Body oblong and compressed. Head long, 36% of SL. Preopercle angulate, with serrae at the angle of the expanded lobe; posterior part of opercle with 3 flat spines. Scales on body small ctenoid and rather smooth. Posterior rays of soft dorsal and anal fins elongated. Caudal fin emarginate, upper and lower lobes projecting posteriorly. Body brown with many small dark brown spots, ventral part dusky; pectoral fin dark brown with marginal pale brown line, other fins dark brown.
Distribution:
Suriname.
Remarks:
This species is similar to M. interstitialis in many characters but differs from it in the coloration. (Matsuura)