The species is considered circumtropical, as it occurs in all tropical and warm temperate waters around the world except for the eastern Pacific.[1][2] The species can be found close to the coast, as well as offshore at a maximum depth of 50 m (160 ft).[7][8]
E. naucrates is a medium-sized fish which can grow up to 110 cm (43 in) length.[9] Its body is elongated and streamlined, and its lower jaw is clearly prognathic (it projects forward well beyond the upper jaw).[3] The jaws, vomer and tongue have villiform teeth.[3]
The main distinctive feature to distinguish from other fishes is the oval-shaped sucking disc, which is a highly modified dorsal fin positioned from the top of the head to the anterior part of the body.[3]
The body background colouration is dark grey to dark brown, with a dark belly. A longitudinal stripe runs along the axis side of the body, it is always darker than its background colour with a whitish margin.
The caudal fin is black with white corners.
Diet
The remora's diet varies according to its maturity or situation (with host or not).[citation needed]
When attached to a host, the remora eats parasitic crustaceans, food scraps from its host's feeding activity, and even some small food captured by filtering water through its villiform teeth.[11]
Without a host, the fish stays close to the shore and can aggregate with other individuals; its diet is then composed of free-living crustaceans, squid, and small fish.[11]
^Cervigón, F., R. Cipriani, W. Fischer, L. Garibaldi, M. Hendrickx, A.J. Lemus, R. Márquez, J.M. Poutiers, G. Robaina and B. Rodriguez, 1992. Fichas FAO de identificación de especies para los fines de la pesca. Guía de campo de las especies comerciales marinas y de aquas salobres de la costa septentrional de Sur América. FAO, Rome.