Age and growth of the subantarctic skates Bathyraja eatonii and B. irrasa in Kerguelen and Amblyraja taaf in Crozet through the use of the vertebrae centrum

In the Patagonian toothfish (Dissostichus eleginoides) fishery occurred in Kerguelen and Crozet, three species of skates are mainly caught as bycatch. Ageing has proven to be difficult for deep-sea skate species though, this is of dire importance to perform fishery assessment and management. Preliminary studies had indicated that centrum observations may provide reliable information when conventional method based on the corpus calcareum is unlikely to produce results due to low calcification. In this analysis, we therefore performed age reading on the centrum of 285 vertebrae resulting in length-at-age and growth curves estimations. Overall, our results revealed that the three skate species display faster growing pattern than expected suggesting relatively productive life-history traits. However, this ageing method was not validated yet.