new species:
Bryconamericus ytu Almirón, Azpelicueta & Casciotta, 2004

type locality:
province of Misiones, río Uruguay basin, arroyo Shangay (27°29’S, 54°40’W); holotype: MACN-Ict 8670, 49.4 mm SL, male

published in:
Almirón, A.E., M. Azpelicueta & J.R. Casciotta (2004):
A new species of Bryconamericus from the arroyo Shangay, río Uruguay basin, Argentina (Teleostei: Characiformes: Characidae).
Zoologische Abhandlungen des Staatlichen Museums für Tierkunde, Dresden 54: 03-10

abstract (from publication):
Bryconamericus ytu sp.n., from arroyo Shangay, río Uruguay basin is distinguished from other species of the genus by the following combination of characters: 17-21 branched anal fin rays, predorsal length (52.5-55.4 % SL), preventral length (47.8-51.0 % SL), preanal length (63.0-68.8 % SL), caudal peduncle length (12.3-14.3 % SL), and eye diameter (33.1-37.0 % HL). Seven to ten dentary teeth decreasing in size gradually, inner premaxillary teeth wider distally. One vertically elongated black humeral spot, separated from a second posterior one by 3 or 4 scales. Narrow lateral band becoming wider below middle of dorsal fin base.

distribution (from publication):
This species is only known from the arroyo Shangay (also named Pindaiti) a tributary of the río Uruguay in Misiones, Argentina. The environments have rapids and small falls with clear flowing water, pools, and some areas with slow current. The depth of the streams varies from 0.40 to 1.3 m and the bottom is composed of sand, and mostly stones.