by zteve t evans

Created on: January 07, 2011   Last Updated: January 08, 2011

The Tucuxi (pronounced ‘too-koo-shee’) is also known as the Estuarine dolphin, or sometimes, Sotalia, from its scientific name of Sotalia fluviatilis.

Range

There are two sub-species of Tucuxi.  One is riverine and found in freshwater lakes and rivers.  The other is marine and found in shallow, warm coastal waters, bays and estuaries along the eastern coasts of Central America, from Nicaragua down the north eastern coasts of South America, to around Florianopolis, Brazil.

The riverine Tucuxi is better known than the marine and can be found along 2,500 kilometres of the Amazon and also 250 km upstream in the Orinoco River.  The marine Tucuxi prefers bays and estuaries along the coasts. 

Physical appearance

The Tucuxi has a small, but robust body that is colored bluish- grey to the upper part and lighter underneath.  Sometimes they can be a pinkish-grey particularly on their sides and under parts.  The dorsal fin is a slightly rounded, triangular, curved shape, set roughly half way down its back. They have a rounded fore-head and a beak that is quite long.  The upper and lower jaws contain 26 to 36 pairs of teeth. 

The marine Tucuxi is the largest and can grow up to 2.1 metres in length and weigh up to 54 kilograms. The riverine Tucuxi is much smaller growing up to 1.5 metres in length and being much lighter in weight.

At first the sight the marine Tucuxi resembles a small Bottle-nosed dolphin though there are differences. The Tucuxi can sometimes been seen somersaulting, spy hopping and breaching the waters in a similar way to Bottle-nosed dolphins though unlike them they tend to follow in the wake of boat rather than swimming and breaching the waters before the bow.

Diet

The diet consists mostly of fish supplemented with krill and crustaceans.

Breeding

The riverine Tucuxi calve around October or November time after a gestation of up to 12 months.

Of the family Delpinidae

Tucuxis are social animals forming small, tightly knit groups of 10-15.  Even though there is a large riverine population it is not a true river dolphin but a member of the family Delpinidae which are oceanic dolphins.  Nevertheless, it is quite common in the Amazon River Basin to see them in the company of river dolphins feeding together.

Threats

Although the Tucuxi is fairly common in its range it does suffer mainly man-made threats from hunting, accidental drowning in fishing nets, destruction or damage to river banks by human development and pollution along the coasts and rivers.

References

http://www.baiji.org/in-depth/freshwater-dolphins/sp ecies-guide/tucuxi.html

http://en.wikipedia.org/wiki/Tucuxi

http://dolphins.jump-gate.com/differnt_dolphins/%20t ucuxi.shtml

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