Sperm whale the line, sparing the whales the need to hunt. However, the amount of fish taken is very little compared to what the sperm whale needs per day. Video footage has been captured of a large male sperm whale "bouncing" a long line, to gain the fish. Sperm whales are believed to prey on the megamouth shark, a rare and large deep-sea species discovered in the 1970s. In one case, three sperm whales were observed attacking or playing with a megamouth. The sharp beak of a consumed squid lodged in the whale's intestine may lead to the production of ambergris, analogous
Fear of fish by what is now called graduated exposure therapy: In contrast, radical exposure therapy was used successfully to cure a man with a "life affecting" fish phobia on the 2007 documentary series, "The Panic Room". Historically, the Navajo people were described as being ichthyophobic, due to their aversion to fish. However, this was later recognised as a cultural or mythic aversion to aquatic animals, and not a psychological condition. The "Journal of the American Medical Association" have published a research paper addressing the fears of eating fish because contaminants, such as mercury may be accumulated in fish. In his autobiography, Italian