Production of the copepods euchaeta plana and paraeuchaeta russelli in the Southeastern sea of Korea

Abstract

Production from copepodite IV to adult of two euchaetid species Euchaeta plana and Paraeuchaeta russelli was measured at the southeastern sea of Korea from April to November, 2014. The mean density was 2.0 ind m -3 for E. plana and 4.1 ind m -3 for P. russelli, with the high contribution of copepodite V to total density. The densities of total individuals, adult females and eggs were highest in November for both species. The mean egg production rate (EPR) was 1.7 eggs female -1 d -1 for E. plana and 3.1 eggs female -1 d -1 for P. russelli. Both of them showed the highest EPR in September but zero EPR in summer. The mean weight-specific EPR was 0.038 d -1 for E. plana and 0.079 d -1 for P. russelli. The mean total production rates of E. plana and P. russelli were 5.3 µg C m -3 d -1 and 17.8 µg C m -3 d -1 , respectively, with the largest production in November. The mean Production/Biomass ratio was 0.06 d -1 for E. plana and 0.07 d -1 for P. russelli, with its peak in September for both. The total production of E. plana and P. russelli was positively correlated with the density of a copepod Oncaea venusta, rather than chl-a concentration, indicating that the two copepods might be carnivores. This study evaluates the contribution of euchaetids to the copepod community in the southeastern sea of Korea. © 2018, Korea Ocean Research and Development Institute. All rights reserved.