Reproductive and population parameters of spiny dogfish Squalus acanthias in the south-western Atlantic Ocean

The objective of this study was to estimate reproductive and population parameters of the spiny dogfish Squalus acanthias for the south-western Atlantic Ocean. In total, 2714 specimens (1616 males and 1098 females) were collected from surveys carried out using research vessels. Males ranged from 225 to 861 mm total length (LT) and females from 235 to 925 mm LT. The size at maturity of females (651 mm) was significantly greater than that of males (565 mm). The maximum proportion of mature individuals (Pmax) of the gestation ogive was 156 mm). The temporal and spatial co-occurrence of non-gravid adult females at different stages of ovarian development, as well as gravid females at all embryonic development stages would indicate that the female reproductive cycle in the south-western Atlantic Ocean is asynchronous. The results indicate that S. acanthias is susceptible to fishing pressure on account of its length at maturity, extended reproductive cycles and low fecundity.Fil: Colonello, Jorge Horacio. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cortés, Federico. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Belleggia, Mauro. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Massa, A. M.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentin