There are approximately 87 species of cetaceans worldwide, belonging to two major groups: Odontoceti (toothed whales) and Mysticetes (baleen whales).
Mysticetes are the largest animals on our planet. Instead of teeth, they have baleen which they use to filter the water and scavenge small prey such as krill and other crustaceans, or small fish such as herring. They also have two breathing holes (vents).
In contrast, odontocetes have a single respiratory orifice and teeth which they use to capture larger animals like squid or fish.
16 species of cetaceans are present in Polynesia, the most frequently observed are the dlong-beaked dolphin , the dRough-toothed dolphin, the spotted dolphin, the Electra's dolphin, the pilot whale and the bottlenose dolphin including about thirty well-known individuals divers, are settled around Rangiroa atoll. It is also possible to meet killer whales, sperm whales as well as the Cuvier's beaked whale and Blainville, the Minke whale and of course the famous humpback whale.
The Society Islands (Tahiti, Raiatea, Tahaa, Bora Bora, Huahine, Moorea etc) is the only one where 4 families of cetaceans are listed (balenoptera, beaked whales, sperm whales and dolphins).
As cetaceans are mammals, what distinguishes this class of vertebrate animals of which we are part is that they suckle their young, breathe air, therefore have lungs and have blood warm. They may gather in groups based on sex and age or live alone most of the time.
Some species migrate long distances to reach their feeding grounds, to breed or nurse their young, or to spend the winter. They produce a wide variety of sounds for communication and echolocation, which allow them to navigate, identify their prey as well as find other cetaceans and avoid predators.