Aspects of the morphology and ecology of some unusual deep‐sea eels (Synaphobranchidae, Derichthyidae and Nettastomatidae) from the eastern North Atlantic

Specimens of Haptenchelys texts (9), Ilyophis arx (3), I. brunneus (36) (Synaphobranchidae), Nessorhamphus ingolfianus (5) (Derichthyidae), Nettastoma melanurum (9) and Venefica proboscidea (3) (Nettastomatidae) have been studied from collections in the eastern North Atlantic. An additional two V. proboscidea were also included from eastern South Atlantic material. The samples were used to augment the incomplete descriptions of these scantily known species, in order to allow further clarification of their taxonomic status. Data from the three synaphobranchid species have been used to clarify the sub‐familial relationships and provide a preliminary family diagnosis. They have also been incorporated in an annotated key to the identification of the species found in the area. In an addition, all the specimens have provided supplementary information on the ecology of the various species, in aspects of distribution, both horizontal and vertical, diet and reproduction.