Amphipod Under Arctic Sea Ice

Preview An amphipod within Arctic sea ice.
(S. Harper, UAF, Hidden Ocean 2005, NOAA. )

Several species of amphipod like this one, Gammarus wilkitzkii, live permanently within Arctic sea ice. These animals are endemic, meaning they only live here. They acclimate to a wide range of salt levels in the water using a physiological response called osmoregulation.