Life history of

Abstract

Mustelus mustelus from the Langebaan Marine Protected Area (LMPA) has been largely protected from fishing activities for the past 30 years; therefore, its biology represents those of an unfished stock. The reproductive biology, diet, growth and maturity of M. mustelus was studied in the Langebaan Lagoon region in the south-western Cape Coast of South Africa between 2007 and 2009. In total, 217 sharks (females: 381–1734 mm total length (TL); males: 467–1267 mm TL) were examined. Sharks in the Bay represented the largest specimens among six regions, globally. Female parturition, ovulating and mating occurred between November and December after a gestation period of 10–11 months. No ontogenetic shift in diet was evident, with the diet predominantly consisting of the following three species of crustaceans; Hymenosoma orbiculare, Upogebia africana and Callichirus kraussi. The von Bertalanffy growth parameters for combined sexes were L∞ = 1594 mm TL, k = 0.15 year–1, t0 = –2.01 year (n = 95). Possible age over-estimation was investigated using micro-computed tomography, which highlighted the existence of false check marks. This study indicated that the LMPA represents a pupping, nursery and feeding ground as well as a refuge area for the largest and oldest recorded smoothhound sharks globally, emphasising its importance in spatial conservation of this species.