Balaenoptera borealis   Lesson, 1828

sei whale
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Image of Balaenoptera borealis (sei whale)
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Mammalia | Cetacea | Balaenopteridae
Common names | Synonyms | CoL | ITIS | WoRMS

Main reference
Jefferson, T.A., S. Leatherwood and M.A. Webber. 1993. (Ref. 1394)
References | Biblio | Coordinator | Collaborators

Size / Weight / Age
Max length : 1,800 cm TL male/unsexed; (Ref. 1394); max. published weight: 30.0 t (Ref. 1394)


Climate / Range
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).
Countries | FAO areas | Ecosystems | Occurrences | Introductions

Biology     Glossary (e.g. epibenthic)

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, Bryde’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).

IUCN Red List Status (Ref. 96402)

  Endangered (EN) (A1ad)

CITES status (Ref. 94142)

Threat to humans

Human uses
Fisheries: commercial
FAO(fisheries: production) | FisheriesWiki | Sea Around Us |

More information

Common names
Egg development
Mass conversion

Internet sources
BHL | BOLD Systems | Check for other websites | Check FishWatcher | CISTI | DiscoverLife | FAO(fisheries: species profile; publication : search) | GenBank (genome, nucleotide) | GOBASE | Google Books | Google Scholar | Google | ispecies | National databases | PubMed | Scirus | Sea Around Us | FishBase | Tree of Life | uBio | uBio RSS | Wikipedia (Go, Search) | Zoological Record

Estimation of some characteristics with mathematical models

Vulnerability (Ref. 71543)
Very high vulnerability (90 of 100)
Price category (Ref. 80766)