Oithona similis Claus 1866

The most abundance surface-dwelling copepod of Arctic

Body almost completely transparent, red tinting may be present on female urosome (the tail); Lipid sac can be prominent; Urosome (tail) long (40-50% of prosome); Antennae longer then prosome, but less than total length

Boreal to arctic waters; Bipolar; Abundant on shelves, as well as over deep basins

Females spawn year-round, less in winter; Female carries eggs in 2 elongate clutches until hatching; Clutch size dependent on size of female, with maximums of ~30 and typically ~15-25 eggs; Generation length unclear, suggested as 1 year for Arctic and multiple generations per year in the sub-arctic; Life expectancy uncertain

Microcarnivore feeding on motile phytoplankton and protists, plus copepod nauplii