盅口属三种线虫扫描电镜的比较研究(杆形目,圆线科)

COMPARATIVE STUDIES ON THE MORPHOLOGY OF THREE SPECIESOF THE GENUS CYATHOSTOMUM(RHABDITIDA,STRONGYLIDAE)

利用扫描电镜技术首次对四刺盅口线虫Cyathostomum tetracanthum、碗形盅口线虫C.catinatum和蝶状盅口线虫C.pateratum的体表结构特征进行观察和比较。结果表明:3种线虫在外叶冠的形状和数目、雄虫生殖锥和雌虫尾部等结构方面存在一定的差异。四刺盅口线虫的外叶冠由20或22个小叶组成,小叶末端尖,向外翻卷;雄虫生殖锥背唇上有1对大的乳房状附属物;雌虫尾部直,尾长114(92～128)μm。碗形盅口线虫的外叶冠由22个小叶组成,小叶末端钝圆,平直伸向口孔;雄虫生殖锥背唇上无明显的附属物;雌虫尾部呈"人脚形",尾长62(54～68)μm。蝶状盅口线虫的外叶冠由24个小叶组成,小叶末端尖,平直伸向口孔;雄虫生殖锥背唇上有1对细长的指状附属物;雌虫尾部呈"人脚形",尾长93(78～109)μm。研究结果为盅口线虫的分类鉴定提供了更稳定的形态学依据。

The body surface structures of three species of the genus Cyathostomum were first observed and studied with scanning electronic microscope （SEM）. The results showed that morphological characters of three species presented distinct differences in the number and shape of elements of external leaf-crown （ELC）, the appendages of genital cone in male, the shape of posterior end and tail length in female. In C. tetracanthum, ELC with 20 or 22 elements, 26. 8 （25 - 28） pm long and 5. 6 （5-6） prn wide at the base, and tips of ELC elements pointed, recurved outwards; a pair of breast-shaped appendages on the genital cone; female tails almost straight, 114 （92 -128 ） μm long.In C. catinatum, ELC with 22 elements, 13.4 （11 - 15 ） μm long and 3.6 （ 3 - 4 ） μm wide at the base, and tips of ELC elements blunt, extended towards the buccal aperture; appendages of the genital cone inconspicuous; female tails fat, foot-shaped, 62 （54 - 68 ）pm long. In C. pateratum, ELC with 24 elements, 20. 4 （ 18 - 22 ） μm long and 7.6 （7 - 8 ） μm wide at the base, and tips of ELC elements pointed, extended towards the buccal aperture; a pair of fmgerlike appendages on the genital cone; female tails fat, foot- shaped, 93 （78 - 109） μm long. The present research provides theoretical basis for taxonomy and identification of the species in the genus Cyathostomum.