Age and growth of two smooth-hound shark species from the eastern central Pacific Ocean

Context Understanding age and growth is fundamental for fisheries management, yet these parameters remain unestimated for sicklefin smooth-hound shark (Mustelus lunulatus) and brown smooth-hound shark (Mustelus henlei) in the Ecuadorian Pacific, limiting population assessments and management efforts. Aims To estimate the age and growth parameters of M. lunulatus and M. henlei in the Ecuadorian Pacific. Methods Vertebrae from 129 M. lunulatus and 164 M. henlei were sectioned for age estimation. Length-at-age data were analysed using von Bertalanffy, Gompertz and Logistic models under Bayesian and frequentist approaches. Key results Bayesian analysis showed the Gompertz model best fit M. lunulatus (combined sexes and females), whereas the von Bertalanffy model fit males. For M. henlei, von Bertalanffy was optimal across all groups. Model selection was based on the leave-one-out information criterion (LOOIC). Conclusions Both species exhibited moderate growth rates and relatively small asymptotic sizes compared with other shark species. Implications The information presented here has important implications for fisheries management, because it can be incorporated into future population models to improve assessments and conservation strategies.