Several nematode species of family Gnathostomatidae are considered as fish-borne zoonotic parasites, although feral dogs and cats are the commonly identified definitive hosts of these species, humans may accidentally be part of the life cycle of these nematodes by eating undercooked fish infected by the fourth larval stages (L4). In the present study, thirty
five fish specimens of the common sea bream Pagrus pagrus (Sparidae) were collected from a location along the Red Sea at Hurghada city, Cairo, Egypt. Twenty two fish were infected by the nematode parasite Echinocephalus overstreeti (family: Gnathostomatidae) isolated from the peritoneal cavity of infected fish attached externally to host viscera. After
isolation and fixation, worms were examined by light and scanning electron microscopes. Morphologically, parasite possessed most of the features characterizing of Gnathostomatidae members. Body long with very narrow lateral alae, simple pseudolabia, 2 well-developed papillae and amphid, a cephalic bulb armed with six transverse rows of claw-shaped spines and a conical pointed tail equipped with anus.