Name : Sei Whale
Scientific Name : Balaenoptera borealis
Class : Mammalia
Family : Balaenopteridae
Order : Cetacea (suborder) -Mysticeti
Shape : The Sei Whale has a slender head. The head can be between one-fifth and one-quarter of its body length, which increases with age. They have between 318 - 410 baleen plates on each side of the upper jaw. They have 35 - 60 bristles per centimetre whereas all other rorquals have fewer than 35.
Fins : The dorsal fin is slightly further forward on the body than on other rorquals with smooth trailing edges. Flukes are small in relation to body size.
Length : Adults measure between 12 - 16 metres and the newborns between 4.4 - 4.8 metres. Females are larger than males.
Weight : Adults weigh between 20 and 30 tons and newborns 725 kg.
Colour : The baleen is usually grey-black all over (though often with a greenish or bluish metallic sheen). In some individuals, a small number of plates near the tip of the snout are partly white or cream-coloured, or streaked with white.
Diet : Fishes, krill and octopus.
Population : Not normally found in extreme polar waters, although subarctic and subantarctic are favoured summer feeding grounds.
Migration : Migrations are poorly known and probably quite irregular.
Habits : More regular dive sequence than most other rorquals and stays near the surface more consistently. Seldom breaches. Dorsal fin and back remain visible for longer periods of time than with other large whales. Whales skim for their prey rather than lunging or gulping.
Distribution : The Sei Whale is most common in the southern hemisphere. May be seen around islands but rarely close to shore elsewhere.