Congromuraena mystax; Print; The Thinlip conger (Gnathophis mystax; also known as the Blacktailed conger) is an eel in the family Congridae (conger/garden eels). It was described by Fran鏾is 蓆ienne Delaroche in 1809; originally under the genus Muraena. 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; but more commonly reach a TL of 35 centimetres.; 1809