ABSTRACT The giant honeycomb oyster Hyotissa hyotis occurs at a high density in the shallow subtidal rocky bottom of Jeju Island off the south coast of Korea, where the sea surface temperature ranges from 14°C to 25°C seasonally. Unlike other oysters, H. hyotis has an extraordinarily large adductor muscle (AM) that accounts for more than 40% of the total tissue weight. This study analyzed the proximate composition, amino acids, and fatty acids of the AM of H. hyotis in Jeju Island to evaluate the nutritional potential. For the analyses, oysters were grouped based on their reproductive condition as prespawning (May–August), spawning (September–November), and postspawning (December–April). The AM contained a high level of protein (54.7%–69.4%) followed by carbohydrate (16.0%–25.3%) and lipid (4.5%–9.9%) throughout the year, indicating that the AM is enriched with protein. The total amino acids (TAA) in the AM ranged from 9.4 to 12.9 g/100 g dry weight annually, and essential amino acids accounted for up to 36.7% of the TAA. Like other marine bivalves, the AM contained a high level of taurine, which accounted for 26.5%–28.5% of the total free amino acids. The AM also included high levels of essential fatty acids, such as palmitic acid, docosahexaenoic acid, and eicosapentaenoic acid, as these fatty acids accounted for 35.9%–37.0% of the total fatty acids. The AM of prespawning oysters collected during May and August contained comparatively higher total proteins and carbohydrates. Results suggested that, like scallops and pen shells, the AM of the giant honeycomb oyster is highly suitable as seafood, and H. hyotis should be considered as a species of high potential for future aquaculture efforts.
{"title":"Proximate Composition, Amino Acids, and Fatty Acids in the Adductor Muscle of the Giant Honeycomb Oyster Hyotissa hyotis (Linnaeus, 1758) from Jeju Island, Korea","authors":"Hyun-Ki Hong, Jun-Ho Koo, Jun-Cheol Ko, Hee-Do Jeung, Kwang-Sik Choi","doi":"10.2983/035.41.0107","DOIUrl":"https://doi.org/10.2983/035.41.0107","url":null,"abstract":"ABSTRACT The giant honeycomb oyster Hyotissa hyotis occurs at a high density in the shallow subtidal rocky bottom of Jeju Island off the south coast of Korea, where the sea surface temperature ranges from 14°C to 25°C seasonally. Unlike other oysters, H. hyotis has an extraordinarily large adductor muscle (AM) that accounts for more than 40% of the total tissue weight. This study analyzed the proximate composition, amino acids, and fatty acids of the AM of H. hyotis in Jeju Island to evaluate the nutritional potential. For the analyses, oysters were grouped based on their reproductive condition as prespawning (May–August), spawning (September–November), and postspawning (December–April). The AM contained a high level of protein (54.7%–69.4%) followed by carbohydrate (16.0%–25.3%) and lipid (4.5%–9.9%) throughout the year, indicating that the AM is enriched with protein. The total amino acids (TAA) in the AM ranged from 9.4 to 12.9 g/100 g dry weight annually, and essential amino acids accounted for up to 36.7% of the TAA. Like other marine bivalves, the AM contained a high level of taurine, which accounted for 26.5%–28.5% of the total free amino acids. The AM also included high levels of essential fatty acids, such as palmitic acid, docosahexaenoic acid, and eicosapentaenoic acid, as these fatty acids accounted for 35.9%–37.0% of the total fatty acids. The AM of prespawning oysters collected during May and August contained comparatively higher total proteins and carbohydrates. Results suggested that, like scallops and pen shells, the AM of the giant honeycomb oyster is highly suitable as seafood, and H. hyotis should be considered as a species of high potential for future aquaculture efforts.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"101 - 107"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43668438","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}
Xiao-hong Li, YiWen Zhan, Ming Xia, Li Yu, Shouchao Xu, Weifeng Jin
ABSTRACT In the cultivation of freshwater nucleated pearls, the treatment technology of nucleated pearls is very important for the quality and yield of pearls. Pearl nuclei treated with astragalus extract, flavomycin, and oxytetracycline were found to possess anti-inflammatory and antibacterial effects depending on drug concentrations. To optimize the concentration of various drugs for the preparation of medicinal pearl nuclei to enhance pearl production Staphylococcus aureus and Aeromonas hydrophila were used as experimental strains. A comprehensive antibacterial circle diameter was taken as an indicator of drug efficacy. The response surface method based on a central composite design (CCD) was used to explain the combined effect of drugs and optimize their concentrations. The optimal concentrations of flavomycin, oxytetracycline, and astragalus extract were 9.10, 10.50, and 1.50 g/mL, respectively. In these conditions, the predicted antibacterial circle diameter was 1.83 cm and the measured value was 1.81 cm, accounting for a 0.5% relative error. The pearl nuclei coated with the abovementioned drug combinations had a strong antibacterial effect on both A. hydrophila and S. aureus, thus establishing a basis for the development and application of medicinal pearl nuclei.
