Giants of the deep

Compiled by Kristen Jackson

Gwendolyn Brooks College Prep

The sperm whale is the largest toothed whale in the world. (The blue whale is the largest animal in the world but has no teeth.) It is also referred to as Physeter macrocephalus. It has 20 to 26 teeth on each side of its lower jaw. It is one of the deepest diving mammals; its spermaceti organs help adjust the whale’s buoyancy.

A sperm whale can live to about 70 to 80 years. The skin is usually dark gray to black but is occasionally light gray. It has a distinctive, prune-like texture and has the largest brain of any living mammal. An adult male sperm whales weigh 40 to 50 tons and its heart about 277 pounds.

It’s called a sperm whale (see accompanying video) because of the milky white waxy stuff called spermaceti found in its head and once collected for use in candles, ointments and cosmetics. But the original whalers thought it was sperm and that’s how the mammal got its name.

Sperm whales are located pretty much in major oceans of the world. Adult male sperm whales tend to be loners but swim to meet mothers periodically. Sperm whales are curious animals and deep divers and swim leisurely at the surface at about 3 to 9 mph.

The sperm whale has a single blowhole that is s-shaped and is about 20 inches long. It can hold its breath for as long as an hour. It has a 4- to 12-inch-thick layer of blubber. An adult sperm whale can eat about a ton of food each day. The sperm whale swims leisurely at the surface at about 3 to 9 mph. They can swim faster when trying to get away from danger, of 21 to 27 mph for up to an hour.

Sperm whales are considered an endangered species. There are about 200,000 of them worldwide. They were hunted for many years, since their meat, oil and other body parts are very valuable. Since whale hunting has decreased in the last few decades, their populations are starting to recover.

The sperm whale prefers ice-free waters. Although both sexes range through temperate and tropical oceans and seas, only adult males populate higher latitudes. Females stay in groups of about a dozen individuals and their young. Males leave these "nursery pods" at between 4 and 21 years of age and join with other males of similar age and size.

As males grow older, they tend to disperse into smaller groups, and the oldest males typically live solitary lives. Mature males have beached themselves together, which is not really understood.

Sources: enchantedlearning.com; nmfs.noaa.gov; nationalgeographic.com