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메뉴Marine bivalve mollusk defensive system includes hemocytes, the circulating blood cells which are actively engaged in the defense and other physiological processes. This review comprehensively summarizes the current knowledge about hemocytes in marine bivalves, with a primary focus on their immune and non-immune functions. Marine Bivalve hemocytes broadly classified into granulocytes and hyalinocytes, mediate cellular defense through phagocytosis, encapsulation, and secretion of enzymes and reactive oxygen species (ROS). Beyond immunity, they participate in wound healing, shell formation, and nutrient transport, showcasing their diverse and intriguing roles. Recent studies that combine hemocyte subpopulation characterization with functional assays have revealed their versatility. However, challenges persist in establishing a unified nomenclature across species. Environmental factors significantly influence hemocyte populations, highlighting their potential as bioindicators. While significant progress has been made, gaps remain in understanding hemocyte sub-population dynamics and non-immune activities. This review underscoresthe need to consider hemocytes in the broader context of environmental and whole-animal physiology, suggesting future research directions in molecular mechanisms, host-pathogen interactions, and aquaculture applications.
Marine bivalve mollusk defensive system includes hemocytes, the circulating blood cells which are actively engaged in the defense and other physiological processes. This review comprehensively summarizes the current knowledge about hemocytes in marine bivalves, with a primary focus on their immune and non-immune functions. Marine Bivalve hemocytes broadly classified into granulocytes and hyalinocytes, mediate cellular defense through phagocytosis, encapsulation, and secretion of enzymes and reactive oxygen species (ROS). Beyond immunity, they participate in wound healing, shell formation, and nutrient transport, showcasing their diverse and intriguing roles. Recent studies that combine hemocyte subpopulation characterization with functional assays have revealed their versatility. However, challenges persist in establishing a unified nomenclature across species. Environmental factors significantly influence hemocyte populations, highlighting their potential as bioindicators. While significant progress has been made, gaps remain in understanding hemocyte sub-population dynamics and non-immune activities. This review underscoresthe need to consider hemocytes in the broader context of environmental and whole-animal physiology, suggesting future research directions in molecular mechanisms, host-pathogen interactions, and aquaculture applications.
This study aims to re-evaluate risk of extinction the Red List categories of four Korean land snail species, Euhadra dixoni (Pilsbry, 1900), E. herklotsi (E. von Martens, 1861), Nesiohelix samarangae (Kuroda and Miyanaga, 1943), and Cyclophorus herklotsi E. von Martens, 1861, based on field surveys and genetic diversity analyses. Genetic diversity was evaluated with COI or 16S rRNA. The results suggested that the categorical rank of the Red List of E. dixoni be changed from Endangered (EN) to Critically Endangered (CR). On the other hand, we recommended that the categorical ranks of E. herklotsi, 16S rRNA and C. herklotsi may be kept to the present status, Vulnerable (VU). This study raises the usefulness of the addition of genetic information in evaluating extinction risk of the molluscan species listed in the Red List, which would be helpful for successful management and conservation of land snails in Korea.
This study aims to re-evaluate risk of extinction the Red List categories of four Korean land snail species, Euhadra dixoni (Pilsbry, 1900), E. herklotsi (E. von Martens, 1861), Nesiohelix samarangae (Kuroda and Miyanaga, 1943), and Cyclophorus herklotsi E. von Martens, 1861, based on field surveys and genetic diversity analyses. Genetic diversity was evaluated with COI or 16S rRNA. The results suggested that the categorical rank of the Red List of E. dixoni be changed from Endangered (EN) to Critically Endangered (CR). On the other hand, we recommended that the categorical ranks of E. herklotsi, 16S rRNA and C. herklotsi may be kept to the present status, Vulnerable (VU). This study raises the usefulness of the addition of genetic information in evaluating extinction risk of the molluscan species listed in the Red List, which would be helpful for successful management and conservation of land snails in Korea.
Favorinus tsuruganus Baba & Abe, 1964 was reported based on a specimen collected from Deunggado, Tongyeong, Gyeongsangnam-do, South Korea in October 2022. This species was initially recorded from Tsuruga Bay, Japan, and widely distributed across the western Pacific region. This species can be distinguished from other congenerics by the following characteristics: translucent white body, translucent black rhinophores with three lamellae, orange-colored digestive glands, black apical marking on each ceras, cleioproctic anus and uniseriated radula without denticles. This study includes morphological descriptions, SEM photograph of radula, and DNA barcoding analysis based on mitochondrial COI genes. The uncorrected pairwise genetic distance of F. tsuruganus was calculated to range from 0.0% to 1.07%.