{"title":"Antibacterial Effects of Drug-Coated Pearl Nuclei Used for Freshwater Pearl Cultivation","authors":"Xiao-hong Li, YiWen Zhan, Ming Xia, Li Yu, Shouchao Xu, Weifeng Jin","doi":"10.2983/035.041.0103","DOIUrl":"https://doi.org/10.2983/035.041.0103","url":null,"abstract":"ABSTRACT In the cultivation of freshwater nucleated pearls, the treatment technology of nucleated pearls is very important for the quality and yield of pearls. Pearl nuclei treated with astragalus extract, flavomycin, and oxytetracycline were found to possess anti-inflammatory and antibacterial effects depending on drug concentrations. To optimize the concentration of various drugs for the preparation of medicinal pearl nuclei to enhance pearl production Staphylococcus aureus and Aeromonas hydrophila were used as experimental strains. A comprehensive antibacterial circle diameter was taken as an indicator of drug efficacy. The response surface method based on a central composite design (CCD) was used to explain the combined effect of drugs and optimize their concentrations. The optimal concentrations of flavomycin, oxytetracycline, and astragalus extract were 9.10, 10.50, and 1.50 g/mL, respectively. In these conditions, the predicted antibacterial circle diameter was 1.83 cm and the measured value was 1.81 cm, accounting for a 0.5% relative error. The pearl nuclei coated with the abovementioned drug combinations had a strong antibacterial effect on both A. hydrophila and S. aureus, thus establishing a basis for the development and application of medicinal pearl nuclei.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"67 - 73"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45194697","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}
.. Bahtiar, M. F. Purnama, .. Muis, E. Ishak, M. Kasim
ABSTRACT Freshwater clams, better known as pokea clams in Indonesia, are among the important economy-generating resources whose population continues to decline in line with the increase in fishing activities. The present study aims to determine the age group, growth, mortality, and exploitation rate of pokea clams. This research was conducted in the estuary segment of Laeya River, Southeast Sulawesi, Indonesia, from March 2016 to February 2017. Pokea samples were taken using a traditional fishing tool called Tangge. Data on age groups, growth, mortality (natural, fishing, and total) and exploitation rate were processed using the Bhattacharya method, the von Bertalanffy inverse function, the width converted catch curve, and Pauly's empirical formula, respectively, accommodated in the FiSAT II program version 3.0. The results showed that the male and female pokea were spread out in 1 and 2 size groups. Male pokea was dominated by 2 size groups, whereas the female pokea was dominated by 1 size group. The growth of the male and female clams followed the equations Lt = 83.89 – (83.89–0.025)e–0.54t and Lt = 77.38 – (77.38–0.025)e–0.52t. The male natural mortality (M), fishing mortality (F), and total mortality (Z) were 2.04 y–1, 0.91 y–1, and 2.94 y–1, respectively, whereas the natural mortality, fishing mortality, and total mortality of the female clams were 1.51 y–1, 0.90 y–1, and 2.41 y–1, respectively. In general, the male and female pokea clams in the Laeya River are overexploited, with the exploitation rates of 0.69 and 0.63, respectively.
