Discovery of a new species of troglobitic eel loach from southern India

A new species of troglobitic eel loach Pangio juhuae, is described from Kerala, India. Pangio juhuae sp. nov. is distinguished from its subterranean congeners by the presence of a dorsal fin; four pectoral rays and five segmented anal fin rays. Genetic analyses using mitochondrial cytochrome C oxidase 1 gene revealed that P. juhuae is closely related to P. bhujia, being separated by a genetic distance of 1.5%. However, the current species is conspicuously distinct from P. bhujia by the presence of a dorsal fin, among other features. A low genetic distance and significant morphological difference between these two Pangio species suggest that they have diverged from an immediate common ancestor and have evolved distinct adaptations to intricate subterranean niches of the region. Compared to P. bhujia and P. pathala, less evolved troglobitic traits reflect that P. juhuae can also be a connecting species in the evolutionary ladder of terrestrial loaches to subterranean ones. Hence, this could also be an instance of possible subterranean speciation of fishes in underground habitats. Keywords: Stygobites, Subterranean speciation, Troglobitic traits, Troglomorphism