Whale be used as another indication of animal intelligence. Sperm whales have the largest brain mass of any animal on earth, averaging and in mature males, in comparison to the average human brain which averages in mature males. The brain to body mass ratio in some odontocetes, such as belugas and narwhals, is second only to humans. Small whales are known to engage in complex play behaviour, which includes such things as producing stable underwater toroidal air-core vortex rings or "bubble rings". There are two main methods of bubble ring production: rapid puffing of a burst of air into the water
Whale shark Whale shark The whale shark ("Rhincodon typus") is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of and a weight of about . The whale shark holds many records for size in the animal kingdom, most notably being by far the largest living nonmammalian vertebrate. It is the sole member of the genus Rhincodon and the only extant member of the family Rhincodontidae which belongs to the subclass Elasmobranchii in the class Chondrichthyes. Before 1984 it was classified as "Rhiniodon" into Rhinodontidae. The whale shark is found in open