Favorinus tsuruganus Baba & Abe, 1964 was reported based on a specimen collected from Deunggado, Tongyeong, Gyeongsangnam-do, South Korea in October 2022. This species was initially recorded from Tsuruga Bay, Japan, and widely distributed across the western Pacific region. This species can be distinguished from other congenerics by the following characteristics: translucent white body, translucent black rhinophores with three lamellae, orange-colored digestive glands, black apical marking on each ceras, cleioproctic anus and uniseriated radula without denticles. This study includes morphological descriptions, SEM photograph of radula, and DNA barcoding analysis based on mitochondrial COI genes. The uncorrected pairwise genetic distance of F. tsuruganus was calculated to range from 0.0% to 1.07%.
To date, the family Gonatidae consists of four genera and a total of 20 species. Two species within Gonatidae, Berryteuthis magister and G. makko, have been reported in Korean waters so far. In this study, a specimen of gonate squid was collected during DeepSea surveys and was identified as Gonatopsis japonicus Okiyama, 1969, which is the first record in South Korea. We provide morphological descriptions and photographs of G. japonicus, with the mitochondrial cytochrome c oxidase subunit I gene sequence.
To date, the family Gonatidae consists of four genera and a total of 20 species. Two species within Gonatidae, Berryteuthis magister and G. makko, have been reported in Korean waters so far. In this study, a specimen of gonate squid was collected during DeepSea surveys and was identified as Gonatopsis japonicus Okiyama, 1969, which is the first record in South Korea. We provide morphological descriptions and photographs of G. japonicus, with the mitochondrial cytochrome c oxidase subunit I gene sequence.
The genus Coralliophila H. Adams and A. Adams, 1853, is one of the most diverse groups within the subfamily Coralliophilinae. This group comprises approximately 110 species worldwide and is found in warm temperate to tropical marine environments. To date, only six species have been sparsely recorded in Korean waters, suggesting that further taxonomic studies are necessary to explore the species diversity of this group. In this study, we discovered Coralliophila pulchella (A. Adams, 1854) species for the first time in Korea and provided a detailed description of its morphological characteristics. In addition, morphology-based species identification was confirmed using a partial sequence of the mtDNA cox1 gene, as DNA barcode reference sequence. The morphological information and molecular data presented in this study will help species identification of C. pulchella. Given the global changes in distribution pattern of coral reef due to climate change, which essentially impact the primary habitats of Coralliophila species, it is necessary to pay attention to the changes in species diversity and distributional patterns of Coralliophila species from Korean waters.
The genus Coralliophila H. Adams and A. Adams, 1853, is one of the most diverse groups within the subfamily Coralliophilinae. This group comprises approximately 110 species worldwide and is found in warm temperate to tropical marine environments. To date, only six species have been sparsely recorded in Korean waters, suggesting that further taxonomic studies are necessary to explore the species diversity of this group. In this study, we discovered Coralliophila pulchella (A. Adams, 1854) species for the first time in Korea and provided a detailed description of its morphological characteristics. In addition, morphology-based species identification was confirmed using a partial sequence of the mtDNA cox1 gene, as DNA barcode reference sequence. The morphological information and molecular data presented in this study will help species identification of C. pulchella. Given the global changes in distribution pattern of coral reef due to climate change, which essentially impact the primary habitats of Coralliophila species, it is necessary to pay attention to the changes in species diversity and distributional patterns of Coralliophila species from Korean waters.
Two species of gastropods, Melanella flexuosa (A. Adams) and Similiphora similior (Bouchet & Guillemot) from Dokdo, are marking the new Korean molluscan fauna. M. flexuosa is characterized by round and swollen whorls with slightly leftward curvature near the apex and the aperture's ventrally thickened and raised outer lip. S. similior features uniformly sized longitudinal granules and evenly spaced intercostals with a two-tone coloration. Diagnoses and color plates are provided in this study.
