Effects of two natural diets on the biochemical compositions of post‐mating female mud crab ( Scylla paramamosain )

Abstract

Understanding the effects of different natural diets on the growth performance and nutritional quality of mud crab Scylla paramamosain is important for both aquaculture and human nutrition perspectives. In the present study, female S. paramamosain were fed with two different natural diets, a marine bivalve species Potamocorbula rubromuscula (initial weight of the experimental crabs: 192.1 ± 29.2 g) and lizardfish Harpadon nehereus (initial weight of the experimental crabs: 188.1 ± 42.9 g) during the post-mating period. Furthermore, the weight gain ratio (WGR), specific growth rate (SGR), gonado-somatic index (GSI), hepatosomatic index (HSI), proximate compositions, total carotenoid content, amino and fatty acid profiles were investigated. Different diets affected HSI, carotenoid, lipid, amino acid and fatty acid contents in the claw muscle, hepatopancreas and ovary of female S. paramamosain. However, different diets did not affect the growth parameters including WGR, SGR and GSI. Crabs fed with P. rubromuscula had significantly higher amino acid content in the claw muscle, hepatopancreas and ovary, but lower HSI value and lipid content in the hepatopancreas and ovary compared with the crabs fed with H. nehereus. The carotenoid content was significantly higher in the hepatopancreas and ovary tissues of crabs fed with P. rubromuscula, whereas crab fed with H. nehereus displayed higher carotenoid content in the claw muscle. These results indicated that feeding S. paramamosain with P. rubromuscula could enhance amino acid contents (in claw muscle, hepatopancreas and ovary) and carotenoid contents in the hepatopancreas and ovary. Moreover, this study showed that the post-mating period is a critical period for nutritional deposition and a short feeding strategy during this period dramatically alters the body biochemical compositions.