Sperm whaling was a major industry in the 19th century and featured in the famed novel of the time, Moby Dick. The whales are currently listed as vulnerable by the IUCN. The whales have a distinctive appearance due to their square-shaped heads, easily recognizable in comparison to other whales. These whales are also the loudest animals in the world. They create intense vocalizations that could, in theory, vibrate a human being to death. 


Appearance 

The sperm whale is one of the largest whale species in the world. It can grow to around 67 feet and live to 70 years of age and longer. The sperm whale is also the largest toothed whale, more than 20 feet larger than the second largest toothed whale, Baird’s beaked whale. Some reports have cited far larger sperm whales, up to 80+ feet. But, these are unconfirmed citing and may be exaggerated. 

For example, the famed whale that sunk the Essex, the ship that inspired Moby-Dick,  that’s described as being 85 feet in length. The largest sperm whale ever recorded was fifty-nine feet and weighed in at 56 long tons, or 63 short tons. 

Sperm whale skeleton
Sperm whale skeleton 

Credit: H. Zell 

The sperm whale has a unique appearance making it hard to mix up with another specimen. It has a large, blocky head that takes up a great deal of the animal’s total length. The blowhole is s-shaped and located close to the front of the head. Their spray follows this direction and is forward-leaning. The sperm whale’s tail is very thick and larger, proportionally than all other cetaceans.

The whale also has a series of ridges on its back instead of a dorsal fin. The same skin around its back is usually wrinkled, in contrast to other whales. Sometimes it’s described as “prune-like.” 
Interestingly, the sperm whale also has the largest brain of any known living or extinct animal on earth. It weighs around 17 pounds or 7.8 kilograms. 

sperm whale brain
The sperm whale’s large brain

Credit: Yohei Yamashita


Diet 

Sperm whales can dive between 300-800 meters or 980-2,620 feet in search of food. These dives may last up to an hour. They eat everything from squid to octopuses and rays. Much of what scientists know about some deep-sea creatures, like the deep-sea squid, has been determined based on remains in sperm whales’ stomachs. 

The sperm whale has eighteen to twenty-six teeth on each side of its lower jaw. These teeth fit into sockets on the upper jaw. They are cone-like in shape and around 2.2 pounds each. The teeth can be used, but scientists have posited that they are not necessary for catching and killing prey the whales desire, such as squid. 

Some scientists have suggested that the teeth are used aggressively between males. 

sperm whale on beach
View of sperm whale teeth and upper sockets – see also the reasons behind why whales are endangered

Credit: Julian Ilcheff Borissoff


Habitat 

Sperm whales live around all deep oceans, from the equator to the edge of the Arctic and Antarctic ice packs, according to NOAA. The whale populations are still recovering from commercial whaling in the 19th and 20th centuries that decreased their populations substantially. 

Sperm whales are rarely found close to land due to the fact that they prefer to hunt in deep waters. Sometimes, they do venture close to islands, like New Zealand’s South Island and the Galapagos, according to Whales.org.  

Reproduction 

When choosing a mate, bulls fight over females, often mating with more than one. They do not provide any care for the young but do play a role in the younger bulls’ lives, helping them learn how to survive and exert dominance among other males. 

Male sperm whales become sexually mature around 18 years of age, and female sperm whales are fertile at around nine years of age. They gestate for about 14-16 months and give birth to one baby at a time. They lactate for 19-42 months afterward, and calves may suckle for up to 13 years. 

When born, both sexes of sperm whales are the same. They are sexually dimorphic. They are usually between 12-14 feet when born, with females growing to 35 feet when mature and males to around 60 feet. Sperm whales can live more than seventy years. 

Threats 

The whales are currently listed as vulnerable by the IUCN. This is due to overfishing during the 19th and 20th centuries. Commercial whaling during this period decimated populations, but the moratorium in the mid-1980s stopped much of the predation by human beings. Today, their populations are increasing and recovering. 

Facts about Sperm Whales 

  • The whales are currently listed as vulnerable by the IUCN. 
  • Male sperm whales become sexually mature around 18 years of age and female sperm whales are fertile at around nine years of age.
  • The sperm whale is one of the largest whale species in the world.
  • When born, both sexes of sperm whale are the same.
  • Sperm whales are the loudest animals on the planet. 
  • Sperm whales live around all deep oceans.
  • These whales are the third deepest diving mammal in the world.


FAQs 

Why is the sperm whale called a sperm whale?

Sperm whales are named after the term ‘spermaceti.’ This is a waxy substance that is found on the head of a sperm whale. This is to help with the whale’s ability to ‘click’ for echolocation.

Do sperm whales eat humans?

There are no clear or reliable reports of a sperm whale ever eating a human being. Their prey is located miles beneath the surface and includes squid and octopuses. 

Do sperm whales still exist?

Yes, sperm whales live in deep oceans around the world. They were hunted throughout the 19th and 20th centuries but today, their populations are recovering.

Can sperm whales vibrate you to death?

It’s possible, due to their size, that they might crush a swimmer’s body accidentally with their own bodies or tails. They also, some scientists believe, “vibrate” one’s body to death. This is due to their loud vocalizations. They’re considered to be the loudest animals on the planet. 

Are sperm whales smart?

Yes, scientists consider sperm whales to be intelligent mammals. They have specialized skills that allow them to dive into deep ocean waters and hold their breath for up to two hours.