MORPHOLOGICAL DESCRIPTION OF TWO DIGENEAN PARASITES, FROM LABRIDAE, AND SIGANIDAE HOSTS OF THE RED SEA IN EGYPT

Abstract

During a parasitological survey on marine fish species inhabiting Hurghada Coasts of the Red Sea, Eighty seven fish specimens of 2 different species were found naturally infected by three different species of digenean parasites, one of them was reported as new host and locality in Egypt. These were Phyllodistomum hoggettae (family: Gorgoderidae) infecting the Arabian mallas Thalassoma klunzingeri (family: Labridae). Body length to width ratio 1:3. Oral sucker opened subterminally. Intestinal bifurcation midway between oral and ventral suckers. Ventral sucker distinctly equal in size to the oral sucker. Testes slightly lobed, oblique, in mid-body; ovary entire, heart shaped, sinistrally posterior to ventral sucker and anterior to testes. Vitelline lobes entire and almost round. Gyliauchen volubilis (family: Gyliauchenidae) infecting the marbled spinefoot Siganus rivulatus (family: Siganidae). Body fleshy, robust, conical, tapered anteriorly, convex dorsally, concave ventrally, with small tail-like protubera-nce postero-dorsal to acetabulum. Prepharynx very long and convoluted, occupied greater part of the anterior body half. Pharynx elongated, prephanyx very coiled and situated close to intestinal bifurcation. Ventral sucker well developed and spherical. Oesophagus very long, wide, longer than body straightened length. Two testes oval, symmetrical, dorsal to ventral sucker, subequal in diameter. Ovary spherical, dextro-submedian between right testis and cirrus sac. Vitelline follicles relatively small, irregular, numerous, extended in lateral fields between testes and mid-oesophageal level, confluent in region of intestinal bifurcation. All of the recovered species were compared with others recorded from different hosts.