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

The density, sinking rate and biochemical composition of Centropages tenuiremis subitaneous and diapause eggs were determined in the laboratory. The mean densities of subitaneous and diapause eggs were 1.1176 and 1.1481 g cm super(-3), respectively. Based on Stokes' law, the average sinking rate was 0.0266 cm s super(-1) for subitaneous eggs and 0.0367 cm s super(-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 super(-1), respectively, while those of diapause eggs were 165.0, 57.1, 81.2 and 11.2 ng egg super(-1), respectively. The levels of aspartic acid, glutamic acid, glycine, methionine, isoleucine, leucine, norleucine, lysine, ammonium chloride, and arginine in diapause eggs of C. tenuiremis were significantly higher than in subitaneous eggs. Results of the study showed that there were significant physiological and biochemical differences between subitaneous and diapause eggs of C. tenuiremis.