The total length of representatives of this genus ranges from 33 to 40 cm. The head is long and powerful with large bony plates. There are no odontodes (leather teeth) on the cheeks. Gill openings rather large. The eyes are not large, located on the sides at the top of the head. The mouth is wide, with a short mustache. The body is cylindrical, covered with large and dense bone plates, on the belly to a lesser extent. The ribs are short. Adipose fin missing. The pectoral fins are elongated, the ventral fins are short and wide. Anal fin wide, with a short base. The caudal fin is short and very wide.
The color of the back is monophonic - dark gray, the belly is white.
Biology is not well understood. These are bottom fish. They prefer to live in fresh and transparent reservoirs. During the day they hide among stones, snags or in caves. Active at dusk and at night. They feed mainly on algae , as well as aquatic organisms, less commonly invertebrates .
The female does not lay eggs from caviar, but releases it into a fast stream. Parents do not care about caviar and fry.
They live in the river basins of Uruguay , San Francisco and Parana .
As of May 2018, 2 species are included in the genus [1] :
- Rhinelepis aspera Spix & Agassiz, 1829
- Rhinelepis strigosa Valenciennes, 1840
