To investigate the distribution, abundance, and species composition of dinoflagellate cysts in the Yellow Sea, surface sediment samples were collected at 37 sites, including the Korean dump site. Twenty-one di- noflag...To investigate the distribution, abundance, and species composition of dinoflagellate cysts in the Yellow Sea, surface sediment samples were collected at 37 sites, including the Korean dump site. Twenty-one di- noflagellate cyst taxa were identified, with the assemblages dominated mainly by Spiniferites bulloideus, Operculodinium centrocarpum, and cyst of Alexandrium catenella/tarnarense type. A high frequency of O. centrocarpum in the Yellow Sea was observed for the first time, and it is likely that this can be attributed to the dynamics of the Yellow Sea Cold Water Mass and the Changjiang （Yangtze） River runoff. Total cyst concentrations ranged from 23 to 48 442 cysts/g dry weight, and high cyst concentrations were recorded adjacent to the dumping site. This result suggests that anthropogenic activities such as ocean dumping s- timulate the growth of dinoflagellates in the Yellow Sea, which in turn leads to high levels of dinoflagellate cyst production.展开更多
Ploidy manipulation,such as triploidy,in farmed oysters has been used as a tool to enhance oyster quality throughout all seasons because triploid oysters allocate less energy to gametogenesis,and therefore are deemed ...Ploidy manipulation,such as triploidy,in farmed oysters has been used as a tool to enhance oyster quality throughout all seasons because triploid oysters allocate less energy to gametogenesis,and therefore are deemed better performers than fertile diploids.Nevertheless,scientific reports describing no differences between ploidies and,in certain conditions,disadvantages of triploids are not uncommon.As the use of triploid oyster seed increases culture cost for growers,consistency in performance of triploids is considered to be an important goal.Thus,research to assess how ploidy affects physiological processes underlying oyster performance is fundamental for the aquaculture industry.This work was undertaken to assess if ploidy-based differences in performance in the two most commonly cultivated commercial species of oyster in the United States,Crassostrea virginica and Crassostrea gigas,are associated with filtration,feeding,and metabolism.To test this hypothesis,biodeposition measurements were made with oysters exposed to ambient water conditions at locations and seasons providing a variety of environmental conditions.Oysters did not show differences in filtration and feeding associated with ploidy,but physiological feeding variables fluctuated with environmental characteristics associated with spatial and seasonal differences.A preliminarily test of the hypothesis that differences in energy metabolism may account for differences in performance among ploidy levels indicates that basal metabolic rates of diploid,triploid,and tetraploid Eastern oysters are not different.展开更多
基金Part of the Korea-China Cooperative Project on the Yellow Sea Cold Water Massa grant from the Korea Ocean Research and Development Institute(PE99165)the samples were partly supplied from NFRDI(RP-2012-ME-051)
文摘To investigate the distribution, abundance, and species composition of dinoflagellate cysts in the Yellow Sea, surface sediment samples were collected at 37 sites, including the Korean dump site. Twenty-one di- noflagellate cyst taxa were identified, with the assemblages dominated mainly by Spiniferites bulloideus, Operculodinium centrocarpum, and cyst of Alexandrium catenella/tarnarense type. A high frequency of O. centrocarpum in the Yellow Sea was observed for the first time, and it is likely that this can be attributed to the dynamics of the Yellow Sea Cold Water Mass and the Changjiang （Yangtze） River runoff. Total cyst concentrations ranged from 23 to 48 442 cysts/g dry weight, and high cyst concentrations were recorded adjacent to the dumping site. This result suggests that anthropogenic activities such as ocean dumping s- timulate the growth of dinoflagellates in the Yellow Sea, which in turn leads to high levels of dinoflagellate cyst production.
基金This work was funded by NOAA Internal Competitive Aquaculture Grant,by the South Korean National Institute of Fisheries Science(R2018012)a JPA project between the U.S.and South Korea,and by a fellowship award from the United States National Academy of Sciences.
文摘Ploidy manipulation,such as triploidy,in farmed oysters has been used as a tool to enhance oyster quality throughout all seasons because triploid oysters allocate less energy to gametogenesis,and therefore are deemed better performers than fertile diploids.Nevertheless,scientific reports describing no differences between ploidies and,in certain conditions,disadvantages of triploids are not uncommon.As the use of triploid oyster seed increases culture cost for growers,consistency in performance of triploids is considered to be an important goal.Thus,research to assess how ploidy affects physiological processes underlying oyster performance is fundamental for the aquaculture industry.This work was undertaken to assess if ploidy-based differences in performance in the two most commonly cultivated commercial species of oyster in the United States,Crassostrea virginica and Crassostrea gigas,are associated with filtration,feeding,and metabolism.To test this hypothesis,biodeposition measurements were made with oysters exposed to ambient water conditions at locations and seasons providing a variety of environmental conditions.Oysters did not show differences in filtration and feeding associated with ploidy,but physiological feeding variables fluctuated with environmental characteristics associated with spatial and seasonal differences.A preliminarily test of the hypothesis that differences in energy metabolism may account for differences in performance among ploidy levels indicates that basal metabolic rates of diploid,triploid,and tetraploid Eastern oysters are not different.
