Eugnathichthys is a genus of African characins in family Distichodontidae, the same broad group as the well-known Distichodus. The atlas' 3 species are known from Congo Basin drainages spanning the Democratic Republic of the Congo, the Republic of the Congo, Cameroon and the Central African Republic, where they inhabit the region's large rivers alongside a diverse community of other citharinoid characins. Like their relatives, they have an elongate, laterally compressed body suited to schooling in open water.
Little published information exists on the biology of individual Eugnathichthys species, and none of the three - E. eetveldii, E. macroterolepis or E. virgatus - has any real presence in the aquarium trade; data are sparse enough that most of what is known comes from taxonomic and survey literature rather than husbandry accounts. Sizes in the atlas range from about 4.5–11.5 in. Two species are assessed Least Concern and one has not yet been evaluated, consistent with a genus that draws mostly scientific rather than hobbyist attention.