ABSTRACT In this work, an inadvertent discovery revealed that the prolonged starvation of brooding Crepidula fornicata L. caused the irreversible shell loss of the offspring. This study hypothesized that the shell loss resulted from the hypoxia suffered by the embryos during the incubation period, given that if a brooding snail is starved, the pumping rate is reduced, producing a drop in oxygen diffusion through the egg capsule walls, and thus hypoxic conditions in the intracapsular environment occur. As a result, the embryos trapped within the capsules suffer hypoxia and are forced to shift into anaerobic metabolism to survive, producing CaCO3 destined for the shell to be alternatively used as a pH buffer during metabolic acidosis. Under these sublethal conditions, embryos continue their development until hatching. The resulting shell-less larvae continue their free-swimming period and undergo metamorphosis to give way to crawling radula-feeder juveniles. Several experiments were carried out to test this hypothesis. First, the reduction in the pumping rate of starved snails (13.3±0.3mL h–1) was confirmed compared with fed snails (31.6±0.3mL h–1). The calcium content of larvae from egg capsules from fed and starved snails was 537.4 and 125.4 ngCa µgdtw–1, respectively. To simulate conditions inside the mantle cavity of the mother, groups of detached egg capsules were exposed for 24 days to different water flows in open-flow glass chambers. The results indicated egg capsule survival of 93% and 83% at flow rates of 197 and 103mL h–1, respectively. Total capsule mortality was found on days 12 and 15, at 16 and 811mL h–1, respectively, indicating a flow range for the normal development of the encapsulated embryos and larvae. Morphological features of embryos, larvae, and juveniles from fed and starved brooding snails were compared using a scanning electron microscope. The results supported the original hypothesis that starvation of adult egg-bearing C. fornicata results in irreversible shell loss in offspring.
{"title":"The Effect of Starvation on Broodstock during Egg Capsule Incubation and Early Shell Formation in the Common Atlantic Slippersnail Crepidula fornicata L.","authors":"Alfonso N. Maeda-Martínez","doi":"10.2983/035.042.0211","DOIUrl":"https://doi.org/10.2983/035.042.0211","url":null,"abstract":"ABSTRACT In this work, an inadvertent discovery revealed that the prolonged starvation of brooding Crepidula fornicata L. caused the irreversible shell loss of the offspring. This study hypothesized that the shell loss resulted from the hypoxia suffered by the embryos during the incubation period, given that if a brooding snail is starved, the pumping rate is reduced, producing a drop in oxygen diffusion through the egg capsule walls, and thus hypoxic conditions in the intracapsular environment occur. As a result, the embryos trapped within the capsules suffer hypoxia and are forced to shift into anaerobic metabolism to survive, producing CaCO3 destined for the shell to be alternatively used as a pH buffer during metabolic acidosis. Under these sublethal conditions, embryos continue their development until hatching. The resulting shell-less larvae continue their free-swimming period and undergo metamorphosis to give way to crawling radula-feeder juveniles. Several experiments were carried out to test this hypothesis. First, the reduction in the pumping rate of starved snails (13.3±0.3mL h–1) was confirmed compared with fed snails (31.6±0.3mL h–1). The calcium content of larvae from egg capsules from fed and starved snails was 537.4 and 125.4 ngCa µgdtw–1, respectively. To simulate conditions inside the mantle cavity of the mother, groups of detached egg capsules were exposed for 24 days to different water flows in open-flow glass chambers. The results indicated egg capsule survival of 93% and 83% at flow rates of 197 and 103mL h–1, respectively. Total capsule mortality was found on days 12 and 15, at 16 and 811mL h–1, respectively, indicating a flow range for the normal development of the encapsulated embryos and larvae. Morphological features of embryos, larvae, and juveniles from fed and starved brooding snails were compared using a scanning electron microscope. The results supported the original hypothesis that starvation of adult egg-bearing C. fornicata results in irreversible shell loss in offspring.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43460902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eric H. Andrianasolo, L. Haramaty, Kerry L. Mcphail, Richard A. Lutz
ABSTRACT Three ceramides with intriguing structural features, bathymodiolamides C (1), D (2), and E (3), were isolated from the deep-sea hydrothermal vent invertebrate mussel Bathymodiolus azoricus that inhabits vent environments along the Mid-Atlantic Ridge. The molecular structures of these compounds were elucidated using a combination of Nuclear Magnetic Resonance spectroscopy, mass spectrometry, and chemical degradation. Biological activities were assessed by Lactate Dehydrogenase assay for necrosis induction and the patented ApopScreen cell-based screen for apoptosis-induction and potential anticancer activity. This represents a second report of ceramide natural products from B. azoricus.
