猪蛔虫感觉器官的扫描电镜观察

Sense organs of Ascaris suum viewed by scanning electron microscope

流行病学及实验感染证明,猪蛔虫(Ascaris suum Geeze 1782)与人蛔虫(A.lum-bricoides L. 1758)有明显的不同,在形态学上是否有种的差异仍是一个有争议的问题。鉴于此,我们用扫描电镜先对猪蛔虫的外部结构作了初步观察,以供今后与人蛔虫加以比较。

The head,caudal region and cuticle of adult worms of A.suum were examined with scanning electron microscope,particularly the sense organs were emphasized to view the surface structure in this study.Both dorsal and ventral papillae of lips have two invaginations on their surface respectively.Just located in dorsal-anterior region of the ventral papillae,there is a lateral papilla and an amphid on the subventral lips.The ratio of distance between dorsal papilla to lateral papilla and lateral papilla to amphid is 2:1 Each lip has one dentigerous ridge formed by a row of denticles.When the denticles are examined by a higher magnification,they are showing a conoidalshape or a molar teeth form.The variation and distribution of the denticles are irregular.They arc usually appearing to be an equilateral triangle shape with a straight side as they are viewed by lower magnification.The SEM images on the posterior region of the male made it easier to understand the complicated arrangement of many papillae before and behind the cloaca.There are 5 post-cloacal papillae with mammilliform,located at each side of the caudal end.Both of the first and second post-cloacal papillae are binary,protruding prominently and bigger than another.Three remain papillae located in the end of male are different distance from each other.In candal region,a knob or buton-like node is shown.Sometimes it seems to be a vermiform protrusion out of the end.One pre-cloacal central papilla is present,just at the anterior on the cloacal lip.It is combined from two papillae.The body cuticle of A.suum is smooth and transversely striated.When the striations arrive to the sense organ around cloaca,they are abrupt or disappeared.In three lips and their papillae there are no striations.