Two pairs of barbels on rostral region, one pair on lower jaw, one pair on posterior end of maxilla. End of maxilla barbel beyond anal fin origin. Pectoral spine filament long, reaching anal fin origin. Dorsal fin spine filament flattened, extremely long reaching caudal fin origin. Anal fin base long, depressed pelvic fin tip reaching anal fin origin. Dorsal, pectoral, and pelvic fin membranes black. Anal fin membrane black distally (some individuals white), white proximally. Body silver gray or blue gray dorsally, silver white ventrally.
Distribution:
From Colombia to Brazil.
Remarks:
Another species B. marinus having short anal fin base and depressed pelvic fin tip far from anal fin origin. (Shimizu)