Bayesian estimation of the age and growth of the golden cownose ray (Rhinoptera steindachneri) in the southern Gulf of California in Mexico

The aim of this study was to use a Bayesian approach to estimate age and growth parameters for the golden cownose ray (Rhinoptera steindachneri) in the southern Gulf of California in Mexico. Age estimates were obtained through analysis of vertebrae of 249 individuals. The von Bertalanffy growth function (VBGF) and Gompertz growth model (GM) were fit to length-at- age data by using a Markov chain Monte Carlo algorithm for parameter estimation. Prior distributions of parameters were included for an informative prior for disc width at birth (DW0) and uninformative priors for the theoretical maximum disc width (DW∞) and growth coefficients (k and g, for the VBGF and GM, respectively). Our results indicate that the golden cownose ray lives up to 13 years. The GM for combined sexes was selected as the best model by using the Watanabe–Akaike information criterion for model selection suitable for Bayesian estimation. The mean values of the GM parameters were as follows: DW∞=101.10 cm (95% credible interval [CI]: 94.19–110.43), g=0.15 year−1 (CI: 0.12–0.18), and DW0=40.00 cm (CI: 39.29–40.71). This study of the golden cownose ray contributes to the information available to develop better management and conservation strategies for this species.