Morphological Characterization of Two Species of the Freshwater Fish Genus Dawkinsia (Osteichthyes: Cyprinidae), with Emphasis on Stream Habitat Characteristics

Abstract

Abstract

Macro and microhabitat analyses were carried out for two cyprinid fishes of Dawkinsia sp., (D. filamentosa and D. tambraparniei) from the two selected rivers of South Indian river system (Thalayanai and Gadana). Macrohabitat features such as habitat structure and types; and microhabitat features such as stream depth, width, riparian cover, instream cover and substrates were studied. Suitable microhabitats for D. filamentosa were shallow, marginal waters of rivers and for D. tambraparniei it was shallow pools with moderate flow. The dietary analyses of the selected fishes revealed that D. filamentosa was an algivore and D. tambraparniei was a benthic insectivore. The morphometric variations between the two species of the freshwater cyprinid Dawkinsia were also investigated. Based on the 50 morphometric characters employed during this study among the two species and hence were utilized for the Principal Component Analysis (PCA) ordination. The detected phenotypical divergence between D. filamentosa and D. tambraparniei specimens revealed the fact of existing of two morphologically separated stocks within the sites may imply as a possibility of a relationship among the extent of phenotypic heterogeneity and the geographic distance; and shows limited combine into one among the populations. The two stocks of D. filamentosa and D. tambraparniei were distinct with each other; there is a complete variation between the Thalayanai and Gadana river populations.

Keywords: Cyprinids, Dawkinsia species, macro and microhabitat approaches, morphometric variation, dietary composition

Cite this Article

Kanthimathi M, Soranam R. Morphological characterization of two species of the freshwater fish genus Dawkinsia (Osteichthyes: Cyprinidae), with emphasis on stream habitat characteristics. Research & Reviews: Journal of Ecology. 2016; 5(3): 8–21p.