Grundulus bogotensis Humboldt 1821 (Guapucha) and Eremophilus mutisii Humboldt 1805 (Capitan), from the Neusa reservoir (Cundinamarca-Colombia), were characterized on the basia cariology. The Guapucha, Grundulus bogotensis (Pisces: characidae), exhibited a basic number oC2n= 50 chromosomes. There is not chromosomic sexual dimorfism. The Capitan, Eremophilus mutisii (Piscee: Tricomycteridae), on the other hand, has a basic chromosomes number of 2n = 54; and similarly does not show sexual dimorfism at the level chromosomes.