They are restricted to seasonal blackwater pools in forests in coastal parts of Santa Catarina and São Paulo states.

[2] Uniquely among killifish, Campellolebias and the closely related Cynopoecilus have internal fertilization.

A part of the males' anal fin forms a "pseudo-gonopodium" that is used for inseminating the female.

[1] There are currently four recognized species in this genus:[2] The generic name Campellolebias is a combination of Campello, which honours the Brazilian chemical engineer, aquarist and amateur ichthyologist Gilberto Campello Brasil (1945–2008) and lebias a Greek word for a small fish which was applied to Killifish by Georges Cuvier and is now used a root for names within the order Cyprinodontiformes.

Vaz Ferreira & Sierra de Soriano described Campello Brasil as an "enthusiastic scholar" of Brazilian killifishes and he also collected specimens, sending them to the Vaz Ferreira & Sierra de Soriano.