Mammalia | Cetacea
Environment / Climate / Range
Pelagic; depth range 0 - 342 m (Ref. 116169). Tropical; 8°C - 25°C (Ref. 75906); 90°N - 90°S, 180°W - 180°E
Circumglobal: Balaenoptera borealis borealis: Greenland, Iceland, Norway, North Carolina, Bay of Biscay, Mediterranean Sea, South Carolina, Gulf of Mexico, Bay of Campeche, Caribbean Sea, Cuba, Anguilla, Morocco, Mauritania, Alaska, Bering Sea, Gulf of Alaska, Japan, Southern California, Ogasawara, Mexico, Islas Revilla Gigedo (Pacific Ocean); Balaenoptera borealis schlegellii: Antarctica, Brazil, Angola, South Africa, Western Australia, Cook Straits, New Zealand, Peru, Java Indonesia (Ref. 1522).
Length at first maturity / Size / Weight / Age
Maturity: Lm 1,330.0  range ? - ? cm Max length : 1,800 cm TL male/unsexed; (Ref. 1394); max. published weight: 30.0 t (Ref. 1394)
Largest of the sei whales. Found in open oceans, restricted to mid-latitude temperate zones. Skims copepods and other small prey types (Ref. 1394). Mean lengths at maturity is 1330 cm for females and 11280 cm for males (Ref. 75906). As the larger rorquals became scarce in recent decades, hunting pressure on sei, Brydeâ€™s, and minke whales increased, largely in the Antarctic. Although heavily depleted, sei whales have recovered somewhat more successfully from hunting than other large baleen whales (Ref. 1394). Found in open oceans (Ref. 1394); feed at the shelf break and seaward throughout the summer (Ref. 96832). Restricted to mid-latitude temperate zones. Skims copepods and other small prey types (Ref. 1394); also feeds on euphausiids and a variety of fish including saury and whiting. Also a "swallower". Zooplankton concentrations influence where the whales feed. Migratory (Ref. 96832). Commonly in groups of 2 to 5 individuals (Ref. 801).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Jefferson, T.A., S. Leatherwood and M.A. Webber. 1993. (Ref. 1394)
IUCN Red List Status (Ref. 115185)
CITES status (Ref. 108899)
Threat to humans
FAO(fisheries: production) | FisheriesWiki | Sea Around Us
Estimates of some properties based on models
Very high vulnerability (90 of 100)