Amphipods
Amphipod means "duel footed", referring to differing design of their forward legs compared to the rear legs.
Gammariid amphipods are among the more mobile of the seafloor epifauna, as well as including a number of tub-dwelling forms. They occur through all depths from the upper intertidal to the deepest basin on both hard and soft bottoms. When you turn over seaweed washed ashore, the tiny creatures springing out of it are amphipods. They can occur in abundances of 100s of individuals per square meter. In nearshore regions, benthic species like Onisimus litoralis frequent the under-ice.
They are one of the most specious and morphologically diverse benthic groups, represented by at least 920 benthic species in the Arctic. The group ranges from carnivorous to herbivorous in feeding preferences, also acting as major scavengers on dead or detrital material as large as marine mammals. They are consumed mostly by fish, but are also important prey for benthic-feeding gray whales and some seabirds.
The ecology of some of the dominant nearshore forms is reasonabley weel known, but relatively little is known about most species. They are thought to have from single to multi-year life cycles in the Arctic.
Page Author: Russ Hopcroft
Updated: Feb 1, 2011
