Which New Zealand dolphin has a rounded dorsal fin and black facial markings?

The New Zealand dolphin with a rounded dorsal fin and black facial markings is Hector's dolphin.

Hector's dolphin (Cephalorhynchus hectori) is endemic to New Zealand and is among the world's smallest dolphins. Its most recognizable feature is a rounded dorsal fin, sometimes compared with a Mickey Mouse ear, rather than the pointed or sickle-shaped fin seen in many other dolphins. Its body combines gray, white, and black areas, including a dark mask around the eyes and black markings on the head, flippers, tail, and fin.

The species was scientifically described in 1881 by Belgian zoologist Pierre-Joseph van Beneden, who named it after New Zealand naturalist Sir James Hector. It generally lives in coastal waters and feeds using echolocation on fish, squid, and crustaceans.

A common mix-up is Māui dolphin: it is not a separate species, but the critically endangered North Island subspecies of Hector's dolphin. Dusky and common dolphins can occur in similar New Zealand waters, but their dorsal fins are not the distinctive rounded shape.