Spatio-temporal modelling of the maturity, sex ratio, and physical condition of nylon shrimp Heterocarpus reedi (Decapoda, Caridea), off Central Chile

Abstract

Two key elements in the adequate, sustained exploitation of any fishery should be considered; the biological attributes of the species and how these vary over time and space. Research is needed to obtain a more thorough understanding of these effects, how they vary, and how they relate to environmental factors. For 17 years, biological information has been collected for Heterocarpus reedi (nylon shrimp) caught off central Chile (25-37 °S). Here, we analyze these data using generalized linear models and determine the factors responsible for changes in carapace length, body weight, maturity, and sex ratio. The environmental and alimentary conditions are better south of 32 °S, and this is probably associated with the better physical condition and reproductive attributes of H. reedi there. For example, individuals are larger, females are longer at first maturity (CL), and mature females are less prevalent. We outline a theoretical foundation that can guide future research on H. reedi. We also suggest that future conservation measures consider biological attributes within a spatial context