new species:
Trichomycterus yuska Fernández & Schaefer, 2003

type locality:
Argentina, Provincia de Catamarca, Departamento Tinogasta, Arroyo Aguas Calientes, 4.050 m elevation (27°14’S 68°16’W); Holotype FML 2535 (88,5 mm SL)

published in:
Fernández, L. & S.A. Schaefer (2003):
Trichomycterus yuska, a new species from high elevations of Argentina (Siluriformes: Trichomycteridae).
Ichthyological Explorations of Freshwaters 14 (4): 353-360

abstract (from publication):
Trichomycterus yuska, new species, is described from a stream at 4,000 m elevation in the Andean Cordillera of catamarca, Argentina. The new species shares the synapomorphies diagnosing the trichomycterid clade comprised of the Trichomycterinae, Scleronema, Ituglanis, plus the TSVSG clade (subfamilies Tridentinae, Stegophilinae, Vandeliinae, Sarcoglanidinae, and Glanapteryginae), but lacks the diagnostic synapomorphies for the clade comprised of Scleronema, Ituglanis, and TSVSG. Trichomycterus yuska is assigned to the patently non-monophyletic subfamily Trichomycterinae and, because it lacks characters which place it within any other trichomycterine genus, it is assigned to the genus Trichomycterus by default. The news species is excluded from membership in other genera of the subfamily Trichomycterinae by the combination: presence of pelvic fins and girdle, 6-7 principal dorsal-fin rays, 18-19 ribs, transversely flattened caudal peducnle, lack of a very thick layer of fatty tissue on the body and head, presence of a portion of the laterosensory canal system in the sphenotic, and first dorsal fin pterygiophore inserting on vertebra 21. The following combination serves to further distinguish T. yuska from the other species of the genus Trichomycterus, include the well-developed head musculature, first pectoral fin ray prolonged as a short filament, tip of pelvic fin not reaching to anus, no bands or spots on the boday, premaxilla rectangular with outer row teeth incisiform and not spatulate or bifid.