Life-history traits of the false jacopever Sebastes capensis (Scorpaenidae: Sebastinae) in South African waters

Abstract

The genus Sebastes (rockfishes) of family Scorpaenidae (scorpionfishes) contains over 110 species, of which the false jacopever Sebastes capensis is the only one found in South African waters. Although it is a commonly caught linefish along the west coast of South Africa, information about this species is limited. In this study, biological data were extracted for 269 specimens (size 205–372 mm total length [TL]), caught from boats using hook-and-line, to describe the life-history traits of this poorly known rocky-reef fish. The length–weight models indicated hyperallometric growth for females (W = 5.08 × 10^–6 TL^3.23) and isometric growth for males (W = 1.39 × 10^–5 TL^3.04) for fish in the age range 3 to 23 years. The best-fit von Bertalanffy growth model for females was TL = 358.1(1 – e^{−0.105(t + 5.70)}), and for males TL = 355.4(1 – e^{−0.138(t + 3.21)}). Males outnumbered females in the catches at a ratio of 2.68:1. Females matured at age 6 years and males at age 4 years. The spawning period lasted from late autumn to early spring (May–September). Notably, females are capable of storing sperm in their ovaries over the reproductive period; the presence of oocytes of different developmental stages in the ovaries suggests multiple brooding is a feature of its reproductive strategy. Brood fecundity was estimated at ∼40 000–100 000 embryos. Sebastes capensis is a benthos-associated opportunistic and generalist predator. As a slow-growing and late-maturing rockfish, the species is potentially vulnerable to overfishing, particularly given its prevalence in catches of recreational and commercial boat fishers along South Africa’s west coast.