Age, Growth, and Reproduction of Sheepsheads in South Carolina

The sheepshead Archosargus probatocephalus is a common estuarine and reef species that is found year round in South Carolina. Although not commercially important, the sheepshead is a significant recreational species, and most of the fishing pressure occurs in state waters. From 1990 to 2005, 5,692 sheepsheads were collected from fishery‐dependent and fishery‐independent monitoring programs in South Carolina. Fish ranged from 102 to 605 mm in fork length (FL) and were caught during every month of the year. Ages ranged from 0 to 19 years for males and from 0 to 23 years for females; the dominant age‐classes were ages 2–5. Marginal increment analysis confirmed the formation of a single annulus per year, and annulus formation began in May. Males and females did not significantly differ in FL at age t (FL t ) or total weight at age t ( W t ); the pooled von Bertalanffy growth models were FL t = 498[1 − e −0.297( t + 1.10) ] and W t = 3,778[1 − e −0.165( t − 0.548) ] 2.997 . Both males and females exhibited the first signs of sexual maturity at age 1, and 100% maturity was reached at age 4. Batch fecundity estimated late in the spawning season ranged from 18,400 to 738,500 oocytes/spawning event and averaged 235,000 oocytes/spawning event. Fork length, W , and age were positively correlated with fecundity. Although size was a better predictor of fecundity than age, the relationship was weak due to the high variability in size at age. Comparisons of growth parameters for sheepsheads studied in the southeastern United States indicated that South Carolina sheepsheads tend to have a larger maximum FL and a greater maximum age than fish found in the Gulf of Mexico. Received May 24, 2010; accepted July 26, 2011