The fin whale is the second-largest living animal, after the blue whale. This animal is very streamlined in appearance with a distinct ridge along the back behind the dorsal fin, which gives it the nickname "razorback". The dorsal fin, which is about 60 cm high, is set two thirds of the way along the back. The jaw is large and when the mouth is closed the lower jaw protrudes slightly beyond the tip of the snout.
Fin whales are slimmer and not as heavy as blue whales. On average, 85 ventral grooves run along the underside of their body and there are 350-400 baleen plates in their mouths.
Fin whales are found in all the oceans of the world, but their migration patterns are not well understood. In the Southern Hemisphere, fin whales migrate south to feed on krill and other plankton in the summer, and north to likely give birth in warm waters closer to the Equator in the winter. However, it is not clear whether all of the population engages in this migration every year.
In the Northern Hemisphere there are similar north-south migrations, and many whales appear to return to the same feeding grounds every year, but the pattern is not so clear, perhaps because of the influence of the Gulf Stream in the North Atlantic. Populations of northern and southern hemispheres never meet.
Adult fin whales are about 19 m long for males and 20 m for females, with a maximum of 25 m in males and 27 m in females. It is estimated that a 25-metre whale would weigh about 70,000 kg.
Fin whales are dark grey to brownish black, with pale or white undersides. The undersides of the flippers and flukes are also white. Some fin whales have a pale grey chevron on each side behind the head and there may be a dark stripe running up and back from the eye, and a light stripe arching down to where the flipper joins the body.
This species has a rare characteristic among mammals, known as asymmetrical pigmentation: the lower right jaw is bright white, the lower left jaw black. The reason for this unusual coloring is unknown, but some scientists have speculated that fin whales circle schools of fish with the white side facing the prey and frightening them into denser schools that are easier for the whale to catch.
Angola, Argentina, Australia, Bangladesh, Brazil, Canada, Ecuador, Faroe Islands, French Polynesia, French Southern Territories, Greenland, Hong Kong, Iceland, India, Indonesia, Italy, Japan, Kenya, Democratic People's Republic of Korea, Republic of Korea, Madagascar, Mexico, Myanmar, Namibia, New Zealand, Norway, Pakistan, Poland, Portugal, Russian Federation, South Africa, South Georgia and the South Sandwich Islands, Spain, Sri Lanka, Suriname, Svalbard and Jan Mayen, Taiwan, United Republic of Tanzania, Tunisia, United Arab Emirates, United Kingdom
Antarctic Peninsula and Weddell Sea, Bering-Beaufort-Chukchi Seas, Barents-Kara Seas, Mediterranean Sea, Northeast Atlantic Shelf Marine, Grand Banks, Chesapeake Bay, Yellow Sea, Okhotsk Sea, Patagonian Southwest Atlantic, Southern Australian Marine, New Zealand Marine, California Current, Benguela Current, Humboldt Current, Agulhas Current, Western Australia Marine, Panama Bight, Gulf of California, Galapagos Marine, Canary Current, Nansei Shoto, Sulu-Sulawesi Seas, Bismarck-Solomon Seas, Banda-Flores Sea, New Caledonia Barrier Reef, Great Barrier Reef, Lord Howe-Norfolk Islands Marine, Palau Marine, Andaman Sea, Tahitian Marine, Hawaiian Marine, Rapa Nui, Fiji Barrier Reef, Maldives, Chagos, Lakshadweep Atolls, Red Sea, Arabian Sea, East African Marine, West Madagascar Marine, Mesoamerican Caribbean Reef, Greater Antillean Marine, Southern Caribbean Sea, Northeast Brazil Shelf Marine.