J. Genodepa, Chaoshu Zeng, T. Militz, P. Southgate
ABSTRACT There is considerable interest in improving hatchery production of the mud crab, Scylla serrata. Although some progress has been made toward identifying appropriate feeding protocols for live-foods, the density at which food is first provided to larvae varies greatly in practice. This study examined relationships between rotifer density and activity patterns of enzymes critical to digestion in S. serrata to evaluate feeding protocols from a nutrient utilization perspective. Activities of trypsin-like proteases, nonspecific esterases, and α-amylase were quantified to determine the response of newly hatched (Zoea I) larvae of S. serrata to rotifers provided at four different densities (i.e., 10, 20, 40, and 80 mL–1) from first-feeding. Results showed that rotifer density significantly (P < 0.01) influenced total activity (mU larva–1) patterns within 24 h of first-feeding for all the enzymes assayed. Based on these patterns, utilization of the associated macronutrients (i.e., protein, lipid, and carbohydrate) was presumably similar when larvae were provided with rotifers at densities of 10, 20, or 40 mL–1 and increased when larvae were provided with rotifers at a density of 80 mL–1. An optimal density at which to provide rotifers to S. serrata for first-feeding is likely to be >40 mL–1. The comparative analyses of enzyme activities presented in this study represent an innovative approach to quickly (within 24 h) identify optimal food densities for larval crustaceans at first-feeding.
{"title":"Influence of Live-Food (Brachionus rotundiformis) Density at First-Feeding on Digestive Enzyme Activities in Newly Hatched (Zoea I) Larvae of the Mud Crab, Scylla serrata","authors":"J. Genodepa, Chaoshu Zeng, T. Militz, P. Southgate","doi":"10.2983/035.042.0315","DOIUrl":"https://doi.org/10.2983/035.042.0315","url":null,"abstract":"ABSTRACT There is considerable interest in improving hatchery production of the mud crab, Scylla serrata. Although some progress has been made toward identifying appropriate feeding protocols for live-foods, the density at which food is first provided to larvae varies greatly in practice. This study examined relationships between rotifer density and activity patterns of enzymes critical to digestion in S. serrata to evaluate feeding protocols from a nutrient utilization perspective. Activities of trypsin-like proteases, nonspecific esterases, and α-amylase were quantified to determine the response of newly hatched (Zoea I) larvae of S. serrata to rotifers provided at four different densities (i.e., 10, 20, 40, and 80 mL–1) from first-feeding. Results showed that rotifer density significantly (P < 0.01) influenced total activity (mU larva–1) patterns within 24 h of first-feeding for all the enzymes assayed. Based on these patterns, utilization of the associated macronutrients (i.e., protein, lipid, and carbohydrate) was presumably similar when larvae were provided with rotifers at densities of 10, 20, or 40 mL–1 and increased when larvae were provided with rotifers at a density of 80 mL–1. An optimal density at which to provide rotifers to S. serrata for first-feeding is likely to be >40 mL–1. The comparative analyses of enzyme activities presented in this study represent an innovative approach to quickly (within 24 h) identify optimal food densities for larval crustaceans at first-feeding.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139388347","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}
Jennifer E. Granneman, E. Levine, Cameron Baxley, Zoe Cross, Rosemary Murphy, Sarah Sharkey, Kelly Williams
ABSTRACT The Florida bay scallop (Argopecten irradians concentricus Say, 1822) is a relatively short-lived species that resides in dynamic marine systems and is subject to multiple stressors, although the environmental drivers of bay scallop abundance along the Florida Gulf Coast are not well understood. The use of an ecosystem approach to fisheries management may be particularly relevant for short-lived species that are highly susceptible to environmental changes, but this approach requires an understanding of how environmental variables, such as salinity and temperature, may influence bay scallops throughout their range. This study was designed to identify the relationships between environmental variables and bay scallop abundance and to evaluate the relative effect of these relationships. Scallop surveys conducted in the spring and fall along the Florida Gulf Coast from 1992 to 2019 were compared with seasonal water quality parameters, streamflow discharge, precipitation, wind speed, and climate indices. The size and spawning success of the fall scallop population were negatively affected by relatively high Karenia brevis counts, low dissolved oxygen, and low phosphorus availability. During the period of early postsettlement growth in the winter, scallops were negatively impacted by salinities outside the range of 22–27 due to increased rainfall and low nitrogen availability. Finally, the factors that negatively affected juvenile scallop growth and survival in the spring included increased rainfall and wind speed resulting in relatively high turbidity and comparatively low chlorophyll a.
