The costero is found close to estuaries, inlets and other protected shallow-water areas around the eastern and northern South American coast. It has been reported as far south as southern Brazil and north as far as Nicaragua.
The costero (Sotalia guianensis, also known as the Guiana dolphin and the estuarine dolphin) is a dolphin found in the coastal waters to the north and east of South America, and east of Central America. The costero is a member of the oceanic dolphin family (Delphinidae).
The Guiana Dolphin (Sotalia guianensis) is frequently described as looking similar to the bottlenose dolphin. The dolphin is colored light to bluish grey on its back and sides. The ventral region is light gray. The dorsal fin is typically slightly hooked, with a triangule shape. The beak is well-defined and of moderate length.
Guiana Dolphins are very conspicuos, considered a "shy" species. Does not bow ride on boats and normally swims away from them.
Researchers have recently shown that the costero has an electroreceptive sense, and speculate this may also be the case for other odontocetes.
It is typically smaller, at only up to 2.1 m (6.9 ft) in length.
They feed on a wide variety of fish, shrimps and squid.
Studies of growth layers suggest the species can live up to 30 years.
This species forms small groups of about 2-10 individuals, occasionally up to 100, and swim in tight-knit groups, suggesting a highly developed social structure. They are quite active and may jump clear of the water (a behavior known as breaching), somersault, spy-hop or tail-splash.