DNA barcoding revealed a new species of <i>Neolissochilus</i> Rainboth, 1985 from the Kaladan River of Mizoram, North East India

<i>Neolissochilus kaladanensis</i> sp. nov., a new cyprinid species, is described from the Kaladan River drainage of Mizoram. It differs from all other valid <i>Neolissochilus</i> species in having higher number of gill rakers on the lower arm of the first gill arch (13–14 vs. 12 or below in all the species). The analysis of mitochondrial gene cytochrome c oxidase subunit I (COI) sequences separated <i>N. kaladanensis</i> sp. nov. from all other <i>Neolissochilus</i> and <i>Tor</i> species with an average genetic distance of 6.0%. It is further separated from the morphologically most similar species <i>N. hendersoni</i> and <i>N. soroides</i> by a genetic distance of 6.7% and 6.8%, respectively. Based on the lowest BIC and AICc scores, best fit model for COI dataset was TN93 + G + I, out of 24 different nucleotide substitution models tested. The maximum-likelihood (ML) phylogenetic tree was constructed using the COI sequences of representative <i>Neolissochilus</i> and <i>Tor</i> species. The anomalies observed among the GenBank sequences of the genera <i>Tor</i> and <i>Neolissochilus</i> are also discussed.