ABSTRACT
The mitogenome of Lepidopygopsis typus, an evolutionarily distinct, endangered, cyprinid fish from the Western Ghats Biodiversity Hotspot, was characterized. Total length of the mitogenome was 16,729 bp, and comprised of 13 protein coding, 22 tRNA and two rRNA genes. Thirteen protein coding genes contributed a total nucleotide length of 11,408 bp, which coded for a total of 3794 amino acids and accounting for 68.2 % of the mitogenome. A maximum likelihood phylogenetic tree based on mitogenomes of members of cyprinid subfamilies Torinae, Schizothoracinae and Schizopygopsinae, recovered L. typus in a well-resolved clade of Torinae with members of the Western Ghats endemic genus Hypselobarbus as sister taxa. Selection analysis suggested that the branch of L. typus and Hypselobarbus spp. was under intensified selection with reference to other members of Torinae. There were 19 codons under diversifying selection in L. typus, which could be the result of positive selection for adapting to high-altitude, upstream tributaries of Periyar River, where the species has a restricted distribution. With respect to Hypselobarbus spp., L. typus was under relaxed selection with about 68 % of codons experiencing neutral evolution. Restricted distribution, low population size and relaxation in selection can likely trigger extinction in L. typus, and therefore urgent conservation and monitoring plans are required to secure the future of this evolutionary distinct, and globally endangered species.
