Atlantic Spotted Dolphin, Stenella frontalis
The Atlantic spotted dolphin (Stenella frontalis) can be found in the Gulf Stream of the North Atlantic Ocean, including the area between Florida and Bermuda and the Gulf of Mexico. Its eastern range may extend as far as the Azores and Canary Islands, although sightings in these areas have been uncommon. Its northern range begins at Cape Cod and extends to the southwestern portion of Spain. It is thought that the southern portion of its range extends from West Africa to Rio Grande do Sul in Brazil. It prefers tropical and temperate habitats within this range.
First discovered by Cuvier in 1828, the Atlantic spotted dolphin has been difficult to classify. It has many color variants within its large range, and even a possible subspecies that resides near Florida, although there is not enough evidence to support this. Individuals have been spotted mating with bottlenose dolphins in the Bahamas, suggesting a closer relation with this species than other members of the Stenella genus.
The Atlantic spotted dolphin varies in size depending on the sex of each individual. Males can have an average body length of up to 7.5 feet and a weight of up to 310 pounds, while females average at 7.6 feet with an average weight of 290 pounds. Calves are born at up to 43 inches in length.
Markings also vary, although only with age. Calves are nearly all gray in color and will not start showing spots until they are weaned, and these spots will increase in number as they become juveniles, when the spots turn dark on the dorsal area and white on the underbelly. When full maturation is attained, these spots appear to be all white on a dark body. The adult coloration consists of a dark grey dorsal area, a white underbelly, and light grey sides.
The Atlantic spotted dolphin is a well-known athletic species, and can often be seen jumping and twirling out of the water. It is not a surprise that they often swim beside boats, and in the Bahamas, cruises are conducted that allow humans to watch and even swim with the dolphins in that area. Unfortunately, some individuals have fallen prey to harpoon fishing, but this is not thought to be a major threat to the species.
Although the IUCN has not been able to give the Atlantic spotted dolphin a conservation status on its Red List, it is one of many species included in the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU).
Image Caption: Atlantic Spotted Dolphin, Stenella frontalis. Credit: Tursiops/Wikipedia(CC BY-SA 3.0)