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Delphinus delphis - Common Dolphin

Common Dolphin image

Geographic range:

Continental shelf of Pacific and Atlantic Oceans.

Key features:

Dark on top with a whitish belly and along the upper third there is a distinctive gray-yellow patch. Maximum length 2.7 meters.

Similar species:

Delphinus capensis -- Long-beaked common dolphin

Habitat(s):

bay (rocky shore), bay (sandy shore), Continental shelf, continental slope, pelagic zone, seamount
 

Primary common name:

Common Dolphin

General grouping:

Whales, seals and sea lions, otters

ITIS code:

180438
 

Geographic Range

Range Description:

Delphinus delphis occurs in the western Atlantic from Newfoundland to Florida and in the eastern Atlantic from the North Sea to Gabon (including the Mediterranean and Black Seas). It occurs in the southwestern Pacific around New Caledonia, Tasmania, New Zealand, and the southern half of Australia and in the western North Pacific around Japan and eastward to160ºW between 28ºN and 43ºN. It also occurs in the tropical and warm temperate eastern Pacific from southern California to central Chile westward to 135ºW. It may also occur in other areas, but confusion with the Long-beaked Common Dolphin, Delphinus capensis, creates uncertainty.

Maximum depth:

243 meters OR 809.19 feet

Habitats

bay (rocky shore), bay (sandy shore), Continental shelf, continental slope, pelagic zone, seamount

Habitat notes:

Delphinus delphis occupies continental shelf and pelagic waters. It is especially common along shelf edges and over areas with sharp bottom relief, such as seamounts and escarpments. This dolphin shows high affinity for areas with warm, saline surface waters with temperatures between 10ºC - 20ºC. They are only occasionally inshore and in rare cases may be found far up rivers. In the eastern North Pacific, they shift their distribution northward in warm-water years.

Abundance

Relative abundance:

Delphinus delphis is the most abundant and wide spread species of dolphins.

Species Description

General description:

Delphinus delphis is a member of the Family Delphinidae in the Order Cetacea and Class Mammalia. It is widespread in tropical and temperate waters of the Atlantic and Pacific Ocean. This dolphin is often spotted in fairly large groups and is very active at the surface. Some uncertainly remains about how many species should be recognized in the genus Delphinus. The current contention is for two species, the Short-Beaked Common Dolphin, Delphinus delphis, and the Long-Beaked Common Dolphin, Delphinus capensis. However, much of the literature published prior to the last few years treats all common dolphins as a single species.

Distinctive features:

Delphinus delphis has a fusiform and slender body. The back is black or dark gray and dips low onto the sides below the dorsal fin in a V-shaped saddle configuration resulting in an hourglass, or crisscross pattern, on the sides. The anterior segment of the hourglass is light gray to medium golden-yellow and contrasts sharply with the dark dorsal color. The posterior segment is a dirty gray that sweeps over the caudal peduncle. The chest and belly are cream to white. There is a dark eye patch that is continuous with a dark stripe that extends forward and joins the blackness of the lips. It has a moderately long beak that is often white or gray on the upper surface with a dark tip. There are one or more dark stripes from the center of the lower jaw to the flipper. The dorsal fin is tall, falcate and usually black with a lighter grayish region of varying size near the middle. It has moderately large, tapered flippers that are similar color to the dorsal fin. Tooth counts range from 41 to 54 pairs in both jaws, with the upper jaw usually having one or two more pairs than the lower jaw.

Delphinus delphis is most often confused with the Long-beaked Common Dolphin, Delphinus capensis. Not only do both of these species have similar features, but they also are often seen near each other. Delphinus capensis has a noticeably longer beak and a longer, narrower head. Its melon is also less rounded and flatter in profile. Thus, Delphinus capensis gives an overall impression of a more slender, longer-bodied animal. The color differences are subtle, the thoracic patch of Delphinus capensis tends to be darker and to contrast less with the dark back color and it also has a dark gray stripe from flipper to anus that separates the ventral whiteness from the hourglass segment.

Delphinus delphis can be differentiated from the Pacific white-sided dolphin, Lagenorhynchus obliquidens, which has gray flippers. The Clymene Dolphin, Stenella clymene has a distinguishing stripe from eye to flipper and they lack the hourglass pattern. The Striped Dolphin,Stenella coeruleoalba, has a bold eye-to-anus and eye-to-flipper stripes, a white shoulder blaze and lacks the distinctive crisscross pattern on its sides. The Spinner Dolphin, Stenella longirostris has a black circle around its eye. In the North Atlantic the Atlantic White-sided Dolphin, Lagenorhynchus acutus, has a more robust body, a much shorter beak, an unmistakable bright white patch below the dorsal fin and its tan patch is on the rear portion of its die rather than the front when compared with Delphinus delphis.

