(Family):Dorsal fin with a deep notch or completely divided in two. Caudal fin not furcated. Anal fin with 1〜2 spines. Head mostly covered with scales. Lateral line extending to hind margin of caudal fin. Lower jaw with a single or more barbels in some species. (Genus):Lower jaw bearing 3〜5 pairs of small barbels along its inner edgds, without a tuft of barbels at apex. Preopercular margin with many strong spines. (Species):Dorsal side of body with many oblique dark streaks along scale rows. Dorsal fin without scattered dark spots.
Distribution:
From Antilles, Venezuela, to Argentina.
Remarks:
Another species of this genus in the western Atlantic, M. undulatus, has scattered dark spots on dorsal side of body and on dorsal fin.