Malay Peninsula Eastern Slope




J. Hales



Major Habitat Type

Tropical and subtropical coastal rivers

Drainages flowing into

South China Sea, Gulf of Thailand, Malacca Strait

Main rivers to other water bodies

Rivers in the ecoregion include the Tapi River and Pattani River, which drain into the Gulf of Thailand; Kelantan River, Pahang River, and Rompin River, which drain into the South China Sea; and Muar River, which drains into the Malacca Strait. The largest natural lake in the ecoregion is Songhkla Lake. Other natural and manmade lakes include Cheow Lan Lake, Thale Noi Lake, Phru Khuan Khi Sian wetlands, Bang Lang Reservoir, and Kenyir Lake.



This ecoregion represents the eastern drainages of the Malay Peninsula, from Prachuap Khiri Khan (Thailand) to Singapore. It also includes Tioman Island and the Anambas Islands.

Terrestrial habitats

The terrestrial ecoregions that occur in this region largely comprise Tenasserim-South Thailand semi-evergreen forests in the north and Peninsular Malaysian rain forests in the south. Other ecoregions that occur here to a lesser degree include Chao Phraya lowland moist deciduous forests, Peninsular Malaysian montane rain forests, Peninsular Malaysian peat swamp forests, and Indochina mangroves (Wikramanayake et al. 2002).

Description of endemic fishes

This ecoregion contains around 50 endemic species, including Akysis alfredi, Pangio alcoides, Betta pulchra, B. persephone, Parosphromenus tweediei, and P. paludicola. Betta Persephone is listed as Critically Endangered by the IUCN Red List (IUCN 2012).

Justification for delineation

For Southeast Asia, delineations were determined using a bottom-up approach that employed both published and unpublished field data and expert assessment (Abell et al. 2008). This ecoregion represents a transition zone between the Sunda Shelf fauna, the Mekong Chao Phraya fauna, and the Burmese fauna, with species of the different fauna extending to various degrees along the south-north axis. Lake Songkhla (Thale Sap) has a complex hydrology and its freshwater fauna is poorly known. Most of the lake is actually under tidal influence, with large scale penetration of marine and estuarine species. There are also endemic cave fish in Tioman Island (M. Kottelat pers. comm. 2006).


  • Abell, Robin,M.L. Thieme,C. Revenga,M. Bryer,M. Kottelat,N. Bogutskaya,B. Coad,N. Mandrak,S.C. Balderas,W. Bussing,M.L.J. Stiassny,P. Skelton,G.R. Allen,P. Unmack,A. Naseka,R. Ng,N. Sindorf,J. Robertson,E. Armijo,J.V. Higgins,T.J. Heibel,E. Wikramanayake, (2008). "Freshwater Ecoregions of the World: A New Map of Biogeographic Units for Freshwater Biodiversity Conservation" BioScience 58 (5) pp. 403-414.
  • Wikramanayake, Eric,Dinerstein, Eric,Loucks, C.,Olson, D.M.,Morrison, J.,Lamoreux, J. L.,McKnight, M.;Hedao, P. (2002). "Terrestrial ecoregions of the Indo-Pacific: A conservation assessment" Washington, DC: Island Press.
  • IUCN (2012) \IUCN Red List of Threatened Species. Version 2012.2\ "<"">" (21 May 2013)