Aspects of the biology of the abalone Haliotis midae (Linne, 1758) on the east coast of South Africa. 2. Reproduction

The South African abalone Haliolis midae is a dioecious, broadcast spawner with a high fecundity. Histological examination and gonad bulk indices showed that individuals are iteroparous, asynchronous spawners, and that the breeding season extends from March through to October, spawning peaking between April and June. The structure of the ovary and testis, and the process of gametogenesis are typical of haliotid species. Males and females spawn partially or totally, with atresia of residual gametes occurring after spawning. No resting stage was apparent and gonadal recrudescence began immediately after spawning. Sexual maturity was first attained at 20–25 mm shell width, and the size at 50% sexual maturity was attained at approximately 35 mm shell width in all of the populations studied, a size considerably lower than that of previously studied West Coast populations of H. midae.