Gammarus wilkitzkii

The largest of the common Arctic's sea ice amphipods

Single clutch of 90-250 eggs per female per year; 6-7 months breeding period; Egg hatching from spring to fall; Period of retention of hatched juveniles within marsupium unclear; estimated life span 6-7 years

Adults predatory, omnivorous; Prey include harpacticoid and calanoid copepods, conspecifics, detritus, and ice algae; Juveniles mostly herbivorous

Transparent to whitish, eyes dark; Front part of antennae and part of some legs red-brownish; Strong claws; Antennae thick and hairly; Strong claws; Three upward-bent pairs of legs; Largest of all underice amphipods

Panarctic, endemic (only found in Arctic); Only found in association with sea ice; Often 'borrows' into ice for protection; Prefers multiyear ice, but can be found on first year ice