The Atlantic Spotted Dolphin is born completely smooth and without a single spot. Throughout its life, it gradually becomes covered in increasingly dense spotting, which gives it its common name. The approximate age of an individual can be estimated quite precisely based solely on the extent of its body's spotting.
The Atlantic Spotted Dolphin lives in warm and temperate Atlantic waters, where it forms active and acrobatic social groups. These often approach boats to play at the bow. This behaviour has made it a regular highlight of cetacean watching excursions in several areas of the western Atlantic.
Its resemblance to the Pantropical Spotted Dolphin of other oceans, along with its own progressive spotting process, has generated considerable identification confusion throughout the history of its study.
A medium-sized Atlantic Spotted Dolphin with a slender grey body. Its spotting increases in density with age, being completely absent in young and very dense in old adults. It has a moderately long beak with a white tip, and a high, falcate dorsal fin.
It is confused with the Common Dolphin, which has a more contrasted striped colour pattern, and with the Bottlenose Dolphin, which is larger and lacks spotting. The progressive spotting pattern is the most reliable feature to differentiate it from both in adult individuals.
The Atlantic Spotted Dolphin leaves no tracks on land; it is detected by a low blow, followed by a rapid emergence of its back with its high, falcate dorsal fin clearly visible. It is very active and acrobatic at the surface, with frequent leaps and a notable tendency to approach boats to bow-ride. Underwater, it emits whistles and echolocation clicks used for social cohesion and cooperative group hunting.
Warm-temperate and tropical waters of the Atlantic Ocean, both coastal and oceanic depending on the population, from the continental shelf to deeper waters. Distributed throughout the Atlantic, from eastern North America and the Caribbean to the Gulf of Guinea, with no presence outside this ocean basin.
It feeds on small pelagic fish and squid, caught through cooperative group hunting, sometimes with the aid of echolocation to locate prey schools under the sand in shallow waters.
Highly social, the Atlantic Spotted Dolphin lives in groups of variable size, from a few individuals to several tens. Its social structure is well-studied in some coastal populations of the western Atlantic, where long-term individual tracking is possible thanks to the unique spotting pattern of each adult animal.
Lack of sufficient population data across much of its oceanic range prevents accurate determination of global population trends, although some well-studied coastal populations in the western Atlantic remain relatively stable.
Bycatch in coastal and offshore fishing gear, contamination by persistent compounds accumulated in its blubber, and in some areas, behavioural alteration due to unregulated dolphin-watching tourism.
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