injection of 85nmolTFMg -1 body mass were 1.7-1.8 fold greater at pH8.96 than at pH6.43 during 2-4h of depuration in TFM-free water. Greater initial excretion rates at pH8.96 were presumably due to predicted increases in outward concentration gradients of un-ionized TFM. The present findings suggest that TFM is mainly taken-up in its un-ionized form, more lipophilic form, but there is also significant uptake of the ionized form of TFM via an unknown mechanism. Moreover, we provide an explanation to how small increases in pH can undermine lampricide treatment success increasing residual lamprey populations. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Cytochrome P460 Genes from the Methanotroph Methylococcus capsulatus Bath†

    Science.gov (United States)

    Bergmann, David J.; Zahn, James A.; Hooper, Alan B.; DiSpirito, Alan A.

    1998-01-01

    P460 cytochromes catalyze the oxidation of hydroxylamine to nitrite. They have been isolated from the ammonia-oxidizing bacterium Nitrosomonas europaea (R. H. Erickson and A. B. Hooper, Biochim. Biophys. Acta 275:231–244, 1972) and the methane-oxidizing bacterium Methylococcus capsulatus Bath (J. A. Zahn et al., J. Bacteriol. 176:5879–5887, 1994). A degenerate oligonucleotide probe was synthesized based on the N-terminal amino acid sequence of cytochrome P460 and used to identify a DNA fragment from M. capsulatus Bath that contains cyp, the gene encoding cytochrome P460. cyp is part of a gene cluster that contains three open reading frames (ORFs), the first predicted to encode a 59,000-Da membrane-bound polypeptide, the second predicted to encode a 12,000-Da periplasmic protein, and the third (cyp) encoding cytochrome P460. The products of the first two ORFs have no apparent similarity to any proteins in the GenBank database. The overall sequence similarity of the P460 cytochromes from M. capsulatus Bath and N. europaea was low (24.3% of residues identical), although short regions of conserved residues are present in the two proteins. Both cytochromes have a C-terminal, c-heme binding motif (CXXCH) and a conserved lysine residue (K61) that may provide an additional covalent cross-link to the heme (D. M. Arciero and A. B. Hooper, FEBS Lett. 410:457–460, 1997). Gene probing using cyp indicated that a cytochrome P460 similar to that from M. capsulatus Bath may be present in the type II methanotrophs Methylosinus trichosporium OB3b and Methylocystis parvus OBBP but not in the type I methanotrophs Methylobacter marinus A45, Methylomicrobium albus BG8, and Methylomonas sp. strains MN and MM2. Immunoblot analysis with antibodies against cytochrome P460 from M. capsulatus Bath indicated that the expression level of cytochrome P460 was not affected either by expression of the two different methane monooxygenases or by addition of ammonia to the culture medium. PMID

  11. An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife.

    Science.gov (United States)

    Fisk, Aaron T; de Wit, Cynthia A; Wayland, Mark; Kuzyk, Zou Zou; Burgess, Neil; Letcher, Robert; Braune, Birgit; Norstrom, Ross; Blum, Susan Polischuk; Sandau, Courtney; Lie, Elisabeth; Larsen, Hans Jørgen S; Skaare, Janneche Utne; Muir, Derek C G

    2005-12-01

    , with the possible exception of PCBs in burbot (Lota lota) in some Yukon lakes, Greenland shark (Somniosus microcephalus), glaucous and great black-backed gulls (Larus hyperboreus and L. marinus), and TEQs of dioxin-like chemicals in seabird eggs. PCB and DDT concentrations in several arctic marine mammal species exceed effects thresholds, although evidence of stress in these populations is lacking. There is little evidence that contaminants are having widespread effects on the health of Canadian arctic organisms, with the possible exception of polar bears. However, further research and better understanding of organohalogen exposure in arctic biota is needed considering factors such as tissue levels that exceed effects thresholds, exposure to "new" organohalogen contaminants of concern, contaminated regions, and climate change.