{"title":"The Size Structure, Growth, Mortality, and Exploitation Rate of Freshwater Clam (Batissa violacea var. Celebensis) from Southeast Sulawesi, Indonesia","authors":".. Bahtiar, M. F. Purnama, .. Muis, E. Ishak, M. Kasim","doi":"10.2983/035.041.0112","DOIUrl":"https://doi.org/10.2983/035.041.0112","url":null,"abstract":"ABSTRACT Freshwater clams, better known as pokea clams in Indonesia, are among the important economy-generating resources whose population continues to decline in line with the increase in fishing activities. The present study aims to determine the age group, growth, mortality, and exploitation rate of pokea clams. This research was conducted in the estuary segment of Laeya River, Southeast Sulawesi, Indonesia, from March 2016 to February 2017. Pokea samples were taken using a traditional fishing tool called Tangge. Data on age groups, growth, mortality (natural, fishing, and total) and exploitation rate were processed using the Bhattacharya method, the von Bertalanffy inverse function, the width converted catch curve, and Pauly's empirical formula, respectively, accommodated in the FiSAT II program version 3.0. The results showed that the male and female pokea were spread out in 1 and 2 size groups. Male pokea was dominated by 2 size groups, whereas the female pokea was dominated by 1 size group. The growth of the male and female clams followed the equations Lt = 83.89 – (83.89–0.025)e–0.54t and Lt = 77.38 – (77.38–0.025)e–0.52t. The male natural mortality (M), fishing mortality (F), and total mortality (Z) were 2.04 y–1, 0.91 y–1, and 2.94 y–1, respectively, whereas the natural mortality, fishing mortality, and total mortality of the female clams were 1.51 y–1, 0.90 y–1, and 2.41 y–1, respectively. In general, the male and female pokea clams in the Laeya River are overexploited, with the exploitation rates of 0.69 and 0.63, respectively.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"145 - 152"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42882377","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}
Maritza García-Flores, B. Ceballos-Vázquez, M. O. Rosales‐Velázquez
ABSTRACT The life history including embryonic development of most species of octopus is still poorly understood. This makes the identification of eggs and juveniles difficult, hampering distribution and dispersal studies. The Pacific pygmy octopus, Paroctopus digueti (Perrier & Rocheburne 1894), exhibits features, including its direct embryonic development, that make it an ideal candidate for aquaculture. This study provides detailed information on the embryonic development, the morphological characteristics of eggs, and the fecundity of wild female P. digueti maintained under laboratory conditions that replicate natural environmental conditions. The Pacific pygmy octopus showed a monocyclic spawning pattern that takes place in time-separated batches, leading to asynchronous embryonic development in the batch. Eggs are between 7 and 10 mm (8.9 ± 0.71 mm) in total length. During the embryonic development, 31 distinct stages were identified with a total duration of 38 days. The distribution of chromatophores showed a specific pattern, with dorsal chromatophores being more abundant and larger than ventral ones. An observed fecundity of 300 eggs per female was twice as high as the value previously reported for this species in Bahia Choya, Sonora. This study contributes to the better understanding of the life cycle of P. digueti. Besides being a basic reproductive aspect, fecundity is a key element for studies on the reproductive potential and population dynamics of the species.
{"title":"Embryonic Development and Fecundity of the Pacific Pygmy Octopus, Paroctopus digueti","authors":"Maritza García-Flores, B. Ceballos-Vázquez, M. O. Rosales‐Velázquez","doi":"10.2983/035.41.0110","DOIUrl":"https://doi.org/10.2983/035.41.0110","url":null,"abstract":"ABSTRACT The life history including embryonic development of most species of octopus is still poorly understood. This makes the identification of eggs and juveniles difficult, hampering distribution and dispersal studies. The Pacific pygmy octopus, Paroctopus digueti (Perrier & Rocheburne 1894), exhibits features, including its direct embryonic development, that make it an ideal candidate for aquaculture. This study provides detailed information on the embryonic development, the morphological characteristics of eggs, and the fecundity of wild female P. digueti maintained under laboratory conditions that replicate natural environmental conditions. The Pacific pygmy octopus showed a monocyclic spawning pattern that takes place in time-separated batches, leading to asynchronous embryonic development in the batch. Eggs are between 7 and 10 mm (8.9 ± 0.71 mm) in total length. During the embryonic development, 31 distinct stages were identified with a total duration of 38 days. The distribution of chromatophores showed a specific pattern, with dorsal chromatophores being more abundant and larger than ventral ones. An observed fecundity of 300 eggs per female was twice as high as the value previously reported for this species in Bahia Choya, Sonora. This study contributes to the better understanding of the life cycle of P. digueti. Besides being a basic reproductive aspect, fecundity is a key element for studies on the reproductive potential and population dynamics of the species.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"125 - 134"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47717162","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 Bivalve molluscs record histories of individual growth as alternating periods of activity (shell deposition) and inactivity (growth cessation marks) within their multilayered shells, and in some species, as alternating sublayers with different morphology. Shell growth patterns reflect tidal, daily, and seasonal cycles of key environmental parameters, such as submergence and temperature, which influence physiology (e.g., feeding, respiration, metabolic rates, and reproductive cycles). Knowledge of the periodicity of formation of various structures within the shell enables researchers to place a calendar across the growth history of an animal knowing only the date of collection. In turn, this enables both the determination of age (essential in studies of population dynamics) and the assessment of how bivalve populations responded to known environmental events, be they anthropogenic or natural, after the event has occurred. Seasonal microstructural shell growth patterns of six common bivalve species living in fresh (Corbicula fluminea O. F. Müller, 1774), brackish (Rangia cuneata G. B. Sowerby I, 1832), lower estuarine (Geukensia demissa Dillwyn, 1817), coastal (Mytilus edulis Linnaeus, 1758 and Mya arenaria Linnaeus, 1758), and continental shelf (Spisula solidissima Dillwyn, 1817) habitats in the mid-Atlantic region of the United States are documented using optical and scanning electron microscopy based on collections in the late 1980s. Some of the works have been published previously, but the results for each of the six species are combined and summarized in one volume as a guide to the seasonal shell microstructure for some common bivalves in New Jersey waters. The utility of shell growth pattern analysis in environmental impact assessments and population dynamics studies is evaluated within each habitat and example applications are provided. Although the results reported here were from studies conducted over 30 y ago, they represent collectively a contribution to our knowledge of molluscan shell microstructure that remain relevant today and are published as a coherent monograph before they are lost as so many other important unpublished works have been as time ran out on aging authors before they could relay the precious secrets they uncovered over the years.
