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메뉴Nineteen individuals of abyssal transparent scallop species were collected by standard bottom trawl survey (East Sea) and were identified as Delectopecten vitreus (Gmelin, 1791). To date, 23 species, including 14 fossil species, in genus Delectopecten R. B. Stewart, 1930, have been reported worldwide; however, there is no report in Korea thus far. In this study, we provide morphological descriptions and photographs of D. vitreus, with the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA cox1) sequence, as a new record of the Korean waters.
Nineteen individuals of abyssal transparent scallop species were collected by standard bottom trawl survey (East Sea) and were identified as Delectopecten vitreus (Gmelin, 1791). To date, 23 species, including 14 fossil species, in genus Delectopecten R. B. Stewart, 1930, have been reported worldwide; however, there is no report in Korea thus far. In this study, we provide morphological descriptions and photographs of D. vitreus, with the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA cox1) sequence, as a new record of the Korean waters.
A yoldiid species, Megayoldia toyamaensis (Kuroda, 1929) is newly recorded from Korea. Six individuals were collected by standard bottom trawl survey (East Sea) from April and October 2023. To date, three species, belonging to the genus Megayoldia have been reported from Korea. In this study, we have added M. toyamaensis (Kuroda, 1929) as a new record from Korean waters with its morphological description.
A yoldiid species, Megayoldia toyamaensis (Kuroda, 1929) is newly recorded from Korea. Six individuals were collected by standard bottom trawl survey (East Sea) from April and October 2023. To date, three species, belonging to the genus Megayoldia have been reported from Korea. In this study, we have added M. toyamaensis (Kuroda, 1929) as a new record from Korean waters with its morphological description.
A tritoniid species, Marionia olivacea Baba, 1937 belonging to the family Tritoniidae was collected by SCUBA survey in Korean fauna. Since only the scientific name of this species was listed on the National List of Marine Species 2023, we provide more information about M. olivacea, including an additional name in Korean and its morphological description in this study.
A tritoniid species, Marionia olivacea Baba, 1937 belonging to the family Tritoniidae was collected by SCUBA survey in Korean fauna. Since only the scientific name of this species was listed on the National List of Marine Species 2023, we provide more information about M. olivacea, including an additional name in Korean and its morphological description in this study.
In this study, a list of mollusca species was obtained by reviewing previous reports from 1997 to 2018. Also, the survey to fundamental data for monitoring environmental changes on mollusca inhabiting Gyeongpo Lake was conducted in May 2023. Precedent research was reviewed using databases such as ScienceOn (Web based DB) and NTIS, from 1997 to 2018. We confirmed that 19 species of 16 families of 11 orders have been reported. In this study, 5 species of 4 families were found; Magallana gigas (Bivalvia: Ostreidae), Mytilus galloprovincialis (Bivalvia: Mytilidae), Arcuatula senhousia (Bivalvia: Mytilidae), Potamocorbula amurensis (Bivalvia: Corbulidae), and Batillaria cumingii (Gastropoda: Batillariidae). The relationship between salinity change and the appearance of mollusca is not clear, according to previous studies as 7.4‰ in 1997, and in this study, it was confirmed that the salinity had 22-30‰. As a result of morphological identification and molecular phylogenetic analysis (Cytochrome Oxidase I (CO1)) of the collected mollusca, they were confirmed to be the same species. Comparative analysis with previously analyzed sequences, subtle genetic differences within the same species were confirmed. Taken together, it can be used for basic research related to species identification of molluscs living in lagoons and follow-up research related to DNA barcoding.
In this study, a list of mollusca species was obtained by reviewing previous reports from 1997 to 2018. Also, the survey to fundamental data for monitoring environmental changes on mollusca inhabiting Gyeongpo Lake was conducted in May 2023. Precedent research was reviewed using databases such as ScienceOn (Web based DB) and NTIS, from 1997 to 2018. We confirmed that 19 species of 16 families of 11 orders have been reported. In this study, 5 species of 4 families were found; Magallana gigas (Bivalvia: Ostreidae), Mytilus galloprovincialis (Bivalvia: Mytilidae), Arcuatula senhousia (Bivalvia: Mytilidae), Potamocorbula amurensis (Bivalvia: Corbulidae), and Batillaria cumingii (Gastropoda: Batillariidae). The relationship between salinity change and the appearance of mollusca is not clear, according to previous studies as 7.4‰ in 1997, and in this study, it was confirmed that the salinity had 22-30‰. As a result of morphological identification and molecular phylogenetic analysis (Cytochrome Oxidase I (CO1)) of the collected mollusca, they were confirmed to be the same species. Comparative analysis with previously analyzed sequences, subtle genetic differences within the same species were confirmed. Taken together, it can be used for basic research related to species identification of molluscs living in lagoons and follow-up research related to DNA barcoding.
