Interpreting male body language dating
) are a widely distributed and diverse clade of aquatic mammals that today consists of the whales, dolphins, and porpoises. There are around 89 extant species, which are divided into two groups or parvorders, the Odontoceti or toothed whales, a group of more than 70 species that includes the dolphins and porpoises, and the Mysticeti or baleen whales, of which there are now 15 species. The name is derived from the Latin cetus "whale" and Greek ketos "huge fish".Their hearing is so well-adapted for both air and water that some blind specimens can survive.Some species, such as sperm whales, are well adapted for diving to great depths.Dolphins are commonly kept in captivity and are even sometimes trained to perform tricks and tasks, other cetaceans aren't as often kept in captivity (with usually unsuccessful attempts).Cetaceans have been relentlessly hunted by commercial industries for their products, although this is now forbidden by international law.They spend their lives in the water, having to mate, give birth, molt or escape from predators, like killer whales, underwater.This has drastically affected their anatomy to be able to do so.
Balaenids (right whales and bowhead whales) have massive heads that can make up 40% of their body mass.
They feed largely on fish and marine invertebrates; but a few, like the killer whale, feed on large mammals and birds, such as penguins and seals.
Some baleen whales (mainly gray whales and right whales) are specialised for feeding on benthic creatures.
Male cetaceans typically mate with more than one female (polygyny), although the degree of polygyny varies with the species. Male cetacean strategies for reproductive success vary between herding females, defending potential mates from other males, or whale song which attracts mates.
Calves are typically born in the fall and winter months, and females bear almost all the responsibility for raising them.
The hindlimbs of cetaceans are internal, and are thought to be vestigial.