Cetacean - Marine Mammals, Aquatic Adaptations, Conservation | Britannica

Cetacean - Marine Mammals, Aquatic Adaptations, Conservation: Cetaceans are carnivorous aquatic mammals distributed in all oceans and some river systems. All are social to some extent, and many exhibit epimeletic behavior. Play is a common behavior. Many species are menaced by human activities. Cetaceans sounds can be roughly divided into communication and echolocation signals.