Gnathophis castlei, or Castle's conger,Common names for Gnathophis castlei at www.fishbase.org. is an eel in the family Congridae (conger/garden eels).Gnathophis castlei at www.fishbase.org. It was described by Emma Stanislavovna Karmovskaya and John Richard Paxton in 2000.Karmovskaya, E. S., and J. R. Paxton, 2000 [ref. 25768] Revision of the Australian congrid eels of the genus Gnathophis (family Congridae), with descriptions of six new species. Journal of Ichthyology v. 40 (Suppl. 1): S1-S14. It is a marine, deep water-dwelling eel which is known from Queensland, Australia, in the western central Pacific Ocean. It dwells at a depth range of 131–366 metres. Males can reach a total length of 34.2 centimetres.

Etymology The species epithet refers to Peter Henry John Castle.

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