{"title":"Seasonal Changes in Shell Microstructure of Some Common Bivalve Molluscs in the Mid-Atlantic Region","authors":"L. Fritz, Lisa M. Calvo, Lisa Wargo, R. Lutz","doi":"10.2983/035.041.0101","DOIUrl":"https://doi.org/10.2983/035.041.0101","url":null,"abstract":"ABSTRACT Bivalve molluscs record histories of individual growth as alternating periods of activity (shell deposition) and inactivity (growth cessation marks) within their multilayered shells, and in some species, as alternating sublayers with different morphology. Shell growth patterns reflect tidal, daily, and seasonal cycles of key environmental parameters, such as submergence and temperature, which influence physiology (e.g., feeding, respiration, metabolic rates, and reproductive cycles). Knowledge of the periodicity of formation of various structures within the shell enables researchers to place a calendar across the growth history of an animal knowing only the date of collection. In turn, this enables both the determination of age (essential in studies of population dynamics) and the assessment of how bivalve populations responded to known environmental events, be they anthropogenic or natural, after the event has occurred. Seasonal microstructural shell growth patterns of six common bivalve species living in fresh (Corbicula fluminea O. F. Müller, 1774), brackish (Rangia cuneata G. B. Sowerby I, 1832), lower estuarine (Geukensia demissa Dillwyn, 1817), coastal (Mytilus edulis Linnaeus, 1758 and Mya arenaria Linnaeus, 1758), and continental shelf (Spisula solidissima Dillwyn, 1817) habitats in the mid-Atlantic region of the United States are documented using optical and scanning electron microscopy based on collections in the late 1980s. Some of the works have been published previously, but the results for each of the six species are combined and summarized in one volume as a guide to the seasonal shell microstructure for some common bivalves in New Jersey waters. The utility of shell growth pattern analysis in environmental impact assessments and population dynamics studies is evaluated within each habitat and example applications are provided. Although the results reported here were from studies conducted over 30 y ago, they represent collectively a contribution to our knowledge of molluscan shell microstructure that remain relevant today and are published as a coherent monograph before they are lost as so many other important unpublished works have been as time ran out on aging authors before they could relay the precious secrets they uncovered over the years.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"1 - 59"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44492579","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 The spatial expression patterns of three genes [kelch-like protein homolog 10 (klhl10); armadillo repeat-containing protein 4 isoform X2 (armc4); mitochondria cytochrome oxidase I (mt-co1)] known to be important mechanistic components of spermatogenesis/spermiogenesis were localized in mantle tissue sections of male Mytilus edulis using nonisotopic in situ hybridization and RNA probes based on sequences derived from available mantle RNA sequencing libraries. The expression patterns showed that all three genes are primarily localized in a layer of cells adjacent to the outer wall of the testicular acini. This layer is known to contain developing stages of spermatogonia, spermatocytes, and spermatids. Kelch-like protein homolog 10 was expressed in immature spermatogonial cells/spermatocytes characterized by large round central nuclei and situated near the periphery of the testicular acini with little to no expression in adjacent populations of spermatids or mature spermatozoa at the center of the acini. Like klhl10, armc4 transcripts were also detected in the cells near the inner periphery of the outer acinar wall. In contrast, however, the armc4 expressing cells appeared to be spatially shifted more toward the inner edge of the cell layer and toward the center of the acini. The localization of cells expressing armc4 transcripts near the inner edge of the developing sperm layer in the testicular acini of M. edulis supports a role for armc4 in spermatid morphogenesis and maturation. Mitochondria-specific cytochrome c oxidase transcripts were localized in cells throughout the inner periphery of the testicular acini wall but not in association with mature spermatozoa in the center of the acini reflecting the significant level of cellular activity that occurs during early sperm development. This supports an important mitochondrial role in early and mid-spermatogenesis in M. edulis potentially related to sperm quality control. This work provides a first view into the molecular mechanisms behind spermatogenesis/spermiogenesis in M. edulis.
