Whale is any of the largest species of marine mammals that belong to the order Cetacea. It is possible to use the phrase whale is used in reference to any cetacean such as dolphins and porpoises however in general, it is applied to those more than 3 meters (10 feet) long. A notable instance of this to this is the 2.7-metre dwarf Sperm whale ( Konia sinus) which is named because of its otherwise striking resemblance to its larger namesake. Whales are the heaviest known species of animal, either living or fossilized, with a maximum size in the blue whale (Balaenopterid musculus) which is perhaps greater than 30 meters and 200 metric tons (220 small [U.S. tons).
Whales can be found throughout the oceans and the seas of the world, from to the Equator up to the Polar ice, except of the island-free Caspian as well as Aral seas. They are mammals, and they share the distinctive traits of that group that they breathe air, are warm-blooded, give birth in live form, suck their infants with milk and also have hair. They’re all completely aquatic with special adaptations like tail flukes and flippers for living in water. Whales have to surface frequently to breathe, clearing their lungs faster than mammals. This is due to the breath of almost explosive force called a blow. The blows are evident because the they contain water vapor. The hot breath condenses after they blow.
Despite being in a space that has greater thermal conduction properties in comparison to air, whales, like all mammals, have to control their temperature. Hair is only visible on the head, and is visible as isolated whiskers (vibrissae) near the mouth and blowholes. Blubber acts as an insulation layer to safeguard small whales from suffering hypothermia. Large whales have the opposite issue, which is that they produce too much heat; they possess elaborate thermoregulation mechanisms to avoid overheating.
Due to the insufficient utility of their vision underwater Whales rely on audio to sense and interpret their surroundings as well as communicate, often across vast distances. Biologists have estimated that 10-hertz sounds of fin whales ( Balaenopterid physiques), for example, could travel for up to one hundred and eighty kilometers (1,100 miles). Toothed whales produce sound waves and interpret their reflections through active echolocation. The extent to which baleen whales possess this ability is unknown.
After internal fertilization, female whales are pregnant for about an entire year. The newborns are quite large when they arrive, about one-third to one-half of the length of their mother. They are nursed for six months with extremely rich milk that contains more than 50% fat. Whales have a pair of Nipples that are located in the rear of the abdomen close to the opening in the genital tract.
The first fossil whales were discovered from rocks that are approximately 50 millennia old (Early Eocene Epoch). These extinct members of the suborder Archaeoceti are the whales of the early stages from the which modern whales have their origins. They have many resemblances to terrestrial mammals, which includes an equidistant dentition (heterodonty) consisting of canines, incisors and premolars, and molars. Archeocytes were the genesis of the living suborders, namely the baleen whales (suborder Masticate) and the toothed whales (suborder Odontocete).
Masticates come with baleen plates and take small prey by the mouthful, mainly as moving (planktonic) crustaceans, such as copepods and krill. However they may also consume small schooling fish or squid. One interesting departure from this type of pattern is that of the gray whale ( Eschrichtius robustus) that mainly eats shrimp as well as other creatures that live in the bottom It scoops up mud and then strains it through baleen plates and keeps its food. Odontocetes possess simple teeth (homodonty) and hunt specific squids, fish and other prey. The largest odontocete, the sperm whale ( Physeter catodon) is occasionally fed on giant squid.