Crenicara latruncularium sp. n. is collected in the upper and lower Rio Guaporé and in the lower Rio Mamoré drainages. The largest specimen is 883.9 mm SL. It differs from C. punctulatum (Günther) in lower meristics, serrated supracleithrum and colour pattern. The two species appear to be allopatric although C. puntulatum occurs in the Central and Western part of Bolivian Amazonia, and there are no obvious physical barriers separating the two species within Bolivian Amazonia. The falls of the Rio Madeira may be limiting to northward dispersal of C. latruncularium.