Two species of gastropods, Melanella flexuosa (A. Adams) and Similiphora similior (Bouchet & Guillemot) from Dokdo, are marking the new Korean molluscan fauna. M. flexuosa is characterized by round and swollen whorls with slightly leftward curvature near the apex and the aperture's ventrally thickened and raised outer lip. S. similior features uniformly sized longitudinal granules and evenly spaced intercostals with a two-tone coloration. Diagnoses and color plates are provided in this study.
Assiminea hiradoensis (Assiminidae, Gastropoda), a species native to Northeast Asia, is currently classified as Near Threatened (NT) on the Korean national Red List due to its restricted distribution and vulnerability to environmental changes. Given the threats posed by habitat degradation, including coastal development and climate change, understanding the genetic diversity and structure of A. hiradoensis populations is essential for its conservation. Between 2022 and 2023, we collected 113 A. hiradoensis individuals from 12 brackish coastal areas across Korea to examine the genetic diversity and population based on COI. Additionally, we incorporated two COI sequences from populations in Japan and China, retrieved from NCBI. A total of 34 unique COI haplotypes were identified from 115 A. hiradoensis individuals. Phylogenetic, TCS network, and PCoA analyses revealed weak spatial genetic structure among populations, suggesting that gene flow between populations is limited. However, relatively high genetic diversity was observed within local populations, indicating that these populations may be genetically distinct from each other. The localized genetic diversity appears to be influenced by specialized environmental factors specific to each site, as reflected in the analysis of molecular variance (AMOVA), which indicated that the majority of genetic variation occurs within populations rather than between them. These findings underscore the importance of conserving localized brackish coastal habitats, as they play a pivotal role in maintaining the genetic diversity of A. hiradoensis. In conclusion, this study highlights the urgent need for targeted conservation strategies to protect the specialized brackish coastal habitats of Northeast Asia.
Assiminea hiradoensis (Assiminidae, Gastropoda), a species native to Northeast Asia, is currently classified as Near Threatened (NT) on the Korean national Red List due to its restricted distribution and vulnerability to environmental changes. Given the threats posed by habitat degradation, including coastal development and climate change, understanding the genetic diversity and structure of A. hiradoensis populations is essential for its conservation. Between 2022 and 2023, we collected 113 A. hiradoensis individuals from 12 brackish coastal areas across Korea to examine the genetic diversity and population based on COI. Additionally, we incorporated two COI sequences from populations in Japan and China, retrieved from NCBI. A total of 34 unique COI haplotypes were identified from 115 A. hiradoensis individuals. Phylogenetic, TCS network, and PCoA analyses revealed weak spatial genetic structure among populations, suggesting that gene flow between populations is limited. However, relatively high genetic diversity was observed within local populations, indicating that these populations may be genetically distinct from each other. The localized genetic diversity appears to be influenced by specialized environmental factors specific to each site, as reflected in the analysis of molecular variance (AMOVA), which indicated that the majority of genetic variation occurs within populations rather than between them. These findings underscore the importance of conserving localized brackish coastal habitats, as they play a pivotal role in maintaining the genetic diversity of A. hiradoensis. In conclusion, this study highlights the urgent need for targeted conservation strategies to protect the specialized brackish coastal habitats of Northeast Asia.
Three newly recorded mollusks, Pteria penguin (Bivalvia: Pteriidae), Rotaovula septemmacula (Gastropoda: Fasciolariidae), and Turrilatirus turritus (Gastropoda: Ovulidae) are described from Jeju Island, Korea. P. penguin is characterized by its large, black, wing-shaped valves. T. turritus resembles T. nagasakiensis in morphology but can be distinguished by its well-developed black axial ribs and low spire in height. R. septemmacula is notable for its kite-rhomboidal shell shape, with seven distinct thick brown spots on the dorsal surface. The genus Rotaovula C. N. Cate & Azuma, 1973 is rare worldwide, representing the first record of this genus from Korea. Diagnoses, remarks, and color plates are provided for each species. In addition, to perform molecular species identification, we compared intraspecific and interspecific genetic variation based on two mitochondrial genetic markers: the 16S rRNA gene for P. penguin and the COI gene for T. turritus. The results showed few intraspecific sequence differences, but more notable congeneric sequence differences. Maximum likelihood trees revealed that the two species are closely related to other individuals of the same species, respectively, indicating that their morphology-based species identifications are reliable.