{"title":"Spatial Expression Patterning of Kelch-Like Protein Homolog 10 (klhl10), Armadillo Repeat-Containing Protein 4 Isoform X2 (armc4), and a Gamete-Specific Mitochondrial Cytochrome C Oxidase (mt-co1) during Spermatogenesis/Spermiogenesis in the Mantle of Male Blue Mussel (Mytilus edulis)","authors":"H. Murray, K. Hobbs","doi":"10.2983/035.041.0108","DOIUrl":"https://doi.org/10.2983/035.041.0108","url":null,"abstract":"ABSTRACT The spatial expression patterns of three genes [kelch-like protein homolog 10 (klhl10); armadillo repeat-containing protein 4 isoform X2 (armc4); mitochondria cytochrome oxidase I (mt-co1)] known to be important mechanistic components of spermatogenesis/spermiogenesis were localized in mantle tissue sections of male Mytilus edulis using nonisotopic in situ hybridization and RNA probes based on sequences derived from available mantle RNA sequencing libraries. The expression patterns showed that all three genes are primarily localized in a layer of cells adjacent to the outer wall of the testicular acini. This layer is known to contain developing stages of spermatogonia, spermatocytes, and spermatids. Kelch-like protein homolog 10 was expressed in immature spermatogonial cells/spermatocytes characterized by large round central nuclei and situated near the periphery of the testicular acini with little to no expression in adjacent populations of spermatids or mature spermatozoa at the center of the acini. Like klhl10, armc4 transcripts were also detected in the cells near the inner periphery of the outer acinar wall. In contrast, however, the armc4 expressing cells appeared to be spatially shifted more toward the inner edge of the cell layer and toward the center of the acini. The localization of cells expressing armc4 transcripts near the inner edge of the developing sperm layer in the testicular acini of M. edulis supports a role for armc4 in spermatid morphogenesis and maturation. Mitochondria-specific cytochrome c oxidase transcripts were localized in cells throughout the inner periphery of the testicular acini wall but not in association with mature spermatozoa in the center of the acini reflecting the significant level of cellular activity that occurs during early sperm development. This supports an important mitochondrial role in early and mid-spermatogenesis in M. edulis potentially related to sperm quality control. This work provides a first view into the molecular mechanisms behind spermatogenesis/spermiogenesis in M. edulis.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"109 - 117"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46096705","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 Despite estimates of very high (>99.9%) pre-settlement mortality, the extremely large numbers of eggs released into the plankton means that there are abundant post-larval softshell clams (Mya arenaria) available to settle and populate intertidal flats. Many seemingly suitable flats remain devoid of clams, presumably due to post-settlement predation. Predator exclusion/clam recruitment boxes (wooden frames covered top and bottom with a fine plastic screening) were set on a mudflat in Salem Harbor, Salem, MA from April to November 2019. Clam larvae were able to settle through the screen into the boxes but large (>1.9 mm) predators such as European green crabs (Carcinus maenas) and milky ribbon worms (Cerebratulus lacteus) were excluded. At the end of the study, four of five boxes contained between 121 and 290 juvenile softshell clams ranging in size from 7 mm to 32 mm shell length. A bimodal frequency distribution of sizes likely illustrates an early summer (June) set represented by a larger size grouping followed by a second late-summer set represented by a smaller size grouping. Small green crabs (9–46 mm carapace width) found in all five boxes must have grown from extremely small stage 1 crabs that were able to settle or crawl through the screening as recently settled individuals. Resulting empty clam shells could be paired to yield the equivalent of additional clams, making the total number per box between 147 and 417 individuals. No clams were found in samples outside of the boxes, indicating that the absence of a clam population on the mudflat is due to post-settlement predation and not pre-settlement mortality.