  12. Nerve–muscle activation by rotating permanent magnet configurations

    Science.gov (United States)

    Nicholson, Graham M.

    2016-01-01

    (Bufo marinus). Activation was readily observed of the muscle directly, at frequencies as low as 180 Hz, and of nerves bent around insulators, at frequencies as low as 230 Hz. Nerve–muscles, with the muscle elevated to avoid its direct activation, were occasionally activated, possibly in the straight section of the nerve, but more likely in the nerve where it curved up to the muscle, at radius of curvature 10 mm or more, or at the nerve end. These positive first results suggest the opportunity for a new class of small, low‐cost devices for magnetic stimulation of nerves and/or muscles. PMID:26661902

  13. Sex differences in contaminant concentrations of fish: a synthesis

    Science.gov (United States)

    Madenjian, Charles P.; Rediske, Richard R.; Krabbenhoft, David P.; Stapanian, Martin A.; Chernyak, Sergei M.; O'Keefe, James P.

    2016-01-01

    Comparison of whole-fish polychlorinated biphenyl (PCB) and total mercury (Hg) concentrations in mature males with those in mature females may provide insights into sex differences in behavior, metabolism, and other physiological processes. In eight species of fish, we observed that males exceeded females in whole-fish PCB concentration by 17 to 43%. Based on results from hypothesis testing, we concluded that these sex differences were most likely primarily driven by a higher rate of energy expenditure, stemming from higher resting metabolic rate (or standard metabolic rate (SMR)) and higher swimming activity, in males compared with females. A higher rate of energy expenditure led to a higher rate of food consumption, which, in turn, resulted in a higher rate of PCB accumulation. For two fish species, the growth dilution effect also made a substantial contribution to the sex difference in PCB concentrations, although the higher energy expenditure rate for males was still the primary driver. Hg concentration data were available for five of the eight species. For four of these five species, the ratio of PCB concentration in males to PCB concentration in females was substantially greater than the ratio of Hg concentration in males to Hg concentration in females. In sea lamprey (Petromyzon marinus), a very primitive fish, the two ratios were nearly identical. The most plausible explanation for this pattern was that certain androgens, such as testosterone and 11-ketotestosterone, enhanced Hg-elimination rate in males. In contrast, long-term elimination of PCBs is negligible for both sexes. According to this explanation, males ingest Hg at a higher rate than females, but also eliminate Hg at a higher rate than females, in fish species other than sea lamprey. Male sea lamprey do not possess either of the above-specified androgens. These apparent sex differences in SMRs, activities, and Hg-elimination rates in teleost fishes may also apply, to some degree, to higher

  14. Structure and stability of metagenome-derived glycoside hydrolase family 12 cellulase (LC-CelA) a homolog of Cel12A from Rhodothermus marinus☆

    Science.gov (United States)

    Okano, Hiroyuki; Ozaki, Masashi; Kanaya, Eiko; Kim, Joong-Jae; Angkawidjaja, Clement; Koga, Yuichi; Kanaya, Shigenori

    2014-01-01

    Ten genes encoding novel cellulases with putative signal peptides at the N-terminus, termed pre-LC-CelA–J, were isolated from a fosmid library of a leaf–branch compost metagenome by functional screening using agar plates containing carboxymethyl cellulose and trypan blue. All the cellulases except pre-LC-CelG have a 14–29 residue long flexible linker (FL) between the signal peptide and the catalytic domain. LC-CelA without a signal peptide (residues 20–261), which shows 76% amino acid sequence identity to Cel12A from Rhodothermus marinus (RmCel12A), was overproduced in Escherichiacoli, purified and characterized. LC-CelA exhibited its highest activity across a broad pH range (pH 5–9) and at 90 °C, indicating that LC-CelA is a highly thermostable cellulase, like RmCel12A. The crystal structure of LC-CelA was determined at 1.85 Å resolution and is nearly identical to that of RmCel12A determined in a form without the FL. Both proteins contain two disulfide bonds. LC-CelA has a 16-residue FL (residues 20–35), most of which is not visible in the electron density map, probably due to structural disorder. However, Glu34 and Pro35 form hydrogen bonds with the central region of the protein. ΔFL-LC-CelA (residues 36–261) and E34A-LC-CelA with a single Glu34 → Ala mutation were therefore constructed and characterized. ΔFL-LC-CelA and E34A-LC-CelA had lower melting temperatures (Tm) than LC-CelA by 14.7 and 12.0 °C respectively. The Tm of LC-CelA was also decreased by 28.0 °C in the presence of dithiothreitol. These results suggest that Glu34-mediated hydrogen bonds and the two disulfide bonds contribute to the stabilization of LC-CelA. PMID:25426413