{"title":"Bathymodiolamides C, D, and E, Necrosis Inducers from a Deep-Sea Hydrothermal Vent Invertebrate Mussel, Bathymodiolus azoricus","authors":"Eric H. Andrianasolo, L. Haramaty, Kerry L. Mcphail, Richard A. Lutz","doi":"10.2983/035.042.0201","DOIUrl":"https://doi.org/10.2983/035.042.0201","url":null,"abstract":"ABSTRACT Three ceramides with intriguing structural features, bathymodiolamides C (1), D (2), and E (3), were isolated from the deep-sea hydrothermal vent invertebrate mussel Bathymodiolus azoricus that inhabits vent environments along the Mid-Atlantic Ridge. The molecular structures of these compounds were elucidated using a combination of Nuclear Magnetic Resonance spectroscopy, mass spectrometry, and chemical degradation. Biological activities were assessed by Lactate Dehydrogenase assay for necrosis induction and the patented ApopScreen cell-based screen for apoptosis-induction and potential anticancer activity. This represents a second report of ceramide natural products from B. azoricus.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43271040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Rupp, Adriano Weidner Cacciatori Marenzi, R. V. de Souza, L. Martins
ABSTRACT Sea cucumbers are important components of marine ecosystems and also highly valued commodities in Asian markets because of their use in oriental cuisine and traditional medicine. The increasing demand for sea cucumbers has elicited intense worldwide capture and many species are currently considered vulnerable or threatened due to overexploitation. The coast of Santa Catarina State (South Brazil) is the distribution limit of several tropical species in the Western South Atlantic, but little is known about the sea cucumber species occurring in this region. This study aimed to identify the holothuroids occurring in the littoral of Santa Catarina State and to survey their abundance and distribution along the coast. Visual and tactile inspections were carried out following transects in the intertidal zone of 11 locations and subtidal surveys were carried out by diving in two sites. The surveys indicated the occurrence of three species: Parathyone braziliensis in the intertidal zone, Holothuria (Halodeima) grisea in the intertidal as well as in the sublittoral, and Isostichopus badionotus in the sublittoral. The most abundant species was H. (H.) grisea, which occurred in several sites along the coast, up to Lat. 28° 01′ 07.67″ S, its likely southern limit of distribution. The species I. badionotus was for the first time recorded to occur on the continental coast of the State, expanding its area of distribution. This study registers for the first time the occurrence of P. braziliensis in southern Brazil, expanding its limit of geographic distribution.
{"title":"Sea Cucumbers (Echinodermata: Holothuroidea) from Santa Catarina Coast, Southern Brazil, with Notes on Their Abundance and Spatial Distribution","authors":"G. Rupp, Adriano Weidner Cacciatori Marenzi, R. V. de Souza, L. Martins","doi":"10.2983/035.042.0115","DOIUrl":"https://doi.org/10.2983/035.042.0115","url":null,"abstract":"ABSTRACT Sea cucumbers are important components of marine ecosystems and also highly valued commodities in Asian markets because of their use in oriental cuisine and traditional medicine. The increasing demand for sea cucumbers has elicited intense worldwide capture and many species are currently considered vulnerable or threatened due to overexploitation. The coast of Santa Catarina State (South Brazil) is the distribution limit of several tropical species in the Western South Atlantic, but little is known about the sea cucumber species occurring in this region. This study aimed to identify the holothuroids occurring in the littoral of Santa Catarina State and to survey their abundance and distribution along the coast. Visual and tactile inspections were carried out following transects in the intertidal zone of 11 locations and subtidal surveys were carried out by diving in two sites. The surveys indicated the occurrence of three species: Parathyone braziliensis in the intertidal zone, Holothuria (Halodeima) grisea in the intertidal as well as in the sublittoral, and Isostichopus badionotus in the sublittoral. The most abundant species was H. (H.) grisea, which occurred in several sites along the coast, up to Lat. 28° 01′ 07.67″ S, its likely southern limit of distribution. The species I. badionotus was for the first time recorded to occur on the continental coast of the State, expanding its area of distribution. This study registers for the first time the occurrence of P. braziliensis in southern Brazil, expanding its limit of geographic distribution.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47677756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Charlotte A. Berry-Powell, Z. Forster, D. Ayres, Clayton Parson, J. Losee
ABSTRACT Since 1898, the Pacific razor clam, Siliqua patula has represented an important resource for commercial and recreational diggers and has been an important source of economic revenue to coastal communities in the Pacific Northwest from central California to southern Alaska. In 1996, Washington State adopted the Pumped Area Method as the preferred method to accurately assess populations of razor clams on coastal beaches. The Pumped Area Method utilizes a water pump and a series of hoses to draw water out of the surf to liquefy the clam bed exposing clams so they can be measured and recorded. This method relies on a fixed stratified random sampling of transects across all managed beaches to produce a robust estimate of the total population of clams. The Pumped Area Method has been adopted by state and tribal management agencies along the west coast to determine the total allowable catch in each management area but never been formally described. This method in conjunction with a biweekly sampling of toxic algae abundance supports the sustainable harvest of razor clams, providing up to 40 million dollars annually in economic income to the state of Washington for the last 25 y.
