Malacoctenus zonifer and Malacoctenus sudensis with number of symphysial pores increasing with size, but more pores are present in M. zonifer at any given size;

Malacoctenus zonifer differs from M sudensis by the following characters: gill rakers 9-12, usually 10-11 (vs. 10-13, usually 11-12) and, total anal-fin elements 19-22, usually 21-22 (vs. 20-23, usually 22). Several aspects of coloration are better developed in M. sudensis where it has dark pigment on the interspinal membrane of the first dorsal fin, spots on the gular fold, two spots ventrally on the opercle and spots on the anal fin of males, all of which are lacking or weakly expressed in M. zonifer (Ref. 82814).