  15. Acute toxicity of two lampricides, 3-trifluoromethyl-4-nitrophenol (TFM) and a TFM: 1% niclosamide mixture, to sea lamprey, three species of unionids, haliplid water beetles, and American eel

    Science.gov (United States)

    Boogaard, Michael A.; Rivera, Jane E.

    2011-01-01

    We conducted a series of toxicological treatments with 3-trifluoromethyl-4-nitrophenol (TFM) and a TFM:1% 2′,5-dichloro-4′-nitrosalicylanilide (niclosamide) mixture, two compounds used to control larval sea lamprey (Petromyzon marinus) in Great Lakes tributaries, to evaluate the acute toxicity of the lampricides to a number of nontarget species of concern. Treatments were conducted with yellow stage American eel (Anguilla rostrata), adult and larval haliplid water beetles (Haliplus spp.), a surrogate for the endangered Hungerford’s crawling water beetle (Brychius hungerfordi), and adults of three unionid species—giant floater (Pyganadon grandis), fragile papershell (Leptodea fragilis), and pink heelsplitter (Potamilus alatus). Treatments were conducted using a serial dilution system consisting of nine test concentrations and an untreated control with 20% dilution between concentrations. Narcosis was evident among giant floaters exposed to the TFM and the TFM:1% niclosamide mixture and among pink heelsplitters exposed to the TFM:1% niclosamide mixture only but mostly at concentrations greater than 2-fold that required to kill 100% of larval sea lamprey (minimum lethal concentration (MLC)). Tests with the haliplid beetle suggest the risks to the Hungerford’s crawling water beetle associated with TFM applications are minimal. Concentrations over 2-fold the sea lamprey MLC did not kill adult or larval water beetles. Preliminary behavioral observations suggest water beetles may avoid treatment by crawling out of the water. Adult water beetles exposed to TFM at 3-fold the sea lamprey MLC were observed above the water line more often than controls. The lampricide TFM was not acutely toxic to American eel. Mortalities were rare among American eel exposed to TFM concentrations up to 7-fold the observed sea lamprey MLC. Similarly, for the TFM:1% niclosamide mixture, mortalities were rare among American eel exposed to nearly 5-fold the observed sea lamprey MLC

  16. RNA interference technology to control pest sea lampreys--a proof-of-concept.

    Directory of Open Access Journals (Sweden)

    George Heath

    Full Text Available The parasitic sea lamprey (Petromyzon marinus has caused extensive losses to commercial fish stocks of the upper Great Lakes of North America. Methods of controlling the sea lamprey include trapping, barriers to prevent migration, and use of a chemical lampricide (3-trifluoromethyl-4-nitrophenol to kill the filter-feeding larvae. Concerns about the non-specificity of these methods have prompted continued development of species-specific methods to control lampreys outside their native range. In this study, we considered the utility of RNA interference to develop a sea lamprey-specific lampricide. Injection of six different short interfering, double-stranded RNAs (siRNAs into lamprey embryos first confirmed that the siRNAs could reduce the targeted transcript levels by more than 50%. Two size classes of lamprey larvae were then fed the siRNAs complexed with liposomes, and three of the siRNAs (targeting elongation factor 1α, calmodulin, and α-actinin reduced transcript levels 2.5, 3.6, and 5.0-fold, respectively, within the lamprey midsections. This is not only the first demonstration of RNAi in lampreys, but it is also the first example of delivery of siRNAs to a non-mammalian vertebrate through feeding formulations. One of the siRNA treatments also caused increased mortality of the larvae following a single feeding of siRNAs, which suggests that prolonged or multiple feedings of siRNAs could be used to kill filter-feeding larvae within streams, following development of a slow-release formulation. The genes targeted in this study are highly conserved across many species, and only serve as a proof-of-concept demonstration that siRNAs can be used in lampreys. Given that RNA interference is a sequence-specific phenomenon, it should be possible to design siRNAs that selectively target gene sequences that are unique to sea lampreys, and thus develop a technology to control these pests without adversely affecting non-target species.

