Acta Parasitologica, Vol. 52, No. 1, 2007, 18-23. DOI: 10.2478/s11686-007-0004-5 Reda M. El-S. Hassanine - Trematodes from Red Sea fishes: On the validity of Helicometra marmoratae Nagaty et Abdel-Aal, 1962 and the description of H. aegyptense sp. nov.(Opecoelidae Ozaki, 1925)
Department of Sciences and Mathematics, New Valley-Faculty of Education, Assiut University, El-Kharga, New Valley, Egypt
Corresponding author: Redaaa2003@yahoo.com
Specimens of the fishes Siganus spinus L. (Siganidae) and Sargocentron spiniferum Forsskål (Holocentridae) were caught in
the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt. Twenty-three (46%) and 12 (20%) of these fishes, respectively,
were found to harbour intestinal trematodes. Siganus spinus was parasitized by Helicometra marmoratae Nagaty et
Abdel-Aal, 1962 (Opecoelidae Ozaki, 1925) and S. spiniferum by Helicometra aegyptense sp. nov. (Opecoelidae Ozaki, 1925).
Based on a large number of specimens collected from its type host and locality, H. marmoratae is broadly redescribed for the
first time, and its type specimen is re-examined. The validity of this species is discussed and considered a new synonym of
H. fasciata (Rudolphi, 1819) Odhner, 1902 (type species of the genus). Helicometra aegyptense sp. nov. is similar to H. equilata (Manter, 1933) Siddiqi et Cable, 1960, H. nasae Nagaty et Abdel-Aal, 1962, H. pteroisi (Gupta, 1956) Fischthal et Kuntz, 1965 and H. interrupta Hassanine, 2005 in having a short forebody and a long cirrus sac extending posterior to the ventral sucker, but differs significantly from them or unique in having a distinctly elongate pharynx, a larger sucker ratio and vitelline follicles grouped in small clusters arranged in two lateral rows on each side of the body. The valid species of Helicometra are listed in four principal groups.
KEY WORDS: Digenea, Opecoelidae, Helicometra marmoratae Nagaty et Abdel-Aal, 1962, Helicometra aegyptense sp. nov., fishes,Red Sea