Poecilopanchax Costa, 2016 Cynopoecilus is a genus of killifish in the family Rivulidae.

They are endemic to seasonal temporary pools in Southern Brazil and northeastern Uruguay.

The region inhabited by C. intimus has experienced extensive habitat destruction and recent surveys have not been able to locate this species; it may already be extinct.

[3] They are small fish, up to 4.4 cm (1.7 in) in standard length.

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