Editing Whale (section)

===Senses===
[[File:Delfinekko.gif|thumb|right|[[Biosonar]] by cetaceans]]
[[File:Sperm whale drawing with skeleton.jpg|thumb|right|Sperm whale skeleton. Richard Lydekker, 1894.]]

The whale ear has specific adaptations to the [[Ocean|marine]] environment. In humans, the [[middle ear]] works as an impedance equalizer between the outside air's low [[Acoustic impedance|impedance]] and the [[cochlea]]r fluid's high impedance. In whales, and other marine mammals, there is no great difference between the outer and inner environments. Instead of sound passing through the outer ear to the middle ear, whales receive sound through the throat, from which it passes through a low-impedance fat-filled cavity to the inner ear.{{sfn|Cranford et al.|2008}} The whale ear is acoustically isolated from the skull by air-filled sinus pockets, which allow for greater directional hearing underwater.{{sfn|Nummela et al.|2007|pp=716–733}} Odontocetes send out high-frequency clicks from an organ known as a [[melon (cetacean)|melon]]. This melon consists of fat, and the skull of any such creature containing a melon will have a large depression. The melon size varies between species, the bigger the more dependent they are on it. A beaked whale for example has a small bulge sitting on top of its skull, whereas a sperm whale's head is filled up mainly with the melon.{{sfn|Jeanette et al.|1990|pp=1–19}}{{sfn|Reidenberg|2012|p=512}}{{sfn|Thewissen|Perrin|Wirsig|2002|p={{page needed|date=April 2021}}}}{{sfn|Ketten|1992|pp=717–750}}

The whale eye is relatively small for its size, yet they do retain a good degree of eyesight. As well as this, the eyes of a whale are placed on the sides of its head, so their vision consists of two fields, rather than a binocular view like humans have. When belugas surface, their lens and cornea correct the nearsightedness that results from the refraction of light; they contain both [[rod cell|rod]] and [[cone cell|cone]] cells, meaning they can see in both dim and bright light, but they have far more rod cells than they do cone cells. Whales do, however, lack short wavelength sensitive visual pigments in their cone cells indicating a more limited capacity for colour vision than most mammals.{{sfn|Mass et al.|2007|pp=701–715}} Most whales have slightly flattened eyeballs, enlarged pupils (which shrink as they surface to prevent damage), slightly flattened corneas and a [[tapetum lucidum]]; these adaptations allow for large amounts of light to pass through the eye and, therefore, a very clear image of the surrounding area. They also have glands on the eyelids and [[corneal epithelium|outer corneal layer]] that act as protection for the cornea.{{sfn|Jeanette et al.|1990|pp=505–519}}{{sfn|Reidenberg|2012|p=512}}

The [[olfactory lobes]] are absent in toothed whales, suggesting that they have no sense of smell. Some whales, such as the [[bowhead whale]], possess a [[vomeronasal organ]], which does mean that they can "sniff out" krill.{{sfn|Jeanette et al.|1990|pp=481–505}}

Whales are not thought to have a good sense of taste, as their taste buds are atrophied or missing altogether. However, some toothed whales have preferences between different kinds of fish, indicating some sort of attachment to taste. The presence of the Jacobson's organ indicates that whales can smell food once inside their mouth, which might be similar to the sensation of taste.{{sfn|Jeanette et al.|1990|pp=447–455}}