The Irrawaddy dolphin (Orcaella brevirostris) is a rare and vulnerable cetacean. Frequenting the coasts of Southeast Asia, Australia, and Indonesia, these beakless dolphins hunt fish and crustaceans, sometimes using the peculiar technique of expelling a jet of fast-moving water from their mouths to stun or direct fish they are pursuing. One population, in the Mekong River, is considered Critically Endangered by the IUCN, and the species as a whole is considered Threatened. In a rare good news story from the cetacean world, though, it turns out the species is in much better shape than anyone thought. A healthy population of at least five thousand animals has been documented in a mangrove forest region on the shores of Bangladesh.
(FOOTNOTE: Dr. Karl Shuker has reported that one aquarium has four very odd examples, with no teeth, that may belong to an unconfirmed subspecies of the Irrawaddy dolphin or even a different species.)