The rather prominent dorsal fin is nearly triangular, curving only slightly backwards near the tip.
Guiana dolphins are steel blue to dark brown on the back and white on the belly. There is sometimes a brownish band extending from the dark color of the back in front of the dorsal fin back towards but not reaching the anus.
Natural History Notes
Guiana dolphins are usually found in groups of fewer than 10 individuals.
May Be Confused With
Because of their limited range and specialized habitats, Guiana dolphins are unlikely to be confused with any other cetacean species except perhaps Atlantic bottlenosed dolphins (p. [128]). These two species can be distinguished by the following characteristics:
| Guiana Dolphins | Atlantic Bottlenosed Dolphins |
|---|---|
| SIZE | |
| To only 5.6 feet (1.7 m). | 8 to as much as 12 feet(2.4 to 3.7 m). |
| DORSAL FIN | |
| More nearly triangular; curvedonly slightly backwardsnear tip. | Broad-based, tall, andfalcate. |
| DISTRIBUTION | |
| Found in rivers and estuaries,extend into only veryshallow nearshore waters onlimited area of South Americancoast. | Sometimes found nearshoreand in bays, river mouths,and estuaries, but extendfarther offshore. |
Distribution
Guiana dolphins are found in Lake Maracaibo, in the rivers of Guyana, and in the nearshore coastal waters of the northeastern portion of the Guianas.