Whale

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Beaked Whales

Beaked whales are small to medium-sized whales with long, pointed snouts and, in males, two to four protruding teeth on the lower jaw. These whales have slight depressions in the body wall where flippers can be tucked, most likely to reduce drag while swimming. Beaked whales are deep divers and may remain below water for 30 minutes or longer. They have been sighted in polar, temperate, and tropical oceans. The migration pattern of beaked whales is not well understood, but most species seem to travel singly or in pairs and stay within a limited range.

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Narwhals

The narwhal is typically about 4.7 m (15 ft) long and weighs about 1 metric ton. Narwhals have only two teeth, both in the upper jaw. In females the teeth usually remain embedded in the gums. In males the right tooth remains embedded, but the left tooth commonly grows out into a spiraling ivory tusk that grows up to 3 m (10 ft) long, straight forward from its head. Scientists believe that males use this tusk in fights against rival males.

Native to the cool waters of the Arctic and North Atlantic oceans where they live year-round, the narwhal is sometimes found in the company of belugas migrating with the seasonal movements of the Arctic ice. When narwhals surface after a dive, escaping air from the blowhole makes a shrill whistle. Females utter a low-pitched bellow to communicate with young.

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Belugas

Named for the Russian word byelukha, meaning “white,” belugas are black or brown in color at birth, then lighten with age until about age five, when they become milky white. Belugas grow to a length of 7 m (23 ft) and weigh from 700 to 1,600 kg (1,500 to 3,500 lb). The upper jaw contains 20 teeth and the lower jaw contains 16 teeth. The beluga lives year-round in Arctic waters, traveling in groups ranging from five to ten individuals up to a thousand or more. They communicate with a series of whistles, squeaks, bell-like sounds, and clicking noises.

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Dolphins

Sleek and powerful swimmers found in all seas, dolphins have well-defined, beaklike snouts and, depending on the species, 2 to 250 conical teeth. There are 40 species of dolphins, and they range in size from the small tucuxi dolphin, which grows to about 1.2 m (4 ft) long and weighs about 50 kg (110 lb), to the killer whale, which can grow up to 9.8 m (32 ft) in length and weigh over 5,500 kg (12,100 lb). Killer whales are among the fastest toothed whales, achieving bursts of speed close to 50 km/h (30 mph).

Some dolphins, such as the Atlantic bottlenose dolphin, commonly live close to shore, while others, such as the Pacific spinner dolphin, live much of their lives far from land. In Asia and South America, several species of river dolphins inhabit river systems such as the Ganges, Yangtze, Amazon, and La Plata. The Indian river dolphin is nearly blind and finds its way through murky waters using echolocation.

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Porpoises

Some people use the word porpoise to describe any small whale. But scientists typically apply the term to six species of whale. Compared to dolphins, porpoises are relatively small in size, averaging 1.5 m (5 ft) in length and 40 kg (88 lb) in weight. With some exceptions, porpoises have blunt, rather beaked snouts, and the upper and lower jaws each hold about 25 pairs of spoon-shaped teeth, which are expanded and flattened at the tips. Most porpoises have black or dark brownish-gray coloring on their backs and white or pale-gray coloring on their bellies. The common porpoise, also known as the harbor porpoise, is widespread throughout the waters of the Northern Hemisphere. The spectacled porpoise lives in the deep fjords of Tierra del Fuego and in the waters surrounding the Falkland Islands. The Dall's porpoise is among the fastest swimmers of all cetaceans, reaching speeds up to 56 km/h (35 mph).

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