Way more than you've even wanted to know about sperm whales

So, why are they called sperm whales?

Got into an extremely short discussion about this last night... and no one seemed to know the answer.

"Sperm whale" is an apocopation of Spermaceti Whale. Spermaceti is the semi-liquid, waxy substance found in the animal's head. Spermaceti is found in the spermaceti organ or case in front of and above the skull of the whale and also in the junk, the area below the spermaceti organ and just above the upper jaw.^[3] The case consists of a soft white, waxy substance saturated with spermaceti oil. The junk is composed of cavities filled with the same wax and spermaceti oil and intervening connective tissue.

The spermaceti organs may help in diving by adjusting the whale's buoyancy. Before diving, cold water is brought through the organ and the wax is solidified.^[28][36] The increase in specific density generates a down force of about 40 kilograms (88 lb) and allows the whale to dive with minimal effort. During the chase in deep levels (max. 3,000 m) the stored oxygen is consumed and excess heat melts the spermaceti. Now only hydrodynamic forces generated by swimming keep the whale down, and it can surface without effort.

some more facts about sperm whales..

- Sperm whales can live 70 years or more.
- The sperm whale is among the most cosmopolitan species in the world, as it is relatively abundant from polar waters to the equator, and is found in all the oceans and the Mediterranean Sea.
- A single calf is born after a gestation period of 14 to 16 months.
- The brain of the sperm whale is the largest known of any modern or extinct animal, weighing on average about 8 kilograms (18 lb).^[33][34] However, it is not particularly large in proportion to its body size. For example, the sperm whale has a lower encephalization quotient than many other whale and dolphin species, lower than that of non-human anthropoid apes and much lower than humans'.


Straight from wikipedia...