What is a Sperm Whale?

Jessica Ellis
Jessica Ellis

The sperm whale, Physter catadon is the largest toothed whale and largest carnivore alive. They live in every ocean in the world and are believed to live longer than 50 years. Because of their carnivorous diet, this whale has often been maligned as literary villains, including Captain Ahab’s vicious prey in Moby Dick and the terrifying, puppet-eating Monstro in Pinocchio. Despite this fearsome reputation, there are few recordings of attacks on humans or ships, although their fearsome battles with giant squid are believed by some to be titanic clashes.

Sperm whales were hunted for years for their spermaceti, which was often used in lamps.
Sperm whales were hunted for years for their spermaceti, which was often used in lamps.

Sperm whales reproduce rarely, with adult females giving birth every four to six years on average. A calf is between 11-16 ft (3.4-4.9 m) in length and weighs approximately one ton (907 kg.) Calves usually nurse for two years, and remain with pods of adult females and other calves until reaching maturity. Adult males tend to travel alone, interacting with the matriarchal pods only for breeding purposes.

Sperm whales are the largest carnivores alive.
Sperm whales are the largest carnivores alive.

Adult males typically grow to be 50-60 feet long, weighing about 35-45 tons, although some specimens have been much larger. Unlike most other whale species, where females are similarly sized or even larger, adult females are considerably smaller than males. The typical adult female is between 30 and 36 feet long and usually weighs no more than 14 tons. Coloration between genders is similar, with both sexes having a dark gray or gray-brown back and light gray underbelly.

The most characteristic feature of a sperm whale is its gigantic head, which contains a liquid, waxy substance called spermaceti. The spermaceti aids the whale in its incredibly deep dives by helping maintain body pressure and store oxygen. It may also help the whale find food and discover obstacles through echolocation.

Unfortunately for the whales, the spermaceti is also prized by whalers as an oil and lubricant, and lead to three centuries of commercial slaughter of the whales. Experts suggest that, despite an International Whaling Commission ban on hunts in 1986, the population is slow to recover. Some recent population estimates suggest a worldwide population of 360,000 animals, down from a pre-whaling estimate of 1.1 million.

Despite the famous elusiveness of the giant squid Architeuthis, they are believed to make up some part of the diet of the whale. Stomach contents of whale carcasses often contain indigestible squid beaks, and skin samples often show scarring from squid suckers. Although a battle between squid and whale has never been officially recorded, experts have various theories as to how a sperm whale kills and eats the 50 ft long squid. Some suggest that, as the squid remnants discovered show no bite marks, the whale may carefully sneak up on its prey. Others favor the idea that the whale can use the large cavity of its head to produce a sound wave, stunning the squid.

Despite these theories, fiction cannot seem to let go of its violent picture of the sperm whale. Two records exist of sperm whales attacking ships in the 19th century, although some accounts suggest that the whales were wounded and acting in self-defense. Still, the idea of a true man-eating whale appears throughout literature and film.

In Moby Dick, the white whale is not only remarkably adept at evading attack, but also can be interpreted as genuine evil. Unlike the book version where one of the antagonists is a blood-thirsty shark, the beloved Disney film of Pinocchio casts a sperm whale as the evil Monstro. This whale, which seems to have dragon-like properties as it snorts smoke, is intent on nothing more than keeping a loveable puppet from a happy life.

Although often maligned in fiction, the sperm whale has many fans. Some whale watching aficionados consider the sperm whale a prime sighting, and conservation efforts to protect the species have increased in the past few decades. Like all whales, the species is vulnerable to pollution and to climate change. Although population has increased since the IWC ban, experts believe this enormous animal needs human protection in order to continue a healthy existence.

Jessica Ellis
Jessica Ellis

With a B.A. in theater from UCLA and a graduate degree in screenwriting from the American Film Institute, Jessica is passionate about drama and film. She has many other interests, and enjoys learning and writing about a wide range of topics in her role as a wiseGEEK writer.

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Discussion Comments


I just want to mention that the over-size head of the sperm whale is not only for show; it is not an empty show piece. Out of all the known mammals on earth and all the mammals that have every been on earth, the sperm whale has the largest brain. I guess that explains why Moby Dick was so tricky and difficult to capture.


Sperm whales can dive almost two miles down into the ocean, which for some reason I find contradictory because of their massive size. However, they can remain under water for about an hour and a half, so they have plenty of time to get those large bodies back to the surface to take in air.


I have spent a large portion of my life on and in the water. One of the most remarkable and awe inspiring sites I have seen while exploring the ocean is the sperm whale. While the overall size of the body is enough to make you take notice, the vision that sticks with me is the enormous head of the whale.

I can understand why writers think this creature makes for a worthy villain in their stories, but in my experience I have found the animal more majestic than evil.

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