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

Abstract

Pangio juhuae sp nov, a new species of subterranean eel loach, is described from Kerala, India. It is distinguished from its subterranean congeners by the presence of a dorsal fin, four pectoral rays and five segmented anal fin rays. Genetic analyses suggest that P. juhuae is closely related to P. bhujia but is distinct in morphology, particularly by the presence of a dorsal fin. The low genetic distance and significant morphological difference between these two Pangio species suggest that they have diverged from an immediate common ancestor and evolved distinct adaptations to subterranean niches. P. juhuae exhibits less evolved troglobitic traits compared to P. bhujia and P. pathala, suggesting it could be a connecting species in the evolutionary transition from terrestrial to subterranean loaches. This discovery provides evidence for possible subterranean speciation of fishes in underground habitats.