Whales

Wikipedia tells us about whales:

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 rorqual whales), Balaenidae (right whales), Eschrichtiidae (the grey 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.

1. Blowhole: Whales breathe via blowholes; baleen whales have two and toothed whales have one. These are located on the top of the head, allowing the animal to remain almost completely submerged while breathing. Breathing involves expelling stale air (which is warm and moist), as well as some mucus and excess water from the blowhole, forming an upward steamy spout, followed by inahing fresh air into the lungs. Spout shapes differ among species, which facilities identification.
2. Ears: The whale ear has specific adaptations to the marine environment. In humans, the middle car 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, however, there is no great difference between the outer and inner environments. Instead of sound passing through the outer ear to the middle ear which 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.

Pictures!