Whales, dolphins and porpoises belong to the Order Cetacea.
There are over 80 species of whales, dolphins and porpoises (cetaceans) found throughout the world’s oceans. Of these, 53 species are known to inhabit Australian waters.
Following the decline of the dinosaurs more than 50million years ago, the evolutionary process of whales and dolphins began. Around 10 million years ago, most of the whales and dolphins that we know today were present.
There are two main types of cetacean: Odonotocetes or toothed whales and Mysticetes or baleen whales.
Sperm whales, killer whales, belugas, narwhals, beaked whales, dolphins, pilot whales, killer whales, porpoises and river dolphins belong to the Odontoceti whale group. These whales have a single blowhole, teeth and use echolocation to find their prey of fish and squid amongst others.
Dolphins are mammals; they breathe air and give birth to live young. Dolphins also have small hairs which grow on their rostrums.
Dolphins and whales have a layer of fatty tissue under the skin, called blubber which maintains the animals’ body heat. This layer of fat also provides an important energy source.
Dolphins and whales have very good eyesight both above and below the water.
External Features of a Dolphin (c) E. Hawkins 2010