{"title":"Effect of Predator Exclusion on Softshell Clam (Mya arenaria L.) Recruitment","authors":"A. Young","doi":"10.2983/035.041.0109","DOIUrl":"https://doi.org/10.2983/035.041.0109","url":null,"abstract":"ABSTRACT Despite estimates of very high (>99.9%) pre-settlement mortality, the extremely large numbers of eggs released into the plankton means that there are abundant post-larval softshell clams (Mya arenaria) available to settle and populate intertidal flats. Many seemingly suitable flats remain devoid of clams, presumably due to post-settlement predation. Predator exclusion/clam recruitment boxes (wooden frames covered top and bottom with a fine plastic screening) were set on a mudflat in Salem Harbor, Salem, MA from April to November 2019. Clam larvae were able to settle through the screen into the boxes but large (>1.9 mm) predators such as European green crabs (Carcinus maenas) and milky ribbon worms (Cerebratulus lacteus) were excluded. At the end of the study, four of five boxes contained between 121 and 290 juvenile softshell clams ranging in size from 7 mm to 32 mm shell length. A bimodal frequency distribution of sizes likely illustrates an early summer (June) set represented by a larger size grouping followed by a second late-summer set represented by a smaller size grouping. Small green crabs (9–46 mm carapace width) found in all five boxes must have grown from extremely small stage 1 crabs that were able to settle or crawl through the screening as recently settled individuals. Resulting empty clam shells could be paired to yield the equivalent of additional clams, making the total number per box between 147 and 417 individuals. No clams were found in samples outside of the boxes, indicating that the absence of a clam population on the mudflat is due to post-settlement predation and not pre-settlement mortality.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"119 - 124"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42223982","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}
Horacio Bervera-León, M. Monteforte, J. A. De-Anda-Montañez
ABSTRACT In general, pearl cultivation has advanced with organisms produced and improved in hatchery; however, wild spat collection is still the primary source for commercial cultivation. In Mexico, progress toward pearl oyster hatchery spat production is yet in the experimental stage. The only three farms established in the country (Guaymas, La Paz, and Cozumel Island) rely on extensive culture. Constant spat supply is imperative to ensure a successful operation; at La Paz Bay, however, larval uptake of the pearl oyster Pinctada mazatlanica in artificial collectors has always been low. This study aimed to assess spatio-temporal and bathymetric patterns of spat distribution across the area to locate suitable sites to install spat collecting stations. Our results showed significant differences (P < 0.05) between stations. Mogote, Caimancito, Punta Colorada, and Gaviota Island were the stations with the highest spat abundance at 1-m depth in July–September after 40 and 60 days of immersion. The data were also analyzed with generalized linear models. The best models, selected with the Akaike and Bayesian criteria, suggest that 1-m depth, 40- and 60-day immersion time, and site (particularly, Caimancito Beach, Punta Colorada, and Gaviota Island) contributed significantly to explaining the highest catches (mean: 5–8 organisms/collector) of P. mazatlanica spat in La Paz Bay. Therefore, the area within these sites should be considered suitable for installing the network of artificial collectors during the season of high spat abundance.