Three newly recorded mollusks, Pteria penguin (Bivalvia: Pteriidae), Rotaovula septemmacula (Gastropoda: Fasciolariidae), and Turrilatirus turritus (Gastropoda: Ovulidae) are described from Jeju Island, Korea. P. penguin is characterized by its large, black, wing-shaped valves. T. turritus resembles T. nagasakiensis in morphology but can be distinguished by its well-developed black axial ribs and low spire in height. R. septemmacula is notable for its kite-rhomboidal shell shape, with seven distinct thick brown spots on the dorsal surface. The genus Rotaovula C. N. Cate & Azuma, 1973 is rare worldwide, representing the first record of this genus from Korea. Diagnoses, remarks, and color plates are provided for each species. In addition, to perform molecular species identification, we compared intraspecific and interspecific genetic variation based on two mitochondrial genetic markers: the 16S rRNA gene for P. penguin and the COI gene for T. turritus. The results showed few intraspecific sequence differences, but more notable congeneric sequence differences. Maximum likelihood trees revealed that the two species are closely related to other individuals of the same species, respectively, indicating that their morphology-based species identifications are reliable.
Occurring in a high density on numerous tidal flats on the west coast, Manila clam Ruditapes philippinarum is one of the crucial shellfish resources on the west coast of Korea where clams are explored on a commercial scale. Histology has been utilized in monitoring clam populations by providing detailed insights into the health, reproduction, and overall condition of clam populations. This study provides comprehensive guidelines involved in sample processing, tissue slide preparation, digitizing, and subsequent image analysis. These technical details for each step are expected to standardize mollusk tissue research by ensuring accurate and reproducible results for researchers.
Occurring in a high density on numerous tidal flats on the west coast, Manila clam Ruditapes philippinarum is one of the crucial shellfish resources on the west coast of Korea where clams are explored on a commercial scale. Histology has been utilized in monitoring clam populations by providing detailed insights into the health, reproduction, and overall condition of clam populations. This study provides comprehensive guidelines involved in sample processing, tissue slide preparation, digitizing, and subsequent image analysis. These technical details for each step are expected to standardize mollusk tissue research by ensuring accurate and reproducible results for researchers.
Hypoxia coupled with high water temperatures during summer poses a significant threat to aquatic animals. This study investigated the combined effect of these stressors on the bay scallop, Argopecten irradians, to understand potential causes of mass mortality events. Scallops were exposed to control (19℃, 6.76 mg O2/L), hypoxia (19℃, 1.01 mg O2/L), and combined hypoxia and high temperature (28℃, 1.02 mg O2/L) conditions for 48 hours. Quantitative PCR (qPCR) assessed mRNA expression of hypoxia-inducible factor 1-alpha (HIF1-α) and heat shock protein 90 (HSP90) in the digestive gland. Flow cytometry evaluated cellular responses, including phagocytosis capacity, nitric oxide (NO) production, and reactive oxygen species (ROS) production of hemocytes. Scallops exposed to combined stressors showed 50% mortality within 48 h, starting at 30 h, while hypoxia alone caused only 18% mortality. Gene expression remained unchanged under hypoxia, but HIF1-α and HSP90 were significantly upregulated under combined stressors. Hemocyte parameters did not show statistically significant differences across groups; however, there was a trend of decreased phagocytic capacity and increased ROS and NO production under combined stressors. These results suggest that the synergistic effect of hypoxia and high temperature during summer can exert sublethal to lethal impacts on bay scallops, potentially explaining mortality events in this species. Further research is needed to explore the underlying mechanisms and potential adaptive strategies in scallops facing such environmental challenges.
Hypoxia coupled with high water temperatures during summer poses a significant threat to aquatic animals. This study investigated the combined effect of these stressors on the bay scallop, Argopecten irradians, to understand potential causes of mass mortality events. Scallops were exposed to control (19℃, 6.76 mg O2/L), hypoxia (19℃, 1.01 mg O2/L), and combined hypoxia and high temperature (28℃, 1.02 mg O2/L) conditions for 48 hours. Quantitative PCR (qPCR) assessed mRNA expression of hypoxia-inducible factor 1-alpha (HIF1-α) and heat shock protein 90 (HSP90) in the digestive gland. Flow cytometry evaluated cellular responses, including phagocytosis capacity, nitric oxide (NO) production, and reactive oxygen species (ROS) production of hemocytes. Scallops exposed to combined stressors showed 50% mortality within 48 h, starting at 30 h, while hypoxia alone caused only 18% mortality. Gene expression remained unchanged under hypoxia, but HIF1-α and HSP90 were significantly upregulated under combined stressors. Hemocyte parameters did not show statistically significant differences across groups; however, there was a trend of decreased phagocytic capacity and increased ROS and NO production under combined stressors. These results suggest that the synergistic effect of hypoxia and high temperature during summer can exert sublethal to lethal impacts on bay scallops, potentially explaining mortality events in this species. Further research is needed to explore the underlying mechanisms and potential adaptive strategies in scallops facing such environmental challenges.
