Sexual development and demography of the rock hind Epinephelus adscensionis, a protogynous grouper, in the south-west Atlantic

Abstract

This study reports on the pattern of sexual development and demography of Epinephelus adscensionis sampled on the north-east coast of Brazil. The species is a protogynous hermaphrodite, with males (26–44-cm total length, TL) transitioning from mature females (20–33cm TL). This species presented multiple spawning, with peaks in the gonadosomatic index indicating that the spawning period of the rock hind occurred along 3 months per year, where for 2008 was between August and October, and for 2009 was between July and September. Age was determined from otoliths and periodicity was validated from captive fish treated with tetracycline. The resulting von Bertalanffy growth parameters were as follows: theoretical maximum length (L∞) 34.82cm TL, growth coefficient (k) 0.26 and theoretical age at L=0 (t0) 0.86years. The size and age at sexual maturity for females were 20cm TL and 4 years. The total rate of mortality was 0.28year–1. Older fish were males and had a maximum longevity of 15 years. This species is an important resource for local communities, but is also currently caught by trap fisheries, which have been expanding in recent decades in response to demands of export markets. Lack of monitoring and management of these and other reef fisheries in north-east Brazil makes fishing sustainability uncertain.