Biochemical composition of gonads during reproductive cycle in the Sea Urchin Echinometra mathaei (Echinodermata: Echinoidea)

Abstract

Maturation can also be assessed based on biochemical changes in the gonads of sea urchins. The biochemical composition (proteins, carbohydrates, and lipids) of gonads of Echinometra mathaei was assessed during the ovarian reproductive stages between April 2011 and November 2012. Protein constituted the major storage part of gonads in both sexes in all months (males: 47.0±22.2 mg g^-1, females: 73.8±25.8 mg g^-1) followed by lipids (males: 43.4±12.8 mg g^-1, females: 62.1±14.5 mg g^-1), and carbohydrates (males: 32.2±20.2 mg g^-1, females: 46.9±23.8 mg g^-1). The results revealed that the protein, carbohydrate, and lipid contents of gonads exhibited significant shifts from highest to lowest concentrations. This indicates that the proximate composition of the gonads of E. mathaei is intrinsically linked to the species' annual reproductive cycle, representing a critical consideration for assessing its potential for nutritional and commercial utilisation. The greatest quality in biochemical content was observed from February to May on the coast of Pakistan, when individuals with Stage I and II possess significantly higher concentrations of proteins and lipids, upheld by the nutritive phagocytes. Although, in Pakistan, there is no custom to eat sea urchin roe, and no sea urchin fishery exists; however, in the future, when this species becomes exploitable, such studies will be very important.