DIGENETIC TREMATODES OF RIBBONFISH,TRICHIURUS HAUMELA (FORSKAL) AND THEIR DISTRIBUTION IN THE FISHING GROUNDS OF CHINA SEAS

Thriteen species of digenetic trematodes belonging to family Hemiuridae (Looss,1899) of 306 ribbonfish,Trichiurus haemela (Forskal) are reported from ten fishing grounds of China Seas.One new genus and six new species are described and diagonos-ed in table 1.Seven previously described species are secured namely Tubulovesicula anguillae Yamaguti,1934;Lecithocladium pagrosomi Yaznaguti,1934;Lecithocladium parviovum Yamaguti,1931;Erilepturus trichiuri Gu et Shen,1978;Lecithochirium holocentri Yamaguti,1970;Plerurus carangis Yamaguti,1970 and Plerurus longicauda-tum (Yamaguti,1935) Manter et Pritchard,1960.All measurements are expressed in millimeters except ova in microns.The type and paratype specimens are deposited in Institute of Oeeanology,Academia Sinica.Lecithochirium trichiuri sp.nov.(fig.1)This species resembles closely Lecithochirium microstomum Chandler,1931 and L.apharei Yamaguti,1970 but differs from the former in the lacking of hermaphroditic pouch and the presence of a distinct pre-acetabular pit,and from the latter in body size being larger,cuticle smooth,sucker ratio being 1: 2.6,intestinal caeca extending into the tail,seminal vesicle wider and extending to anterior border of acetabulum and proximal portion of pars prostatica convoluted.Musculovesicula trichiuri sp.nov.(fig.2)This species is distinguished from the closely related Musculovesicvla bilobiaia Manter et Pritchard,1960 by the testes obliquly arranged behind acetabulum,seminal vesicle obliquely arranged in front of acetabulum,vitellaria in globular shape laying behind ovary,preoral lobe single instead of double and without pad.Plerurus trichiuri sp.nov.(fig.3)This species differs from the closely related Plerurus apakapaka Yamaguti,1970 in the body smaller with a short tail,suckers ratio being 1:3,testes diagonal,postace tabulum.Ovary situated behind the posterior testes and with genital sinus.Plerurus haincnensis sp.nov.(fig.4)Our specimens are similar to Plerurus kawakawa Yamaguti,1970 but differ from the latter in the intestinal ceca extending into tail,testes symmetrical,ovary semig- lobular instead of reniform or beanshaped,arranged with testes in tripodal position.Plerurus spatulocirrus sp.nov.(fig.5)This species is characterized by the spatulate shape of the cirrus.The specific name refers to this characteristic.Trilecithotrema trichiuri gen.nov.et sp.nov.(fig.6)This species is characterized by having spindle-shaped seminal vesicle and three compact masses of vitellaria,thus denoting an important generic character not found in all the known genera of the subfamily Hemiurinae Looss,1899.Generic diagnosis: Hemiuridae,Hemiurinae.Body small.Cuticle annulated and serrated,oral sucker small,subterminal.Acetahulum subcircular.near anterior extremity.Pharynx small,Oseophagus short,Caeca extending into tail.Testes diagonal,some distance posterior to acetabulum.Seminal vesicle fusiform,pretesticular,pars pros-tatica long and curved.Hermaphroditic duct extending nearly to pharynx.Genital pore postpharyngeal.Ovary subeireular,postequatorial,far apart from testes.Seminal receptacle present.Vitellaria behind ovary,consisting or three compact masses with somewhat indented.Uterus extending into tail,egg numerous,without polar filaments.Stomach parasite of marine teleosts.Type species:Trilecithotrema trichiuriThe distribution of the digenetir trematodes in the fishing grounds of the seas of China is shown in table 2 in the Chinese text.Except for Lecithochirium holocentri Yamaguti,1970 and Lecithochirium trichiuri sp.nov.,all the species found from the seas of China are to be identified as different species,even they are not to be overlapped in distribution.According to the distribution of the trematodes,therefore,we are of the opinion that is the ribbonfish is to be classified into races : north race and south race,which suggestion is in support of Chu's hypothesis (1959).