The limp eelpout, Melanostigma gelatinosum, is an eelpout, of the genus Melanostigma, found in all oceans at depths of between 50 and 2,500 m. Their length is between 15 and 30 cm. The limp eelpout is a small elongate fish with a rather flabby body and blunt head with large eyes. There are no pelvic fins and the anal fins are small, reduced to a few short rays, but both the dorsal and anal fins are long and fused to the tail fin. The gill slits are reduced to small openings immediately above the pectoral fins, a distinctive feature of this fish.
Limp eelpouts have a loose delicate skin that has a purple-grey tinge on the back, becoming paler on the belly, and more intense towards the tail where it is almost black.