Reproductive biology, age and growth in the chocolate hind, Cephalopholis boenak (Bloch, 1790), in Hong Kong

Abstract

The chocolate hind, Cephalopholis boenak, is a relatively small grouper, attaining a maximum standard length (SL) of 215 mm. The females mature at 80 mm SL and aged one year or less, if increments in sagittal otoliths form annually. Based on gonadal histology, this species was determined to be a diandric protogynous hermaphrodite with two possible pathways of male development, although all testes were similar in morphology. Crypts of spermatogenic cells may be present at all female developmental stages and sex change from female to male occurs at between 100 and 150 mm SL (ages one to four years). Spawning season for this species, around Hong Kong, is from April to October, as indicated both by the gonadosomatic index (GSI) and histological examination of gonads. Half of all specimens sampled from local municipal markets were small and young, between 112 mm and 142 mm SL (ages two to four years). Sectioned sagittal otoliths suggested that sampled fishes ranged from 0 to 11 years, although most fishes taken in the fishery are below age five years. The von Bertalanffy growth-curve parameters were, provisionally, L∞ = 147.66 mm SL, K = 0.49 and t0 = -1.52 years. Fisheries management should be applied to this last remaining commercially important local grouper in the Hong Kong market.