Despite its confusing name, the killer whale is actually the largest member of the dolphin family.
The killer whale/orca (Orcinus orca) is well known and can be identified relatively easily by its distinctive black and white markings and very tall, prominent dorsal fin. They can grow up to 9 m in length, with male dorsal fins reaching higher than a metre.
Orca flippers are large and paddle-shaped and overall the body is robust. They are acrobatic and are commonly seen breaching and flipper-slapping.
Females and males differ in that males are longer and bulkier than females and females have smaller, more curved dorsal fins, and smaller flippers.
Source: Department of Conservation and licensed by greatbarrierisland.nz for re-use under the Creative Commons Attribution 4.0 International licence at http://creativecommons.org/licenses/by/4.0/