|
Page 1 of 2 The cetaceans consist of a diversified group of marine mammals namely whales, dolphins and porpoises. Like fish, they have a caudal fin, peitoral fins, which are used in the propulsion and orientation, and a dorsal fin that has a stabilization role. Unlike fishes, the cetaceans have lungs forcing them to come to the surface to breath. Cetaceans are homoeothermic animals, i.e. maintain a constant body temperature whatever the external water temperature. Tursiops truncatus The Cetaceans are subdivided into two groups: Mysticeti – cetaceans that have long filaments of queratin (the same substance found in nails) – the baleen, used for plankton and filtration of small fishes from which they nourish. They are usually cetaceans of great size, namely the great whales (exception made to sperm whales).
Odontoceti – cetaceans with teeth, that feed on a great variety of bate (fish, squid, marine mammals). They are part of a vast variety of species including the porpoises, dolphins and sperm whales.
<< Start < Prev 1 2 Next > End >>
|
Cetaceans 
