Length is about 1 m at birth and 2.3 m at full maturity. Birth weight is about 10 kg. Adult weight exceeds 130 kg. Lifespan is about 30 years.
The Irrawaddy Dolphin is a slow swimmer. It surfaces in a rolling fashion and lifts its tail fluke clear of the water for a deep dive only. Irrawaddy Dolphins spit streams of water from their mouths while spyhopping. Dolphins of the species kept in captivity have been trained to do this on command.
Genetically the Irrawaddy Dolphin is closely related to the Orca. The species name brevirostris comes from the Latin meaning short-beaked. In 2005 genetic analysis showed that the Australian Snubfin Dolphin found at the coast of northern Australia forms a second species in the Orcaella genus.
On account of their coastal nature Irrawaddy Dolphins are more susceptible to interference than other river dolphins. The most direct threat is the capturing of Irrawaddys for their oil. As an endangered species, they are legally protected from hunting; however, enforcement may be poor along tens of thousands of miles of coast line. Entanglements in gillnets and deaths or injury due to explosives used in fishing are common in Vietnam and Thailand. All along its distribution population and other habitat degradation worries conservationists. Human influence such as nets crossing river channels restrict movement and isolate populations, causing them to decline. The population in India's Chilka Lake, which has suffered from entanglement in fisher's gill nets and drag nets, is believed to have dwindled to as few as 50 individuals.
Irrawaddy dolphins in Myanmar have been documented participating in cooperative fishing with humans using cast nets by driving the fish towards these fisherman in response to acoustic signals from them.
Irrawaddys are also taken to perform in aquariums. Though this practice is less common than it used to be, it still has a significant local impact.
DOLPHINS IN MEKONG RIVER ON BRINK OF EXTINCTION, NEW STUDY REVEALS URGENT ACTION NEEDED TO SAVE CRITICALLY ENDANGERED IRRAWADDY DOLPHIN.
Aug 16, 2011; WASHINGTON, DC -- The following information was released by World Wildlife Fund (WWF): Irrawaddy dolphin numbers have declined to...
Saving freshwater dolphins means saving their rivers.(irrawaddy dolphin protection must include river habitats in Cambodia)
Jun 03, 1999; The sound came first, a sharp blowing sound from somewhere in the muddy waters of the Mekong River. Then Phong Choeun got a...