Parâmatros de crescimento do tubarão rabo-seco, Rhizoprionodon porosus (POEY, 1861), no litoral do estado de Pernambuco-Brasil.

Abstract

The objective of the present work was to describe the general growth parameters of the dry-tailed shark, Rhizoprionodon porosus (Poey, 1861), using the length frequency distribution method, using the von Bertalanffy growth equation, focusing on possible correlations with the operational conditions of the artisanal fishing fleet off the coast of the State of Pernambuco. The composition of the catches indicates a high participation of adult females and juvenile males, suggesting that this population is segregated by size, sex and reproductive stage, and that the operation of the fleet is restricted to coastal areas. The analysis carried out to verify the existence of differences between the parameters related to the growth rates of males and females indicated to be significantly high, showing that the females reach larger dimensions, but that the males grow faster, with the parameters K = 0, 42, t0 = -1.10 years and L∞ = 87.13 cm for males; and K = 0.30, t0 = -1.12 years and L∞ = 106.82 cm for females, respectively, close compared to other species of the genus Rhizoprionodon and even if compared to other small and medium sized sharks . Females have a greater weight gain in relation to the total length, as can be seen in the relationship between the eviscerated weight and the total length. Considering the current pressure to which the stocks of small coastal sharks are subjected in our coast and the importance of validating the parameters verified here, additional information and studies will be necessary to allow an evaluation of this stock and to facilitate the determination of acceptable levels of fishing effort.