Common Bottlenose Dolphin, Tursiops truncatus
Common Bottlenose Dolphin, Tursiops truncatus. Underwater photograph taken in Zihuatanejo Bay, Guerrero, March 2018. Photograph courtesy of Maude Jette, Dive Zihuantanejo, www.Divezihuantanejo.com. Identification courtesy of Bob Hillis, Ivins, Utah.
Common Bottlenose Dolphin, Tursiops truncatus. Underwater photograph taken in coastal waters off Kona, Hawaii, September 2015. Photography and identification courtesy of Bob Hillis, Ivins, Utah.
Common Bottlenose Dolphin, Tursiops truncatus. Photograph taken just east of Isla Colorado, Loreto, Baja California Sur, October 2019. Identification courtesy of Bob Hillis, Ivins, Utah.
Common Bottlenose Dolphin, Tursiops truncatus. Photograph taken within the Sea of Cortez off the west coast of the mainland, December 2019. Photograph and identification courtesy of David F Smith, Alamos, Sonora.
Phylogeny: The Common Bottlenose Dolphin, Tursiops truncatus (Montagu, 1821), is a member of the Delphinidae Family of Oceanic Dolphins. The Tursiops Genus is one of eighteen genera in the Delphinidae Family, and there are four species in the Tursiops Genus. There are currently two accepted subspecies. The genus name Tursiops comes from both the Greek and Latin word meaning “dolphin-like”. The species name truncatus is Latin for “cut-off”. The first specimen used to describe this species had worn-down, flattened teeth, which appeared to be truncated or cut-off. Their common name refers to the shape of their stout beak. They are known in Mexico as the Delfín Nariz de Botella.
Morphology: Common Bottlenose Dolphins are the dolphins of “Flipper” and ocean aquarium fame, as well as the artwork of the ancient Greeks and Romans. They have a mouth that appears to be grinning and the dorsal fin is moderate in height and falcate (concave posteriorly). Dorsally they are vary subtly from light gray to medium gray in color and light gray, pinkish or whitish ventrally. Adults often show battle scars from being raked by the teeth of competing dolphins and from Cookiecutter Sharks, Isistius brasiliensis. Common Bottlenose Dolphins reach a maximum of 3.81 m (12 feet 6 inches) in length and 500 kg (1,100 lbs) in weight.
Habitat and Distribution: Common Bottlenose Dolphins may be found as individuals or in schools containing hundreds of individuals. They can be found in widely differing habitats including bays and estuaries, along surf beaches, and far offshore. They have been recorded diving to depths in excess of 1,000 m (3,280 feet). They are found worldwide in tropical to temperate seas. The Common Bottlenose Dolphin is found in all Mexican waters of the Atlantic and Pacific Oceans.
Diet: The Common Bottlenose Dolphin feed on cephalopods, crustaceans and fish that are found both in the water column or benthic zones. They employ various feeding techniques such as herding fish onto the beach, using bubble curtains to herd fish in to tight schools, tail slapping fish to stun them, and hunting close to human fishing activities to pick off lost or discarded fish.
Predators: The Common Bottlenose Dolphin are preyed upon by large sharks and Killer Whales, though some have been killed by large stingrays.
Reproduction: As mammals, Common Bottlenose Dolphins are gonochoric (male or female for life) and reproduce sexually with internal fertilization. Females give birth to a single calf after a twelve month gestation period. Females typically give birth every three to six years. Calves nurse on average for eighteen to twenty four months. Female dolphins reach sexual maturity and begin reproducing between five and ten years of age, while male dolphins don’t reach sexual maturity until later, between eight and thirteen years of age. Common Bottlenose Dolphins have have life-spans of up to forty years, with some females living until sixty years or more.
Ecosystem Interactions: Common Bottlenose Dolphins are highly communicative, intelligent, and social. They also seem to enjoy playing, including surfing ocean waves and bow waves. This playfulness can become ugly, when small groups of these dolphins abuse other, smaller, marine mammals for sport. Common Bottlenose Dolphins are known to host a variety of endoparasitic organisms including flukes, lung wormws, round worms, tape worms, lung worms, and thorny-headed worms. Ectoparasites include barnacles, copepods and whale lice. Commensalism or mutualistic relationships of Common Bottlenose Dolphins has not been documented.
Human Interactions: Common Bottlenose Dolphins have played a role in human storytelling and art for thousands of years. They have a reputation for being friendly, with many demonstrating an affinity for human contact. Humans have trained dolphins to provide entertainment and to perform underwater tasks more efficiently or more safely than divers. In some areas Common Bottlenose Dolphins are a food source, though this is becoming less common. From a conservation perspestive the Common Bottlenose Dolphin is currently considered to be of Least Concern. However there are a variety of factors that pose a threat to their long term survival which include entanglement in commercial fishing gear like gillnets, seines, trawls, trap pots, and longlines. Vessel strikes and poaching sometimes harm dolphins. Biotoxins like algal blooms also pose a large threat to dolphins and often cause unexpected mortalities.
Synonyms: Delphinus (Tursio) cymodoce, Delphinus compressicauda, Delphinus erebennus, Delphinus metis [No. 1], Delphinus nesarnack, Delphinus nesarnak, Delphinus parvimanus, Delphinus troncatus, Delphinus truncatus, Delphinus tursio, Delphinus tursio obtusus, Tursio cymodice, Tursio metis, Tursio truncatus, Tursiops gephyreus, Tursiops gilli, Tursiops gillii, Tursiops maugeanus, Tursiops nuuanu, Tursiops parvimanus, Tursiops subridens, Tursiops truncantus, Tursiops truncatus gilli, Tursiops truncatus gillii, and