Subterranean Fishes of the World

3703

2017

PeerJ Preprints

5:e3251v1

Background: India is one of the mega biodiverse countries with a large number of endemic freshwater fishes. Recently, species of genus Horaglanis (family: Clariidae) have been reported from the southern part of India. Due to their unique morphological adaptations, these enigmatic species have been subjected to phylogenetic studies to understand the evolution of adaptive traits. Further, the taxonomic status of these species has not been verified using molecular data. Methods: In the present study, secondary data i.e. reported sequences of mitochondrial cytochrome c oxidase subunit I gene was used to estimate the genetic divergence values for 14 species of the family Clariidae. Phylogenetic trees were reconstructed using maximum parsimony, maximum likelihood and Bayesian Inference methods. Results: The average genetic divergence value among genera Clarias-Clariallabes-Platyallabes-Dolichallabes-Gymnallabes-Tanganikallabes-Channallabes was 0.082 ± 0.01. However, these genera showed an average divergence value of 0.296±0.02 with genus Horaglanis. In all tree topologies, species of the genus Horaglanis formed a basal group to all other clariids. Discussion: The higher genetic divergence value between genus Horaglanis and other genera of Clariidae family suggested that genus Horaglanis may belong to a separate sub family. Based on phylogenetic trees, it is evident that species of Horaglanis might have originated early in the evolution of Clariids than other species.

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