In this study, we evaluated the effect of inland pollution sources on seawater and shellfish(Ark shell) in the Yeoja bay after 20.5 and 83.3 mm rainfall events. We analyzed the sanitary indicator microorganism such as total coliform, fecal coliform Escherichia coli (E. coli) and Male-specific coliphage (MSC) in the discharge water of waste water treatment plant (WWTP), major inland pollution sources, seawater and shellfish for 4 days after rainfall events. The range of coliform group and fecal coliform was from < 1.8 to 1,600,000 and from <1.8 to 140,000 MPN/100 mL after rainfall of 20.5 mm and from < 1.8 to 330,000 and from < 1.8 to 230,000 MPN/100 mL after rainfall of 83.3 mm in the discharge water of 13 waste water treat plants. Also The range of fecal coliform and radius of impacted area of 4 contaminants (domestic waste water and stream water) was from 49 to 1,100,000 MPN/100 mL and from 4 to 1,870 m after rainfall of 20.5 mm and from 170 to 130,000 MPN/100 mL and from 58 to 1,794 m after rainfall of 83.3 mm. The fecal coliform of seawater at 21 stations ranged from < 1.8 to 540 MPN/100 mL. And the E. coli level of shellfish at 3 stations ranged from < 18 to 78 MPN/100 g.
In this study, we evaluated the effect of inland pollution sources on seawater and shellfish(Ark shell) in the Yeoja bay after 20.5 and 83.3 mm rainfall events. We analyzed the sanitary indicator microorganism such as total coliform, fecal coliform Escherichia coli (E. coli) and Male-specific coliphage (MSC) in the discharge water of waste water treatment plant (WWTP), major inland pollution sources, seawater and shellfish for 4 days after rainfall events. The range of coliform group and fecal coliform was from < 1.8 to 1,600,000 and from <1.8 to 140,000 MPN/100 mL after rainfall of 20.5 mm and from < 1.8 to 330,000 and from < 1.8 to 230,000 MPN/100 mL after rainfall of 83.3 mm in the discharge water of 13 waste water treat plants. Also The range of fecal coliform and radius of impacted area of 4 contaminants (domestic waste water and stream water) was from 49 to 1,100,000 MPN/100 mL and from 4 to 1,870 m after rainfall of 20.5 mm and from 170 to 130,000 MPN/100 mL and from 58 to 1,794 m after rainfall of 83.3 mm. The fecal coliform of seawater at 21 stations ranged from < 1.8 to 540 MPN/100 mL. And the E. coli level of shellfish at 3 stations ranged from < 18 to 78 MPN/100 g.
The Manila clam (Ruditapes philippinarum), commonly found on mudflats and sandy beaches along the coastal Yellow Sea, is frequently infected by the protozoan parasite Perkinsus olseni. The intensity and prevalence of P. olseni infection in Manila clams vary spatially and seasonally, often peaking during the post-spawning period. In this study, we investigated the infection intensity and prevalence of P. olseni in Manila clams collected in October 2013, when most clams had completed spawning. Using Ray’s fluid thioglycollate medium assay (RFTM), we found that, except for clams from Pohang and Imwon on the east coast, P. olseni infection was widespread among clams from tidal flats and sandy beaches on the west coast, with prevalence rates ranging from 87% to 100%. The infection intensity varied widely, from no infection (Pohang and Imwon) to over a million cells per gram of gill tissue at most sampling sites. Clams from sites on the west coast, such as Seonjae, Hwangdo, and Gomso, exhibited infection levels of 1.0 to 4.3 × 106 cells/g gill, while those from the south coast, including Wanddo, Yeosu, Tongyeong, and Masan, showed levels of 1.1 to 4.8 × 106 cells/g gill. Histological analysis revealed a similar range of infection intensity, from 0 (no infection in Pohang and Imwon) to 3.6 (Hwangdo). The high infection intensities and prevalence observed in the clams during this study may be partly attributed to elevated water temperatures and physiological stress during the post-spawning period, a pattern previously noted in clams from tidal flats along the west coast.
