Nemacheilus rueppelli

Nemacheilus ruppelli, also known as the mongoose loach is a species of fish in the genus Nemacheilus. This fish is endemic to the Western Ghats of India. Recent evidence shows that there is only a marginal raw mitochondrial genetic distance between Nemachilichthys shimogensis and N. ruppelli. Although morphometric difference occur at the population level, Keskar et al. conclude that there are no significant differences separating the two species. Therefore they treat N. shimogensis as a synonym of N. ruppelli. The Eschmeyer's Catalog of Fishes follows this treatment.

Nevertheless, Nemachilichthys shimogensis is listed as a separate species by the IUCN and Fishbase to this day.

Distribution
N. ruppelli is presently reported from the Krishna River system in the Western Ghats, India. Specimen where found in the following rivers: Thunga, Mula-Mutha, Krishna River, Indrayani, Hiranyakeshi, Nira River and Koyna.

Habitat
N. ruppelli lives in moderate to fast-flowing rivers, usually on the bed. N. ruppelli prefers mud, small rocks, silt and pebbles. It frequently occurs in association with submerged roots of riparian plants and aquatic vegetation.