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.