Honshu - Shikoku - Kyushu




J. Hales



Major Habitat Type

Temperate coastal rivers

Drainages flowing into

Pacific Ocean; East China Sea, Philippine Sea, Sea of Japan, Korea Strait, Inland Sea

Main rivers to other water bodies

Rivers in the ecoregion include the Omono, Mogami, Chikuma (Shinano), Kitakami, Arakawa, Fuji, and Shōnai rivers on Honshū; Yoshino and Shimanto rivers on Shikoku; and Chikugo River on Kyūshū.



This ecoregion extends from the Japanese Ryukyu Islands (or Nansei Islands) north to Kyūshū, Shikoku, and Honshū. The boundaries exclude Lake Biwa, which is distinguished separately as ecoregion 643 [Biwa Ko], and the island of Hokkaido, which falls into ecoregion 641 [Sakhalin, Hokkaidō, & Sikhote - Alin Coast].

Terrestrial habitats

Terrestrial ecoregions in this ecoregion include the Nansei Islands subtropical evergreen forests, Taiheiyo evergreen forests, Taiheiyo montane deciduous forests, Nihonkai montane deciduous forests, Nihonkai evergreen forests, and Honshu alpine conifer forests (Wikramanayake et al. 2002).

Description of endemic fishes

The ecoregion contains around twenty endemic species, such as Pseudobagrus ichikawai and Tanakia tanago on Honshū and Lentipes armatus on the Ryukyu Islands.

Justification for delineation

East Asian ecoregions were delineated through a top-down process using major basins as a starting point and incorporating traditionally recognized zoogeographic patterns where appropriate (Abell et al. 2008).


  • 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.