Body moder ately compr essed and r elativelythick. Snout moderately stout and rounded. Mouthoblique and subterminal. Tip of mouth cleft on the levelof lower margin of eye. The junction of lower jaw andquadrate, on about a vertical through the anterior marginof eye. Ventral keel between pelvics and anal fin smoothand completely scaled. Unbranched pectoral fin raystrongly lined with melanophores on its inner margin.Orbit diameter equal to snout length and smaller thaninterorbital width. Pelvic axillary scales extend overproximal bases of anal fin, forming a sheath. Upper bodyprofile less convex than the lower profile. Pigmentationabove and below lateral line pores more evident on thecaudal peduncle. Gill rakers short. Peritoneum silverywith dark pigmentations. Inhabits upper riches of rivers,in clear, well-oxygenated, low in pollutions waters below20°C, with a stony bed and almost neutral pH and bushyshore. Maximum age 3 years and total length 108 mm.Maturity at 1-2 years. Spawning in spring, on sand orgravel and in fast-flowing waters. Eggs adhesive. Foodmostly include insect larvae and aquatic plants.