EFFECT OF Rhizophora mucronata LEAF EXTRACT ON THE GONAD MATURITY OF MUD CRAB Scylla olivacea

Abstract

Female mud crabs are a high-value fishery commodity due to the market demand for their gonadal development potential. To date, market supply remains predominantly dependent on wild-caught populations. This condition threatens the sustainability of mud crab stocks, both for market supply and the conservation of natural populations. The present study aimed to evaluate the effect of mangrove leaf extract (Rhizophora mucronata) on the gonadal maturation of mud crab (Scylla olivacea). The study employed a Completely Randomized Design, consisting of four dosages of mangrove leaf extract (0, 0.5, 1, and 1.5 mg/100 g body weight), with each treatment conducted in triplicate. The mangrove leaf extract was injected into the experimental animals on the fourth day after stocking. The crabs were fed trash fish at 10–15% of body weight twice daily. Gonadal maturity stage (GMS), gonado-somatic index (GSI), and hepatopancreas-somatic index (HSI) were observed on day 15 post-injection (one individual from each treatment) and day 30 post-injection (all individuals from each treatment). Descriptive analysis indicated that the gonadal maturity stage of the experimental crabs increased across all treatments. The highest GMS and GSI values, along with the lowest HSI value, were obtained in the treatment receiving 1 mg/100 g body weight. Water quality parameters during the culture period remained within the optimal range for mud crab cultivation. Injection of R. mucronata leaf extract at a dosage of 1 mg/100 g body weight was found to be the most effective dose for enhancing gonadal maturation and GSI in mud crabs.