Common bottlenose dolphin

Tursiops truncatus
Other names: 
  • Bottle-nosed dolphin
  • Bottlenose dolphin
Maximum length: 
  • Male: 3.8m
  • Female: 3.7m
  • Calf: 1.3m
Maximum weight: 
  • Male: 650 kg's
  • Female: Unknown
  • Calf: Unknown
Diet: 
  • Fish (including sciaenids, scombrids and mugilids)
  • Squid
  • Shrimp and other crustaceans
Estimated population: 
600,000
IUCN Listing: 
LC (T. t. ponticus listed as EN)
CITES Appendix: 
II (Black Sea population has zero export quota)
CMS Appendix: 
I (T. t. ponticus), II (North Sea, Baltic Sea, Mediterranean and Black Sea populations)
Classification: 

The bottlenose dolphin is the most well-known of all dolphins, likely because of its frequent appearances on television and in film and its popularity with the captivity industry. They were one of the first species (and continue to be the most popular) regularly captured live for display purposes and by the US Navy for ‘research'. Bottlenose dolphins are highly intelligent, adaptable predators, capable of problem solving, tool-use and exhibiting some flexibility in terms of prey. Until recently all bottlenose dolphins were classified as the same species, Tursiops truncatus. In recent years, however, a distinct species found in the Indo-Pacific region has been recognised, Tursiops aduncus, hence now the recognition of 2 species of bottlenose dolphin; the "common" (T.truncatus) and the "Indo-Pacific" (T. aduncus) bottlenose dolphin. In addition, the population found in the Black Sea is recognised as a separate subspecies, T. t. ponticus, the Black Sea common bottlenose dolphin.

Appearance: 

The size and appearance of the common bottlenose dolphin is highly variable both among individuals and between different populations. It is generally a large dolphin, robust and chunky, and under most lighting conditions it appears a featureless uniform grey. In actuality, its colouring is fairly complex. The common bottlenose dolphin is actually a dark grey, sometimes bluish or brownish grey, with a darker dorsal cape, paler lower sides with a subtle eye-flipper stripe, and lighter belly. It has a distinctly short, stubby beak, set off from the melon by a crease, a high falcate dorsal fin, long slender pointed flippers, and pointed flukes. In areas where more than one population can be found they are often separated into inshore and offshore types, the inshore ones generally being smaller. They can be easily confused with Indo-Pacific bottlenose dolphins where their range overlaps, as well as with young spotted dolphins, rough-toothed dolphins and dolphins from the genus Sotalia. Correct identification is sometimes a process of elimination.

Behaviour: 

Common bottlenose dolphins are extremely inquisitive and playful, highly sociable and highly surface active. They can often be seen lobtailing, breaching, spyhopping, bowriding on ships and large whales and playing with fish, seaweed or marine debris. They can often be found in small groups associating with other species of dolphins, whales, and even sharks and sea turtles. They are known to co-operate with local fishermen, driving fish towards shore into nets. Solitary individuals are known from several locations around the world.

Distribution: 

Common bottlenose dolphins have a wide distribution and can be found in coastal and continental shelf waters in tropical and temperate zones. Found in most enclosed and semi-enclosed seas, for example the Black Sea and the Mediterranean Sea, they also frequent river mouths, lagoons and shallow bays. Unfortunately, bottlenose dolphins have a high rate of accidental mortality through bycatch. Other threats to this species include direct hunting in Japan and other countries, chemical and noise pollution, and habitat degradation. In some countries they are still captured live and exported for public display. The IUCN classify the common bottlenose dolphin as of Least Concern worldwide. However, many inshore bottlenose dolphins exist in small, relatively isolated populations and these groups may be especially vulnerable to human activities. For example there remains only one resident population in the North Sea and the Black Sea common bottlenose dolphin is classified as Endangered.

Distribution map: