considered a valid species from Argentina:
Percichthys laevis Jenyns, 1840
Santa Cruz River, Patagonia. Holotype: BMNH 19126.96.36.199
López-Arbarello, A. (2004):
Taxonomy of the genus Percichthys (Perciformes: Percichthyidae).
Ichthyological Explorations of Freshwaters 15 (4): 331-350
abstract (from publication):
In Argentina, recent percichthyids are represented by a single genus, Percichthys, of which four nominal species were recognized previous to this study. Morphometric analyses of the Argentinean species of Percichthys are carried out in order to study intraspecific and individual variation within these fishes. A total of 24 distance measurements, evaluated on each of 220 specimens, are analysed using multivariate (principal components and discriminant analyses) and bivariate (regressions) statistical methods. The analyses resulted in the recognition of three morphometrically distinct species of Percichthys in Argentina, P. trucha, P. colhuapiensis, and P. laevis. The latter species was previously considered to be a junior synonym of P. trucha. Two other species, P. vinciguerrae and P. altispinis are indistinguishable from P. trucha and thus, considered junior synonyms. The species-level taxonomy of the genus Percichthys is discussed and the Chilean species P. chilensis, previously considered to be a junior synonym of P. trucha, is shown to be morphometrically distinct from the latter.