Black-tailed Conger
Gnathophis mystax
- Least concern
- Card rarity: Common
- Fish

Gnathophis mystax, the thinlip conger or blacktailed conger, is an eel in the family Congridae. It was described by François Étienne 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.
Classification
- Class
- Actinopterygii
- Order
- Anguilliformes
- Family
- Congridae
- Genus
- Gnathophis