Chorimycterus Cope, 1894 Geryichthys Zarske, 1997 Jobertina Pellegrin, 1909 Microcharax Eigenmann, 1909 Nanognathus Boulenger, 1895 Poecilosomatops Fowler, 1906 Characidium is a genus of fish in the family Crenuchidae (South American darters).

They are mainly found in South America, but C. marshi is from Panama.

[1] They are small (less than 10 cm or 4 in long), slender fish that live on the bottom in flowing fresh waters and feed on small animals such as insects.

[2] There are currently 81 recognized species in this genus:[1]