Seasonal changes in biochemical composition and energy content of the three-spot swimming crab Ovalipespunctatus(De Haan) (Crustacea:Brachyura)

Abstract

The biochemical composition of the three-spot swimming crab Ovalipes punctatus (De Haan) fluctuated during the period of investigation, probably due to the large variation between individuals and the absence of a distinct breeding cycle. In the females there was a build-up of protein and lipid before the main breeding period. The mean values for protein (35.0%), lipid (2.9%), carbohydrate (11.53%) and ash (49.55%) expressed on a dry-wt basis are similar to values for other Brachyura. The mean energy values for males and females were 10.42 kJ · g −1 and 10.88 kJ · g −1 respectively, with high values for the females during the main breeding period due to gonad development. Analyses of the exuvium revealed low energy (2.94 kJ · g −1) content due to high (92.11%) ash content. Results are discussed in relation to the breeding cycle and moulting period of the crabs.