Number of symphysial pores in Malacoctenus zonifer and Malacoctenus sudensis increases with size, but more pores are present in M. zonifer at any given size. M sudensis differs from Malacoctenus zonifer by the following characters: gill rakers 10-13, usually 11-12 (vs. 9-12, usually 10-11) and total anal-fin elements 20-23, usually 22 (vs. 19-22, usually 21-22). 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).