Age and Growth of the Bull Shark,Carcharhinus leucas, from Southern Gulf of Mexico
- 9 December 2004
- journal article
- Published by Northwest Atlantic Fisheries Organization (NAFO) in Journal of Northwest Atlantic Fishery Science
- Vol. 35, 367-374
- https://doi.org/10.2960/j.v35.m481
Abstract
Age and growth of bull shark, Carcharhinus leucas, was investigated in the southern Gulf of Mexico (Veracruz and Campeche, Mexico) from December 1993 through June 1997. Ninety-five specimens were obtained from commercial fishery catches, and vertebrae were examined from 20 males, 61 females and 14 individuals unidentified to sex. Vertebrae were examined using five different techniques to enhance the visibility of growth rings: i) alizarin red stain, ii) crystal violet stain, iii) X-ray, iv) silver nitrate stain, and v) without staining. Verification of temporal growth ring forma - tion was done by the indirect method of marginal increment analysis. An isometric relationship was found between growth and length of centrum, is described by a linear equation. Age-at-maturity was 10 years (204 cm total length, TL) for females and 9-10 years (190-200 cm TL) for males. The old- est female was 28 (256.0 cm TL), and the oldest male was 23 (243.0 cm TL). The von Bertalanffy growth parameters were estimated for the species (L∞ = 256.4 cm TL, k = 0.1397 per year and to = -1.935), for males (L∞ = 248.4 cm TL, k = 0.1692 per year and to = -1.03), and for females (L∞ = 262.1 cm TL, k = 0.1235 per year and to = -2.44). Sexual differences for each particular growth curve were found, L∞ being the parameter that showed the greatest difference between males and females; females attain a larger size.This publication has 0 references indexed in Scilit: