The Smallfish snake-eel (Quassiremus nothochir, also known as the Redsaddled snake eel in Mexico) is an eel in the family Ophichthidae (worm/snake eels). It was described by Charles Henry Gilbert in 1890. It is a marine, tropical eel which is known from the eastern central Pacific Ocean, including Mexico, Nicaragua, Panama, the Gulf of California and Costa Rica. It dwells in shallow waters at a maximum depth of 20 metres (66 ft), and inhabits sand and rock sediments. Males can reach a maximum total length of 70 centimetres (28 in).