Knowledge of the phylum Nematomorpha in the Iberian peninsula, and in the southern Mediterranean area in general, is still extremely limited. In Gerlach’s (1978) checklist five species are recorded from the Iberian peninsula south of the Pyrenees, and one from the Pyrenean area. Of these, Gordius angulatus Linstow, 1906 should be excluded because it was described from Madeira, not from continental Portugal. Similarly, Parachordodes speciosus (Janda, 1894), considered to be of a dubious taxonomic status by Schmidt-Rhaesa (1997), was described from Galizia (Poland), and its inclusion in Iberia must be a confusion with the Spanish Galicia. The Iberian records of Gordius pioltii Camerano, 1887, Parachordodes tolosanus (Dujardin, 1842), and Gordionus violaceus (Baird, 1853) were not considered by Schmidt-Rhaesa, (1997) in his recent revision of the European fauna of Nematomorpha, which included only Parachordodes gemmatus (Villot, 1885), recorded from the French Pyrenees. Other records are generic (e.g. Gordionus spp. From Portugal, Schmidt-Rhaesa, 1997), or have no reliability (e.g. Codina, 1925).
Recent captures of free-living adults of Nematomorpha in NE Spain by the junior authors allowed detailed study, for the first time, of Iberian representatives of this interesting group. Four species of Gordiidaeare redescribed, Gordius aquaticus Linnaeus, 1758, G. plicatulus Heinze, 1937, Gordionus wolterstorffii (Camerano, 1888) and Paragordius tricuspidatus (Dufour, 1828). Males of G. plicatulus are described for the first time, and the redescription of G. plicatulus, G. wolterstorffii and P. tricuspidatus includes also for the first time scanning electron microscope observations. Some comments on the ecology and intraspecific variability of the species are included.