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74 Venkatesh, Ramalingam and Vijaylakshmiform an almost continuous covering of the worm.Earlier ultrastructural studies of T. hydatigena(Featherston, 1972) have revealed three differenttypes of microthrix each associated with a particulararea of the strobila. Jha and Smyth (1971) haveexamined the rostellum of E. graunlosus and reported,"The microtriches and their branches are curved invarious directions to form a criss-cross pattern". Thesurface of the scolex of Silurotaenia siluri is coveredwith filiform microtriches and giant spine-like andblase-like microtriches. They are also present on theneck region and posterior margins and internalcavities of the suckers (Scholz et al., 1999). Caira andRuhnke (1991) noted substantial changes in thepattern and distribution fo microtriches duringontogeny of the scolex in Calliobothriumverticillatum. Vijayalakshmi and Ramalingam (2005)observed filament-like, blade-like and intermediatetypes of microtriches on the tegument of A. lahorea byusing SEM and TEM studies.The present SEM and TEM study also clearly revealedthe existence of microtrichial polymorphism all alongthe strobilar length of S. globipunctata. It revealed acomplex pattern of microtrochial brush bordershowing wide range of morphological variations.Species specific pattern of papilliform, filiform,spiniform and blade- like microtriches were alsoobserved in S. globipunctata.In the light of the observations, results and discussionsof previous studies, the results on TEM studies on thetegument of S. globipunctata thus infer that theadhesive and absorptive microtriches of the tegumentnot only allow the diffusion and intake of variousnutrients, micro/trace elements and electrolytesindispensable for the growth of the parasites but affordfirm positions inside the intestinal cavity wall againstthe immune factors of the host which could reject theparasite's holdfast. The above dense distribution ofmicrotriches in the scolex region of S. globipunctataalso strengthens the above suggestion. Its absence inthe gravid region is due to the morphological changesin the tegument and the interaction of luminalenvironment.REFERENCESAnderson KI. 1975. Comparison of surface topography of threespecies of Diphyllobothrium (Cestoda, Pseudophyllidea) byscanning electron microscopy. Int J Parasitol 5:293-300.Braten T. 1968. An electron microscopy study of the tegumentand associated structures of the plercercoid ofDiphyllobothrium latum (L). Z Parasitenk 30:95-103.Caira JN and Ruhnke TR. 1991. A comparison of soclexmorphology between the plerocercoid and the adult ofCalliobothrim verticillatum (Tetraphyllidea:Onchobothridae). Can J Zool 69:1484-1488.Conn DB. 1993. Ultrastructure of the gravid uterus ofHymenolepis diminuta (Platyhelminthes: Cestoda). JParasitol 794: 584-590.Featherston DW. 1972. Taenia hydatigena. IV Ultrastructurestudy of the tegument. Z Parasitend 38:214-232.Granath WO, Lewis JC and Esch GW. 1983. An ultrastructuralexamination of the scolex and tegument of Bothriocephalusacheilognathi (Cestoda: Pseudophyllidea). Trans AmMicrosc Soc 102:240-250.Hayat MA. 1977. Principal and Techniques of ElectronMicroscopy. Biological applications. Vol. 1-9. New York.Van Nostrand Reinhold.Hayunga EG. 1991. Morphologica adaptations of intestinalhelminthes. J Parasitol 77:865-873.Hess E and Guggenheim R. 1977. A study of microtriches andsensory processes of the tetrathyridium of Mesocestoidescorti hoeppli, 1925, by transmission and scanning electronmicroscopy. Z Parasitenk 53:189-199.Holy JH and Oaks JA. 1986. Ultra structure of tegumentalmicrovilli (Microtriches) of Hymenolepis diminuta. CellTissue Res 244:457-466.Jha RK and Siyth JD. 1969. Echinococcus granulosus:Ultrastructure of Microtriches. Exptl Parasitol 25:232-24.Jha RK and Siyth JD. 1971. Ultrastructure of the rostellartegument of Echinococcus granulosus with specialreference to biogenesis of mitochondria. Int J Parasitol169-177.Jones MK. 1998. Structure and siversity of cestode epithelia.Int J Parasitol 28:913-123.Lumsden RD. 1975. Parasitological review: Surface andcytochemistry of parasitic helminthes. Exptl Parasitol37:267-339.Lumsden RD and Hildreth MB. 1983. The fine structure ofadult tapeworms. Biology of the Eucestoda. Vol. 1 pp. 177-233. Academic Press London.Lumsden RD and Specian R. 1980. The morphology, histology,and fine structure of the adult stage of cyclophyllidentapeworm Hymenolepis diminuta In: The Biology ofHymenolopis diminuta. 147-280. Academic Press, NewYork.Morseth DJ. 1966. The fine structure of tegument of adultEchinococcus granulosus, Taenia hydatigena and TaeniaBerger J and Mettrick DF. 1971. Microtrichial polymorphismamong hymenolepid tapeworms as seen by scanning pisiformis. J Parasitol 52:1074-1085.electron microscopy. Trans Am Microsc Soc 90:393-403.