In order to investigate the changes in nutrient availability after the introduction of oyster farms in 2015, an investigation of seawater analysis was carried out from March 2011 to December 2012 for the before and from September 2015 to April 2018 for the after. Although there was a significant increase in nitrite, dissolved inorganic nitrogen was significantly decreased to half of what it had been before. The spatial discrimination of each nitrogenous nutrient was observed in CV% for ammonia, nitrite, and nitrate twice as much as before but not for DIN. No significant difference was observed in dissolved inorganic phosphate but not in CV%, which rose from 12.67% to 36.62%. Consequently, the chlorophyll-a concentration significantly decreased from 2.242 μg/L to 1.244 μg/L, negatively correlated with salinity while positively with nitrate and DIN. The grazing pressure from the introduced oyster farm has significantly decreased the phytoplankton stocks and successively increased metabolite sedimentation. The metabolite has been remineralized by oxidation-reduction reaction rather than bioturbation in hyperoxic sediment of a shallow tidal zone. As well as food availability, nutrient availability from top-down control should be considered for maximum sustainable yield when introducing oyster farms in closed waters.
In order to investigate the changes in nutrient availability after the introduction of oyster farms in 2015, an investigation of seawater analysis was carried out from March 2011 to December 2012 for the before and from September 2015 to April 2018 for the after. Although there was a significant increase in nitrite, dissolved inorganic nitrogen was significantly decreased to half of what it had been before. The spatial discrimination of each nitrogenous nutrient was observed in CV% for ammonia, nitrite, and nitrate twice as much as before but not for DIN. No significant difference was observed in dissolved inorganic phosphate but not in CV%, which rose from 12.67% to 36.62%. Consequently, the chlorophyll-a concentration significantly decreased from 2.242 μg/L to 1.244 μg/L, negatively correlated with salinity while positively with nitrate and DIN. The grazing pressure from the introduced oyster farm has significantly decreased the phytoplankton stocks and successively increased metabolite sedimentation. The metabolite has been remineralized by oxidation-reduction reaction rather than bioturbation in hyperoxic sediment of a shallow tidal zone. As well as food availability, nutrient availability from top-down control should be considered for maximum sustainable yield when introducing oyster farms in closed waters.
In this study, as the water temperature rises due to climate, we tried to reset the 50% lethal temperature and critical water temperatures of the ark shell, Scapharca subcrenata. Determine the effect of high water temperatures on the survival of the ark shells, they were exposed for 7 days at 26, 28, 30, 32, 34 and 36℃. As a result, the survival rate was higher than 90.0% from 26 to 32℃, and the mortality rate appeared rapidly at 36℃, and all of them died on the 5th day. Based on this, the 50% lethal temperature (7 day-LT50) was 35.7℃ and the critical water temperature was 36℃. In order to analyze the cause of death of S. subcrenata at the aquaculture, thought that long-term and combination factors should be analyzed.
In this study, as the water temperature rises due to climate, we tried to reset the 50% lethal temperature and critical water temperatures of the ark shell, Scapharca subcrenata. Determine the effect of high water temperatures on the survival of the ark shells, they were exposed for 7 days at 26, 28, 30, 32, 34 and 36℃. As a result, the survival rate was higher than 90.0% from 26 to 32℃, and the mortality rate appeared rapidly at 36℃, and all of them died on the 5th day. Based on this, the 50% lethal temperature (7 day-LT50) was 35.7℃ and the critical water temperature was 36℃. In order to analyze the cause of death of S. subcrenata at the aquaculture, thought that long-term and combination factors should be analyzed.
A Korean strain of Alexandrium affine (TY150902) was exposed to adult Thamnaconus modestus and Haliotis discus hannai for a comparative toxicity evaluation. Tests were done in two subsequent ways in the chamber (70 L carrying 30 L alga) for 24 hours. The first test was to find the first damage concentration (FDC) at 4 allocations (0, 1.25, 2.5, or 5.0 × 103 cells mL-1) at 20℃. The second was to detail at a median concentration (MC) between FDC and its previous concentration at 20 and 25℃. In the first test FDC was 5.0 × 103 cells mL-1 for both species, calculating 3.75 × 103 cells mL-1 as an MC in common. The algal toxicities at FDC were species-specific with bigger toxicity to the finfish. Toxicities at MC were also species-specific: harmless to the shellfish and temperature-dependently toxic to the finfish with mortalities of 20% at 20℃ and 0% at 25℃. These results elucidated that A. affine is no longer harmless with an estimated potent concentrations near MC for the finfish and close to FDC for the shellfish. In the toxicity evaluation, particularly to T. modestus, temperature should be taken into account as it might be a parameter influencing the algal damage potential.
