The re-discovery of Caligus lichiae Brian, 1906 (Copepoda: Caligidae) parasitic on two carangid fishes in the Mediterranean Sea, and the recognition of Caligus aesopus Wilson C. B., 1921 as a junior subjective synonym.

The caligid copepod Caligus lichiae Brian, 1906 is redescribed based on new material collected from the type-host, Lichia amia (Linnaeus), and from a second carangid, Seriola dumerili (Risso), both caught in the Gulf of Iskenderun, Turkey. Key diagnostic characters of both sexes are reported, supported by drawings and scanning electron microscopy images. Despite the commercial importance of its type-host, L. amia, C. lichiae has not been reported since its original description. After detailed comparison with recent descriptions of Caligus aesopus Wilson C. B., 1921, commonly found on S. dumerili, we recognise these two species as conspecific and propose to relegate C. aesopus Wilson C. B., 1921 to a junior subjective synonym of C. lichiae Brian, 1906. Caligus lichiae is a member of the C. confusus group of species and an identification key to species in this group is provided.