Irrawaddy dolphin

Irrawaddy dolphin

The Irrawaddy dolphin ( Orcaella brevirostris ) is a mainly living in Asian coastal regions dolphin from the order of whales, through its mapping a long time there was disagreement. In some places it is also called river hog.

Features

The body length of this dolphin is 2.30 meters, very large individuals are up to 2.75 meters long. The weight can reach 150 kg. The one without the typical dolphin snout rounded head resembles the head shape of the beluga. With predominantly gray body color different variants come from pale whitish gray to dark slate gray before.

Dissemination

Although he is named after the river Irrawaddy, is no true river dolphin.

Most populations live near the coast in bays and estuaries, where they occasionally swim upstream, but others keep permanently in rivers such as the Mekong on. While the former have their habitat on the coasts of Bangladesh, Myanmar, Thailand, Cambodia, Vietnam, Malaysia, Indonesia, Palawan, New Guinea and northern Australia, reaching the population in the Mekong River from Cambodia, even the Laotian river section.

Way of life

Irawadidelfine have no long dive times, about every minute they come, only her head and back pointing to the surface to breathe. They do not jump, follow occasionally boats. Their diet consists of crustaceans, which are dug from the ground mud. In addition, fish and cephalopods are eaten. Like other dolphins, they live in schools, which consist of up to six animals, a maximum of 15 specimens have been observed in isolated cases. Occasionally, especially in the rivers, individual animals seen.

Average every two years is a young Irrawaddy dolphin to the world.

Endangering

Little is known about the population numbers. In the Mekong live according to a count of the WWF (as of August 2011) only 85 copies. In most countries of its range it is under protection. However, he often caught in fishing nets, whereby he suffocated. In some areas, such as in the Mekong Delta, he was thereby almost exterminated. The geographically isolated population in Malampaya Sound in Palawan is classified by the IUCN as endangered ( "vulnerable "). Sedimentation, heavy ship traffic as well as environmentally harmful fishing methods are decisive factors of the steady detaching the population.

Reserve on the Mekong River

On August 24, 2012, the Government of Cambodia decided to devote the Irawadidelfinen of the Mekong River, a 180 km long and reserve. It extends from the province of Kratie in Ostkambodscha to the border with Laos. Although allowed in this section of the river continues to be fished, but the use of raft houses, net baskets and fishing nets prohibited.

Taxonomy

Because of striking similarities to the Irrawaddy dolphin beluga was occasionally associated with the (actually ) Gründel arctic whales. Due to its uniqueness the other hand, was a separate family, the Oracellidae postulated. Currently, zoologists are virtually unanimous in him taxonomically classified as a real dolphin.

Which family circle he performs within the dolphins, remains largely controversial. His beak missing because he could be a close relative of the pilot whales, genetic studies, however, see him as a close relative of the Orca.