ABSTRACT
Hysterothylacium sebae Bruce, 1990 [Nematodea: Raphidascadae] was collected from the small intestine of the marine fish Scarus psicattatus caught from Northern Red Sea, of Sharm El-Naga, Makady Bay, Sothern Hurgada, Red Sea Governorate. Out of eight examined fish, three [37.5%] were found naturally infected with H. sebae Bruce, 1990. The parasites [one adult male and eight females] were examined morphologically and morphometrically by light microscopy. According to the previouse literature, the present nematode parasite was never redescribed or reported from the marine fish Scarus psicattus. Therefore, Scarus psittacus is reported as a new host record for Hysterothylacium sebae Bruce, 1990 and re-described in details for the first time from Egypt