Sei Whale

The sei whale ( SAY; Balaenoptera borealis) is a baleen whale. It is one of ten rorqual species, and the third-largest member after the blue and fin whales. It can grow to 19.5 m (64 ft) in length and weigh as much as 28 t (28 long tons; 31 short tons). Two subspecies are recognized: B. b. borealis and B. b. schlegelii. The whale's ventral surface has sporadic markings ranging from light grey to white, and its body is usually dark steel grey in colour. (Wikipedia, general species account).

It is a filter feeder, with its diet consisting primarily of copepods, krill, and other zooplankton. It is typically solitary or can be found in groups numbering half a dozen. The species vocalizations usually last approximately half a second, and occur at 240–625 hertz. "Sei whale" is an anglicization of the Norwegian seihval, meaning "pollock whale". The species was so called because it "appeared off the coast of Norway at the same time each year as the pollock that came to feed on the abundant plankton". (Wikipedia, general species account).