{"title":"Using the Pumped Area Method for the Assessment of Recreational Razor Clam, Siliqua patula Populations in Washington State","authors":"Charlotte A. Berry-Powell, Z. Forster, D. Ayres, Clayton Parson, J. Losee","doi":"10.2983/035.042.0109","DOIUrl":"https://doi.org/10.2983/035.042.0109","url":null,"abstract":"ABSTRACT Since 1898, the Pacific razor clam, Siliqua patula has represented an important resource for commercial and recreational diggers and has been an important source of economic revenue to coastal communities in the Pacific Northwest from central California to southern Alaska. In 1996, Washington State adopted the Pumped Area Method as the preferred method to accurately assess populations of razor clams on coastal beaches. The Pumped Area Method utilizes a water pump and a series of hoses to draw water out of the surf to liquefy the clam bed exposing clams so they can be measured and recorded. This method relies on a fixed stratified random sampling of transects across all managed beaches to produce a robust estimate of the total population of clams. The Pumped Area Method has been adopted by state and tribal management agencies along the west coast to determine the total allowable catch in each management area but never been formally described. This method in conjunction with a biweekly sampling of toxic algae abundance supports the sustainable harvest of razor clams, providing up to 40 million dollars annually in economic income to the state of Washington for the last 25 y.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47787389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Many authors have tested a large number of tagging methodologies on sea urchins, either with the aim to study the growth of urchins, their movement patterns, the dynamics of their populations, or their ecology and development in the natural environment. Different types of markings, both external and internal, have been used for the individual identification of sea urchins since the year 1935. Since the year 1969, marking techniques based on different chemical substances were also implemented, either by immersion in fluorochrome baths or by injecting these substances directly into the sea urchin. There is a clear need to collect all the existing information to date related to the marking methodologies for sea urchins, to establish the most appropriate marking methodology for each species of sea urchin, depending on the objective and duration of the study to be performed. This report presents for the first time a complete review of tagging methodologies used until the date in different species of sea urchins, from physical methods, such as the use of Passive Integrated Transponder (PIT) Tags, Anchor tags, and so on, to chemical ones, in which different fluorochromes are used that adhere to the calcified structures of the sea urchin and are subsequently detected using a fluorescence microscope. We also analyzed the effectiveness of the methods used in each case, comparing the survival rate, the tag retention rate, or the recapture rate of tagged urchins obtained with each tagging methodology. The evolution of the physical tags for sea urchins should be oriented toward the development of more durable markings over time, which allow marking urchins of smaller diameter and which in turn present a higher retention rate in the long term, both in captivity conditions and in the natural environment. The chemical tags should be aimed at reducing costs through the development of methods, where the mark can be visualized without the need of fluorescence microscopes, the development of methods in which the dyes can be reused, and finally to the development of techniques that allow to visualize the fluorochrome marks externally, without the need to sacrifice the urchin for the mark detection.
