Growth performance and biochemical composition dynamics of ovary, hepatopancreas and muscle tissues at different ovarian maturation stages of female mud crab, Scylla paramamosain

Abstract

Mud crab (Scylla paramamosain) is an economically important crustacean species due to its high market price, especially females with mature ovaries. Therefore, it is vital to better understand the growth performance and biochemical composition dynamics of ovary at different maturation stages. To accomplish this, one hundred female mud crabs were obtained and their morphometric characters, ovary morphology and weight were analysed. Further, the biochemical composition dynamics of ovary, hepatopancreas and muscle tissues at various ovarian maturation stages were compared. The ovarian maturation process of S. paramamosain is divided into five developmental stages based on coloration and size. Gonadosomatic index (GSI) and six growth traits increased with ovarian maturation stages. Protein content was found constant in ovary throughout all stages, and the lipid content was similar in all three tissues. Total carotenoid content in ovary tissues increased with maturation stages whereas no significant difference was observed in the hepatopancreas and muscle tissues across stages. Highly-unsaturated fatty acid (HUFA) was the dominant group in all three tissues. Ovarian saturated fatty acid (SFA), mono-unsaturated fatty acid (MUFA) and HUFA increased with maturation stages whereas ovarian essential amino acids (EAA) increased significantly during initial vitellogenesis and oogenesis stage (stage II and III). Glutamate was the dominant amino acids in all three tissues throughout maturation stages. There was no significant difference in the individual amino acid composition, flavor amino acids (FAA) and EAA profiles of hepatopancreas and muscle tissues across maturation stages. The knowledge of growth performance and biochemical composition dynamics across ovarian maturation stages should be helpful for the establishment of suitable broodstock diet that would promote ovarian maturation and better larval quality.