Age and Feeding Habits of Caml Grenadier Macrourus caml in Cosmonauts Sea

Macrourus caml is a main by-catch in the Southern Ocean fishery and a main prey species of Antarctic toothfish Dissostichus mawsoni; it plays an important role in the Southern Ocean ecosystem. In this study, age estimation and stomach content analysis were conducted by using samples collected from the Cosmonauts Sea in 2021. The main objectives of this study were to estimate the age and diet of grenadier M. caml and explore the feeding habits of M. caml. Morphological analysis and molecular identification were conducted to determine the diet of M. caml in this study. Stomach content analysis showed that M. caml mainly fed on Malacostraca, Sagittoidea, Cnidaria and Algae, with the Malacostraca accounting for over 50%. The feeding habits of male and female M. caml were similar. The age of M. caml ranged from 9 to 19 years. Additionally, with the increase of body size, the proportion of Cnidaria was decreasing whereas the proportion of Malacostraca was increasing. The results would provide a reference for exploring the trophic level of M. caml and the food web in the Cosmonauts Sea.