{"title":"Marking Methodologies for Sea Urchins: A Review","authors":"Noelia Tourón, Sara Campos, D. Costas, E. Paredes","doi":"10.2983/035.042.0116","DOIUrl":"https://doi.org/10.2983/035.042.0116","url":null,"abstract":"ABSTRACT Many authors have tested a large number of tagging methodologies on sea urchins, either with the aim to study the growth of urchins, their movement patterns, the dynamics of their populations, or their ecology and development in the natural environment. Different types of markings, both external and internal, have been used for the individual identification of sea urchins since the year 1935. Since the year 1969, marking techniques based on different chemical substances were also implemented, either by immersion in fluorochrome baths or by injecting these substances directly into the sea urchin. There is a clear need to collect all the existing information to date related to the marking methodologies for sea urchins, to establish the most appropriate marking methodology for each species of sea urchin, depending on the objective and duration of the study to be performed. This report presents for the first time a complete review of tagging methodologies used until the date in different species of sea urchins, from physical methods, such as the use of Passive Integrated Transponder (PIT) Tags, Anchor tags, and so on, to chemical ones, in which different fluorochromes are used that adhere to the calcified structures of the sea urchin and are subsequently detected using a fluorescence microscope. We also analyzed the effectiveness of the methods used in each case, comparing the survival rate, the tag retention rate, or the recapture rate of tagged urchins obtained with each tagging methodology. The evolution of the physical tags for sea urchins should be oriented toward the development of more durable markings over time, which allow marking urchins of smaller diameter and which in turn present a higher retention rate in the long term, both in captivity conditions and in the natural environment. The chemical tags should be aimed at reducing costs through the development of methods, where the mark can be visualized without the need of fluorescence microscopes, the development of methods in which the dyes can be reused, and finally to the development of techniques that allow to visualize the fluorochrome marks externally, without the need to sacrifice the urchin for the mark detection.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47007878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Rudders, Sally A. Roman, Robert A. Fisher, J. McDowell
ABSTRACT The Anaskid nematode, Sulcascaris sulcata has a worldwide distribution and utilizes benthic molluscs as an intermediate host with sea turtles (Chelonioidea) serving as definitive hosts. During the spring of 2015, sea scallops (Placopecten magellanicus) harvested along the mid-Atlantic Bight (MAB) presented with rust-colored lesions on the surface of the adductor muscles. Morphological and molecular investigations determined that the lesions were caused by an infection by third- and fourth-stage larval S. sulcata. Seasonal monitoring from 2015 to 2018 delineated a stable spatial distribution of infected scallops that corresponded to a large 2013 year-class of scallops and persistent utilization of this habitat by seasonally resident loggerhead turtles. Given the life cycle and etiology of S. sulcata, the risk to human health via direct infection or allergic reaction appears to be low, however, the spatiotemporal scale of nematode-infected scallops resulted in fishery-level impacts with respect to the spatial distribution of fishing effort in response to product quality and depreciation of the value of landed scallops. The long-term trajectory of the epizootic remains unclear and continued monitoring of the spatiotemporal distribution of nematode-infected scallops is warranted as S. sulcata spatial distribution is likely dependent upon sea scallop abundance, which is currently trending toward more northerly portions of the MAB.
{"title":"Observations on a Reemerging Epizootic of the Sea Scallop, Placopecten magellanicus, Resource","authors":"D. Rudders, Sally A. Roman, Robert A. Fisher, J. McDowell","doi":"10.2983/035.042.0106","DOIUrl":"https://doi.org/10.2983/035.042.0106","url":null,"abstract":"ABSTRACT The Anaskid nematode, Sulcascaris sulcata has a worldwide distribution and utilizes benthic molluscs as an intermediate host with sea turtles (Chelonioidea) serving as definitive hosts. During the spring of 2015, sea scallops (Placopecten magellanicus) harvested along the mid-Atlantic Bight (MAB) presented with rust-colored lesions on the surface of the adductor muscles. Morphological and molecular investigations determined that the lesions were caused by an infection by third- and fourth-stage larval S. sulcata. Seasonal monitoring from 2015 to 2018 delineated a stable spatial distribution of infected scallops that corresponded to a large 2013 year-class of scallops and persistent utilization of this habitat by seasonally resident loggerhead turtles. Given the life cycle and etiology of S. sulcata, the risk to human health via direct infection or allergic reaction appears to be low, however, the spatiotemporal scale of nematode-infected scallops resulted in fishery-level impacts with respect to the spatial distribution of fishing effort in response to product quality and depreciation of the value of landed scallops. The long-term trajectory of the epizootic remains unclear and continued monitoring of the spatiotemporal distribution of nematode-infected scallops is warranted as S. sulcata spatial distribution is likely dependent upon sea scallop abundance, which is currently trending toward more northerly portions of the MAB.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49404450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Klinck, E. Powell, Kathleen M. Hemeon, Jill R Sower, D. Hennen
