Reproductive parameters of the Pacific angel shark Squatina californica (Selachii: Squatinidae).

ABSTRACT

Reproductive characteristics of the Pacific angel shark, Squatina californica, were evaluated from 420 specimens obtained from the artisanal fishery in La Paz Bay, Gulf of California, Mexico. Females (99 cm, 6000 g) were larger than males (95 cm, 5000 g) in terms of both total length (L(T)) and body mass (M(T)). The overall sex ratio was significantly different from the expected 11, suggesting sexual segregation of mature individuals in La Paz Bay. Males had developed reproductive organs and calcified claspers from 72 cm L(T); the median size at maturity (LT50 ) was 75.6 cm. In females, only the left ovary was functional and mature ovarian follicles were present from 77 cm L(T); the estimated LT50 was 77.7 cm. For the 10 gravid females sampled, uterine fecundity was between two and 10 embryos. Mature, non-gravid females with small and large ovarian follicles appeared simultaneously with gravid females with follicles that did not exceed 1.9 cm diameter.