The sperm whale is the largest of the toothed whales, known for its gigantic head, which can be up to one-third the total length of the whale's body.
Scientific & Common Names
Kingdom - Animalia
Phylum - Chordata
Class - Mammalia
Order - Artiodactyla
Infraorder - Cetacea
Family - Physeteridae
Genus - Physeter
Species - P. macrocephalus
Common Names – Sperm Whale, Cachalot
Sperm whales are large cetaceans that can grow up to 60 feet long. Their heads are square-ish and extremely large, and are mostly full of a waxy substance called spermaceti. The whale uses this to create sounds used in a process called echolocation to help it navigate in the deep ocean depths, and also for communication purposes. The sperm whale only has teeth in its lower jaw, and its upper jaw has holes that the teeth fit into when the mouth is closed. Its body is covered in a rippled, wrinkled texture. The sperm whale has no dorsal fin, but does have a series of fin-like ridges down the rear half of its back. Its blowhole is off center, to the left, producing a very distinct spray when the whale surfaces to breathe.
Sperm whales do not mature until they reach teenage years, and they produce offspring every three to six years. Males will fight each other to impress females and win the right to mate. They travel to warmer waters to give birth, usually in the summer and fall. Females birth a single calf, after a gestation of 14 to 16 months. Males do not provide parental care, leaving the mothers of the pod to raise the young.
Females and young whales travel together in groups called pods, while males typically live on their own. Sperm whales can dive as far as a mile deep to find prey, which is mainly squid. Sperm whales often bear scars from battles with giant squid, though their usual food are smaller squids that are easier to catch.
The sperm whale is one of the most historically important whales in terms of its commercial use. The oil from its spermaceti organ was used for a variety of functions in the 18th, 19th and 20th centuries. Everything from make-up to candles was made with spermaceti oil. The famous novel "Moby-Dick" deals heavily with sperm whaling, and in particular the large white sperm whale of the title. The sperm whale's ivory-like teeth have also been historically used to make scrimshaw carvings. These days, sperm whales are a popular attraction for whale watching and ecotourism.
Sperm whales are currently listed as "Vulnerable". Their populations were severely reduced by the commercial whaling industry, from over a million whales to an estimated hundred thousand. However, with a worldwide ban on commercial whaling, the sperm whale population has bounced back. Ocean pollution, including trash and chemicals, can cause harm to whale populations. Ocean noise from human vessels is also thought to have a negative effect on their migration and navigation.
- Princeton Field Guides: Whales, Dolphins and Other Marine Mammals; Shirihai & Jarrett; 2016
- Guide to Marine Mammals of the World; Reeves, Stewart, Clapham & Powell; 2008