REDESCRIPTION OF CLAVINEMA PARASILURI YAMAGUTI (NEMATODA),A PARASITE OF THE SILURUS FISH

Host Silurus asotus (Linn.) and Silurus soldatovi-meridiondls ChenHabitat Female found under skin of operculum and supraeoracoid, male in air bladder and pleural cavity.Localities Wuhan City, Hubei Province. Yueyang County (Dongting Lake), Hunan Province. Haicheng County (Liao He River). Liaoning Province. Hongze County (Hongze Lake), Jiangsu Province.Female: Elongate club-shaped body 6.20—10.17 mm in length. Maximun breadth 0.81—0.95mm, near the anterior extremity.Colour red when living. Mouth simple, approximately triangular in apical view. No lips and papillae around the mouth. Cylindrical straight oesophagus proper muscular, around its middle part being a fusiform oesophageal gland with a central nucleus. Nerve ring located 0.09 mm behind the muscular bulb and 0.30—0.34 mm behind the head. Excretory pore invisible. Female viviparous, with numerous larvae in uterus when fully mature. Larvae 0.47—0.54 mm long and 0.011—0.016 mm broad (n=20). Other characteristics of female identical with the oringinal description.Male: Approximately club-shaped body 1.14—1.16 mm in length, with maximum breadth of 0.033—0.035 mm, near anterior extremity. Milky colour when living. Cuticle smooth. Simple mouth closly connecting with inconspicuous muscular bulb. Two spicules similar in shape. Length of left spicule 0.070—0.073 mm and right 0.067 mm. Gubernaculum long, 0.040—0.046 mm in length, with a minute barb near the tip on the dorsal side. Spicules and gubernaculum brownish in colour when living. Cloacal opening situated at ventral side of the caudal tip. Two hemispherical lobes also present in lateral sides of caudal tip.The present paper describes the male of Clavinema parasiluri for the first time. Silurus soldatovi meridionalis is recorded as new host of this parasitic nematode.