The dusky dolphin (Aethalodelphis obscurus) is a small oceanic dolphin found in coastal waters of the Southern Hemisphere. It is most closely related to the Pacific white-sided dolphin. The dolphin's range is patchy, major populations occurring around South America, southwestern Africa, New Zealand, and several oceanic islands, with some sightings around southern Australia. It has a somewhat stocky body with a short beak and a curved dorsal fin and flippers. Like its closest relative, the dusky dolphin has a multi-coloured pigmentation of black, grey, and white.
The species prefers cool currents and inshore waters. It lives in a fission–fusion society where groups change size based on social and environmental conditions. The dolphin feeds on several fish and squid species and has flexible hunting tactics, including daytime bait ball herding and nightime feeding in layers of scattered organisms. Mating is promiscuous, and several males will chase after a single female, the fittest being able to catch her and reproduce. Females raise their young in nursery groups. The dusky dolphin is known for its acrobatics, displaying leaping behaviours which vary in complexity and may or may not create splashes.
The dusky dolphin is classified as Least Concern by the IUCN Red List as many populations appear to be healthy and stable. It has been caught in gill nets and killed to be used as bait. It is a popular tourist attraction and the object of whale watching tours. Both vessels and mussel farms can interfere with the dolphin's activities.
