(Linnaeus, 1758) - Fin whale
Distinctive Characteristics
Fin whales are large, but very sleek and streamlined. From above, the head is more pointed than that of the blue whale, and the dorsal fin tends to be taller, more falcate, and set farther forward on the tail stock than in the blue whale. The dorsal fin rises at a shallow angle from the animal's back.
The most distinctive feature of the fin whale, however, is its coloration. The body is black or dark brownish grey above and on the sides, and white below, but the head colour is asymmetrical. The left lower jaw is mostly dark, while the right jaw is largely white. There tend to be several light grey V-shaped “chevrons” on the back behind the head.
Fin whales have 260 to 480 baleen plates per side; the plates are dark, often striated with bands of grey and fringed with horizontal lines of yellowish white. Usually, the front one-half to one-third of the right side plates have more light pigmentation than those on the left. The 50 to 100 throat pleats are long, and reach to the navel. The thin blow is 4 to 6 m tall.
Can be confused with
The other 3 medium to large balaenopterids (blue, sei, and Bryde's whale) are likely to be confused with fin whales. Careful attention to colour pattern, head shape, and dorsal fin shape and position will help to distinguish them. The head of fin whales is much more pointed than that of blue whales, and the dorsal fin is set further back and rises at a shallower angle than those of sei or Bryde's whales. The best clue to identification, however, is the asymmetrical coloration of the head.
Size
Length at birth is 6 to 6.5 m. Adults can reach a maximum of 27 m in the Southern Hemisphere, but most Northern Hemisphere adults are less than 24 m long. Large animals may attain weights of up to 75 t.
Geographical Distribution
Fin whales inhabit primarily oceanic waters of both hemispheres. They are seen near shore, most commonly where deep water approaches the coast. Fin whales can be seen in tropical, temperate, and polar zones of all oceans.
Biology and Behaviour
Fin whales are capable of attaining high speeds, possibly to 37 km/h, making them one of the fastest great whales. They rarely raise their flukes on a dive, but they do occasionally breach. Fin whales tend to be slightly more social than other rorquals, gathering in pods of 2 to 7 whales, or more.
Young are born on breeding grounds in tropical and subtropical areas in mid winter.
Fin whales feed on small invertebrates, schooling fishes, and squid. They are active lunge feeders.
Exploitation
Following depletion of blue whale stocks, whalers shifted their attention to fin whales. Populations everywhere were substantially reduced. At present the worldwide population does not seem to appear in any immediate danger.
IUCN Status
Vulnerable.