{"title":"Spatio-Temporal Variation of the Abundance of Pearl Oyster (Pinctada mazatlanica) Spat and Its Relevance in the Location of Suitable Sites for Extensive Pearl Oyster Culture","authors":"Horacio Bervera-León, M. Monteforte, J. A. De-Anda-Montañez","doi":"10.2983/035.041.0105","DOIUrl":"https://doi.org/10.2983/035.041.0105","url":null,"abstract":"ABSTRACT In general, pearl cultivation has advanced with organisms produced and improved in hatchery; however, wild spat collection is still the primary source for commercial cultivation. In Mexico, progress toward pearl oyster hatchery spat production is yet in the experimental stage. The only three farms established in the country (Guaymas, La Paz, and Cozumel Island) rely on extensive culture. Constant spat supply is imperative to ensure a successful operation; at La Paz Bay, however, larval uptake of the pearl oyster Pinctada mazatlanica in artificial collectors has always been low. This study aimed to assess spatio-temporal and bathymetric patterns of spat distribution across the area to locate suitable sites to install spat collecting stations. Our results showed significant differences (P < 0.05) between stations. Mogote, Caimancito, Punta Colorada, and Gaviota Island were the stations with the highest spat abundance at 1-m depth in July–September after 40 and 60 days of immersion. The data were also analyzed with generalized linear models. The best models, selected with the Akaike and Bayesian criteria, suggest that 1-m depth, 40- and 60-day immersion time, and site (particularly, Caimancito Beach, Punta Colorada, and Gaviota Island) contributed significantly to explaining the highest catches (mean: 5–8 organisms/collector) of P. mazatlanica spat in La Paz Bay. Therefore, the area within these sites should be considered suitable for installing the network of artificial collectors during the season of high spat abundance.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"41 1","pages":"85 - 94"},"PeriodicalIF":1.3,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49506967","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 The goal of this study was to initiate a program for producing Florida tetraploid founders to meet the needs of the fast-growing oyster farming industry in the Gulf of Mexico. The objectives were to: (1) produce chemically induced triploids originated from Florida wild stocks and (2) screen and identify triploid females for induction of tetraploid founders. By use of Florida wild stocks from different locations, chemically induced triploids were produced in three spawn groups. Compared with diploid siblings, triploids at juvenile stages did not show significant fast growth (shell metrics and body weight) in every group, but at 1-y-old in spawning season did show significantly faster growth (P < 0.0001) than their diploid siblings. Among triploids, the occurrence of female averaged 1.66% (43 out of 2,597 triploids), ranging from 0.68%, 1.2%, and 4.26% in the three spawn groups. Oocytes from these 43 triploid females averaged 214,715 per female ranging from <100 to 1,800,000. Flow cytometry analysis of gonad from the nonfemale triploids (n = 186) showed five types of ploidy composition. A majority of these nonfemale triploids (66.1%) showed 3n only, indicating no gametogenesis occurred, and other different ploidy compositions showed initiation of gametogenesis with different chromosome segregations. Tetraploid induction was conducted by fertilizing the oocytes from triploid females with sperm from diploid males followed by polar body inhibition. The fertilization varied greatly ranging from 12% to 91%, and survival to D-stage swimming larvae ranged from 0% to 24%. Ploidy of pooled D-stage larvae indicated a tetraploid composition ranging from 38% to 80%. Heavy mortality of putative tetraploid larvae occurred at about 7–9 days and juveniles (1, 3, and approximately 200) were harvested in three groups. Unfortunately, these juveniles were lost during a hurricane in October 2018 at the growout site of one collaborating farm before individual ploidy examination. Although no confirmed tetraploid founders were harvested, the occurrence and fecundity of triploid females were documented in detail, which should be useful for future development of tetraploid stock for oyster aquaculture.
{"title":"Performance and Fecundity of Triploid Eastern Oysters Crassostrea virginica (Gmelin, 1791) and Challenges for Tetraploid Production","authors":"Huiping Yang","doi":"10.2983/035.040.0305","DOIUrl":"https://doi.org/10.2983/035.040.0305","url":null,"abstract":"ABSTRACT The goal of this study was to initiate a program for producing Florida tetraploid founders to meet the needs of the fast-growing oyster farming industry in the Gulf of Mexico. The objectives were to: (1) produce chemically induced triploids originated from Florida wild stocks and (2) screen and identify triploid females for induction of tetraploid founders. By use of Florida wild stocks from different locations, chemically induced triploids were produced in three spawn groups. Compared with diploid siblings, triploids at juvenile stages did not show significant fast growth (shell metrics and body weight) in every group, but at 1-y-old in spawning season did show significantly faster growth (P < 0.0001) than their diploid siblings. Among triploids, the occurrence of female averaged 1.66% (43 out of 2,597 triploids), ranging from 0.68%, 1.2%, and 4.26% in the three spawn groups. Oocytes from these 43 triploid females averaged 214,715 per female ranging from <100 to 1,800,000. Flow cytometry analysis of gonad from the