AbstractA total of 38 Coryphaenoides mediterraneus from the Charlie-Gibbs Fracture Zone (CGFZ), a part of the Mid-Atlantic Ridge (MAR), was studied for parasites and feeding ecology. Sixteen different parasite species were found, most of them belonging to the Digenea (6 species) and Nematoda (6). Twelve new host and 11 new locality records were established, and 8 deep-sea generalists and 5 deep-sea specialists were found. Twelve adult and 3 larval parasites occurred, with Allopodocotyle margolisi (Digenea), Tetraphyllidea indet. (Scolex pleuronectis, Cestoda) and Ascarophis longiovata (Nematoda) being the predominant species. These parasites reached a prevalence of 50.0%, 86.8% and 68.4% with an intensity of infection of 1–10, 1–91 and 1–74, respectively. The food consisted of crustaceans and cephalopods; no further prey items such as fish could be identified. Coryphaenoides mediterraneus demonstrates a parasite fauna similar to that of other deep-sea macrourids. No MAR-specific parasite species were found, and the collected helminths are common fish parasites of the North Atlantic deep-sea basin and the adjacent continental shelf regions. Only few larval epipelagic generalists such as ascaridoid nematodes were found, due to the deep origin of the studied fish between 1700–3500 m. The recorded species rich parasite fauna reflects the wide depth range and opportunistic feeding behaviour of C. mediterraneus on benthopelagic food. The recorded parasite species composition around the MAR appears to be similar to other deep-sea locations in the Atlantic Ocean, demonstrating the wide zoogeographical distribution of these deep-sea metazoans. Consequences of the MAR, the CGFZ and the homogeneous deep-sea environmental conditions for the parasite species distribution are discussed.