Translations:AY Honors/Cetaceans/Answer Key/35/en

Family Physeteridae: Sperm Whales

There are three species in the sperm whale family, including the largest toothed predator in the world and smallest whale in the world. A common characteristic of these species is the spermaceti, a semi-liquid waxy white substance filling the 'case' or spermaceti organ in the whale's head, which is thought to be involved in providing ballast for diving and maintaining buoyancy. This may be done by flushing cold water through the nose, hardening the spermaceti, to dive, and pumping warm blood to melt the spermaceti to surface. All three species dive to great depths to find food, although the sperm whale is believed to dive much deeper than either of its smaller cousins. Sperm whales eat squid, fish, and even sharks.

Physeter macrocephalus

Sperm Whale (Physeter macrocephalus)

Where found: The sperm whale can be found anywhere in the open ocean.

Description: Largest of the toothed whales and largest toothed predator in the world. The Sperm Whale breaks all kinds of records! Mature males may reach 20.5 metres (67 ft) and 57,000 kilograms (males much larger than females). It is the loudest of any animal, second deepest diving mammal with dives of up to 90 minutes, largest brain (five times heavier than a human brain), 116 kg (255 lbs) heart, longest intestinal system (exceeding 300 m in larger specimens) and other mind blowing measurements. The sperm whale's distinctive shape comes from its very large, block-shaped head, which can be one-quarter to one-third of the animal's length. The S-shaped blowhole is located very close to the front of the head and shifted to the whale's left, giving a distinctive bushy, forward-angled spray. Primary food is squid and they can live for more than 60 years. The sperm whale's flukes are triangular and very thick. Proportionally, they are larger than that of any other cetacean, and are very flexible. The whale lifts its flukes high out of the water as it begins a feeding dive. It has a series of ridges on the back's caudal third instead of a dorsal fin. The largest ridge was called the 'hump', and can be mistaken for a dorsal fin because of its shape and size. In contrast to the smooth skin of most large whales, its back skin is usually wrinkly and has been likened to a prune by whale-watching enthusiasts. From the early 18th century through the late 20th the species was a prime target of whalers. The head of the whale contains a liquid wax called spermaceti, which was used in lubricants, oil lamps, and candles. Ambergris, a waste product from its digestive system, is still used as a fixative in perfumes. The Sperm Whale is now protected by a whaling moratorium, and is currently listed as vulnerable. Sperm whales have sunk ships, including the real life Moby Dick who sunk the Essex. Jonathan Bird's Blue World: Sperm Whales

Kogia breviceps

Pygmy & Dwarf Sperm Whales (Kogia breviceps)

Where found: Dwarf and Pygmy sperm whales are found throughout the tropical and temperate waters of the Atlantic, Pacific and Indian Oceans. However, they are rarely sighted at sea, so most data come from stranded and captured animals - making a precise range and migration map difficult. The dwarf is more coastal than the pygmy. There is no accurate estimate of number of these whales in the world or good data on conservation status.

Description: The dwarf sperm whale is the smallest species commonly known as a whale. It grows up to 2.7 m (8.9 ft) in length and 250 kilograms (550 lb) in weight. The species makes slow, deliberate movements with little splash or blow and usually lies motionless when at the sea's surface. Consequently it is usually observed only in very calm seas. These two species were not distinguished from each other until 1966 and are difficult to tell apart but the dwarf is slightly smaller and has a larger dorsal fin than the pygmy. The body is mainly bluish gray with a lighter underside with slightly yellow vein-like streaks possibly visible. There is a white false gill behind each eye. The flippers are very short and broad. The top of the snout overhangs the lower jaw, which is small. The whales have long, curved and sharp teeth (0–6 in the upper jaw, between 14 and 26 in the lower). These whales expel a dark reddish substance when frightened or attacked—possibly to put off any predators. They are usually solitary or paired but have occasionally been seen in small groups. All sperm whales have a spermaceti organ in the forehead. The brain of the dwarf sperm whale is roughly half a kilogram in mass.Video of stranded Pygmy Sperm Whale