Opistognathus cuvierii

Common Name

Bartail Jawfish

Year Described

Valenciennes, 1836


Dorsal Fin: XI, 16
Anal Fin: III, 16
Pelvic Fin: I, 5
Pectoral Fin: 18-19
Gill Rakers: 30-35 (total)
Vertebrae: 10 precaudal, 19 caudal; 29 total

Maxilla of males with thin, flexible posterior extension. Jaws large; reaching well past rear margin of orbit. Premaxillary and dentary with teeth. Vomer with 2 teeth. Lateral line extends posteriorly to 2nd segmented dorsal ray. Nape, head, pectoral base, and anterior area above lateral line scaleless. Rest of body fully scaled, including posterior area above lateral line. Lateral scale rows: 60-72. Dorsal fin spines slender with sharp, flexible tips. Anterior nostril with a short cirrus.


Body brown with dark markings, spots, and mottling. Most obvious marking a irregular dark lateral stripe. Head with dark speckling, a dark eye-band, and a dark stripe running from above lip to opercle. Lips banded with dark brown. Males with two bands on the inside of the maxilla (female with no stripe). Dorsal and anal fins dark brown with numerous white spots distally and marbling basally. Ocellus on dorsal fin between spines 3 and 7. Caudal fin dark with two basal white spots and two vertical whitish bands.


Adults range from 80-114mm SL.


Forms burrows in sand and rubble bottoms.


Known only from southern Brazil.


Smith-Vaniz, W. F. 1997. Five new species of jawfishes (Opistognathus: Opistognathidae) from the western Atlantic Ocean. Bulletin of Marine Science v. 60 (3): 1074-1128.