new species:
Cnesterodon raddai Meyer & Etzel, 2001

type locality:
Argentina, province of Formosa, swamp near Resistencia, Río Paraná basin; Holotype MTD-F 25416 (male, 16.6 mm SL)

published in:
Meyer, M.K. & V. Etzel (2001):
Desciption of Cnesterodon raddai sp.n. from a swamp near Resistencia, Rio Paraná basin, Argentina (Teleostei: Cyprinodontiformes: Poeciliidae).

Zoologische Abhandlungen des Staatlichen Museums für Tierkunde Dresden 51 (17): 247-252

abstract (from publication):

Cnesterodon raddai sp.n. (locus typicus: swamp near Resistencia, Rio Paraná basin, Argentina), is described, illustrated and compared to all members of the genus Cnesterodon. The new species is closely related to Cnesterodon decemmaculatus (Jenyns). Cnesterodon raddai sp.n. differs from all hitherto known members of the genus Cnesterodon in morphological characters and colouration.

distribution (from publication):
Cnesterodon raddai sp.n. is restricted so far as known to central Rio Paraná basin in the north of Argentina, but it would not be surprising to find the new species also further north in the region of the Rio Paraguay basin.