The Manila clam (Ruditapes philippinarum), commonly found on mudflats and sandy beaches along the coastal Yellow Sea, is frequently infected by the protozoan parasite Perkinsus olseni. The intensity and prevalence of P. olseni infection in Manila clams vary spatially and seasonally, often peaking during the post-spawning period. In this study, we investigated the infection intensity and prevalence of P. olseni in Manila clams collected in October 2013, when most clams had completed spawning. Using Ray’s fluid thioglycollate medium assay (RFTM), we found that, except for clams from Pohang and Imwon on the east coast, P. olseni infection was widespread among clams from tidal flats and sandy beaches on the west coast, with prevalence rates ranging from 87% to 100%. The infection intensity varied widely, from no infection (Pohang and Imwon) to over a million cells per gram of gill tissue at most sampling sites. Clams from sites on the west coast, such as Seonjae, Hwangdo, and Gomso, exhibited infection levels of 1.0 to 4.3 × 106 cells/g gill, while those from the south coast, including Wanddo, Yeosu, Tongyeong, and Masan, showed levels of 1.1 to 4.8 × 106 cells/g gill. Histological analysis revealed a similar range of infection intensity, from 0 (no infection in Pohang and Imwon) to 3.6 (Hwangdo). The high infection intensities and prevalence observed in the clams during this study may be partly attributed to elevated water temperatures and physiological stress during the post-spawning period, a pattern previously noted in clams from tidal flats along the west coast.
This study was conducted to get a basic information on the avoidance effects from shell-boring and biofouling on a bay scallop (Argopecten irradians) cultivated in Jaran Bay, located on the southern coast of Korea by applying three different submerging times from May, August, and September 2023. A significant difference in the biomass of biofoulers on the scallops was observed between the two submerging periods in August and September. The mean biomass of biofoulers attached on the shells of scallops submerged in Jaran Bay during August, 2023 was highest as 6.3 g wet/scallop corresponding to 14% of the mean scallop biomass, and decreased to 1.8 g of scallops submerged in May and 0.7 g in September. The dominant biofoulers on scallops submerged in August were barnacles and juvenile oysters, whereas scallops submerged in September were primarily fouled by juvenile barnacles, with no juvenile oysters observed. The mean number of blisters made by shell-boring worms per scallop shell was highest as 1.5 in the scallops submerged in May, but it decreased to 0.9 and 0.3 individuals from scallops submerged in Aug. and Sept., respectively. There were no significant correlations between the fresh weight of scallops and the shell-boring worms or biomass of fouling organisms during this study period. This finding is significant for the scallop cultivation industry because the growth rate of scallops submerged in September was comparable to the somatic growth rates of scallops submerged during spring and summer.
This study was conducted to get a basic information on the avoidance effects from shell-boring and biofouling on a bay scallop (Argopecten irradians) cultivated in Jaran Bay, located on the southern coast of Korea by applying three different submerging times from May, August, and September 2023. A significant difference in the biomass of biofoulers on the scallops was observed between the two submerging periods in August and September. The mean biomass of biofoulers attached on the shells of scallops submerged in Jaran Bay during August, 2023 was highest as 6.3 g wet/scallop corresponding to 14% of the mean scallop biomass, and decreased to 1.8 g of scallops submerged in May and 0.7 g in September. The dominant biofoulers on scallops submerged in August were barnacles and juvenile oysters, whereas scallops submerged in September were primarily fouled by juvenile barnacles, with no juvenile oysters observed. The mean number of blisters made by shell-boring worms per scallop shell was highest as 1.5 in the scallops submerged in May, but it decreased to 0.9 and 0.3 individuals from scallops submerged in Aug. and Sept., respectively. There were no significant correlations between the fresh weight of scallops and the shell-boring worms or biomass of fouling organisms during this study period. This finding is significant for the scallop cultivation industry because the growth rate of scallops submerged in September was comparable to the somatic growth rates of scallops submerged during spring and summer.
