Reproduction, age, growth and mortality of axillary seabream, Pagellus acarne (Sparidae), from the Canarian archipelago

Axillary seabream Pagellus acarne (Risso 1826) caught off the Canary Island s from January 1991 to December 1994 were studied. The length range of the catches was between 11 and 31 cm, with a modal distribution between 17 and 21 cm. The overall ratio of males to females was 1:1.74. Males were observe d up to a length of 24 cm. Hermaphrodites were recorded at lengths between 15 and 23 cm. The species was characterized by protandric hermaphroditism. The reproductive season extended from October to March, with a peak in spaw ning activity in December-January. The size at sexual maturity was 15.8 cm total length (2 years old) for males and 19.4 cm total length (3 years old) for females. The total length-total weight relationship for the entire pop ulation is described by the parameters a = 0.0068, and b = 3.2401. Otolith age readings showed that the population exploited consisted of 10 age group s (1-10 years), including a very high proportion of individuals between 1 a nd 4 years old. The von Bertalanffy growth parameters for all individuals w ere L-infinity = 32.98 cm, k = 0.22 years(-1), and t(o) = -0.87 years. Male s grew comparatively slower than females. The instantaneous rates of mortal ity for all fish were Z = 0.96 years(-1), M = 0.30 years(-1), and F = 0.66 years(-1). The exploitation ratio and the length at first capture were, res pectively, E = 0.69 and LC50 = 16.1 cm. The stock is overexploited, therefo re measures such as closed seasons or changes in fishing patterns would be desirable to safeguard the spawning stock and recruits.