Differences in the density, sinking rate and biochemical composition of Centropages tenuiremis (Copepoda: Calanoida) subitaneous and diapause eggs

Abstract

The density, sinking rate and biochemical composition of Centropages tenuiremis subi- taneous and diapause eggs were determined in the laboratory. The mean densities of subitaneous and diapause eggs were 1.1176 and 1.1481 g cm -3 , respectively. Based on Stokes' law, the average sinking rate was 0.0266 cm s -1 for subitaneous eggs and 0.0367 cm s -1 for diapause eggs. The dry weight, lipid, protein and carbohydrate contents of subitaneous eggs were 117.7, 32.9, 59.1 and 9.4 ng egg -1 , respectively, while those of diapause eggs were 165.0, 57.1, 81.2 and 11.2 ng egg -1 , respectively. The levels of aspartic acid, glutamic acid, glycine, methionine, isoleucine, leucine, nor- leucine, lysine, ammonium chloride, and arginine in diapause eggs of C. tenuiremis were signifi- cantly higher than in subitaneous eggs. Results of the study showed that there were significant phys- iological and biochemical differences between subitaneous and diapause eggs of C. tenuiremis.