ABSTRACT Organisms increase in size over time (age) due to excess assimilation over metabolic (respiration) energy demands. Most organisms reach a maximum size with increasing age as gain and loss balance. The von Bertalanffy length-at-age relationship, which is commonly used in fishery assessment calculations, imposes such a maximum size. However, some fished species, such as ocean quahogs, Arctica islandica, are long lived and continue to grow at old age. The Tanaka age-at-length relationship has continued growth at old age, but is rarely used in stock assessment models. A modified form of the von Bertalanffy model is presented, which mimics the continued growth at old age of the Tanaka model by allowing the growth parameter (K) to decline with age. This form is suitable for inclusion in stock assessment models based on von Bertalanffy. The proposed model matches Tanaka curves with precision appropriate for the scatter of data used to fit the curves. The observations of ocean quahog length at age and growth rate from New Jersey and Georges Bank demonstrate the ability of the modified von Bertalanffy relationship to represent continued growth at old age for this fished species. Simulated data generated with continued growth at old age were fit with the Stock Synthesis model (SS3). Results comparing traditional and modified growth relationships showed that the original von Bertalanffy model can reasonably approximate modest nonasymptotic growth as long as the number of observations is sufficient to constrain the parameter values.
{"title":"A Growth Model for Arctica islandica: The Performance of Tanaka and the Temptation of Von Bertalanffy—Can the Two Coexist?","authors":"J. Klinck, E. Powell, Kathleen M. Hemeon, Jill R Sower, D. Hennen","doi":"10.2983/035.042.0108","DOIUrl":"https://doi.org/10.2983/035.042.0108","url":null,"abstract":"ABSTRACT Organisms increase in size over time (age) due to excess assimilation over metabolic (respiration) energy demands. Most organisms reach a maximum size with increasing age as gain and loss balance. The von Bertalanffy length-at-age relationship, which is commonly used in fishery assessment calculations, imposes such a maximum size. However, some fished species, such as ocean quahogs, Arctica islandica, are long lived and continue to grow at old age. The Tanaka age-at-length relationship has continued growth at old age, but is rarely used in stock assessment models. A modified form of the von Bertalanffy model is presented, which mimics the continued growth at old age of the Tanaka model by allowing the growth parameter (K) to decline with age. This form is suitable for inclusion in stock assessment models based on von Bertalanffy. The proposed model matches Tanaka curves with precision appropriate for the scatter of data used to fit the curves. The observations of ocean quahog length at age and growth rate from New Jersey and Georges Bank demonstrate the ability of the modified von Bertalanffy relationship to represent continued growth at old age for this fished species. Simulated data generated with continued growth at old age were fit with the Stock Synthesis model (SS3). Results comparing traditional and modified growth relationships showed that the original von Bertalanffy model can reasonably approximate modest nonasymptotic growth as long as the number of observations is sufficient to constrain the parameter values.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44402061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas C. Coxe, Genesis Mize, S. Casas, M. L. La Peyre, R. Lavaud, Brian Callam, Scott Rikard, Jerome La Peyre
ABSTRACT Increasing reliance on the use of triploid oysters to support aquaculture production relies on their generally superior growth rate and meat quality over that of diploid oysters. Reports of elevated triploid mortality have generated questions about potential trade-offs between growth and tolerance to environmental stressors. These questions are particularly relevant as climate change, coastal activities, and river management impact water salinity, temperature, nutrients, pH, and oxygen levels within key estuarine oyster growing areas. In particular, the co-occurrence of warm water temperatures and low dissolved oxygen concentration (DO) events are increasingly reported in estuaries, with potentially lethal impacts on sessile, oyster resources. To investigate potential differences in DO tolerance, diploid and triploid market-sized or seed oysters were exposed to continuous normoxia (DO > 5.0 mg L–1), hypoxia (DO < 2.0 mg L–1), and anoxia (DO < 0.5 mg L–1) at 28°C and their mortalities were monitored. The hemolymph of the market-sized oysters was collected to measure cellular and biochemical changes in response to hypoxia and anoxia, whereas their valve movements were also measured. In general, about half of market-sized oysters died within about 1 wk under anoxia (LT50: 5.7–8.9 days) and within about 2 wk under hypoxia (LT50: 11.9–19.4 days) with diploid oysters tending to die faster than triploid oysters. Seed oysters took longer to die than market-sized oysters under both anoxia (LT50: 9.5–12.1 days) and hypoxia (LT50: 21.8–25.0 days) with diploid oysters (LT50: 9.5–11.8 days) dying slightly faster than triploid oysters (LT50: 11.8–12.1 days) under anoxia. Hemolymph pH decreased and plasma calcium and glutathione concentrations increased with decreasing DO, with values under anoxia being different than those under normoxia. Hemocyte density was also lower under anoxia than under either normoxia or hypoxia. Overall, few differences in physiological responses to hypoxia and anoxia were found between diploid and triploid oysters suggesting that ploidy (2N versus 3N) had limited effect on the tolerance and response of eastern oysters to low DO.