{"title":"Environmental Drivers of Bay Scallop (Argopecten irradians concentricus) Abundance along the Florida Gulf Coast","authors":"Jennifer E. Granneman, E. Levine, Cameron Baxley, Zoe Cross, Rosemary Murphy, Sarah Sharkey, Kelly Williams","doi":"10.2983/035.042.0307","DOIUrl":"https://doi.org/10.2983/035.042.0307","url":null,"abstract":"ABSTRACT The Florida bay scallop (Argopecten irradians concentricus Say, 1822) is a relatively short-lived species that resides in dynamic marine systems and is subject to multiple stressors, although the environmental drivers of bay scallop abundance along the Florida Gulf Coast are not well understood. The use of an ecosystem approach to fisheries management may be particularly relevant for short-lived species that are highly susceptible to environmental changes, but this approach requires an understanding of how environmental variables, such as salinity and temperature, may influence bay scallops throughout their range. This study was designed to identify the relationships between environmental variables and bay scallop abundance and to evaluate the relative effect of these relationships. Scallop surveys conducted in the spring and fall along the Florida Gulf Coast from 1992 to 2019 were compared with seasonal water quality parameters, streamflow discharge, precipitation, wind speed, and climate indices. The size and spawning success of the fall scallop population were negatively affected by relatively high Karenia brevis counts, low dissolved oxygen, and low phosphorus availability. During the period of early postsettlement growth in the winter, scallops were negatively impacted by salinities outside the range of 22–27 due to increased rainfall and low nitrogen availability. Finally, the factors that negatively affected juvenile scallop growth and survival in the spring included increased rainfall and wind speed resulting in relatively high turbidity and comparatively low chlorophyll a.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139388387","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}
Karen E. Jensen, R. Barry, Mickie L. Powell, L. D’Abramo, D. A. Davis, Stephen A. Watts
ABSTRACT Shrimp (Litopenaeus vannamei) were provided access to sea urchin (Lytechinus variegatus) egesta to investigate whether fresh egesta (containing an active microbiome) consumed alone or in combination with a commercial shrimp feed could influence growth, feed conversion, body composition, and survival of L. vannamei in co-culture. In an initial experiment conducted for 8 wk, shrimp were proffered a full or reduced ration (100%, 60%, and 20%) of commercial shrimp feed with or without access to sea urchin egesta serving as a source of supplemental nutrients and presumptive probiotics. Individual weight gain of shrimp provided sea urchin egesta only (10.37 ± 0.35 g) did not differ significantly from that of shrimp proffered a full ration of feed (9.46 ± 0.39 g) despite significant compositional differences. Consumption of sea urchin egesta combined with commercial shrimp feed resulted in significantly greater weight gain of shrimp when compared with shrimp proffered the same level of commercial shrimp feed only. The largest weight gains of shrimp were found for those groups fed rations of 60% and 100% and had access to egesta (14.09 ± 0.75 g and 14.72 ± 0.68 g, respectively). In the next experiment, shrimp were stocked at different densities (approximately 23, 45, 68, and 90 individuals m–2) and were not proffered feed directly. All replicates were provided access to fresh sea urchin egesta produced by four urchins that were fed at a daily rate of 3% of the total initial group weight (140.4 ± 0.7 g) for 8 wk. The largest individual weight gain was found in the lowest density treatment (6.55 ± 0.38 g). Harvested biomass significantly increased as density increased, except for the highest density treatment. These results indicate that sea urchin egesta may provide some growth enhancement factor(s) to shrimp when proffered in conjunction with a commercial diet, and at a certain density of shrimp sea urchin egesta may actually serve as a nutritionally complete diet.
