(Family): Snout protruding prominently beyond jaws. Hind end of maxilla elongated extremely. No abdominal scute. No spine in fins. Pectoral fin abdominal. (Genus): Hind end of maxilla elongated extremely, somewhat extending to hind end of 2nd supramaxilla, with sharp angle tip. At least a few gill rakers on inner face of upper limb of 3rd gill arch. Dorsal fin origin anterior to anal fin origin. Teeth on jaws close set. (Species): Upper angle of subopercle with a small triangular projection.
Distribution:
Coasts of Panama to Brazil.
Remarks:
A. spinifer is distinguishable easily by its small triangular projection on subopercle. This fish inhabits in coastal water to mouth of river. (Shimizu)