  17. An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, Aaron T. [Warnell School of Forest Resources, University of Georgia, Athens, GA 30602-2152 (United States)]. E-mail: afisk@forestry.uga.edu; Wit, Cynthia A. de [Department of Applied Environmental Science, Stockholm University, Stockholm (Sweden); Wayland, Mark [Prairie and Northern Wildlife Research Centre, Environment Canada, 115 Perimeter Rd., Saskatoon, SK, S7N 0X4 (Canada); Kuzyk, Zou Zou [Environmental Sciences Group, Royal Military College of Canada, Kingston, ON, K7K 7B4 (Canada); Burgess, Neil [Canadian Wildlife Service, Environment Canada, 6 Bruce St. Mt. Pearl, NL, A1N4T3 (Canada); Letcher, Robert [National Wildlife Research Centre, Environment Canada, Ottawa, ON, K1A 0H3 (Canada); Braune, Birgit [National Wildlife Research Centre, Environment Canada, Ottawa, ON, Canada K1A 0H3 (Canada); Norstrom, Ross [National Wildlife Research Centre, Environment Canada, Ottawa, ON, K1A 0H3 (Canada); Blum, Susan Polischuk [Office of Research Services, University of Saskatchewan, Saskatoon, SK, S7N 4J8 (Canada); Sandau, Courtney [Jacques Whitford Limited, Calgary, AB, T2R 0E4 (Canada); Lie, Elisabeth [National Veterinary Institute, P.O. Box 8156, Dep 0033, Oslo (Norway); Larsen, Hans Jorgen S. [Norwegian School of Veterinary Science, P.O. Box 8146, Dep 0033, Oslo (Norway); Skaare, Janneche Utne [National Veterinary Institute, P.O. Box 8156, Dep 0033, Oslo (Norway); Norwegian School of Veterinary Science, P.O. Box 8146, Dep 0033, Oslo (Norway); Muir, Derek C.G. [National Water Research Institute, Environment Canada, Burlington, ON, L7R 4A6 (Canada)

    2005-12-01

    , with the possible exception of PCBs in burbot (Lota lota) in some Yukon lakes, Greenland shark (Somniosus microcephalus), glaucous and great black-backed gulls (Larus hyperboreus and L. marinus), and TEQs of dioxin-like chemicals in seabird eggs. PCB and DDT concentrations in several arctic marine mammal species exceed effects thresholds, although evidence of stress in these populations is lacking. There is little evidence that contaminants are having widespread effects on the health of Canadian arctic organisms, with the possible exception of polar bears. However, further research and better understanding of organohalogen exposure in arctic biota is needed considering factors such as tissue levels that exceed effects thresholds, exposure to 'new' organohalogen contaminants of concern, contaminated regions, and climate change.

