Gut contents and stable isotope analyses of the Antarctic fish, Notothenia coriiceps (Richardson), from two macroalgal communities

Gut contents studies have shown that Notothenia coriiceps, a prevalent shallow water fish species along the western Antarctic Peninsula, has a highly variable diet. This variability, coupled with small home ranges, suggest that microhabitat may play a role in determining the chief prey items of N. coriiceps. We trapped fish from three sites comprised of two different algal microhabitats around Palmer Station, Antarctica and investigated their diets via gut contents and stable isotope analyses. Gut contents analysis revealed that amphipods were the primary prey item at all three sites, but the distribution of amphipod species eaten varied between sites. Other important prey classes were snails, limpets, algae and fish. Overall, the gut content data suggested that algal microhabitat was less important than geographic location in determining diet. On the other hand, stable isotope analysis indicated that fish from the Palmaria decipiens site were more enriched in both carbon and nitrogen than fish from Desmarestia menziesii sites. Hence, it would appear that in the longer term, algal microhabitat may influence fish diets and trophic relationships.