TucuxiSotalia fluviatilisOnde e quando observá-los

The tucuxi is a small freshwater dolphin native to the Amazon basin in South America. Despite sharing rivers with the Amazon river dolphin, or boto, it belongs to the oceanic dolphin family, Delphinidae. It has a compact body, a distinct beak and a triangular dorsal fin. The tucuxi is a separate species from the closely related Guiana dolphin, Sotalia guianensis, which inhabits coastal and estuarine waters. Major threats include accidental capture in fishing gear, deliberate killing, pollution and changes to river habitats.

Size

Adults typically measure about 1.2–1.6 m in length.

Weight

Adults typically weigh about 35–55 kg.

Lifespan

Estimated to reach about 35 years, although longevity in the wild is poorly documented.

Status

Endangered (IUCN)

Tucuxis are social dolphins usually seen in small groups, although larger gatherings can form at feeding sites. They surface frequently to breathe, often revealing their back and dorsal fin in a quick rolling motion. They can be energetic at the surface, performing leaps, tail slaps and other splashing displays. Underwater, they use echolocation to navigate and locate prey in cloudy river water. Whistles and other sounds help them communicate. Feeding groups may gather where currents concentrate fish, including river junctions and eddies. Their movements respond to changes in water level and prey availability.

• The tucuxi is one of the smallest members of the oceanic dolphin family.
• It shares Amazon waters with the distantly related Amazon river dolphin.
• Its close coastal relative, the Guiana dolphin, was once classified as the same species.
• It uses echolocation to find prey in murky freshwater.

Wildlife opportunities depend on the river reach, water levels and species. River-specific viewing months have not been confirmed; general species seasons are not a local sighting forecast.

Tucuxis inhabit freshwater rivers and connected lakes throughout much of the Amazon basin. They occur in the main Amazon channel and many of its tributaries. River confluences, channel margins and areas with swirling currents can provide productive feeding habitat. They generally favour open water rather than the densely flooded forest habitats used by Amazon river dolphins. Seasonal flooding changes the extent and connections of available habitat, while rapids and waterfalls limit their distribution in some tributaries.

Tucuxis feed mainly on fish, taking a variety of relatively small species. Their prey includes schooling fish found in river channels and connected lakes. They use echolocation to detect prey where visibility is poor. Diet varies with local fish communities and seasonal availability.

Common name

Tucuxi

Scientific name

Sotalia fluviatilis

Animal group

Mammals

Size

Adults typically measure about 1.2–1.6 m in length.

Weight

Adults typically weigh about 35–55 kg.

Lifespan

Estimated to reach about 35 years, although longevity in the wild is poorly documented.

Status

Endangered (IUCN)

Identification

Look for a small, streamlined dolphin with a grey back, paler flanks and a whitish to pinkish underside. Its distinct beak and prominent triangular dorsal fin give it a more familiar marine-dolphin shape than the Amazon river dolphin. The Amazon river dolphin is generally larger, with a much longer beak and a low dorsal ridge rather than a pronounced triangular fin. Tucuxis closely resemble Guiana dolphins, so location is important when distinguishing these two species.