nonfemale triploids (n = 186) showed five types of ploidy composition. A majority of these nonfemale triploids (66.1%) showed 3n only, indicating no gametogenesis occurred, and other different ploidy compositions showed initiation of gametogenesis with different chromosome segregations. Tetraploid induction was conducted by fertilizing the oocytes from triploid females with sperm from diploid males followed by polar body inhibition. The fertilization varied greatly ranging from 12% to 91%, and survival to D-stage swimming larvae ranged from 0% to 24%. Ploidy of pooled D-stage larvae indicated a tetraploid composition ranging from 38% to 80%. Heavy mortality of putative tetraploid larvae occurred at about 7–9 days and juveniles (1, 3, and approximately 200) were harvested in three groups. Unfortunately, these juveniles were lost during a hurricane in October 2018 at the growout site of one collaborating farm before individual ploidy examination. Although no confirmed tetraploid founders were harvested, the occurrence and fecundity of triploid females were documented in detail, which should be useful for future development of tetraploid stock for oyster aquaculture.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"40 1","pages":"489 - 497"},"PeriodicalIF":1.3,"publicationDate":"2022-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69620947","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}
Xiaocheng Tang, Aitao Mao, Yu Ding, Zhigang Liu, Huazhong Liu
ABSTRACT The complete cDNA sequence of chaperonin-containing T-complex polypeptide 1-alpha (CCT-alpha) gene of the pearl oyster Pinctada maxima was determined using rapid amplification of cDNA ends technique and characterized with bioinformatic analysis. Its expression profile in different organs and under cold stress was characterized using real-time quantitative polymerase chain reaction. Results revealed that the complete cDNA sequence of P. maxima CCT-alpha has 1,803 base pairs (bp), including a 1,608-bp open reading framework that codes 535 amino acids. The protein has three conservative functional domains: equatorial, apical, and intermediate domains. The equatorial domain is 20 amino acids shorter than that of other species, and contains the three signature sequences of CCT family protein. The CCT-alpha of P. maxima has nine conservative ATP-binding sites and six protein-binding sites, and has high homology with Aplysia californica (80.7%), Delia antiqua (77.4%), Danio rerio (77.1%), Xenopus laevis (76.7%), Gallus gallus (76.4%), and Homo sapiens (75.4%). The CCT-alpha shows tissue-specific expression profile in P. maxima, with expression levels higher in gill, mantle, and adductor muscle than in hepatopancreas and heart. Cold stress markedly increased mRNA contents of CCT-alpha in the organs of P. maxima, but different organs showed distinct cold stress response pattern. Chaperonin-containing T-complex polypeptide 1-alpha transcription in adductor muscle, hepatopancreas, and heart increased at 2 h, and reached peak values at 6 h, maintained high levels at 12 h, and significantly decreased at 24 h. The product in gill and mantle decreased at 2 h, began to increase at 6 h, and showed a large increase at 12 h, but reduced to below the initial level at 24 h.
{"title":"Cdna Cloning and Expression Analysis of Chaperonin Containing T-Complex Polypeptide 1-Alpha in the Pearl Oyster Pinctada maxima Exposed to Cold Stress","authors":"Xiaocheng Tang, Aitao Mao, Yu Ding, Zhigang Liu, Huazhong Liu","doi":"10.2983/035.040.0307","DOIUrl":"https://doi.org/10.2983/035.040.0307","url":null,"abstract":"ABSTRACT The complete cDNA sequence of chaperonin-containing T-complex polypeptide 1-alpha (CCT-alpha) gene of the pearl oyster Pinctada maxima was determined using rapid amplification of cDNA ends technique and characterized with bioinformatic analysis. Its expression profile in different organs and under cold stress was characterized using real-time quantitative polymerase chain reaction. Results revealed that the complete cDNA sequence of P. maxima CCT-alpha has 1,803 base pairs (bp), including a 1,608-bp open reading framework that codes 535 amino acids. The protein has three conservative functional domains: equatorial, apical, and intermediate domains. The equatorial domain is 20 amino acids shorter than that of other species, and contains the three signature sequences of CCT family protein. The CCT-alpha of P. maxima has nine conservative ATP-binding sites and six protein-binding sites, and has high homology with Aplysia californica (80.7%), Delia antiqua (77.4%), Danio rerio (77.1%), Xenopus laevis (76.7%), Gallus gallus (76.4%), and Homo sapiens (75.4%). The CCT-alpha shows tissue-specific expression profile in P. maxima, with expression levels higher in gill, mantle, and adductor muscle than in hepatopancreas and heart. Cold stress markedly increased mRNA contents of CCT-alpha in the organs of P. maxima, but different organs showed distinct cold stress response pattern. Chaperonin-containing T-complex polypeptide 1-alpha transcription in adductor muscle, hepatopancreas, and heart increased at 2 h, and reached peak values at 6 h, maintained high levels at 12 h, and significantly decreased at 24 h. The product in gill and mantle decreased at 2 h, began to increase at 6 h, and showed a large increase at 12 h, but reduced to below the initial level at 24 h.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":"40 1","pages":"505 - 510"},"PeriodicalIF":1.3,"publicationDate":"2022-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44344692","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：