摘要
作者利用扫描和透射两种电镜详细研究了吸口凿开绦虫(Glaridacris catostomi Cooper,1920)头节体被、细胞器(微毛、结构小体、长形颗粒、线粒体)和神经感受器的超微结构,并将它们与其他绦虫类,尤其是与石竹科Caryophyllidae中的近缘种类的同类细胞器进行了比较。发现绦虫体被细胞器的超微结构具有属的特性。
Glaridacris catostomi Cooper, 1920 is one of the widely distributed tapeworms belonging to Caryophyllidea in North America. Often G. catostomi can be found in the same host with Hunterella nodulosa Mackiewicz & McCrae, 1962 from different parts of the intestine.Materials used for the present paper was obtained from the white sucker Catostomus commersoni (Lacepede) collected from Chain Lakes, Alberta, Canada.1. Microthrix consists of spine, baseplate and shaft. Spine tapering posteriorly is elongated oval shaped and electron dense in cross section. Electron lucent shaft is round or ovate in cross profile. The two parts mentioned above are separated by a baseplate which is electron dense with lamellated substructure. The microthrix is entirely covered by an outer and an inner double plasma membranes. Beneath the inner plasma membrane of the shaft a layer of concentration electron dense matrix and 10—14 microfilamental subunits can be seen in longitudinal section. The microfilamental subunits are connected by septa.2. Structured bodies are produced by the neck cells deeply embedded in the parenchyma of the scolex-neck region of the worm. In cross section the structured bodies have round lucent areas at both ends and faintly lucent 'dots'. These 'dots' are hexagonal subunits arranged regularly in 2 to 5 rows, each row containing 9—16 subunits which are similar to those seen in the rod-shaped bodies in H. nodulosa and C. laticeps (Hayunga & Mackiewicz, 1975; Richards & Arme, 1981). in longitudinal section the structured bodies appear oval form with long unique electron lucent areas on both margins. The structured bodies are filled with distinct striations (hexagonal subunits) underlying the lucent areas. The structured bodies of G. catostomi can be easily distinguished from those of H. nodulosa and C. laticeps and other cestodes by their shapes and also by the presence of unique electron lucent areas.3. Elongated granules produced also by the neck cells are rod-shaped with both ends slightly swollen. The elongated granules are bounded by a cytoplasmic membrane with electron lucent center 'dots' in cross sections, but a peripheral stbstructure present in C. laticeps (Richards & Arme, 1981) was not observed. The neck cells are rich in ribosomes, glycogen granules, hpid-like granules, endoplasmic reticulum and Golgi complex. Beneath the membrane of neck cells a peripherally arranged circle of micro(?)ubules is seen both in the extensions and cell bodies.4. Mitochondria are abundant and concentrated in the basal third of the tegumental syncytium, especially near the invagination of the basal plasma membrane of distal cytoplasm. They are oval shaped with only a few cristae. On the other hand, the mitochondria of the cell cytons are much larger and consist of much more cristae which are longer than those found in syncytium.5. Within the tegument of G. catostomi there are two types of sensory receptors observed. One of them is ciliated, the other one is non-ciliated.The form and substructures of both types of sensory receptors in G. catostomi are similar to those of C. laticeps. The only difference between them is the substructure of the rootlet in non-ciliated sensory receptor. The nonciliated sensory receptor in G. catostomi has the roolet formed of 3 electron dense striae. Each stria consists of numerous longitudinal short striae thickening in basal part and tapering upwards. No mitochondria were observed within the ciliated sensory receptor.The characteristics of the ultrastructure of the tegument, organelles and sensory receptors described above may be of taxonomic significance.
出处
《动物学报》
SCIE
CAS
CSCD
1991年第2期113-122,共10页
ACTA ZOOLOGICA SINICA
关键词
吸口凿开绦虫
细胞器
超微结构
Glaridacris catostomi, Organelles, Ultrastructure.
