Fluctuations in the biochemical composition of the Patagonian stone crab Platyxanthus patagonicus A. Milne Edwards, 1879 (Platyxanthidae: Brachyura) throughout its reproductive cycle

Abstract

We analyzed the gonadosomatic (GSI) and hepatosomatic (HSI) indices, reproductive condition and biochemical composition of the digestive gland, gonads and claw muscle of the Patagonian stone crab over a one-year period. In females, the maximum HSI occurred in spring (gonad recovery period) and summer (maximum maturity period). The maximum female GSI values were found in summer, and fell to minimum values in fall and winter. In males, the highest GSI was observed during winter, which coincided with a non-mating period. The claw muscle biochemical composition did not significantly differ between seasons for either sex, except for the significantly lower glycogen content observed in winter relative to fall and summer in males. For both sexes, the claw muscle contained 72.4 to 81.2% moisture, 12.3 to 19.8% protein, 0.3 to 1.0% fat, 1.1 to 2.7% ash and 0.1 to 1.4% glycogen. In both sexes, the digestive gland was the main storage site for lipids. In the ovary, lipid and protein contents were higher in spring and summer, and decreased to significantly lower values after spawning. Moisture showed the opposite pattern and neither glycogen nor ash contents showed significant differences between seasons. The biochemical composition of the testes-vasa deferentia complex did not show significant seasonal fluctuations, except for higher moisture content in fall compared to summer and spring.

Keywords

• stone crab
• biochemical composition
• reproduction
• gonadosomatic index
• hepatosomatic index