© 2016, Springer Science+Business Media Dordrecht. Hamaticolax resupinus n. sp. is described from specimens collected from the gill cavities of Coelorinchus mediterraneus Iwamoto & Ungaro and Coryphaenoides mediterraneus (Giglioli) (Gadiformes: Macrouridae) caught in the Western Mediterranean Sea at depths between 1,236 and 1,626 m. Hamaticolax resupinus n. sp. closely resembles H. maleus Oldewage, 1994, but differs from the latter by its smaller body size and in having a genital double-somite in the female that is markedly wider than the free abdominal somites and has strongly convex lateral margins. The new species is only the second bomolochid found on a macrourid host and is the first from depths in excess of 1,200 m. Hamaticolax resupinus n. sp. also represents the first parasitic copepod recorded from Coe. mediterraneus and only the third one from Cor. mediterraneus worldwide.