河鲈锚首吸虫体壁的超微结构观察

ULTRASTRUCTURE OF THE BODY WALL OF ANCYROCEPHALUS MOGURNDAE (MONOGENEA:ANCYROCEPHALIDAE)

寄生鳜鳃部的河鲈锚首吸虫的体壁由表皮合胞体、基板、环肌、纵肌和表皮细胞核周体所组成。合胞体顶部质膜起伏形成表皮的嵴纹 ,基部质膜折叠形成指状突起伸入到合胞体中。合胞体表面覆盖着一层糖萼。河鲈锚首吸虫的表皮中含有四类分泌体 ,即电子致密的分泌颗粒、中等电子致密的分泌颗粒、有膜包围的电子稀疏的分泌体和多囊体 ,可见分泌体和合胞体基质通过胞吐作用排到体外 ,未见吞饮小泡 ,推测表皮的主要功能在于分泌和渗透压调节而非营养吸收。在外侧头瓣的乳突状结构所在处 ,合胞层较薄 ,基板平滑 ,在实质组织中的一腔体样结构中可见囊状体、电子致密度各异的颗粒体、泡状体和电子致密的基质团 ,神经突起分布于腔体周围 。

The body wall of the monogenean, Ancyrocephalus mogurndae, parasitic on the mandarin fish, Siniperca chuatsi , consists of a syncytium, a basal lamina with circular and longitudinal muscles and pericaryon. The infolded apical plasma membrane forms tegumental ridges on both the ventral and dorsal surfaces. The infolded basal plasma membrane forms numerous finger like projections through the syncytium. A thin coat of glycocalyx is present on the tegument surface. The syncytium contains four kinds of secretory bodies, i.e. the electron dense granules, the moderately electron dense granules, the electron lucent vesicles and the multivesicular bodies. Exocytosis of the electron dense granules, the multivesicular bodies and the syncytial cytoplasm apparently occurs in the syncytium of the general body surface. The absence of pino and phagocytotic vesicles from the tegument suggests that excretion or osmoregulation is the primary function of the tegument, but not nutrient uptake. The presumed non ciliated sensory papilla on the lateral head lobe consists of an ellipse shaped structure situated beneath the thin tegument with the smooth basal lamena. A large versicular body, numerous granules and vesicles and the electron dense cytoplasmic mass are observed in the ellipse shaped structure. Nerve process is rich in the vicinity. It is suggested that this kind of papilla may play a role in attachment.