Sperm Whale
The Sperm Whale is found in all oceans of the world, and, although well-known in the Mediterranean, rarely enters semi-enclosed or shallow seas. Males venture into the extremes of the Northern and Southern Hemispheres more frequently than females ever do. In summer they migrate to higher latitudes in both hemispheres but return to lower latitudes in winter, though some populations are resident all year round.
Classification: The Sperm Whale, Physeter macrocephalus, was classified by Linnaeus, with Physeter meaning 'blower' (referring to the whale's forceful, singular spout). There is, however, some disagreement about whether the Sperm Whale's specific name should be macrocephalus (meaning 'big head') or catodon (meaning 'teeth only in lower jaw'), although the former is generally accepted.
Local Names: Cachalot; Kaskelot; Cachalote; Great Sperm Whale. This cetacean's common name is derived from the milky wax substance in its head which early whalers likened to the fluid produced by the testes to carry sperm.
Description: Made famous by Herman Melville's Moby Dick, this is the species most people associate with the word 'whale'. The largest of the toothed whales, it is dark brown to dark grey in colour, with occasional albino and black individuals being recorded. The skin is wrinkly and may be scarred. Although the triangular tail flukes are broad and powerful, flippers are short and stubby, and the dorsal fin is usually more akin to a series of humps down the tail stock's ridge than an actual 'fin'. The Sperm Whale's head is over a third of the total body length of the animal, and is well-known for being big and bulky and barrel-shaped. Males are 15-20.5m in length and weigh between 45-57 tonnes, with females measuring 11-13m and weighing around 20 tonnes. The lower jaw holds approximately 50 rounded teeth in two parallel rows, each tooth weighing over a kilogram.
Recognition at sea: Sperm Whales show little of themselves above the surface, appearing as a large 'log', often lying motionless. Their blow is one of the most recognisable of all cetaceans: single, bushy, about 5m and projecting to the forward-left of the animal.
Habitat: Sperm Whales normally only venture close to shore when the depth of the water increases rapidly away from the coast (as it does around volcanic islands), or when ill. Other than this, they are mainly oceanic creatures, with males withstanding virtually all temperatures from extreme cold to extreme warm, although females remain in areas with a surface temperature of 15°C or more.
Food & Feeding: In most areas, Sperm Whales feed on squid and octopi alone, often taking prey at considerable depths. In other areas, fish - including sharks, rays, cod, redfish and laternfish are also taken. Krakens, or giant squids, are also prey to this huge animal. Floating debris is also ocassionally ingested.
Behaviour: The family group of around 10-20 individuals is the basic social unit, consisting mainly of mature females (cows) with their calves. The females remain in this tight-knit family throughout their lives, from birth to death, whereas young males leave at puberty to join a pod of medium-sized 'batchelors'. As they get older, the males (bulls) become more anti-social and may eventually become the solitary individuals seen in cold temperate and polar waters. Often Sperm Whales gather together, en masse, in groups of hundreds and even thousands, covering an area of many kilometers but obviously travelling as a unit. The deepest and longest-diving of all cetaceans, the Sperm Whale can remain below the surface for around 90minutes, at depths of 1,100-3,200m. They communicate via pulsed clicks, and it has been theorised that some of these clicks are so powerful that they are used to 'stun' their prey.
Longevity: Approximately 70 years.
Estimated Current Population: Approximately 2,000,000 animals.
The Influence of Man: Sperm Whales were killed mainly for the oil produced from their thick blubber, and for the wax found in the head - known as spermaceti. Originally used for purfume, ambergris also came from this species of whale; and the black, oily meat of the Sperm Whale was never taken for food, except by a few communities. This cetacean has been killed every year from around 1690-1987, with the heavy commercial fishery beginning in earnest in the early Eighteenth Century. Hundreds of thousands had been killed in all oceans of the world, with a peak in the 1963/64 whaling season of 29,300 individuals. In 1971 the first International Whaling Commission restrictions were enforced, and by 1984 all commercial Sperm Whale catches were banned. Sperm Whales are now common whale-watching attractions, especially in the waters around New Zealand.
Source: CETACEA
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