bottlenose dolphin
- Also called:
- bottle-nosed dolphin
bottlenose dolphin, (genus Tursiops), any of two or three species of oceanic dolphins classified within the marine mammal family Delphinidae and characterized by a bottle-shaped snout. The common bottlenose dolphin (Tursiops truncatus), which is the most widely recognized dolphin species, is found worldwide in warm and temperate seas. In contrast, the Indian Ocean bottlenose dolphin (T. aduncus) inhabits continental shelf areas of the Indian Ocean and the waters fringing Southeast Asia, Indonesia, and Australia. The southern Australian bottlenose dolphin (T. australis), or Burrunan dolphin, is considered by some researchers to be a third species, whereas others argue that it is a subspecies of the Indian Ocean bottlenose dolphin. It frequents the waters off Australia’s southern and southeastern shores and has the smallest geographic range.
Bottlenose dolphins reach an average length of 2.5–3 metres (8–10 feet) and weight of 135–300 kg (300–650 pounds). Males are generally larger than females. A familiar performer at marine shows, T. truncatus is known for its “built-in smile” formed by the curvature of its mouth. It has also become the subject of scientific studies because of its intelligence and its ability to communicate with its kind through sounds and ultrasonic pulses.
Numerous studies have highlighted the bottlenose dolphins’ intelligence. They have the longest social memories of any nonhuman species and have been shown to recognize the unique whistles of individual dolphins they once associated with some 20 years after becoming separated from them. Captive specimens have demonstrated the ability to recognize their reflections in several experiments, suggesting a degree of self-awareness. That capability has been observed only in higher primates and a few other animal species. Studies also suggest that some bottlenose dolphins self-medicate by seeking out and rubbing their bodies against specific corals and sponges to obtain antimicrobial compounds that these invertebrates produce.
