Irrawaddy dolphin
Key Facts
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Common Name
Irrawaddy dolphin, snubfin dolphin ; orcelle (Fr); delfín de Irrawaddy(Sp)
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Scientific Name
Orcaella brevirostris
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Status
IUCN: Vulnerable; CITES: Appendix I
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Population
About 6,000
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Length
180-275 cm
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Skin colour
Slaty blue to slaty gray
Related Links
Patchy distribution for a vulnerable species
The species is patchily distributed in South-East Asia, and is primarily found in estuaries and mangrove areas, with freshwater populations occurring in river systems.The Mahakam river (Kalimantan, Indonesian Borneo) population of Irrawaddy dolphins is severely threatened by fisheries bycatch and habitat degradation, and may number as few as 34 animals.
Surveys conducted in 2001 estimated that the Malampaya Sound population in the Philippines consists of just 77 individuals, confined to a small area in the inner sound, and is the only known population of this species in the country.
During 2001 there were reports that as many as five animals from this population were killed incidentally in fishing operations, indicating that the Irrawaddy dolphins of Malampaya Sound are in immediate danger of extinction due to low numbers, limited range, and high mortality.
The Mekong River Irrawaddy dolphin (Orcaella brevirostris) population inhabits a 190km stretch of the Mekong River between Cambodia and Lao PDR. The latest population is estimated between 64 and 76 members (2008 figures).
Physical Description
The Irrawaddy dolphin is identified by a bulging forehead, a short beak, and 12-19 teeth on each side of each jaw. The pectoral fin is broadly triangular. There is a small dorsal fin, on the posterior end of the back.When diving, this dolphin breathes at intervals of 70-150 seconds; the head appears first and then disappears, and then the back emerges, but the tail is rarely seen.
Size
Head and body length is 180-275 cm.
Colour
Irrawaddy dophins are slaty blue to slaty gray throughout, with the underparts slightly paler.