Oesophagotrema mediterranea n. gen., n. sp. (Platyhelminthes, Digenea, Zoogonidae), parasite of the needlefish Tylosurus acus imperialis (Beloniformes, Belonidae) from off Tunisia Author Chaari, Manel Author Derbel, Hela Author Neifar, Lassad Laboratoire de Biodiversité et Écosystèmes aquatiques, Département des Sciences de la Vie, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax (Tunisie) htchaari. m @ gmail. com h _ derbel @ yahoo. fr lassad. neifar @ fss. rnu. tn m@gmail.com text Zoosystema 2011 2011-09-30 33 3 281 286 http://dx.doi.org/10.5252/z2011n3a2 journal article 10.5252/z2011n3a2 1638-9387 4546920 52F33767-001D-44E7-8E5B-20100B2F64BA Genus Oesophagotrema n. gen. TYPE SPECIES . — Oesophagotrema mediterranea n. sp. ETYMOLOGY. — The generic designation in part derives from the combination of the site of infection in the fish host, oesophagus in Latin, and trema for trematoda . DIAGNOSIS.— Zoogonidae , Lepidophyllinae . Body fusiform.Tegument spinous, spines decreasing in number to posterior level of body. Oral sucker globular, subterminal. Ventral sucker prominent, rounded, with mid-ventral aperture and small papillae. Prepharynx short. Pharynx oval. Oesophagus elongate, with slightly thickened wall. Intestinal bifurcation in posterior forebody. Caeca long, reaching anterior edge of posterior testis. Testes 2, oval to subspherical, tandem, postequatorial in middle third of hindbody. Cirrus sac claviform, curved, extending to intestinal bifurcation. Internal seminal vesicle saccular. Pars prostatica short, narrow. Ejaculatory duct straight. Genital pore in sinistral submarginal forebody, at level of pharynx. Ovary subspherical pretesticular, in hindbody. Seminal receptacle immediately postovarian, ovoid elongate. Vitellaria follicular, in two symmetrical lateral bunches, 9 follicles on poral side, 8 on antiporal side, between ovary and anterior testis. Eggs small, tanned and operculate. Excretory pore terminal. Parasitic in oesophagus and on vomer teeth of T. a. imperialis ( Belonidae ).