Common names: snake-eel (English), tieso (Espanol)
 
Ethadophis merenda Rosenblatt and McCosker 1970

Snack snake-eel

Very elongate, body depth at anus 1.8% of TL; head compressed; body cylindrical at front, compressed at rear; tail 49% of TL; snout rounded, overhanging well beyond lower jaw, which, ends just behind front nostrils, without a median longitudinal groove on underside; front nostril a short tube near tip of snout, rear nostril inside mouth just before eye, in a short tube with a front flap; eye small, behind center of mouth by a distance equal to distance between front nostrils; teeth small, conical, pointed, in single series on jaws and roof of mouth,  only the first central, upper front teeth exposed under overhanging snout when mouth is closed; gill openings crescent shaped, vertical, low on sides, widely separated under throat; gill pouch expanded; dorsal and anal fins forming ridges below the skin; dorsal fin origin on head, 1.5 snout lengths before gill opening; no pectorals; tip of tail finless, blunt and fleshy, dorsal and anal fin rays join tail fin rays underneath skin of tail; skin smooth, with papillae on front of head and tip of tail; lateral line from head to near tip of tail,  line straight between each pore; 159 vertebrae.
Color of preserved fish: Brown, paler below; dorsal fin ridge white

Length 53 cm.

Habitat and depth are not known as this species is only from the holotype collected from the stomach of a White weakfish, Atractosion nobilis, on the Pacific coast of Baja.