sei whale (redirected from Balaena borealis)

sei whale

 or Rudolphi's rorqual

Swift species (Balaenoptera borealis) of baleen whale in the rorqual family. It is 40–50 ft (13–15 m) long and is bluish gray or blackish above and paler below. It has small flippers, about 50 short lengthwise grooves on its chest, and dark baleen with pale, silky, inner fringes. It inhabits oceans from the Arctic to the Antarctic, migrating between cold and temperate summer waters and winter breeding grounds in warmer regions.