Size:

At birth, Delphinus delphis is 80 100 cm in length. Males can grow to a length of 2.7 m and females to 2.6 m. They probably reach a weight of about 150 kg.

Natural History

General natural history:

Delphinus delphis is extremely gregarious and can be seen traveling in schools of hundreds to thousands, though it typically gathers in groups of 30 or less. They are very active at the surface, frequently leaping clear of the water and riding bow waves of vessels for a long time. Delphinus delphis, like other cetaceans, is also a very vocal species. These dolphins communicate with each other using two voices, one is for navigation and location and the other is for social communication. The voice has been described as whistle-like pulse sounds. Delphinus delphis can range over considerable distances in a short time. In one study, a radio-tagged animal traveled at least 270 nautical miles in 10 days. Delphinus delphis has an estimated life span of 35 to 40 years.

Estimates for the number of Delphinus delphis vary throughout its distribution with many populations disappearing or declining. There are at least tens of thousands Delphinus delphis off the eastern United States, about 100,000 off the British Isles and France, and hundreds of thousands off the western United States. Estimates in the eastern tropical Pacific total about 3 million. They seem to have almost disappeared from the northern basin of the western Mediterranean Sea and along the coast of northeastern Florida in the last few decades. The Black Sea is also thought to have seriously depleted populations. Declines are likely due to habitat degradation and incidental catch in commercial fisheries.

Predator(s):

Delphinus delphis used to be hunted by humans in the Black Sea until they were protected in the 1980s. They are still killed accidentally in industrial trawls, gillnets and many other types of fisheries throughout their range. They may occasionally be eaten by sharks or Orcas, orcinus orca.

Prey:

Delphinus delphis feeds on squid and small schooling fish. Anchovies, lanternfish, hake, and deep-sea smelt, Glossanodon semifasciatus, are the principal prey of these dolphins.

Feeding behavior

Carnivore

Feeding behavior notes:

The foraging behavior of Delphinus delphis is apparently attuned to the nighttime vertical migration of the deep scattering layer. Large schools of these dolphins will disperse into smaller groups by the late afternoon and begin feeding at dusk as their prey species ascend during the evening hours. After a night of deep diving and feeding the dolphins gather into large groups once again in the early morning. During the daylight hours, they rest and socialize until the nighttime feeding cycle resumes.

January - December

Migration:

Migrations of Delphinus delphis is not well known. In some parts of their range, these dolphins are present year round. However, there appear to be clear seasonal shifts in distribution and abundance in other parts of their range, often having to do with water temperature. For example, in Nova Scotia Delphinus delphis is absent until July when water temperatures have increased. There may also be some movement due to prey availability which may also be affected by water temperatures. Studies have also shown that Delphinus delphis preferentially travel over underwater escarpments and sea mounts.

January - December

Reproduction:

In tropical waters, the reproduction of Delphinus delphis is relatively non-seasonal. However, in higher latitudes, calving peaks in the late spring or early summer. Gestation lasts 10 or 11 months and the calving interval is at least two years. During calving and lactations periods, females tend to remain in lower latitudes. Delphinus delphis reach sexual maturity after 12 to 15 years.
Click on an image below to view a larger version in the SIMoN Photo Library. You will also be able to view important information on each photo such as photographer, date, caption and more.
Alspaugh, M. 2000. Delphinus delphis, Animal Diversity Web. World Wide Web electronic publication. http://animaldiversity.ummz.umich.edu, Accessed [07/03/06].
Boschung, H.T., J.D. Williams, D.W. Gotshall, D.K. Caldwell, and M.C. Caldwell. 1998. National Audubon Society Field Guide to North American Fishes, Whales and Dolphins. A.A. Knoph, New York, NY. 848 p.
Culik, Boris. 2003. Convention on Migratory Species. World Wide Web electronic publication. http://www.cms.int/reports/small_cetaceans/index.htm, Accessed [07/03/06].
Reeves, R.R., B.S. Stewart, P.J. Clapham, and J.A. Powell. 2002. National Audubon Society Guide to Marine Mammals of the World. A.A. Knopf, New York, NY. 527 p.