{"title":"Hypoxia and Anoxia Tolerance in Diploid and Triploid Eastern Oysters at High Temperature","authors":"Nicholas C. Coxe, Genesis Mize, S. Casas, M. L. La Peyre, R. Lavaud, Brian Callam, Scott Rikard, Jerome La Peyre","doi":"10.2983/035.042.0104","DOIUrl":"https://doi.org/10.2983/035.042.0104","url":null,"abstract":"ABSTRACT Increasing reliance on the use of triploid oysters to support aquaculture production relies on their generally superior growth rate and meat quality over that of diploid oysters. Reports of elevated triploid mortality have generated questions about potential trade-offs between growth and tolerance to environmental stressors. These questions are particularly relevant as climate change, coastal activities, and river management impact water salinity, temperature, nutrients, pH, and oxygen levels within key estuarine oyster growing areas. In particular, the co-occurrence of warm water temperatures and low dissolved oxygen concentration (DO) events are increasingly reported in estuaries, with potentially lethal impacts on sessile, oyster resources. To investigate potential differences in DO tolerance, diploid and triploid market-sized or seed oysters were exposed to continuous normoxia (DO > 5.0 mg L–1), hypoxia (DO < 2.0 mg L–1), and anoxia (DO < 0.5 mg L–1) at 28°C and their mortalities were monitored. The hemolymph of the market-sized oysters was collected to measure cellular and biochemical changes in response to hypoxia and anoxia, whereas their valve movements were also measured. In general, about half of market-sized oysters died within about 1 wk under anoxia (LT50: 5.7–8.9 days) and within about 2 wk under hypoxia (LT50: 11.9–19.4 days) with diploid oysters tending to die faster than triploid oysters. Seed oysters took longer to die than market-sized oysters under both anoxia (LT50: 9.5–12.1 days) and hypoxia (LT50: 21.8–25.0 days) with diploid oysters (LT50: 9.5–11.8 days) dying slightly faster than triploid oysters (LT50: 11.8–12.1 days) under anoxia. Hemolymph pH decreased and plasma calcium and glutathione concentrations increased with decreasing DO, with values under anoxia being different than those under normoxia. Hemocyte density was also lower under anoxia than under either normoxia or hypoxia. Overall, few differences in physiological responses to hypoxia and anoxia were found between diploid and triploid oysters suggesting that ploidy (2N versus 3N) had limited effect on the tolerance and response of eastern oysters to low DO.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43464953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yue Wang, Linxin Dai, Zihao He, Danqing Hou, Chengbo Sun
ABSTRACT Decapod iridescent virus 1 (DIV1), also known as shrimp hemocyte iridescent virus or Cherax quadricarinatus iridovirus, has received extensive attention in recent years due to its highly contagious and lethal properties in crustaceans. In 2019, the Executive Committee of the International Committee on Taxonomy of Viruses approved DIV1 as a new species of the new genus Decapodiridovirus in the family Iridoviridae. To gain a more comprehensive understanding of DIV1, this review summarizes recent advances in DIV1 research, including classification, detection techniques, clinical symptoms, infection mechanisms, and host immune responses. A deeper understanding of the interaction between DIV1 and the host has potentially important implications for developing effective antiDIV1 strategies.
