Hemigrammus yinyang Lima & Sousa 2009

Distinguished from all other species of the genus Hemigrammus by having (in life) an orange blotch, located between two dark humeral blotches, immediately ahead and slightly above the posterior, darker second humeral blotch. Differs further from all congeners, except Hemigrammus haraldi, Hemigrammus luelingi, Hemigrammus neptunus, Hemigrammus ocellifer, Hemigrammus pretoensis, and Hemigrammus pulcher, by the possession of two humeral blotches. Diagnosed from all these species by the absence of a blotch on the caudal peduncle (vs. caudal peduncle blotch present).

Dorsal spines (total): 2; Dorsal soft rays (total): 9; Anal spines: 3 - 4; Analsoft rays: 19 - 23; Vertebrae: 33 - 34

Caught in moderately large (2-6 m wide) streams, with clear water, carrying little suspended sediment. Also collected from dark-colored waters or muddy, silt-laden waters (Ref. 82434).