Age and growth of Pacific cownose ray, Rhinoptera steindachneri: A species with intermediate growth and shorter lifespan than expected

Context: Rhinoptera steindachneri is the third-most abundant batoid species in the artisanal gillnet fishery of the Gulf of California, but there are limited age and growth data available for management. Aims: The aim was to estimate age and growth of this species from vertebral centra of 276 individuals. Methods: Two adjusted data sets were constructed on the basis of the birth and capture months and defining adequately the birth band. Individual growth was described through a multi-model approach and inference by using von Bertalanffy, Gompertz, and Logistic models (two and three parameters), and a two-phase growth model (four and five parameters). Key results: The model with the best fit to the size-At-Age data was the two-phase model for both sexes (females: Dw∞ = 91.21 cm; k = 0.25 year-1, Dw0 = 46.2 cm; males: Dw∞ = 79.1 cm; k = 0.42 year-1, Dw0 = 45.5 cm). Maximum ages ranged from 9.92 to 10.75 years (female) and from 6.92 to 7.67 years (males). Maturity age was estimated in 3.92 years (females) and 3.72 years (males). Conclusions: Rhinoptera steindachneri is a batoid species with intermediate growth and a shorter lifespan than for confamilial species and even than species with similar reproductive traits. Implications: The need to carry out age validation studies for this species is highlighted.