Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal

Freshwater fishes in the river and lake systems Himalayas Tibetan Plateau are morphologically diverged but evolutionary relationship of putative subspecies separated these freshwater has not been explored. Snowtrout ( Schizothorax spp.) minnows (Cyprinidae) broadly distributed Asia. Body shapes 3 Lake Rara (northwest Nepal) endemics S. macrophthalmus , nepalensis raraensis ) 2 widely riverine species progastus richardsonii across drainages Nepal (i.e. Karnali, Gandaki, Koshi Rivers) were studied using geometric morphometry. Data derived from museum voucher specimens/tissues collected 1984-1986 1996 (Lake Rara). Cartesian coordinates 18 anatomical points (Type I landmarks) 528 individuals digitized; shape variation was then quantified with principal component analysis visualized thin-plate splines a Procrustes analysis. Models taxonomy versus geography) tested multivariate variance morphological distance matrix. Phylogeographic relationships examined haplotype network (N = 115) 1140 base pairs mitochondrial DNA cytochrome b gene, selected GenBank sequences 5). River snowtrout conspecifics, consistent phylogeographic data. In contrast, Gandaki Karnali grouped by morphotype (up- downstream) irrespective geographic origin, yet clustered separately within network. genetically distinct, due to incomplete lineage sorting. Morphological genetic variability represent mosaic driven isolation (= vicariance) specialization adaptation), insufficiently reflecting diversity. Additional data required appropriately derive management effective conservation plans.