{"title":"Integrated Aquaculture of Sea Urchins (Lytechinus variegatus) and Shrimp (Litopenaeus vannamei)","authors":"Karen E. Jensen, R. Barry, Mickie L. Powell, L. D’Abramo, D. A. Davis, Stephen A. Watts","doi":"10.2983/035.042.0310","DOIUrl":"https://doi.org/10.2983/035.042.0310","url":null,"abstract":"ABSTRACT Shrimp (Litopenaeus vannamei) were provided access to sea urchin (Lytechinus variegatus) egesta to investigate whether fresh egesta (containing an active microbiome) consumed alone or in combination with a commercial shrimp feed could influence growth, feed conversion, body composition, and survival of L. vannamei in co-culture. In an initial experiment conducted for 8 wk, shrimp were proffered a full or reduced ration (100%, 60%, and 20%) of commercial shrimp feed with or without access to sea urchin egesta serving as a source of supplemental nutrients and presumptive probiotics. Individual weight gain of shrimp provided sea urchin egesta only (10.37 ± 0.35 g) did not differ significantly from that of shrimp proffered a full ration of feed (9.46 ± 0.39 g) despite significant compositional differences. Consumption of sea urchin egesta combined with commercial shrimp feed resulted in significantly greater weight gain of shrimp when compared with shrimp proffered the same level of commercial shrimp feed only. The largest weight gains of shrimp were found for those groups fed rations of 60% and 100% and had access to egesta (14.09 ± 0.75 g and 14.72 ± 0.68 g, respectively). In the next experiment, shrimp were stocked at different densities (approximately 23, 45, 68, and 90 individuals m–2) and were not proffered feed directly. All replicates were provided access to fresh sea urchin egesta produced by four urchins that were fed at a daily rate of 3% of the total initial group weight (140.4 ± 0.7 g) for 8 wk. The largest individual weight gain was found in the lowest density treatment (6.55 ± 0.38 g). Harvested biomass significantly increased as density increased, except for the highest density treatment. These results indicate that sea urchin egesta may provide some growth enhancement factor(s) to shrimp when proffered in conjunction with a commercial diet, and at a certain density of shrimp sea urchin egesta may actually serve as a nutritionally complete diet.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139388354","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 Adductor muscle from Pinctada maxima and Pinctada margaritifera were analyzed for nutrient compositions. Both were characterized by relatively high-protein, low-lipid, and low-cholesterol contents. Palmitic acid and docosahexaenoic acid were the dominant saturated and polyunsaturated fatty acids, respectively, in both species. Amino acid compositions of adductor muscle from both species were characterized by a high abundance of glutamic acid, aspartic acid, and arginine, whereas cysteine, then tryptophan, were least abundant. Overall, these nutrient compositions are similar to those reported for other bivalve molluscs. The results are timely given the growing interest in pearl meat consumption and pearl meat farming.
