Fig. 1. Map of the Indochinese Peninsula with boundaries of study area (in insert) and map of the Upper Nam Ou River drainage with surveyed sites: 1 – Nam Long River; 2 – Nam Singgno Stream; 3 – Nam Phan Stream; 4 – Nam Ong Stream; 5–6 – Nam Pe River (5 – downstream, 6 – upstream); 7 – Nam Leng River; 8 – Nam Houn River; 9 – Nam H. Hu Stream; 10 – Nam Ban River; 11 – Nam Phet Stream.