Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. They are an informal grouping within the infraorder Cetacea, usually excluding dolphins and porpoises. Baleen whales have no teeth; instead they have plates of baleen, a fringe-like structure used to expel water.
About Whale in brief
Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. They are an informal grouping within the infraorder Cetacea, usually excluding dolphins and porpoises. Their closest living relatives are the hippopotamuses, having diverged about 40 million years ago. Baleen whales have no teeth; instead they have plates of baleen, a fringe-like structure used to expel water while retaining the krill and plankton which they feed on. Some species, such as sperm whales, are well adapted for diving to great depths to catch squid and other favoured prey. The North Atlantic right whales nearly became extinct in the twentieth century, with a population low of 450, and the North Pacific grey whale population is ranked Critically Endangered by the IUCN. Whales have been depicted in various cultures worldwide, notably by the Inuit and the coastal peoples of Vietnam and Ghana, who sometimes hold whale funerals in literature and film. Small whales, sometimes kept in captivity, are sometimes trained to perform tricks, but success has been poor and the animals often die within a few months of capture. The word whale comes from the Old English hwæ, from Proto-Germanic *kwalo-, meaning ‘large sea fish’, and the Old Norse hvalr, meaning ‘valr’ or ‘valley’ Whales are fully aquatic, open ocean creatures, and feed, mate, give birth, suckle and raise their young at sea.
Although whales are widespread, most species prefer the colder waters of the Northern and Southern Hemispheres, and migrate to the equator to give birth. Species such as humpbacks and blue whales are capable of travelling thousands of miles without feeding. Once relentlessly hunted for their products, whales are now protected by international law, and face threats from bycatch and marine pollution. The meat, blubber and balean of whales have traditionally been used by indigenous peoples of the Arctic. The whale is also the source of the Old Saxon word hvalhwalon, which means ‘large fish’ and ‘valviskr’, which is also source of Old Norse hvalr hvalfr, Swedish valriskr, Middle Dutch, High Dutch, and Dutch walviscvis, Old Dutch, walvis, Dutch, Old English, and English walvale, meaning ‘large fish’ or ‘valvoss’ Whales evolved from land-living mammals, and must breathe air regularly, although they can remain submerged under water for long periods of time. They have blowholes located on top of their heads, through which air is taken in and expelled. Some species such as the sperm whale are able to stay submerged for as much as 90 minutes, They are warm-blooded, and have a layer of fat, or Blubber, under the skin. The sperm whale is the largest known creature that has ever lived.