Amphipod means "duel footed", referring to differing design of their forward legs compared to the rear legs.
Gammariid amphipods are the dominant fauna at the underside of Arctic sea ice. Three genera dominate in this habitat (Gammarus, Onisimus, Apherusa). Amphipods are consumed by Arctic cod (Boreogadus saida) and Arctic birds and seals. They occur in abundances of <5 to >100 individuals per square meter. In nearshore regions, benthic species like Onisimus litoralis frequent the under-ice habitat while ice endemic species associations occur in the multi-year sea ice regions as well as on first year ice. Recent work has indicated that several other species normally considered bottom-dwelling may at times live in association with the sea ice.
The group ranges from carnivorous to herbivorous in feeding preferences, sometimes acting as scavengers on dead or detrital materia, or even feeding on planktonl. Relatively little is known about their ecology and distribtion records are rare despite a presumed pan-actic distibution for most ice species. They are thought to have a multi-year life cycle in the Arctic.
Page Author: Bodil Bluhm
Created: February 4, 2009