A Korean strain of Alexandrium affine (TY150902) was exposed to adult Thamnaconus modestus and Haliotis discus hannai for a comparative toxicity evaluation. Tests were done in two subsequent ways in the chamber (70 L carrying 30 L alga) for 24 hours. The first test was to find the first damage concentration (FDC) at 4 allocations (0, 1.25, 2.5, or 5.0 × 103 cells mL-1) at 20℃. The second was to detail at a median concentration (MC) between FDC and its previous concentration at 20 and 25℃. In the first test FDC was 5.0 × 103 cells mL-1 for both species, calculating 3.75 × 103 cells mL-1 as an MC in common. The algal toxicities at FDC were species-specific with bigger toxicity to the finfish. Toxicities at MC were also species-specific: harmless to the shellfish and temperature-dependently toxic to the finfish with mortalities of 20% at 20℃ and 0% at 25℃. These results elucidated that A. affine is no longer harmless with an estimated potent concentrations near MC for the finfish and close to FDC for the shellfish. In the toxicity evaluation, particularly to T. modestus, temperature should be taken into account as it might be a parameter influencing the algal damage potential.
In a radiotracer study, assimilation efficiency and efflux rate of Ag and Zn in the fresh water bivalve (Corbicular fluminea) fed to the two types of Ag nanoparticles (coated with citrate or polyvinylpyrrolidone) or ZnO particles amended with algae or seston diets were determined. These were compared with those clams fed to the diets treated with dissolved Ag and Zn. Additionally, subcellular partitioning of Ag and Zn in tissues of the clam after 21d depuration of bioaccumulated metals were compared. The clams were capable of assimilating (AE) Ag and Zn from the ingested nanoparticles and assimilation efficiency was higher for Zn (22-47%) than Ag (15-27%). The AE in the clams fed the food treated with dissolved Zn (56-58%) was higher than those treated with dissolve Ag (7-25%). Ag and Zn release from the clams during 21-d depuration followed two compartment model, initial rapid loss (20-30%) in 3-4 d of depuration and followed by much slower rate for Ag (0.003-0.006 d-1) and Zn (0.002-0.006d-1). The subcellular partitioning of Ag in the clam tissue was mostly in cellular debris (45-60%) and heat sensitive protein (20-30%), while Zn was distributed mostly in cellular debris (50%) and organelles (30%).
In a radiotracer study, assimilation efficiency and efflux rate of Ag and Zn in the fresh water bivalve (Corbicular fluminea) fed to the two types of Ag nanoparticles (coated with citrate or polyvinylpyrrolidone) or ZnO particles amended with algae or seston diets were determined. These were compared with those clams fed to the diets treated with dissolved Ag and Zn. Additionally, subcellular partitioning of Ag and Zn in tissues of the clam after 21d depuration of bioaccumulated metals were compared. The clams were capable of assimilating (AE) Ag and Zn from the ingested nanoparticles and assimilation efficiency was higher for Zn (22-47%) than Ag (15-27%). The AE in the clams fed the food treated with dissolved Zn (56-58%) was higher than those treated with dissolve Ag (7-25%). Ag and Zn release from the clams during 21-d depuration followed two compartment model, initial rapid loss (20-30%) in 3-4 d of depuration and followed by much slower rate for Ag (0.003-0.006 d-1) and Zn (0.002-0.006d-1). The subcellular partitioning of Ag in the clam tissue was mostly in cellular debris (45-60%) and heat sensitive protein (20-30%), while Zn was distributed mostly in cellular debris (50%) and organelles (30%).
