Lesser Sunda Islands




J. Hales


East Timor

Major Habitat Type

Tropical and subtropical coastal rivers

Drainages flowing into

Java Sea, Bali Sea, Flores Sea, Savu Sea, Timor Sea, Banda Sea, Indian Ocean



The Lesser Sunda Islands comprise the eastern part of the Sunda Islands in the Java Sea.  They range from Bali in the west to Timor in the east.

Terrestrial habitats

Terrestrial ecoregions include: Eastern Java-Bali rain forests [IM0113], which extend from Bali to Alor Island; Eastern Java-Bali montane rain forests, which only occur in the ecoregion on Bali [IM0112]; Sumba deciduous forests [AA0203] on Sumba Island; and Timor and Wetar deciduous forests [AA0204], which occur in the eastern end of the ecoregion on the islands of Sawu, Rote, Timor, and Wetar (Wikramanayake et al. 2002).

Description of endemic fishes

This ecoregion may contain as many as 10 endemics (M. Kottelat pers. comm. 2006). For example, Oryzias timorensis is restricted to Timor and Rasbora baliensis is restricted to Lake Bratan in Bali.

Other noteworthy fishes

Rasbora baliensis and Lentipes whittenorum are both listed as Vulnerable according to 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For Southeast Asia, delineations were determined using a bottom-up approach that employed both published and unpublished field data and expert assessment (Abell et al. 2008; Kottelat et al. 1993; Koumans 1953; Watson & Kottelat 1994). The ecoregion is characterized by the absence of primary division freshwater families (except two species of Cyprinidae in Bali and Lombok) and the presence of several endemic species of marine origin (M. Kottelat pers. comm. 2006).

Level of taxonomic exploration

There is little to no data for most of the islands in this ecoregion (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\ "<"www.iucnredlist.org">" (21 May 2013)
  • Kottelat, M.,Whitten, A. J.,Kartikasari, S. N.;Wirjoatmodjo, S. (1993). "Freshwater fishes of Western Indonesia and Sulawesi" Hong Kong: Periplus.
  • Koumans, F. P. (1953). "Gobioidea" Weber, M. ;L. F. de Beaufort (Ed.) Fishes of the Indo-Australian Archipelago ( (Vol. 10, pp. 1-423 ) Leiden: E. J. Brill,.
  • Watson, R.E.;Kottelat, M. (1994). "Lentipes whittenorum and Sicyopus auxilimentus, two new species of freshwater gobies from the western Pacific (Teleostei: Gobiidae: Sicydiinae)" Ichthyological Exploration of Freshwaters 5 (4) pp. 351-364.