(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 with a single stout and rigid barbel. Anal fin with a single spine. Cross section of head and trunk triangular. (Species):Indistinct dark oblique bars on side. Breast scales equal in size to those near lateral line. Anal fin usually with 7 soft rays. Tip of depressed spinous dorsal fin not extending beyond base of 2nd soft ray.
Distribution:
From U. S. Atlantic coast, Gulf of Mexico, Caribbean Sea, to Argentina.
Remarks:
Two other species in this genus are reported from western Atlantic. M. littoralis has silver gray in colour without dark oblique bars, and breast scales smaller in size than those near lateral line. M. saxatilis has usually 8 soft anal rays, and tip of depressed spinous dorsal fin extending beyond base of 2nd dorsal soft ray.