摘要 对 Pinctada maxima 和 Pinctada margaritifera 的内收肌进行了营养成分分析。两者都具有相对高蛋白、低脂和低胆固醇含量的特点。棕榈酸和二十二碳六烯酸分别是这两种鱼的主要饱和脂肪酸和多不饱和脂肪酸。两种动物内收肌氨基酸组成的特点是谷氨酸、天冬氨酸和精氨酸含量高，而半胱氨酸和色氨酸含量最低。总体而言，这些营养成分与其他双壳软体动物的营养成分相似。鉴于人们对珍珠肉消费和珍珠肉养殖的兴趣与日俱增，这些结果非常及时。
{"title":"Nutrient Compositions Of Adductor Muscle from the Pearl Oysters Pinctada maxima and Pinctada margaritifera","authors":"P. Southgate, T. Militz","doi":"10.2983/035.042.0309","DOIUrl":"https://doi.org/10.2983/035.042.0309","url":null,"abstract":"ABSTRACT Adductor muscle from Pinctada maxima and Pinctada margaritifera were analyzed for nutrient compositions. Both were characterized by relatively high-protein, low-lipid, and low-cholesterol contents. Palmitic acid and docosahexaenoic acid were the dominant saturated and polyunsaturated fatty acids, respectively, in both species. Amino acid compositions of adductor muscle from both species were characterized by a high abundance of glutamic acid, aspartic acid, and arginine, whereas cysteine, then tryptophan, were least abundant. Overall, these nutrient compositions are similar to those reported for other bivalve molluscs. The results are timely given the growing interest in pearl meat consumption and pearl meat farming.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139387747","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}
Victor I. López-Rojas, P. Flores-Rodríguez, J. Padilla-Serrato, Rafael Flores-Garza, Carmina Torreblanca-Ramírez
ABSTRACT The coastal fishing of the snail Titanostrombus galeatus is carried out in some coastal countries of the Tropical Eastern Pacific. In this study, the individual growth of T. galeatus that are fished in the community at Punta Maldonado was estimated. The size structure was made using the shell length (SL), and the growth parameters were estimated through the five Schnute cases, where cases 1, 2, and 5 describe asymptotic growth and cases 3 and 4 describe nonasymptotic growth. The male population was more abundant than the females, with 398 and 322 specimens, respectively, but the females were larger (198 ± 9.66 mm). In general, the average SL during the two sampling cycles was 196 ± 9.44 mm; this size was not significantly different between the first and second cycles (P = 0.98). Females had a greater range of SL (170–267 mm) compared with males (170–240 mm). The lengths of both sexes showed significant differences between months (P < 0.05). The multinomial analysis showed a multimodal SL distribution, with one to three modal groups for females and males. In growth, cases 2 and 5 were the ones that best describe the growth in females, in males the best were cases 5 and 2. According to the best case (case 2) in females, the growth curve is sigmoidal. In males, the best case (case 5) describes growth according to an inverted exponential curve. In relation to the estimated growth parameters, females showed faster growth than males, analyzed using Kimura's test. The present investigation is the first that reports the growth for both sexes of T. galeatus using the five cases of the Schnute model. The information generated can be used for management purposes, as this species is not currently regulated in Mexico.
{"title":"Estimation of Individual Growth of Titanostrombus galeatus (Strombidae: Gastropoda) at Punta Maldonado, a Fishing Community in Tropical Eastern Pacific, Mexico","authors":"Victor I. López-Rojas, P. Flores-Rodríguez, J. Padilla-Serrato, Rafael Flores-Garza, Carmina Torreblanca-Ramírez","doi":"10.2983/035.042.0312","DOIUrl":"https://doi.org/10.2983/035.042.0312","url":null,"abstract":"ABSTRACT The coastal fishing of the snail Titanostrombus galeatus is carried out in some coastal countries of the Tropical Eastern Pacific. In this study, the individual growth of T. galeatus that are fished in the community at Punta Maldonado was estimated. The size structure was made using the shell length (SL), and the growth parameters were estimated through the five Schnute cases, where cases 1, 2, and 5 describe asymptotic growth and cases 3 and 4 describe nonasymptotic growth. The male population was more abundant than the females, with 398 and 322 specimens, respectively, but the females were larger (198 ± 9.66 mm). In general, the average SL during the two sampling cycles was 196 ± 9.44 mm; this size was not significantly different between the first and second cycles (P = 0.98). Females had a greater range of SL (170–267 mm) compared with males (170–240 mm). The lengths of both sexes showed significant differences between months (P < 0.05). The multinomial analysis showed a multimodal SL distribution, with one to three modal groups for females and males. In growth, cases 2 and 5 were the ones that best describe the growth in females, in males the best were cases 5 and 2. According to the best case (case 2) in females, the growth curve is sigmoidal. In males, the best case (case 5) describes growth according to an inverted exponential curve. In relation to the estimated growth parameters, females showed faster growth than males, analyzed using Kimura's test. The present investigation is the first that reports the growth for both sexes of T. galeatus using the five cases of the Schnute model. The information generated can be used for management purposes, as this species is not currently regulated in Mexico.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139388599","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}
Lauren L. Hintenlang, Ross M. Brooks, Andrew S. Kane
ABSTRACT Failure of the Apalachicola Bay oyster population to recover since the 2012 fishery collapse, despite a decade of unprecedented restoration efforts and a fishery closure, indicates that the system has lost its former resilience, crossed a critical threshold between ecological steady states, and is experiencing hysteresis. This commentary contributes to the weight of evidence that reflects how accumulated system stressors led to reduced resilience and alterations in the ecological state of Apalachicola Bay. Discussion of resource exploitation, negative shell budget, salinity extremes, predator abundance, parasites, and disease underscore how these stressors accumulate over time to impact oyster populations and system resilience. Additionally, various interpretations of “resilience,” “exploitation,” and “restoration” have facilitated chronic resource over-exploitation and oyster habitat degradation in Apalachicola Bay. Within this context, a necessary cultural shift is described that reframes restoration and management goals to target healthy oyster habitat as the endpoint rather than using fishery metrics based on the number of harvestable oysters per acre. Failure to reframe restoration goals may be the cumulative result of resistance to accepting the presence of ecological state change, economic drivers overshadowing the weight of evidence, and outcomes not directly impacting decision makers.
