Sperm whales are found in all the oceans. There is controversy surrounding the numbers of sperm whales due to the fact that they remain underwater for long periods and move in large groups rendering information from surveys difficult to analyse. It has a huge brain that weighs about 20 pounds; it is the largest brain of any animal. Sperm whales are carnivores that mostly eat giant squid that live on the ocean bottom at great depths. They also eat fish. In 1998, off the coast of Indonesia, 3 sperm whales were observed attacking a rare, filter feeding megamouth shark.
Although commercial hunting of sperm whales began in the 18th century, the majority of reported kills took place between 1950 and 1980 when harpoon guns became more widely used. Whaling records show that more than 638,000 sperm whales were killed during this period. Today, population estimates for sperm whales fall in the range of 300,000 to 400,000, significantly down from more than a million whales worldwide before large-scale hunting began in the last century. Sperm whales are currently classified on the IUCN’s Red List as Vulnerable.