Pachyurus

Pachyurus croakers have a moderately elongated body with a sounded, slightly high dorsal profile and a straight or slightly arched, ventral profile. They have a conical head with a swollen and blunt snout. The mouth is horizontal and may be terminal or below the snout. The eyes are moderately large to large. The snout has five marginal pores, typically they lack upper pores but these are present in some species. The chin has five pores but no barbels. The second spine of the anal fin is moderately sized or robust.^[6] These are relatively small croakers, the largest species is P. junki with a maximum published total length of 35.5 cm (14.0 in).^[7]

Pachyurus croakers are found in freshwater habitats in South America from Guyana south to Argentina.^[6]One species, the La Plata croaker (P. bonariensis), is an invasive, non native species in the Lagoa Mirim and Lagoa dos Patos systems in Uruguay and Brazil where it is already numerous enough to be important in commercial fisheries in these lakes. They reached these lakes either by deliberate introduction or by moving from the nearby river systems through flooded rice fields.^[8]