Sotalia fluviatilis

Other Names: Estuarine Dolphin

Habitat: Riverines and inshore

Status: Locally common

Population: Unknown

Threats: Hunting/whaling, entanglement in fishing nets, and habitat destruction

Group Size: 2-7, marine form may occur in largest groups

Fin Position: Center

Newborns: c.28-32 in (70-80 cm), Unknown weight

Adults: 4 -6 ft (1.3-1.8 m), 75-100 lbs. (35-45 kg)

Diet: Fish and krill or other crustaceans

Teeth: 52-70 teeth on both top and bottom rows


Dorsal fin:

- tip curves backward very slightly
- broad base
- tip may be discolored, from scraping along sea floor or river bed
- tip may be less curved in some animals


- concave trailing edges
- distinct notch in middle
- rounded tips
- broad flukes


- flippers same color as upper side
- large, broad flippers


- underside of beak pale gray, white, or pinking in color
- long beak
- upper side of beak bluish gray, black or brownish gray in color
- slightly rounded melon

Other characteristics:

- bluish gray or brownish gray upper side
- pale gray, white, or pinkish underside
- robust body
- dark, backward-pointing stripe on sides
- dark stripe between eye and flipper


- usually wary of boats, though some individuals may allow a close approach
- may surf in waves made by passing boast, but will not bow-ride
- spy-hopping, lobtailing, flipper-slapping, and porpoising often seen
- capable of very high breaches (usually falling back on one side), especially after being disturbed
- dives are usually short (around 30 seconds) and it is rarely underwater for longer than a minute
- it is an active swimmer
- small groups often swim close together, suggesting strong social ties
- it may be seen feeding in the company of river dolphins and, in the Amazon, often associates with feeding terns
- blow is very quiet compared to that of river dolphins
- normally, coastal animals show little of themselves when surfacing, but river inhabitants usually lift the head and part of the body out of water


- shallow coastal waters and rivers of northeastern South America and eastern Central America
- found in both salt and fresh water
- coastal range extends from Florianopolis, Brazil, north into the Caribbean Sea as far as Panama; however, a resident populations was recently discovered in Leimus Lagoon, Nicaragua, over 500 miles (800 km) north of previously known range
- occurs around some Caribbean islands and also in Lake Maracaibo, Venezuela
- riverine animals found from river mouths to about 155 miles (250 km) up the Orinoco and 1,555 miles (2,500 km) up the Amazon; the best places to look are where tributaries join the main river
- mainly in estuaries and bays, and in deep river channels or floodplain lakes

TMMSN Galveston

TMMSN Corpus Christi

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This page was created by:Candice Orca Mottet