Diet and population size structure of the Arctic shanny,Stichaeus punctatus (Pisces: Stichaeidae), at sites in eastern Newfoundland and the eastern Arctic

Abstract

The size structure and diet of the Arctic shanny,Stichaeus punctatus, were studied at two sites, one at Nuvuk Islands in the Arctic, and one at Newman Sound, in eastern Newfoundland. The Newfoundland population showed peaks corresponding to 0+,1+, and an accumulation of older individuals, while the Nuvuk population was dominated by 2+ and 3+ combined, and individuals aged 6+ and older. Epiphytic, harpacticoid copepods were the most important food items for the smaller Arctic shanny, but the importance of harpacticoid copepods decreased with increasing fish size. Harpacticoid copepods are thus a link between the macro-algae and the young stages of the Arctic shanny. Since Arctic shanny are the main food used by black guillemots to feed chicks, these copepods are also an indirect link between benthic algal production and these seabirds.