Whales, derived from Proto-Germanic word hwæl, are a widely distributed and diverse group of fully aquatic marine mammals. They comprise the extant families Cetotheriidae (whose only living member is the pygmy right whale), Balaenopteridae (the rorquals), Balaenidae (right whales), Eschrichtiidae (the gray whale), Monodontidae (belugas and narwhals), Physeteridae (the sperm whale), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales). There are 40 extant species of whales. The two suborders of whales, Mysticeti and Odontoceti, are thought to have split up around 34 million years ago. Whales belong to the clade Cetartiodactyla and their closest living relative is the hippo having diverged about 40 million years ago.
But I like whales because they are:
Huge!
Friendly
Can hold their breath for a long time
Whale Anatomy
There are some key parts to a whale's anatomy that I think are interesting.
Blowhole: Breathing involves expelling stale airfrom the blowhole, forming an upward, steamy spout, followed by inhaling fresh air into the lungs; a humpback whale's lungs can hold about 5,000 liters of air. Spout shapes differ among species, which facilitates identification.
Ears: he whale ear has specific adaptations to the marine environment. In humans, the middle ear works as an impedance equalizer between the outside air's low impedance and the cochlear fluid's high impedance. In aquatic mammals, such as whales, 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. The whale ear is acoustically isolated from the skull by air-filled sinus pockets, which allow for greater directional hearing underwater.