The purpose of this study is to estimate the effects of environmental factors such as sex that affect the growth traits of the Pacific abalone (Haliotis discus hannai) breeding group and the trend of genetic change by generation. Phenotypic and pedigree data of shell length, shell width, and total weight at 30 months for 12,783 abalone breeding groups (F1 to F5) produced from 2005 to 2017 were used. To estimate genetic parameters, heritability, and breeding values for the growth traits, generation and sex were treated as fixed effects, and the AIREMLF90 and BLUPF90 programs were used. The heritabilities of shell length, shell width, and total weight were 0.461, 0.469, and 0.346, respectively. As a result of estimating the genetic change trend for growth traits, a clear genetic increase trend was shown as generations passed. In order to improve the accuracy of dam selection and genetic improvement of future generations, it is especially important to minimize inbreeding by maintaining the genetic diversity of the population. In addition to systematic pedigree management of the population, continuous breeding research using genetic parameters and breeders is necessary.
The purpose of this study is to estimate the effects of environmental factors such as sex that affect the growth traits of the Pacific abalone (Haliotis discus hannai) breeding group and the trend of genetic change by generation. Phenotypic and pedigree data of shell length, shell width, and total weight at 30 months for 12,783 abalone breeding groups (F1 to F5) produced from 2005 to 2017 were used. To estimate genetic parameters, heritability, and breeding values for the growth traits, generation and sex were treated as fixed effects, and the AIREMLF90 and BLUPF90 programs were used. The heritabilities of shell length, shell width, and total weight were 0.461, 0.469, and 0.346, respectively. As a result of estimating the genetic change trend for growth traits, a clear genetic increase trend was shown as generations passed. In order to improve the accuracy of dam selection and genetic improvement of future generations, it is especially important to minimize inbreeding by maintaining the genetic diversity of the population. In addition to systematic pedigree management of the population, continuous breeding research using genetic parameters and breeders is necessary.
In this study, four nudibranch species including a samlid and three dorids from Korean waters were redescribed, which were discovered while conducting a domestic nudibranch biodiversity survey from 2021 to 2023: Samla takashigei Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl and Picton, 2017, Diaphorodoris mitsuii (Baba, 1938), Atagema intecta (Kelaart, 1858), and Martadoris amakusana (Baba, 1987). In addition, here we provided photographs of living animals and DNA barcode data based on partial sequences of the mitochondrial COI gene. We also analyzed pairwise genetic distances of the COI gene between each species and their congeners, with which we reconstructed neighbor-joining trees to show their phylogenetic relationships and evolutionary distances.
In this study, four nudibranch species including a samlid and three dorids from Korean waters were redescribed, which were discovered while conducting a domestic nudibranch biodiversity survey from 2021 to 2023: Samla takashigei Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl and Picton, 2017, Diaphorodoris mitsuii (Baba, 1938), Atagema intecta (Kelaart, 1858), and Martadoris amakusana (Baba, 1987). In addition, here we provided photographs of living animals and DNA barcode data based on partial sequences of the mitochondrial COI gene. We also analyzed pairwise genetic distances of the COI gene between each species and their congeners, with which we reconstructed neighbor-joining trees to show their phylogenetic relationships and evolutionary distances.
Arginine kinases (AK) are known to be widely distributed in various invertebrates. It has an essential role in cellular energy metabolism. It regulates energy regulation and homeostasis in response to external stress. AK gene is used as a marker in invertebrate phylogenetic analysis. In this study, we verified whether AK can be used in molecular phylogenetic analysis. We sequenced Koreanomelania nodifila cDNA library using Illumina Hiseq 2000. The AK gene of K. nodifila was sequenced using the BLASTx program and PANM DB (v5.1). AK gene was used as a marker to molecular phylogenetic using the MEGA 11 maximum likelihood method. To analyze the 2D structure of the AK gene, the 2D structure was predicted using PSIPRED (v4.0). As a result, the AK gene ORF of K. nodifila is a total of 352 amino acids and AK gene is considered to be highly useful for molecular phylogenetic analysis of Mollusca.
Arginine kinases (AK) are known to be widely distributed in various invertebrates. It has an essential role in cellular energy metabolism. It regulates energy regulation and homeostasis in response to external stress. AK gene is used as a marker in invertebrate phylogenetic analysis. In this study, we verified whether AK can be used in molecular phylogenetic analysis. We sequenced Koreanomelania nodifila cDNA library using Illumina Hiseq 2000. The AK gene of K. nodifila was sequenced using the BLASTx program and PANM DB (v5.1). AK gene was used as a marker to molecular phylogenetic using the MEGA 11 maximum likelihood method. To analyze the 2D structure of the AK gene, the 2D structure was predicted using PSIPRED (v4.0). As a result, the AK gene ORF of K. nodifila is a total of 352 amino acids and AK gene is considered to be highly useful for molecular phylogenetic analysis of Mollusca.
