A new species of Acantholochus Cressey, 1984 (Copepoda: Bomolochidae) parasitic on the gills of common snook, Centropomus undecimalis, from the coastal zone of the State of Rio de Janeiro, Brazil, is described and illustrated. The new species differs from all other species of Acantholochus by the presence of only one inner seta on middle segment of the second and third endopods.
Copepoda; Bomolochidae; Acantholochus; Centropomus undecimalis; Rio de Janeiro; Brazil
