Acta Parasitologica, Vol. 50, No. 4, 2005, 276-280 Reda M. El-S. Hassanine - Trematodes from Red Sea fishes: Gibsonius aegyptensis gen. nov., sp. nov. (Lepocreadiidae Odhner, 1905)
and Helicometra interrupta sp. nov. (Opecoelidae Ozaki, 1925)
Department of Sciences and Mathematics, New Valley Faculty of Education, Assiut University, El-Kharga, New Valley, Egypt
Corresponding address: Redaaa2003@yahoo.com
ABSTRACT
Specimens of the marine fishes Rhabdosargus haffara (Sparidae) and Cociella crocodila (Platycephalidae) were caught in the Red Sea off the coast of Sharm El-Sheikh, South Sinai, Egypt. Eight (20%) and 15 (43%) of these fishes, respectively, were found to harbour intestinal trematodes. R. haffara was parasitised by Gibsonius aegyptensis gen. nov., sp. nov. (Lepocreadiidae) and C. crocodila by Helicometra interrupta sp. nov. (Opecoelidae). Gibsonius is similar to Myzoxenus Manter, 1934 and Diploproctia Mamaev, 1970 in having a ventral sucker with two longitudinal lips of a lamellar nature at its aperture, but differs greatly from each in other features: from Myzoxenus in having tegumental spines heavily distributed throughout the entire body surface, symmetrically arranged testes, a cirrus sac extending well posterior to the ventral sucker, a median genital pore, and vitelline follicles terminating posteriorly at the testicular level; and from Diploproctia in having an oval body, intestinal caeca which end blindly near the posterior extremity, a median genital pore between the intestinal bifurcation and ventral sucker, a pretesticular unlobed ovary, a uterus mainly situated dextral to the ovary, and vitelline follicles terminating posteriorly at the testicular level. Helicometra interrupta sp. nov. is similar to H. equilata, H. nasae and H. pteroisi in having a short forebody and a long cirrus sac extending posterior to the ventral sucker, but differs significantly in having a shorter forebody (about 10% of body length), a curved cirrus sac extending posteriorly to a third of the distance between the ventral sucker and the ovary,
vitelline follicles which terminate anteriorly at considerable distance posterior to ventral sucker and which are distinctly interrupted twice in the pre-testicular region, and smaller eggs.
KEY WORDS: Digenea, Lepocreadiidae, Gibsonius aegyptensis gen. nov., sp. nov., Opecoelidae, Helicometra interrupta sp. nov., fishes, Red Sea