Gammarus wilkitzkii Fabricius, 1775
The largest of the common Arctic's sea ice amphipods
Size
- juveniles ~ 2 mm
- Adults up to 6 cm
Color & Characteristics
- 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
Habitat
- 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
Feeding
- Adults predatory, omnivorous
- Prey include harpacticoid and calanoid copepods, conspecifics, detritus, and ice algae
- Juveniles mostly herbivorous
Life cycle
- 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
Page Author: Bodil Bluhm
Created: Feb 4, 2009
