Tucuxi (Sotalia fluviatilis) is a dolphin found both in the coastal waters and in the rivers of the Amazon Basin to the north and east of South America. These dolphins are very much similar to the bottlenose dolphin. These dolphins are of two types, i.e., the freshwater tucuxi and the marine tucuxi. These species are light grey to bluish-grey on their back, and are pinkish to light grey on their belly. The pink coloration can also be seen sometimes on the lower jaw and the throat. Their dorsal fin is triangular, rounded and curved and it is slightly hooked at the tip. They also have a long and slender beak with a rounded fore-head. Their upper and lower jaw contains (26 to 36) pairs of teeth. These species grow up to a size of 152 cm and weigh up to 55 kg. These dolphins are generally smaller as compared to the other species of the dolphins.
Habitat and Behavior
These species are found in both saltwater as well as freshwater. They can be found in the Brazil, Florianopolis, Caribbean Sea and near Panama Canal. These dolphins are the inhabitants of lakes and rivers. These species avoid flooded forests as well as rapid and fast-moving turbulent water. They can be found along 2500 km of the Amazon and 250 km upstream in the Orinoco River. The marine tucuxi are found in bays and estuaries. These are social creatures and are found in a group of (10 to 15) individuals. Sometimes they can be seen in a group of 30 creatures. These are also seen to be jumping in clear waters.
These dolphins feed mainly on fish as well as krill and crustacean. These species are known to feed on about 28 species of fishes.
Reproduction / Breeding
Much is not known about the reproductive or breeding habits of these species. The calving in these species occurs in September to November. The gestation period in these species is about 11 months. They have a life span of about 30 and 35 years, in marine and river respectively.
Threats and Conservation
These species of dolphins are killed in gillnet fisheries. These are also caught accidentally in fishing nets and killed. The destruction of their natural habitat for development of coasts by human being is also one of the major threats to these species. The hydro-electric damming projects may cause these species to become isolated. These modern projects are also responsible for killing the migratory fishes, which are considered as the important diet of these species. Moreover, pollution level in the water also causes these species to die. The pollution in the water by the industrial companies is becoming one of the biggest threats to these freshwater species. These species are widely distributed in Amazon River but the scientists do not know the exact number of these species. The Orca and Bull Shark are the natural predators of these species. Some of these tucuxi dolphins are also kept in captivity in Europe.