Kingdom Animalia Infraorder Cetacea Phylum Chordata Rank Subspecies | Class Mammalia Family Balaenopteridae Genus Balaenoptera Order Even-toed ungulate | |
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Similar Balaenoptera, Balaenoptera musculus musculus, Even‑toed ungulate, Megaptera, Tropical bottlenose whale | ||
The northern fin whale (Balaenoptera physalus physalus) is a subspecies of fin whale that lives in the North Atlantic Ocean and North Pacific Ocean. It is possible that the population in each ocean represents a separate subspecies. At least one other subspecies of fin whale, the southern fin whale (B. p. quoyi), exists in the southern hemisphere.
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Size
Northern fin whales are smaller than their southern hemisphere counterparts, with adult males averaging 18.5 m (61 ft) and adult females 20 m (66 ft). Maximum reported figures are 22.9 m (75 ft) for males and 24.7 m (81 ft) for females in the North Pacific, while the longest reliably measured were 20.8 m (68 ft) and 22.9 m (75 ft) — all were caught off California, the former in the 1920s and the latter in the 1960s. At sexual maturity, males average 16.8–17.6 m (55–58 ft) in the North Atlantic and 17.4–17.7 m (57–58 ft) in the North Pacific, while females average 17.7–19.1 m (58–63 ft) in the North Atlantic and 18.3–18.6 m (60–61 ft) in the North Pacific. At birth, calves are 6.4 m (21 ft) in the North Pacific.
Reproduction
Because of the opposing seasons in each hemisphere, B. p. physalus breeds at a different time of the year than B. p. quoyi. Peak conception for B. p. physalus is December-January, while peak birthing is in November-December — in both the North Atlantic and North Pacific.