Gnathophis mystax, the thinlip conger or blacktailed conger,[3] is an eel in the family Congridae (conger/garden eels).[4] It was described by François Étienne Delaroche in 1809, originally under the genus Muraena.[5] It is a subtropical, marine eel which is known from the eastern Atlantic Ocean, including southern Portugal, the Mediterranean, and Morocco. It dwells at a depth range of 75–800 metres, and inhabits mud and sand on the continental slope. Males can reach a maximum total length of 60 centimetres (2 ft 0 in), but more commonly reach a TL of 35 centimetres (1 ft 2 in).[4]
^Delaroche, F. E., 1809 [ref. 17380] Suite du mémoire sur les espèces de poissons observées à Iviça. Observations sur quelques-uns des poissons indiqués dans le précédent tableau et descriptions des espèces nouvelles ou peu connues. Annales du Muséum d'Histoire Naturelle, Paris v. 13: 313-361, Pls. 20-25.