The Atlantic Spotted Dolphin
) is a dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
found in the Gulf Stream
The Gulf Stream, together with its northern extension towards Europe, the North Atlantic Drift, is a powerful, warm, and swift Atlantic ocean current that originates at the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean...
of the North Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. Older members of the species have a very distinctive spotted coloration all over their body.
The Atlantic Spotted Dolphin was first described by Cuvier in 1828. There is considerable variation in the physical form of individuals in the species and specialists have long been uncertain as to the correct taxonomic classification. Currently just one species is recognised, however it is quite possible that a large, particularly spotty variant commonly found near Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
may be classified as a formal subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
or indeed a species in its own right.
Atlantic Spotted Dolphins in the Bahamas have been observed mating with bottlenose dolphins. Rich LeDuc has published data that suggests that Atlantic Spotted Dolphins may be more closely related to bottlenose dolphins (genus Tursiops
) than to other members of the genus Stenella
The coloring of the Atlantic Spotted Dolphin varies enormously as they grow.
Calves are a fairly uniform grey colour. When the calves are weaned, they then begin to get their spots. Juveniles have some dark spots on their belly, and white spots of their flanks. Their back and dorsal fin are a darker grey than the rest of the body. As the animal matures the spots became denser and spread until the body appears black with white spots at full maturation.
The Atlantic Spotted Dolphin has a 3-part coloration:
- Dark gray back, lighter sides, and a white belly.
Measurements at Birth:
- Length: about 35"-43" (90-110 cm)
- Weight: unavailable
- Male 2.26 m (7'5")
- Female 2.29 m (7'6")
- Male 140 kg (310 lb)
- Female 130 kg (290 lb)
This is a middle-sized dolphin in both length and weight. At full size South American Spotted Dolphins are about 2.2-2.5 m in length. Compared to their much smaller pantropical spotted dolphin, the Atlantic spotted dolphin is more robust. It lives in common waters with the pantropical spotted dolphin and the bottlenose dolphin.
In common with other species in its genus the Atlantic Spotted is a gregarious creature. It is a fast swimmer, keen bow-rider and prone to acrobatic aerial displays.
Population and distribution
The species is endemic to the temperate and tropical areas of the Atlantic Ocean. It has been widely observed in the western end of the Gulf Stream, between Florida and Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...
. It is also present in the Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
. More infrequent sightings have been made further east, off the Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
and Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
. Northerly sightings have been made as far north as Cape Cod
Cape Cod, often referred to locally as simply the Cape, is a cape in the easternmost portion of the state of Massachusetts, in the Northeastern United States...
across to the south-western tip of Spain. They are certainly present further south too as far as Rio Grande do Sul
Rio Grande do Sul is the southernmost state in Brazil, and the state with the fifth highest Human Development Index in the country. In this state is located the southernmost city in the country, Chuí, on the border with Uruguay. In the region of Bento Gonçalves and Caxias do Sul, the largest wine...
in Brazil and across to west Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. However the distribution is poorly understood in these areas.
About 20 years ago, there were only about 80 dolphins in the Bahamas. Now, 20 years later, there are almost 200 dolphins there. On account of their similar appearance to other dolphins in their range it is difficult to be sure of the Atlantic Spotted Dolphin's population. A conservative estimate is around 100,000 individuals.
Some Atlantic Spotted Dolphins, particularly some of those are around The Bahamas
The Bahamas , officially the Commonwealth of the Bahamas, is a nation consisting of 29 islands, 661 cays, and 2,387 islets . It is located in the Atlantic Ocean north of Cuba and Hispaniola , northwest of the Turks and Caicos Islands, and southeast of the United States...
have become habituated to human contact. In these areas cruises to watch and even swim with the dolphins are common.
Atlantic Spotted Dolphins are an occasional target of harpoon
A harpoon is a long spear-like instrument used in fishing to catch fish or large marine mammals such as whales. It accomplishes this task by impaling the target animal, allowing the fishermen to use a rope or chain attached to the butt of the projectile to catch the animal...
fishermen and every year some creatures are trapped and killed in gillnet
Gillnetting is a common fishing method used by commercial and artisanal fishermen of all the oceans and in some freshwater and estuary areas. The gillnet also is used by fisheries scientists to monitor fish populations. Because gillnets can be so effective their use is closely monitored and...
s. However these activities are not currently believed to be threatening the survival of the species. This species lives in the mesopelagic layer of the ocean