Opistognathus nothus

Common Name

Yellowmouth Jawfish

Year Described

Smith-Vaniz, 1997


Dorsal Fin: X, 14
Anal Fin: II, 13
Pelvic Fin: I, 5
Pectoral Fin: 20-21
Gill Rakers: 26-32 (total)
Vertebrae: 10 precaudal, 18 caudal; 28 total

Maxilla of males without posterior extension. Jaws reaching well past rear margin of orbit. Premaxillary and dentary with teeth. Vomer without teeth. Lateral line extends posteriorly to between 2nd and 4th segmented dorsal ray. Nape, head, belly, and anterior part of body preceding 4th dorsal spine scaleless. Lateral scale rows: 44-50. Dorsal fin spines slender with sharp, flexible tips. Anterior nostril without cirrus.


Body uniformly brown grading to whitish on the belly. Posterior edge of maxilla with a dark V-shaped stripe. Patches of yellow on premaxilla, maxilla, and adjacent membranes. Dark brown spots surround head pores. Fins are brown with a yellow distal stripe. Fin spines and rays with 1-3 dark spots along length. Anterior dorsal fin with small dark blotch between spines 3 and 4. Caudal fin brown with yellowish dorsal and ventral margins.


Adults range from 42-79.3mm SL.


A deepsea jawfish living between 92-100m.


Scattered records from off SE North Carolina, the northern Gulf of Mexico, and off NW Cuba.


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.

Other Notes

This species and Opistognathus melachasme were once considered a single species with extreme sexual dimorphism (Smith-Vaniz, 1972), but additional collections showed that there are two separate species involved (Smith-Vaniz, 1997).