  18. Altererythrobacter soli sp. nov., isolated from desert sand.

    Science.gov (United States)

    Zhao, Qi; Li, Hui-Ru; Han, Qing-Qing; He, Ao-Lei; Nie, Cong-Yuan; Wang, Suo-Min; Zhang, Jin-Lin

    2017-02-01

    An alkaliphilic strain designed MN-1T was isolated from a desert sand sample collected from Tengger desert, north-western China. To delineate its taxonomic position, this Gram-stain-negative, rod-shaped, strictly aerobic bacterium was subjected to a polyphasic taxonomic study. Growth was observed at temperatures from 4 to 37 °C (optimum 30-32 °C), at salinities from 0 to 2 % (optimum 1 %) and at pH from 6.5 to 12.0 (optimum 7.0-9.0). Phylogenetic analysis based on 16S rRNA gene sequencing showed that strain MN-1T was a member of the genus Altererythrobacterbut could be distinguished from recognized species of this genus. Compared to the reference strains, the novel strain was flagellated and motile by means of polar flagella. The predominant respiratory quinone was ubiquinone-10 and the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, one unidentified glycolipid, one unidentified phospholipid and four unidentified lipids. The predominant fatty acids were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. These chemotaxonomic traits were in agreement with the characteristics of the genus Altererythrobacter. Strain MN-1T was most closely related to Altererythrobacter xinjiangensis S3-63T (96.9 % 16S rRNA gene sequence similarity), followed by Altererythrobacter dongtanensis JM27T (96.4 %) and Altererythrobacter marinus H32T (96.1 %). The G+C content of the genomic DNA of strain MN-1T was 67.0 mol%. On the basis of data from this polyphasic taxonomic study, strain MN-1T is proposed as the type strain of a novel species of the genus Altererythrobacter, named as Altererythrobacter soli sp. nov. (=KCTC 52135T=MCCC 1K02066T).

  19. Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia

    Directory of Open Access Journals (Sweden)

    Phalen David N

    2010-06-01

    Full Text Available Abstract Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea found in gallbladders of the invasive cane toad (Bufo marinus was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935. Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115 prior to the cane toad invasion (1879-1935. The green and golden bell frog (Litoria aurea, the Peron's tree frog (Litoria peronii, the green tree frog (Litoria caerulea and the striped marsh frog (Limnodynastes peronii were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5% at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29 of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112 frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be

  20. Improved production of biohydrogen in light-powered Escherichia coli by co-expression of proteorhodopsin and heterologous hydrogenase

    Science.gov (United States)

    2012-01-01

    Background Solar energy is the ultimate energy source on the Earth. The conversion of solar energy into fuels and energy sources can be an ideal solution to address energy problems. The recent discovery of proteorhodopsin in uncultured marine γ-proteobacteria has made it possible to construct recombinant Escherichia coli with the function of light-driven proton pumps. Protons that translocate across membranes by proteorhodopsin generate a proton motive force for ATP synthesis by ATPase. Excess protons can also be substrates for hydrogen (H2) production by hydrogenase in the periplasmic space. In the present work, we investigated the effect of the co-expression of proteorhodopsin and hydrogenase on H2 production yield under light conditions. Results Recombinant E. coli BL21(DE3) co-expressing proteorhodopsin and [NiFe]-hydrogenase from Hydrogenovibrio marinus produced ~1.3-fold more H2 in the presence of exogenous retinal than in the absence of retinal under light conditions (70 μmole photon/(m2·s)). We also observed the synergistic effect of proteorhodopsin with endogenous retinal on H2 production (~1.3-fold more) with a dual plasmid system compared to the strain with a single plasmid for the sole expression of hydrogenase. The increase of light intensity from 70 to 130 μmole photon/(m2·s) led to an increase (~1.8-fold) in H2 production from 287.3 to 525.7 mL H2/L-culture in the culture of recombinant E. coli co-expressing hydrogenase and proteorhodopsin in conjunction with endogenous retinal. The conversion efficiency of light energy to H2 achieved in this study was ~3.4%. Conclusion Here, we report for the first time the potential application of proteorhodopsin for the production of biohydrogen, a promising alternative fuel. We showed that H2 production was enhanced by the co-expression of proteorhodopsin and [NiFe]-hydrogenase in recombinant E. coli BL21(DE3) in a light intensity-dependent manner. These results demonstrate that E. coli can be applied as