Phenotypic variation in the Snowtrout Schizothorax richardsonii (Gray, 1832) (Actinopterygii: Cypriniformes: Cyprinidae) from the Indian Himalayas

Abstract

We investigated intraspecific variation of the Snowtrout, Schizothorax richardsonii on the basis of morphometric characters. Altogether, 217 specimens were collected from four rivers in the Western and Central Indian Himalaya. A truss network was constructed by interconnecting 14 landmarks to yield 31 distance variables that were extracted from digital images of specimens using tpsDig2 and PAST software. Transformed truss measurements were subjected to univariate analysis of variance, factor analysis and discriminant analysis. All variables exhibited significant differences between the populations. Altogether 86.6% of the specimens were classified into their original populations (82.9 % under a ‘leave-one-out’ procedure). With factor analysis measurements of the head region, the middle portion and the caudal region had high loadings on the on first and second axis. The results indicated that S. richardsonii has significant phenotypic heterogeneity between the Western and Central Indian Himalayas. We hypothesize that the marked interspecific variation in S. richardsonii is the result of local ecological conditions.

Studies on morphological variation in three barbin fishes (Cyprinidae:Barbinae) from different water areas of Manipur, India

“…While the closeness between the stocks of P. manipurensis may be due to their similar habitat attributes and to environmental impacts. The results are similar with the findings of Mir et. al.…”

Morphological and molecular divergence of Indian hill trout,Barilius bendelisis(Hamilton, 1822) stocks from different Rivers in Indo‐Burma biodiversity hotspot: Does river altitude and Dam play a role?

“…Truss network system is one of the widely applied methods, which has been upgraded by image processing techniques recently through proper data collection, more effective descriptions of shape and new analytical tools (Strauss & Bookstein, ). Truss network system is based on the measurement of various body distances connecting two morphological landmarks from a sequential series of connected polygons (Mir, Mir, & Chandra, ) and is more potent in identifying stocks and differentiating species in comparison to the traditional morphometric methods (Bookstein et al, ; Strauss & Bookstein, ). This type of landmark‐based technique using geometric morphometrics imposes no restrictions on the direction of variation and localization of shape changes and is highly effective in capturing information about the shape of an organism (Cavalcanti, Monteiro, & Lopes, ).…”

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

“…1) (Pandey & Nautiyal 1997). Similarly, a truss analysis involving 14 anatomical landmarks identified significant phenotypic variability in S. richardsonii distributed across central and western Himalayan rivers of India (Mir et al 2013). A similar approach (Pradhan & Wagle 2013) was used to quantify differences within the same species across 3 tributaries of the Gandaki River, Central Himalayas.…”