Life history of the red grouper (Epinephelus morio) off the North and South Carolina Coast

Julian M. Burgos*
University of Charleston, Grice Marine Laboratory, 205 Ft. Johnson Rd., Charleston, SC 29412 E-mail: jmburgos@edisto.cofc.edu

Patrick J. Harris, George R. Sedberry, David M. Wyanski
South Carolina Department of Natural Resources, Marine Resources Research Institute, 217 Ft. Johnson Rd., Charleston, SC 29412

Red groupers were sampled from commercial catches off North Carolina between December, 1997 and December 1998. A total of 1851 specimens was obtained, ranging from 384 to 851 mm TL (mean=561 mm). Additional samples were obtained through fishery-independent sampling. Ages of 460 red groupers, estimated from sectioned sagittae, ranged from 2 to 18 years. Marginal increment analysis indicated that annulus formation occurred during the late summer and early fall. Observed length at age is described by the following von-Bertalanffy growth equation: TL (mm) = 863(1-exp (-0.1755(age (yrs)-2.252))).

Sex and maturity of 439 red groupers were assessed by histological analysis. Female red grouper (N=387) ranged from 371 to 793 mm TL. Males (N=16) ranged from 610 to 840 mm TL. Spawning females, recognized by the presence of vitellogenic oocytes and post-ovulatory follicles, were found between April and August. Red groupers are protogynous hermaphrodites, and transition (N=36) was observed in individuals between three and eighth years old.