Description of Irrawaddy Dolphin

Description

Common Name:
Irrawaddy dolphin

Latin Name:
Orcaella brevirostris

Other Names:
Snubfin dolphin, Loma Hua Baht (Songkha Lake, Thailand), Pa Ka (Laos) 

Primary Classification:
Odontocete (Toothed whale, dolphin or porpoise)

Sub Classification:
Delphinidae

Description:
The Irrawaddy dolphin has a rounded head with no beak, and a flexible neck. They can vary in colour from dark and light blue- grey, to pale blue. It is grouped as an oceanic dolphin, although some dolphins may live in the freshwater of rivers all their life (such as the Ganges in India). This species of dolphin has a small triangular shaped dorsal fin with a rounded tip, below the centre of the back , and is a slow swimmer - usually moving in small groups. Irrawaddy dolphins are very similar to the shape of the Beluga (toothed whale), and to the shape of the Finless Porpoise with its blunt round head, so they are sometimes difficult to tell apart. They can have up to 40 teeth on their upper jaw, and 36 teeth on the lower jaw.

Field ID:
Streamlined body, Round melon, Flexible neck, No prominent beak, Single blowhole, Long, broad, spatulate flippers, Blue-grey skin colour, Normally in small groups, Shy and retiring by nature

Length (metres):
Adult Irrawaddy dolphins can grow between 2.1 and 2.6 metres long. New-born are about 1m in length.

Weight:
A fully grown Irrawaddy dolphin can weigh between 90 and 150 kg. Birth weight is about 12kg or so.

Diet:
Fish, crustaceans and squid

Behaviour:
The Irrawaddy dolphins usually swim in groups of six, or less. They rarely show themselves above the surface of the water, but sometimes may make low horizontal leaps. They may also do something called 'spyhopping', which is the name given to the activity of poking their heads out of the water - perhaps to have a good look around! They have also been seen to spit out water from their mouths whilst spy-hopping! The Irrawaddy dolphin species do not ride the waters infront of the bows of boats, but they do have a special relationship with fisherman on the Irrawaddy and Mekong rivers, by driving fish into their nets.

source: WDCS