{"title":"Assessing Cumulative Stressors, State Shift, and the Current Outlook for Oyster Habitat in Apalachicola Bay, Florida","authors":"Lauren L. Hintenlang, Ross M. Brooks, Andrew S. Kane","doi":"10.2983/035.042.0311","DOIUrl":"https://doi.org/10.2983/035.042.0311","url":null,"abstract":"ABSTRACT Failure of the Apalachicola Bay oyster population to recover since the 2012 fishery collapse, despite a decade of unprecedented restoration efforts and a fishery closure, indicates that the system has lost its former resilience, crossed a critical threshold between ecological steady states, and is experiencing hysteresis. This commentary contributes to the weight of evidence that reflects how accumulated system stressors led to reduced resilience and alterations in the ecological state of Apalachicola Bay. Discussion of resource exploitation, negative shell budget, salinity extremes, predator abundance, parasites, and disease underscore how these stressors accumulate over time to impact oyster populations and system resilience. Additionally, various interpretations of “resilience,” “exploitation,” and “restoration” have facilitated chronic resource over-exploitation and oyster habitat degradation in Apalachicola Bay. Within this context, a necessary cultural shift is described that reframes restoration and management goals to target healthy oyster habitat as the endpoint rather than using fishery metrics based on the number of harvestable oysters per acre. Failure to reframe restoration goals may be the cumulative result of resistance to accepting the presence of ecological state change, economic drivers overshadowing the weight of evidence, and outcomes not directly impacting decision makers.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139389099","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}
Stephen P. Geiger, Sarah P. Stephenson, Melanie L. Parker, Colin P. Shea, E. Levine, E. Milbrandt, Mark A. Thompson, Rene Janneman, Elizabeth Staugler, Jay R. Leverone, L. Flewelling
ABSTRACT Before collapsing, bay scallops (Argopecten irradians) supported commercial fisheries in Florida but, following decades of restoration efforts and management actions, still support a recreational fishery. Settlement was monitored along the west coast of Florida from 1992 through 2018, using collector traps. The primary environmental variables retained in the analyses included temperature, salinity, and red tide concentration (Karenia brevis). The settlement rate generally increased for the first days of trap deployment, then leveled off or declined. Settlement peaked when the average water temperatures were between 21°C and 23°C at four sites: St. Andrew Bay, St. Joseph Bay, West Coast, and Pine Island Sound, indicative of a fall peak in spawning. At the Tampa Bay and Sarasota Bay sites, settlement peaked when temperatures were around 16°C, indicative of winter spawning. At most sites, the highest peak in settlement occurred in association with declines in temperature of 10°C–15°C during the fall, with a smaller, secondary peak occurring with similar increases in temperature during the spring. Warming winter temperatures may already be negatively affecting the ability of the subpopulations to synchronously spawn, with unknown impacts to population dynamics. At all sites, settlement declined rapidly when salinity fell below 30 with little settlement occurring below 27, and approached zero when salinity fell below approximately 20. The occurrence of K. brevis exceeding 10,000 cells/L resulted in reduced settlement. In the core populations of West Coast and Steinhatchee, K. brevis was uncommon, and settlement resumed rapidly when blooms abated. For sites outside the core population, settlement was reduced for 2–4 y after red tides. Recovery of populations in these noncore sites probably relies on exogenous supply of larvae from the core. If blooms of K. brevis that penetrate the core region, as was observed in 2021, become more severe, more frequent, or have longer durations, the entire Florida scallop population could be endangered.
