Sperm whale (Physeter macrocephalus )
Family Physeteridae
Description: By far the largest of the toothed cetaceans, comparable in size to some of the UAE’s baleen whales, growing to 20m in length. Sperm whales are dark grey-brown in colour, often paler around the belly, throat and mouth. The distinctively shaped head can be a third of the entire body length with a single blowhole at the very front of the blunt snout. Look out for the diagnostic blow, which shoots forward. Following a deep dive, the explosive blow of a sperm whale can be heard from quite a distance. If you are able to get close, you may notice the smooth skin of the head and the wrinkly, corrugated appearance of the rest of the body.
The dorsal fin is more of a hump than a fin, and is set well back on the body. Behind it, smaller knuckle-like lumps reach back to the tail flukes. Unlike the humpback whale, with which it may be confused from a distance, the sperm whale has broad tail flukes, with a straight edge, that are uniform in colour. Sperm whales also lack the long, white flippers and white tail markings of the humpback whale.
Habitat: Individuals observed thirty nautical miles due east of Fujairah were positioned directly above the edge of the continental shelf, where the water depth suddenly changes from less than 600m to well over 1,000m. This is ideal habitat for feeding sperm whales, which may remain submerged for over an hour, hunting giant squid and other prey by use of their sonar.
Range: The deep water feeding requirements of this species restricts it to the offshore environment of the UAE east coast.
Comments: The sperm whale’s huge, blunt head houses the largest brain in the animal kingdom (up to ten kilograms in weight) and contains an asymmetrical array of nasal passages, muscle and oily tissues known as the spermaceti organ. This extraordinary organ, unique to sperm whales is believed to be used in buoyancy regulation and in the reception of ultra-sonic sound waves. The spermaceti it produces was formerly a target of whalers, and was used in the manufacture of certain cosmetics and lubricants. Ambergris was also obtained from sperm whales. This is a fatty concretion formed from bile, in the hind gut of adults. It has also often spelt doom for this creature as it was highly prized by whalers, and was used in the perfume industry until very recently. Synthetic substances which can be used instead of both ambergris and spermaceti have long been available.