Figure 5
From: New freshwater mussel taxa discoveries clarify biogeographic division of Southeast Asia
Updated freshwater biogeographic division of the mainland Southeast Asia based on freshwater mussel phylogenetics. (A) Freshwater biogeographic division of the mainland Southeast Asia. Color circles indicate the localities of taxa having biogeographic affinities to the Indian (yellow), Western Indochina (green), and Sundaland (pink) faunas. Type localities of new freshwater mussel species and occurrences of two cryptic Ensidens lineages are numbered as follows: Parreysia rakhinensis sp. nov. (1), Balwantia baniensis sp. nov. (2), Trapezoideus lenya sp. nov. and Monodontina lenyanensis sp. nov. (3), Yaukthwa avaensis sp. nov. (4), Ensidens sp. ‘Mun’ (5), Ensidens sp. ‘Thai’ (6), Monodontina laosica sp. nov. (7), M. mekongi sp. nov. (8), Nyeinchanconcha nyeinchani gen. & sp. nov. (9), Pseudodon kayinensis sp. nov. (10), Sundadontina brandti sp. nov. and S. taskaevi sp. nov. (11), and S. tanintharyiensis sp. nov. (12). (B) Boundary between the Western Indochina and Sundaland freshwater subregions at the southern margin of the Kra Isthmus (Tanintharyi – Lenya drainage divide). Violet line indicates the boundary between freshwater subregions based on drainage divides of the corresponding river basins. Green circles indicate records of the Western Indochina fauna representatives: Leoparreysia tavoyensis, Trapezidens scutum, T. exolescens4,24, Indochinella pugio daweiensis6. Pink circles indicate records of the Sundaland fauna representatives: Trapezoideus foliaceus7, Trapezoideus lenya sp. nov., Monodontina lenyanensis sp. nov., and Sundadontina tanintharyiensis sp. nov. All freshwater mussel taxa in Malaysia are members of the Sundaland fauna16,22. Arrows indicate putative ancient (pre-Pleistocene) dispersal routes of the Western Indochina (green) and Sundaland (pink) Unionidae species around the Isthmus of Kra and surrounding areas inferred from our statistical biogeographic analyses and distribution data (Supplementary Tables 1 and 3). Blue gradient shading indicates the putative ancient seaways crossing the Thai-Malay Peninsula based on the ArcGIS modeling (hydrologically conditioned DEM with elevation levels < 120 m) and published data36. The map was created using ESRI ArcGIS 10 software (https://www.esri.com/arcgis); the topographic base of the map was created with Natural Earth Free Vector and Raster Map Data (https://www.naturalearthdata.com), Global Self-consistent Hierarchical High-resolution Geography, GSHHG v2.3.7 (https://www.soest.hawaii.edu/wessel/gshhg), HydroSHEDS (https://www.hydrosheds.org)81, The General Bathymetric Chart of the Oceans, GEBCO (https://www.gebco.net), and Vector Map (VMap) Level 0 (http://gis-lab.info/qa/vmap0-eng.html) (Maps: Mikhail Yu. Gofarov).