{"title":"Settlement of the Bay Scallop (Argopecten irradians) along the Gulf Coast of Florida","authors":"Stephen P. Geiger, Sarah P. Stephenson, Melanie L. Parker, Colin P. Shea, E. Levine, E. Milbrandt, Mark A. Thompson, Rene Janneman, Elizabeth Staugler, Jay R. Leverone, L. Flewelling","doi":"10.2983/035.042.0305","DOIUrl":"https://doi.org/10.2983/035.042.0305","url":null,"abstract":"ABSTRACT Before collapsing, bay scallops (Argopecten irradians) supported commercial fisheries in Florida but, following decades of restoration efforts and management actions, still support a recreational fishery. Settlement was monitored along the west coast of Florida from 1992 through 2018, using collector traps. The primary environmental variables retained in the analyses included temperature, salinity, and red tide concentration (Karenia brevis). The settlement rate generally increased for the first days of trap deployment, then leveled off or declined. Settlement peaked when the average water temperatures were between 21°C and 23°C at four sites: St. Andrew Bay, St. Joseph Bay, West Coast, and Pine Island Sound, indicative of a fall peak in spawning. At the Tampa Bay and Sarasota Bay sites, settlement peaked when temperatures were around 16°C, indicative of winter spawning. At most sites, the highest peak in settlement occurred in association with declines in temperature of 10°C–15°C during the fall, with a smaller, secondary peak occurring with similar increases in temperature during the spring. Warming winter temperatures may already be negatively affecting the ability of the subpopulations to synchronously spawn, with unknown impacts to population dynamics. At all sites, settlement declined rapidly when salinity fell below 30 with little settlement occurring below 27, and approached zero when salinity fell below approximately 20. The occurrence of K. brevis exceeding 10,000 cells/L resulted in reduced settlement. In the core populations of West Coast and Steinhatchee, K. brevis was uncommon, and settlement resumed rapidly when blooms abated. For sites outside the core population, settlement was reduced for 2–4 y after red tides. Recovery of populations in these noncore sites probably relies on exogenous supply of larvae from the core. If blooms of K. brevis that penetrate the core region, as was observed in 2021, become more severe, more frequent, or have longer durations, the entire Florida scallop population could be endangered.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139389429","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 Owing to the high cost of microalgal production for bivalve culture, a need for alternatives to live microalgal diets exists, particularly in facilities where space and personnel required for live microalgal culture are limited. This study examined the feasibility of utilizing commercially available microalgal concentrates in place of or in addition to live microalgae as a feed for post set northern quahogs (= hard clams), Mercenaria mercenaria and sunray Venus clams, Macrocallista nimbosa. Clams were fed one of six dietary treatments for 6 wk, and growth, survival, and fatty acid (FA) profiles were evaluated. Treatments included two live microalgal diets Tisochrysis lutea and T. lutea + Chaetoceros neogracile, which served as controls for complete or partial replacements with two commercially available concentrate products, ISO 1800 and Shellfish Diet 1800. The production of both clam species was negatively impacted compared with the live microalgae controls when only concentrates were fed. Survival decreased by 29–33% for hard clams and 42–62% for sunrays; a similar decrease in the growth rate (25–34%, 42–62%) was seen for hard clams and sunrays, respectively. Survival was not affected by feeding the partial replacement diets; however, the growth of sunrays was negatively affected (32–38% decrease) compared with live microalgae controls. Clam tissue FA profiles generally reflected the FA profiles of the dietary treatment fed, yet production was decreased with complete replacement diets, suggesting nonnutritional factors as the cause for the poorer performance seen. These results suggest that a live microalgal diet may be able to be sufficiently replaced with up to 50% of the microalgae concentrates tested without affecting the production of hard clams. For both post set hard clams and sunrays, production will be decreased if the two concentrates used in this study are utilized exclusively.
