New data on three gonad-infecting species of Philometra (Nematoda, Philometridae) from estuarine fishes in South Carolina, USA

The following three gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) were recorded from offshore perciform fishes in South Carolina, USA: Philometra carolinensis Moravec, de Buron et Roumillat, 2006 from the southern kingfish Menticirrhus americanus (Linnaeus) (Sciaenidae) (new host record), Philometra floridensis Moravec, Fajer-Avila et Bakenhaster, 2009 from the red drum Sciaenops ocellatus (Linnaeus) (Sciaenidae), and Philometra saltatrix Ramachandran, 1973 from the bluefish Pomatomus saltatrix (Linnaeus) (Pomatomidae). Findings of the first two species represent the second records since their original descriptions and P. floridensis was for the first time recorded from South Carolina estuaries. Detailed study of these nematode species, using both light (LM) and scanning electron microscopy (SEM), revealed the presence of minute caudal projections in the gravid female of P. carolinensis and four pairs of caudal papillae in the conspecific male; the cephalic and caudal ends of this species were for the first time examined by SEM. The related species P. carolinensis and P. floridensis, both parasitizing sciaenid fishes, can be distinguished from each other mainly by the presence/absence of oesophageal teeth, lengths of spicules and body lengths of gravid females. The morphology of North American specimens of P. saltatrix was found to be identical with that of specimens from Europe, thus confirming their conspecificity.