寄生于牛蛙的拟后盘属吸虫一新种(复殖目:重盘科)

A NEW SPECIES OF THE GENUS PSEUDOPISTHODISCUS YAMAGUTI FROM FROG IN CHINA (DIGENEA: DIPLODISCIDAE)

寄生于广州市郊牛蛙消化道中的一种复殖类吸虫,经鉴定为拟后盘吸虫属一新种,命名为中华拟后盘吸虫。

A new species of the genus Pseudopisthodiscus from frog, Rana catesbiana in Guangzhou, China, is described. The genus is also a new record from China. Measurements are in millimeter. The type specimens are deposited in the Ichthyology Laboratory, Department of Biology, Zhongshan University, Guangzhou, China.Pseudopisthodiscus sinicus sp. nov(figs. 1, 2)Hosts Rana catesbiana Shaw.Location in host Intestine.Locality Guangzhou (23°19’N, 113°49’E).Date May 10, 1986.Type specimens Holotype 1, paratypes 9.Body small, slightly conical, without cuticular spines, length 1.7850-1.8256, average 1.8053, maximum width 0.8037-0.8495 (0 8316). Oral sucker terminal, muscular, 0.0975-0.1026 × 0.0718-0.0836 (0.1001×0.0777), with two oral diverticles 0.07-0.08×0.04-0.05. Oesophagus 0.168-0.189 long, with a developed oesophageal bulb, 0.072-0.090×0.0568-0.085. Caeca wide, reaching to the middle level of the acetabulum. Acetabulum subterminal 0.3045-0.3350×0.3020-0.3450 (0.3148×0.3235), with a central sucker 0.1333-0.145×0.0975-0.1128. The ratios of the two suckers and of the acetabulum to body length are 1: 3.20-3.90 and 1: 5.58-573 respectively. Testes two, situated in posterior one third of the body, slightly oval, not tandem but slightly juxtaposed, left 0.1825-0.1897×0.2650-0.2769, right 0.1625-0.1846 × 0.1949-0.2775. Cirrus pouch of elliptical shape, containing seminal vesicle, prostatic glands and small cirrus. Exoseminal vesicle located in the postbifurcation of the intestine. Male genital pore opening independently in genital atrium lateral to the oral sucker. Ovary elliptical in shape, 0.1875-0.2155×0.1250-0.1350 (0.1925×0.1310), behind the testes, overlapping with the anterior area of acetabulum. Seminal receptacle existed in the front of left testis, 0.1625-0.1949×0.1538-0.1575. Vitellaria distributed in each side behind the testes, consisting of 20 to 25 follicles on the left and 15 to 20 follicles on the right. Uterus very developed, occupying most area of the body, containing a lot of eggs. Egg oval, yellowish, small, 0.0475-0.0498 × 0.0250-0.0275 (0.0487×0.0263). Excretory bladder sac-shaped, and arms extending to the level of oral sucker.The new species differs distinctly from the related Pseudopisthodiscus americanus Holl, 1928 in having larger body, very developed uterus and different position of the genital pore. The ratios of the suckers and of the acetabulum to body length of the latter are 1:5.75-7.33 and 1:1.43 respectively. Testes of the latter, obliquely tandem, genital pore opening immediately po-stbifurcal. The features of this species are also different completly from the known species of the family and genus.