Monognathus, or onejaw, is the only genus of the family Monognathidae of deep-seaeels. The name comes from the Greekmonos meaning "one" and gnathos meaning "jaw", a reference to the large mouth in comparison with the rest of the fish, and also the absence of an upper jaw (maxilla and premaxilla bones are absent).
Description
The dorsal and anal fins lack bony supports and the pectoral fins are missing. The snout has a fang connected to glands, which are venomous in adults. These eels are virtually blind, with rudimentary eyes and small olfactory organs, although the male olfactory organs are enlarged, perhaps suggesting a method of "sniffing out" a mate.
Typical lengths are from 4 to 10cm (1.5–4in), the maximum length recorded is 15.9cm (6.3in).
Distribution
They are found at depths of over 2,000m (6,600ft), and are found in all oceans.
123BÖHLKE, EUGENIA B.; BÖHLKE, JAMES E.; LEIBY, MARK M.; McCOSKER, JOHN E.; BERTELSEN, E.; ROBINS, CATHERINE H.; ROBINS, C. RICHARD; SMITH, DAVID G.; TIGHE, KENNETH A. (1989). Orders Anguilliformes and Saccopharyngiformes: Part 9, Volume 1. Yale University Press. ISBN978-1-933789-19-4. JSTORj.ctvbcd0dm.