{"title":"Recent Progress in the Decapod Iridescent Virus 1 Study","authors":"Yue Wang, Linxin Dai, Zihao He, Danqing Hou, Chengbo Sun","doi":"10.2983/035.042.0113","DOIUrl":"https://doi.org/10.2983/035.042.0113","url":null,"abstract":"ABSTRACT Decapod iridescent virus 1 (DIV1), also known as shrimp hemocyte iridescent virus or Cherax quadricarinatus iridovirus, has received extensive attention in recent years due to its highly contagious and lethal properties in crustaceans. In 2019, the Executive Committee of the International Committee on Taxonomy of Viruses approved DIV1 as a new species of the new genus Decapodiridovirus in the family Iridoviridae. To gain a more comprehensive understanding of DIV1, this review summarizes recent advances in DIV1 research, including classification, detection techniques, clinical symptoms, infection mechanisms, and host immune responses. A deeper understanding of the interaction between DIV1 and the host has potentially important implications for developing effective antiDIV1 strategies.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46303001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Megan M Tomamichel, T. Walters, R. Hall, J. E. Byers, M. Frischer
ABSTRACT Emerging infectious diseases in marine systems threaten food security and ecosystem function. Experiments to determine drivers of transmission and mortality from emerging pathogens require a reliable supply of disease-free animals. Imperfect detection of subclinical, latent, and early stage infections, however, necessitates effective treatments to remove infection from animals with unknown infection status. In this study, a procedure utilizing elevated temperatures and over-the-counter parasiticides to remove Hyalophysa lynni was developed. The apostome ciliate H. lynni is responsible for shrimp black gill (sBG) disease in commercially important southeastern shrimp fishery species, including Litopenaeus setiferus (white shrimp). Following a series of pilot studies to determine parasiticides combination and dosage, L. setiferus of unknown infection status were exposed to either 20°C or 30°C artificial seawater, and a parasiticide cocktail of metronidazole (3.15 mg L–1) and Cu+2 (0.5 mg L–1) or a medication-free control for 14 days in a fully crossed experimental design. All treatments, except for the 20°C without medications treatment, significantly reduced pathogen prevalence. The 30°C artificial seawater with parasiticide treatment resulted in complete curing of the experimental population, but shrimp mortality in this treatment was high (50%). This high mortality may have contributed to the low parasite prevalence found in this treatment by differentially culling infected individuals. If this is the case, the parasiticides may lower the parasite prevalence both by curing infections and heightening stress and subsequent mortality of diseased individuals. Although this procedure was developed to produce H. lynni-free shrimp to facilitate experimental studies of sBG disease, it is likely that this methodology would effectively produce specific-pathogen-free individuals in other crustacean species.
{"title":"A Methodology to Produce Specific-Pathogen-Free Penaeid Shrimp for Use in Empirical Investigations of Parasite Ecology","authors":"Megan M Tomamichel, T. Walters, R. Hall, J. E. Byers, M. Frischer","doi":"10.2983/035.042.0114","DOIUrl":"https://doi.org/10.2983/035.042.0114","url":null,"abstract":"ABSTRACT Emerging infectious diseases in marine systems threaten food security and ecosystem function. Experiments to determine drivers of transmission and mortality from emerging pathogens require a reliable supply of disease-free animals. Imperfect detection of subclinical, latent, and early stage infections, however, necessitates effective treatments to remove infection from animals with unknown infection status. In this study, a procedure utilizing elevated temperatures and over-the-counter parasiticides to remove Hyalophysa lynni was developed. The apostome ciliate H. lynni is responsible for shrimp black gill (sBG) disease in commercially important southeastern shrimp fishery species, including Litopenaeus setiferus (white shrimp). Following a series of pilot studies to determine parasiticides combination and dosage, L. setiferus of unknown infection status were exposed to either 20°C or 30°C artificial seawater, and a parasiticide cocktail of metronidazole (3.15 mg L–1) and Cu+2 (0.5 mg L–1) or a medication-free control for 14 days in a fully crossed experimental design. All treatments, except for the 20°C without medications treatment, significantly reduced pathogen prevalence. The 30°C artificial seawater with parasiticide treatment resulted in complete curing of the experimental population, but shrimp mortality in this treatment was high (50%). This high mortality may have contributed to the low parasite prevalence found in this treatment by differentially culling infected individuals. If this is the case, the parasiticides may lower the parasite prevalence both by curing infections and heightening stress and subsequent mortality of diseased individuals. Although this procedure was developed to produce H. lynni-free shrimp to facilitate experimental studies of sBG disease, it is likely that this methodology would effectively produce specific-pathogen-free individuals in other crustacean species.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49591365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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