{"title":"Feasibility of Microalgal Concentrates for Production of Post Set Northern Quahogs, Mercenaria mercenaria and Sunray Venus Clams, Macrocallista nimbosa","authors":"Edward Perri, Md Mahbubul Hassan, S. Laramore","doi":"10.2983/035.042.0303","DOIUrl":"https://doi.org/10.2983/035.042.0303","url":null,"abstract":"ABSTRACT Owing to the high cost of microalgal production for bivalve culture, a need for alternatives to live microalgal diets exists, particularly in facilities where space and personnel required for live microalgal culture are limited. This study examined the feasibility of utilizing commercially available microalgal concentrates in place of or in addition to live microalgae as a feed for post set northern quahogs (= hard clams), Mercenaria mercenaria and sunray Venus clams, Macrocallista nimbosa. Clams were fed one of six dietary treatments for 6 wk, and growth, survival, and fatty acid (FA) profiles were evaluated. Treatments included two live microalgal diets Tisochrysis lutea and T. lutea + Chaetoceros neogracile, which served as controls for complete or partial replacements with two commercially available concentrate products, ISO 1800 and Shellfish Diet 1800. The production of both clam species was negatively impacted compared with the live microalgae controls when only concentrates were fed. Survival decreased by 29–33% for hard clams and 42–62% for sunrays; a similar decrease in the growth rate (25–34%, 42–62%) was seen for hard clams and sunrays, respectively. Survival was not affected by feeding the partial replacement diets; however, the growth of sunrays was negatively affected (32–38% decrease) compared with live microalgae controls. Clam tissue FA profiles generally reflected the FA profiles of the dietary treatment fed, yet production was decreased with complete replacement diets, suggesting nonnutritional factors as the cause for the poorer performance seen. These results suggest that a live microalgal diet may be able to be sufficiently replaced with up to 50% of the microalgae concentrates tested without affecting the production of hard clams. For both post set hard clams and sunrays, production will be decreased if the two concentrates used in this study are utilized exclusively.","PeriodicalId":50053,"journal":{"name":"Journal of Shellfish Research","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139388124","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 ontogenetic changes of the scallop Patinopecten yessoensis from Dalian, China, were studied during four stages (3, 6, 12, and 24 mo) using a geometric morphometric method and cross-validation method for evaluating the utility of the classification. The results showed that they exhibited characteristically different ontogenetic trajectories within a space defined by test size and shell shape. Landmark and semilandmark analyses were applied to successfully determine the stage of the individuals with approximately 89.04% accuracy. Moreover, each stage had a typical shell shape. The distinction of these patterns was assigned to the circularity and symmetry of the disc and the symmetry of the auricles: the 3 mo shells had a circular disc and asymmetrical auricles, and the 6 and 12 mo shells showed a more elongated disc and more symmetrical auricles, whereas the 24 mo shells showed an elongated disc and relatively small, symmetrical auricles. The ontogenetic shell form changes (size + shape) of P. yessoensis reflected the life history characteristics, which could potentially be used for age stage identification. The results provide a reference for determining the growth stage of P. yessoensis during fisheries and aquaculture management.
