Atlantic Spotted Dolphin

The coloring of the Atlantic spotted dolphin varies enormously as it grows, and is usually classified into age-dependent phases known as two-tone, speckled, mottled, and fused. Calves are a fairly uniform gray-white, with one or no spots. When they are weaned, speckling occurs, typically between 3 and 4 years and lasting for an average of 5 years. A juvenile is considered mottled when it develops merging gray and white spots on the dorsal surface and black spots on the ventral surface. This usually happens between age 8 or 9. A fused pattern is reached when dark and white spots are on both the ventral and dorsal sides. As the animal matures, the spots become denser and spread until the body appears black with white spots at full maturation.

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. Off the Bahamas, tourism industries to swim with dolphins are available. It is also present in the Gulf of Mexico. More infrequent sightings have been made further east, off the Azores and Canary Islands. Northerly sightings have been made as far north as Cape Cod across to the southwestern tip of Spain. They are certainly present further south, too, as far as Rio Grande do Sul in Brazil and across to west Africa, but their distribution is poorly understood in these areas.

Atlantic spotted dolphins are extremely gregarious animals, which gather in complex social groups of 5–15, often in mixed groups with common bottlenose dolphins. They are fast swimmers and known for their bow-riding and long, shallow leaping behaviors. Their mating system consists of one male mating with several females, and the pod is highly protective over pregnant females. The dolphin's gestational period is ~11 months, and the mother cares for its calf for up to 5 years, with the help of the rest of her group.

Some Atlantic spotted dolphins, particularly some of those are around the Bahamas, have become habituated to human contact. In these areas, cruises to watch and even swim with the dolphins are common. They are usually not held in captivity.

Atlantic spotted dolphins are an occasional target of harpoon fishermen, and every year some creatures are trapped and killed in gill nets, but these activities are not currently believed to be threatening the survival of the species. This species lives in the mesopelagic layer of the ocean. These dolphins are not threatened by extinction, however, commercial trade may affect their evolution and sustainability. Sometimes they are killed by harpoons off St. Vincent.