한국 동해 남부 해역의 Euchaetid 요각류 개체군 생태학

Abstract

Euchaetid copepod density (individuals m-3) and their developmental stages were examined at 16 sampling stations in the southeastern sea of Korea from April to November, 2014. Total six euchaetid species appeared in the research area: Euchaeta concinna, E. indica, E. longicornis, E. plana, E. rimana, Paraeuchaeta russelli. Among euchaetid species, E. plana and P. russelli dominated throughout the year. They occupied more than 62% of total euchaetids. Monthly mean density of euchaetids ranged from about 2 to 44 inds. m-3. Density of euchaetids was highest in November and lowest in April. Euchaetid density was positively correlated with surface water temperature and negatively related with bottom temperature. Correlations between euchaetid density and salinity or Chl-a concentration were not significant. Copepodite Ⅱ and Ⅲ accounted for 58.7% of total densities. Adult euchaetid copepods occupied 25.6% in April and 12.8% in October. The density of reproductive female was high in August to November, which means euchaetid copepods had spawning peak in these periods. Monthly mean prosome length of female E. plana adults was 2.15±0.23 mm (n=50). The prosome length was smaller than average in May and September, larger in November. Euchaetid copepods in the southeastern sea of Korea had preference in 14~24℃ of water temperature to develop and spawn. This temperature range coincides with the results of previous researches on euchaetids in Hong Kong and the East China Sea. This study confirms that euchaetids of the southeastern sea of Korea are warm water species, as they are known to us.