Age determination of Notothenia gibberifrons from the South Shetland Islands, Antarctic Peninsula subarea (Subarea 48.1)
ge determination was carried out on Notothenia gibberifrons specimens collected at two localities near the South Shetland Islands (Low I. and Potter Cove, 25 De Mayo/King George I.). Samples consisted of small and medium sized fish (total length - 14.8-38 cm). Otolith and scale readings have been compared in 19 Potter Cove specimens. In some cases scale readings gave a result of one year more. This could arise from the difficulty in differentiating between false and annual checks in scales. Age determination by otolith cross sections proved to be the most reliable method. Mean length data at age presented here for Low I. specimens were compared with previous published values. This confirmed that fish from the Antarctic Peninsula subarea are smaller than those in the same age group around South Georgia. Likewise, our values are lower than the ones reported previously for specimens of South Bay, Palmer Archipelago. Possible reasons for these differences are discussed. It is expected that the Otoliths/Scales/Bones Exchange System established by CCAMLR will help to eliminate discrepancies in age and growth studies of Antarctic fish.