Age and growth of the king mackerel (Scomberomorus Cavalla) off the northeastern coast of Brazil

Abstract

Age and growth of the king mackerel (Scomberomorus cavalla) were estimated for northeastern Brazil. A total of 405 sagittal otoliths from 140 males (24.4-112 cm), 73 females (28-114.8 cm) and 193 specimens of unknown sex (11.5-121 cm) were examined. Marginal increment analysis indicated an annual pattern for growth band deposition. The age classes ranged from 1 to 15 years. Length ranged from 11.5 to 121 cm. The Schnute model indicated that the von Bertalanffy growth model demonstrated the best adjustment, with p=1/b, and was therefore used for estimating growth. Back-calculated curves had smaller variances, giving the following estimated growth parameters for males: L∞= 116.8 cm, K = 0.190, t0 = 0.377; and females: L∞= 132.7 cm, K = 0.159 and t0 = 0.387. In order to compare the curves for males and females, the overlapping of 95% confidence intervals was performed for the parameters generated from the von Bertalanffy non-linear least square method. Specimens between 3 and 8 years of age represented 82.2% (n=5,783) of the catch composition, characterizing the species as a catchable stock in the region.