Dry weight, carbon and nitrogen components of caprellid amphipods (Crustacea) inhabiting the Sargassumyezoense community of Otsuchi Bay, northeastern Japan

Abstract

Dry weight (DW), carbon (C) and nitrogen (N) contents in four species of caprellids, Caprella danilevskii, C. subinermis, C. penantis R-type, and C. verrucosa, inhabiting Sargassumyezoense (Yamada) in Otsuchi Bay, northeastern Japan, were measured based on live specimens. In all species males tend to grow larger than females in pereonite II length, which is used as an indicator of body length, and have greater dry weight, carbon and nitrogen contents. All three parameters (DW, C and N) had highly significant relationships against pereonite II length. Regressions of female pereonite II length against the three parameters significantly differed from males in the four species. Average percentages of carbon and nitrogen contents of the total dry weight ranged from 30.82 to 32.21% and 5.82 to 6.86%, respectively. The carbon/nitrogen ratio tended to decrease against increasing pereonite II length, e.g., 7.2 to 4.3 in C. danilevskii.