The development of a sex-disaggregated Casal2 model for Patagonian toothfish (Dissostichus eleginoides) would better account for the population structure of toothfish in the fishery at Subarea 48.3 compared to the current combined-sex approach. In order to parameterise such a model, sex-specific estimates of key biological parameters are needed.
This paper extends the work of Marsh et al. (2022a, 2022b, 2023) by comparing sex-disaggregated biological parameters for toothfish in Subarea 48.3 to combined-sex estimates. Combined-sex estimates are similar to those from previous works, and sex-disaggregated analyses show significant differences between females and males. Female toothfish in Subarea 48.3 tend to be heavier at a given length, mature later, and grow to larger sizes than their male conspecifics. The combined-sex biological parameters used in the current Casal2 models are more closely aligned to those for females than for males, on account of more female toothfish being caught and sampled in the fishery. This work provides a foundation for the development of a sex-disaggregated Casal2 model for toothfish in Subarea 48.3.