what is a "sperm whale" and why do they call it that?

Answer 1

"The Sperm Whale (Physeter macrocephalus) is the largest of all toothed whales and is the largest toothed animal alive, measuring up to 18 m (60 ft) long. The whale was named after the milky-white substance spermaceti found in its head and originally mistaken for sperm. The Sperm Whale's enormous head and distinctive shape, as well as its central role in Herman Melville's Moby-Dick, have led many to describe it as the archetypal whale. Partly due to Melville, the Sperm Whale is commonly associated with the mythological Leviathan of the Bible."

Here is a painting of one:

http://upload.wikimedia.org/wikipedia/commons/f/f9/Sperm_whale1b.jpg

Answer 2

"Sperm whales are the largest toothed whales. Adult males grow to be about 50-60 feet (17-20 m) long, weighing about 40-50 tons (36-45 tonnes). Females are smaller, about 33-40 feet (11-13 m) long, weighing about 14-18 tons. The four-chambered heart of the average sperm whale weighs about 277 pounds (126 kg) - about as much as two average adult human beings.

The common characteristic of each species is the spermaceti, a semi-liquid waxy white liquid filling the case or spermaceti organ in the whale's head. See the individual species articles for further details."

They are called sperm whales because of the "spermaceti", from the latin for "seed of the whale," that is found in their head case above the jaw. Spermaceti was initially mistaken for sperm because it is a white waxy substance.

Answer 3

Whalers notice that the blubber in their foreheads looks like semen. Ta-da!