Blue Wolffish

They can grow up to 97 cm (38 in) in length and the maximum published weight is 4.99 kg (11 lb 0 oz). he body is elongated with a circular cross section. It has between 6 and 8 pores along the lower surface of the dentary and 43-48 scales along its lateral line, these counts being greater than similar counts for the other species in the H. lacerdae species complex.

Hoplias lacerdae is found in southern Brazil, northeastern Argentina and Uruguay and is found the Ribeira de Iguape River basin and in the Uruguay River basin, as far south as the Rio Negro in Uruguay. This species can be found in streams, rivers and lakes.

Hoplias lacerdae is a species within the genus Hoplias, a word derived from the Greek hoplon, which means "shield" or "armour", an allusion to the armour created by the enlarged cranial bones and large teeth of these fishes. The specific name honours the physician and anthropologist João Batista de Lacerda, the director of the National Museum of Brazil in Rio de Janeiro, because of his interest in the scientific explorations of the region.