Evaluation of the reproduction parameters and length-weigth relationship of the argentine hake Merluccius hubbsi (Teleostei: Merlucciidae), Southeastern brazilian stock (21° s-29° s), year 2004

Abstract

The Argentine hake Merluccius hubbsi is one of the most important targets of the bottom-trawlers fishery in the Southeast-South of Brazil. After stocks definition, this is the first study focusing parameters estimation of the Southeastern stock (21°S-29°S) as length-weight relationship, ovarian maturation, size and age at first gonad maturation and the applicability of condition factors and gonad index to access reproductive cycle. It was obtained Wt=0.000005 Lt ^3.0811 and the condition factors are not useful tools to evaluate reproductive cycle. The analysis of ovarian maturation depends on histology. On the other hand, gonad index was functional, being obtained the reference values (x10⁶) for immature females (IG<0.04), maturing and spent females (0.04<IG<0.11) and mature and spawning females (IG>0.11). The values of first ovarian maturation were L₅₀=280.73 mm and t₅₀=1.99 year. These results were discussed and compared, being verified that Argentine hake Southeastern stock presents clears signs of overexploitation, calling for an urgent management.