Sei Whale

The sei whale is a slender rorqual with a dark steel-grey back, pale underside and a single prominent ridge along the top of the head. Its dorsal fin is tall and strongly curved, and the blowholes are protected by a raised splashguard. Adults commonly measure 12–16m and may weigh around 20 tonnes, with females slightly larger than males (Wikipedia, general species account).

Across its range, the species generally favours deep temperate and subpolar water rather than enclosed coastal seas or heavy ice. It feeds mainly on copepods, krill and small schooling fish, sometimes skimming near the surface instead of making forceful lunges. Sei whales are fast swimmers, usually occur alone or in small groups, and undertake broad seasonal movements that vary among populations (Wikipedia, general species account).