Small to large sized marine fishes. Body moderately to extremely elongate, round in cross-section anteriorly, compressed posteriorly. Throat not swollen. Eye well developed. Snout variable, from long and pointed to short and pug-nosed; tip of snout usually extending at least slightly beyond tip of lower jaw. Mouth variable, gape usually ending at some point beneath eye; in most species tip of lower jaw fits into space behind intermaxillary tooth patch. Flanges on upper and lower lip present or absent. Gill opening a crescentic slit, just in front of pectoral fin. Dorsal and anal fins always present, confluent around tail; dorsal fin beginning over or slightly behind pectoral fins, always closer to pectoral fin than to anus. Pectoral fins usually present. Caudal fin sometimes reduced, but some rays almost always present. Lateral line complete. Scales absent. Anus usually located at anterior half to 3rd of TL. Color: most species plain brown or gray; pale ventrally; vertical fins often edged in black.|
Similar family occurring in the area. Muranidae: pectoral fins absent. Muraesocidae: gill openings nearly meeting each other across ventral midline. Ophichthidae: throat swollen.
Remarks. Congrids are found in tropical to temperate seas worldwide, inhabit primarily on sand or mud bottoms from the coastline to depths of 200 m or more.