#iniidae

Amazon river dolphins (Inia geoffrensis) in an Amazonian floodplain forest, Rio Negro, Brazil

Boto Inia geoffrensis geoffrensis

Amazon River Dolphin or Boto (Inia geoffrensis), family Iniidae, found in freshwater river basins of northern South America

ENDANGERED.

Largest species of river dolphin in the world, reaching 185 kg (408 lb) in weight, and 2.5 m (8.2 ft) in length.

Males are larger than females

Adults become pink(ish), which is more pronounced in males.

They have the widest ranging diet of any of the toothed cetaceans, feeding on a wide variety of small aquatic animals.

photos: Sylvain Cordier, Kevin Schafer, Lauren Van Noort

The Beautiful Boto

Also known as the Amazon river dophin or the pink river dolphin, the boto (Inia geoffrensis) is a species of toothed whale native to the Amazon and Orinoco river basins in South America. Because they reside mainly in rivers, lakes and mangroves, the boto occupies a large range; nearly 7 million square kilometers (435 thousand square miles). Despite being related to whales and dolphins, I. geoffrensis cannot tolerate saltwater and is only found in freshwater.

The Amazon river dolphin is the largest of the four river dolphin species, weighing in at 98-185 kg (215-407 lbs) and measuring 1 to 2.5 m (4-8 ft) in length. Males are larger than females, and are a bright pink to the females’ dull grey. A significant part of the length comes from the dolphin’s distinctive long snout, which is used to hunt for crustaceans and small fish. The boto’s body is designed to be highly flexible, which comes in handy when navigating through flooded forests. One adaptation in particular that makes I. geoffrensis stand out is the unfused neck vertebrae, which allows them to bend at up to a 90-degree angle. Botos also use echolocation to navigate murky river waters. which is enhanced by the large melon on their foreheads.

Breeding for the pink river dophin occurs between May and June, during the rainy season when flooding is at its peak. Males will fight for access to females, and will also perform courtship displays that involve carrying a number of objects-- like branches, fish, or even live turtles-- and slapping them into the water. Successful pregnancies last 11 months, and after giving birth mothers raise their young in the slow-moving waters of flooded forests. Weaning takes about a year, although mother-child pairs will often stay together for much longer. The average lifespan of the boto can be anywhere from 10 to 26 years, as they have no natural predators.

Outside the mating season, I. geoffrensis is a solitary creature. It’s rare to see groups of more than three at a time, and do not heavily defend set territories. However, they are very curious and have been known to readily approach canoes or play with debris in the water. Individuals have also been seen hunting fish in loose cooperation with other species like giant river otters (Pteronura brasiliensis). The bota is crepuscular, active mainly at dawn or dusk, and generally stay close to the surface of the water. Deep dives are rare, as they can only hold their breath for 110 seconds.

Conservation status: Hunting pressure and pollution, as well as dam building and deforestation, are major threats to the amazon river dolphin, which has been classified as Endangered by the IUCN. Conservation efforts are being made, but the species is difficult to keep or breed in captivity so most work is being done in the wild.

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Photos

Sylvain Cordier

Amazon river dolphin (Inia geoffrensis)

Photo: unknown

Pink River Dolphin

Inia geoffrensis

Due to the pink body, it is called pink river dolphin. The family of this species is Iniidae. It is considered as toothed whale. The Orinoco river dolphin, Bolivian river dolphin and Amazon River dolphin are the three subspecies.

Photo: lydiacneal.wordpress.com - flickr

Photo: imgarcade.com