new species:
Crenicichla hu Piálek, Říčan, Casciotta & Almirón, 2010

type locality:
Argentina, Misiones, río Paraná basin, arroyo Piray–Miní, 26°20’00″S 53°52’30″W

ecological notes (from publication):

The arroyo Piray–Miní (the type and only-known locality) has clear and rapidly flowing water. The depth of the arroyo Piray–Miní is variable, 0.20 to 1.40 m. The bottom consists of mud, sand, and mostly stones. Some areas have scarce submerged vegetation.

published in:
Piálek, L., O. Říčan, J. Casciotta & A. Almirón (2010):

Crenicichla hu, a new species of cichlid fish (Teleostei: Cichlidae) from the Paraná basin in Misiones, Argentina.
Zootaxa 2537: 33-46

abstract (from publication):
A new species of Crenicichla Heckel, C. hu, is described from the arroyo Piray–Miní, a left-hand tributary of the río Paraná, Misiones province, Argentina. This new species is easily distinguished from its congeners in the La Plata basin and adjacent coastal rivers by the dark coloration (dark grey or dark brown to black), a color pattern consisting of 7 to 9 black irregular blotches on the flank, and 47–54 scales in the E1 row. Adult females have dorsal fin with an irregular color pattern formed by wide black and white longitudinal stripes and blotches. In addition to standard morphological comparisons, a brief molecular phylogenetic analysis of Crenicichla species from the province of Misiones is also introduced.