{"title":"Ontogenetic Changes during the Life Span of the Scallop Patinopecten yessoensis Determined Using a Geometric Morphometric Method","authors":"Siqi Lai, Yaoyu Xie, Xianpeng Huang, J. Mao, Xubo Wang, Ying Tian, Yaqing Chang","doi":"10.2983/035.042.0208","DOIUrl":"https://doi.org/10.2983/035.042.0208","url":null,"abstract":"ABSTRACT The ontogenetic changes of the scallop Patinopecten yessoensis from Dalian, China, were studied during four stages (3, 6, 12, and 24 mo) using a geometric morphometric method and cross-validation method for evaluating the utility of the classification. The results showed that they exhibited characteristically different ontogenetic trajectories within a space defined by test size and shell shape. Landmark and semilandmark analyses were applied to successfully determine the stage of the individuals with approximately 89.04% accuracy. Moreover, each stage had a typical shell shape. The distinction of these patterns was assigned to the circularity and symmetry of the disc and the symmetry of the auricles: the 3 mo shells had a circular disc and asymmetrical auricles, and the 6 and 12 mo shells showed a more elongated disc and more symmetrical auricles, whereas the 24 mo shells showed an elongated disc and relatively small, symmetrical auricles. The ontogenetic shell form changes (size + shape) of P. yessoensis reflected the life history characteristics, which could potentially be used for age stage identification. The results provide a reference for determining the growth stage of P. yessoensis during fisheries and aquaculture management.","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":"42116554","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}
A. Munguía-Vega, Laura E. Ibarra García, Polo Barajas-Girón, Lorena Rocha Tejeda, Inés López Ercilla, J. F. Dominguez-Contreras, U. Markaida
ABSTRACT The octopus fishery in the state of Yucatan is one of the most important in Mexico and landings have doubled over the past decade causing an increase in the demand for crabs used as bait. Data on bait composition and their harvest are limited even though its economic and ecological impact could be considerable. DNA barcoding of the 16S gene was used to identify the species of crustaceans in 93 samples of bait collected from 12 localities from Yucatan during August to October 2022. A total of nine species of crustaceans were identified, from which the mangrove crab Ucides cordatus was the most frequent (61%), followed by the longnose spider crab (Libinia dubia, 14%), and the Caribbean spiny lobster (Panulirus argus, 8%). The use of bait shows strong spatial patterns, including the local exploitation of some species and the import of bait from various geographical sources from other adjacent Mexican states to meet the demand. Although some sustainable practices were documented, such as using the discarded cephalotorax from the fishery of Caribbean spiny lobster, at least one species banned as bait by fisheries regulations (the stone crab Menippe mercenaria) was also identified. The American horseshoe crab (Limulus polyphemus), a protected species of national and international conservation concern, was absent in this samples. This study suggests that bait harvest for the octopus fishery could potentially impact both local and distant crab populations, and highlights the need to create and improve existing regulations for bait harvest that need to be built and clearly communicated within the fishing communities to improve the sustainability of the fishery.
{"title":"Genetic Identification of Bait to Support Sustainability of the Octopus Fishery from the State of Yucatan, Mexico","authors":"A. Munguía-Vega, Laura E. Ibarra García, Polo Barajas-Girón, Lorena Rocha Tejeda, Inés López Ercilla, J. F. Dominguez-Contreras, U. Markaida","doi":"10.2983/035.042.0212","DOIUrl":"https://doi.org/10.2983/035.042.0212","url":null,"abstract":"ABSTRACT The octopus fishery in the state of Yucatan is one of the most important in Mexico and landings have doubled over the past decade causing an increase in the demand for crabs used as bait. Data on bait composition and their harvest are limited even though its economic and ecological impact could be considerable. DNA barcoding of the 16S gene was used to identify the species of crustaceans in 93 samples of bait collected from 12 localities from Yucatan during August to October 2022. A total of nine species of crustaceans were identified, from which the mangrove crab Ucides cordatus was the most frequent (61%), followed by the longnose spider crab (Libinia dubia, 14%), and the Caribbean spiny lobster (Panulirus argus, 8%). The use of bait shows strong spatial patterns, including the local exploitation of some species and the import of bait from various geographical sources from other adjacent Mexican states to meet the demand. Although some sustainable practices were documented, such as using the discarded cephalotorax from the fishery of Caribbean spiny lobster, at least one species banned as bait by fisheries regulations (the stone crab Menippe mercenaria) was also identified. The American horseshoe crab (Limulus polyphemus), a protected species of national and international conservation concern, was absent in this samples. This study suggests that bait harvest for the octopus fishery could potentially impact both local and distant crab populations, and highlights the need to create and improve existing regulations for bait harvest that need to be built and clearly communicated within the fishing communities to improve the sustainability of the fishery.","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":"46690169","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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