WHAT IS SPERMACETI?

Spermaceti is the semiliquid, waxy substance found in the head of the Sperm Whale. The name derives from the late Latin sperma ceti (both words actually loans from Greek) meaning "sperm of the whale" (strictly, "sperm of the sea monster"). The common name for the species is actually an apocopation of Spermaceti Whale. The substance is not, of course, the whale's semen; it was mistaken for such by early whalers. Spermaceti is found in the spermaceti organ or case in front of and above the skull of the whale and also in the so-called junk which is right at the front of the whale's head just above the upper jaw. The case consists of a soft white substance saturated with spermaceti. The junk is a more solid substance.

The precise function of spermaceti and the organs it fills is not known, but at least three (not necessarily mutually exclusive) hypotheses exist:

One hypothesis, incidentally discussed in Moby-Dick by Melville, is that the case evolved as a kind of battering ram for use in fights between males. This hypothesis is consistent with the well-documented sinking of the ships Essex and Ann Alexander due to attacks by Sperm Whales estimated to weigh only one-fifth as much as the ships. The role of spermaceti as a sexual selector is currently the most in vogue. Spermaceti also plays a huge role in fighting between males, which, sometimes, crush head to head several times; spermaceti also allows sperm whales to attack ships, which happened several times in the 18-19th century and also in the 20th century, with the well-documented attack of a sperm whale on the Russian whaling ship Enthusiast, in 1946, whose propeller shaft was bent and propeller torn off (the whale was said to get away with scratches on "forehead"), and with the sinking of Norwish whaler Durei.

A second, more long-standing suggestion is that the case is an aid to the whale in controlling buoyancy. The density of the wax could be increased by cooling it with water brought in through the blowhole, helping the whale to sink. Conversely, forcing water out through the blowhole again would cause the spermaceti to reheat, become less dense and aid floating. This popularly quoted theory has recently lost some credence. Research suggests that no capillary effect would be extensive enough to change drastically the buoyancy of a 50-tonne whale.

A third possibility is that the case is used as an aid to echolocation. The shape of the organ at any given time is likely to focus or widen the beam of emitted sound. The sound waves may be so focused that they act as a kind of stun gun, temporarily disabling prey. Active research into all these possibilities continues.

Spermaceti was much sought after by 18th-, 19th- and 20th-century whalers. The substance found a variety of commercial applications, such as watch oil, automatic transmission fluid, lubricant for delicate high-altitude instruments, cosmetics, additives in motor oils, glycerine, rust-proofing compounds, detergent, chemical fibres, vitamins and 70 or more pharmaceutical compounds.

See also: Sperm Whale, Pygmy Sperm Whale, and Dwarf Sperm Whale