Irrawaddy dolphin  (Orcaella brevirostris)

Authenticated (11/03/08) by Dr. Brian Smith, Associate Conservation Zoologist, Wildlife Conservation Society and Asia Coordinator, IUCN SSC Cetacean Specialist Group.

• Beak: the bill of a bird. In cetacea (whales and dolphins): the elongated forward part of the head, comprising the lower jaw and upper jaw or ‘rostrum’.
• Cephalopoda: from the Greek for ‘head-foot’, a class of molluscs that occur only in marine habitats. All species have grasping tentacles, and either an internal or external shell. Includes nautiloids, cuttlefish, squids, octopuses, and extinct ammonites and belemnites.
• Cetacean: cetaceans are a group comprising all whale species, therefore including dolphins and porpoises.
• Crustacea: diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
• Dorsal fin: the unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.
• Echolocation: detecting objects by reflected sound. Used by bats and odontocete cetaceans (toothed whales, dolphins and porpoises) for orientation and to detect and locate prey.
• Gestation: the state of being pregnant; the period from conception to birth.

1. IUCN Red List (October, 2008)
   http://www.iucnredlist.org
2. Animal Diversity Web (December, 2004)
   http://animaldiversity.ummz.umich.edu/site/accounts/information/Orcaella_brevirostris.html
3. CITES (December, 2004)
   http://www.cites.org
4. Convention on Migratory Species (December, 2004)
   http://www.cms.int/reports/small_cetaceans/data/O_brevirostris/O_brevirostris.htm
5. Kreb, D., Budiono, X. and Syachraini, X. (2007) Status and conservation of Irrawaddy dolphins Orcaella brevirostris in the Mahakam River of Indonesia. In: Smith, B.D., Shore, R.G. and Lopez, A. (Eds) Status and Conservation of Freshwater Populations of Irrawaddy Dolphins.Wildlife Conservation Society, Bronx, New York.
6. Smith, B.D., Thant, U.H., Lwin, J.M. and Shaw, C.D. (1997) Investigations of cetaceans in the Ayeyarwady River and northern coastal waters of Myanmar. Asian Marine Biology, 14: 173 - 194.
7. Van Parijs, S.M., Parra, G.J. and Corkeron, P.J. (2000) Sounds produced by Australian Irrawaddy dolphins, Orcaella brevirostris. Journal of the Acoustical Society of America, 108 (4): 1938 - 1940.
8. Kamminga, C., Wiersma, H. and Dudok van Heel, W.H. (1983) Sonar sounds in Orcaella brevirostris of the Mahakam River, East Kalimantan, Indonesia; the first descriptions of the acoustic behaviour. Aquatic Mammals, 10: 125 - 136.
9. Beasley, I., Phay, S., Gilbert, M., Phothitay, C., Yim, S., Lor, K.S. and Kim, S. (2007) Status and conservation of Irrawaddy dolphins Orcaella brevirostris in the Mekong River of Vietnam, Cambodia and Laos. In: Smith, B.D., Shore, R.G. and Lopez, A. (Eds) Status and Conservation of Freshwater Populations of Irrawaddy Dolphins.Wildlife Conservation Society, Bronx, New York.
10. Zhang, X., Wang, D., Liu, R., Wei, Z., Hua, Y., Wang, Y., Chen, Z. and Wang, L. (2003) The Yangtze River dolphin or baiji (Lipotes vexillifer): population status and conservation issues in the Yangtze River, China. Aquatic Conservation: Marine and Freshwater Ecosystems, 13: 51 - 64.
11. Smith, B.D. and Mya, T.T. (2007) Status and conservation of Irrawaddy dolphins Orcaella brevirostris in the Ayeyarwady River of Myanmar. In: Smith, B.D., Shore, R.G. and Lopez, A. (Eds) Status and Conservation of Freshwater Populations of Irrawaddy Dolphins, WCS Working Paper Series 31.Wildlife Conservation Society, Bronx, NY.