A. iberus is sexually dimorphic.

Adult males show a coloration pattern characterized by narrow silver transversal bars along the body side, which are continued on the caudal fin (3-4 bars).

Females show numerous small dark spots on the body flanks which tend to form rows, one of them along the lateral line.

Diagnostic description

Morphological analyses revealed the existence of different morphotypes (García-Berthou et al. 1989, Doadrio et al. 2002), however, the degree of differentiation is similar to that detected in closely related species.

A. iberus differs from all other known species of Aphanius in the combination of 8-9 branched rays in the anal fin, 9-10 branched rays in the dorsal fin, short and high caudal peduncle, and greater preorbital length than Aphanius baeticus (the most similar species).