Potamarius

{{Short description|Genus of fishes}}

{{Automatic taxobox

| image = FMIB 40699 Conorhynchos nelsoni, new species.jpeg

| image_caption = Potamarius nelsoni

| taxon = Potamarius

| authority = C. L. Hubbs & R. R. Miller, 1960

| type_species = Conorhynchos nelsoni

| type_species_authority = Evermann & Goldsborough 1902

| subdivision_ranks = Species

| subdivision = See text for species.

}}

Potamarius is a genus of sea catfishes. The three species in this genus exclusively inhabit fresh water in southern Mexico and Guatemala. The individual species have relatively small ranges.{{FishBase genus | genus = Potamarius | month = December | year = 2011}} The highly endangered Paragenidens grandoculis of Brazil was long classified in Potamarius, but a 2019 study has found it to belong in its own genus.{{Cite journal|last=Oliveira|first=Claudio|last2=Gasparini|first2=João Luiz Rosetti|last3=Lima|first3=Flávio César Thadeo|last4=Ingenito|first4=Leonardo Ferreira Da Silva|last5=Marceniuk|first5=Alexandre Pires|date=2019-04-18|title=Systematics, biogeography and conservation of Paragenidens grandoculis n. gen. and n. comb. (Siluriformes; Ariidae), a critically endangered species from southeastern Brazil|url=https://biotaxa.org/Zootaxa/article/view/zootaxa.4586.3.2|journal=Zootaxa|language=en|volume=4586|issue=3|pages=425–444|doi=10.11646/zootaxa.4586.3.2|issn=1175-5334|url-access=subscription}}