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Ultrastructure of microtriches in Stilesia globipunctata69surface is achieved by the presence of delicate a. Immature proglottides containing scolex andcytoplasmic extensions called microtriches, anterior region.reminiscent of mucosal cell microvilli. Themicrotriches on the tapeworm surface increase theb. Mature proglottides with functionalsurface area of the parasite by about 20-times. Thereproductive organs.most dominant feature of the cestode tegument is thecovering by microtriches, which are thought to bec. Gravid proglottides containing eggs.responsible for nutrition and protection and possibly Scanning electron microscopic study : The scanningalso the mechanical functions of anchoring and electron microscopic (SEM) studies of the soclex,traction. They show a wide renge of morphlogical immature, mature and gravid proglottides of S.variations.globipunctata were undertaken to understand itsultrastructure. For this purpose, the specimens wereMicrotriches are unique in the cestodes and are dissected in chilled glutaraldehyde (2.5%) and fixedevident on the tegument and other epithelia that open for 16 h at 4° C. The tissues were subsequently washedinto the tegument. Microtriches have been widely thrice at an interval of 15 min each in phosphate bufferrepeated among all major orders of Eucestoda. These at pH 7.0 and then dehydrated by passing through anare present on the scolices and strobila of ascending series of alcohol from 30 to 100% an h inrepresentatives of most groups that have been each concentration. They were ultimately kept inexamined with SEM. Papilliform, spiniform and 100% alcohol overnight. Following dehydration, thefiliform structures have been variously reported tissues were air-dried in a desiccator for 7 to 10 days.among the Pseudophyllidea (Anderson, 1975, The dried samples were mounted on an aluminiumGranath et al., 1983) Cyclophyllidea (Berger and stub and gold sputtered in vacuum for 10 min, using anMettrick, 1971; Ubelaker et al., 1973; Sampathkumar, Eiko IB-2 ion coater. The samples were observed2001; Vijayalakshmi, 2001; Radha, 2003). eventually on a Hitachi, S-415A scanning electronIn the present study the characterization ofmicroscope, scanned at 25 KV and micrographed atmicrotrichial structure, density, distribution and theirdifferent magnifications (Hayat, 1977).functional significance in S. globipunctata has been Transmission electron microscopic study: Theattempted as the species of cestode has so far not been scolex, mature and gravid proglottid regions of S.exclusively studied due to its inconspicuousness in the globipunctata for transmission electron microscopygut of sheep.(TEM) were immersed in 2.5% glutaraldehyde inMATERIALS AND METHODSMillong's phosphate buffer (pH 7.3, 380 mOsm/L),where they were diced into small pieces. After 3-4hCollection of tapeworms: The tapeworm S. fixation at room temperature, the tissue was rinsed inglobipunctata (Rivolta, 1874) were collected from the Millong's buffer. The tissue was then post-fixed in 1%intestine of naturally infacted sheep autopsied in the osmium tetroxide in Millong's buffer for 1.5 h, rinsedslaughterhouse at Perambur, Chennai. The sheep quickly in distilled weter, dehydrated in an ethanolintestines were transported to the laboratory within series, infiltrated with propylene oxide, embedded inhalf an hour of collection. In the laboratory, each Spurr's low-viscosity epoxy resin and polymerized atintestine was carefully dissected and the tapeworms 60° C. Thin sections were cut at 70-90 nm with awere collected. Then the worms were washed in diamond knife, mounted on uncoated copper grids,distilled water to render them free from intestinal stained with uranyl acetate/ethanol and aqueous leadcontents and rinsed quickly 3-4 times in normal saline. citrate, and examined under a Philips 204 TEM at anThe tapeworms were then observed through aaccelerating voltage of 40 or 60 kV (Conn, 1993).compound microscope to confirm their taxonomic RESULTScharacters. The entire worm was spread out on a boardand the length was measured.The immature, matureSEM observations: Specimens of S. globipunctataand gravid proglottid region of the worm was locatedwere found to have species-specific patterns ofand separated as follows and dried on moist blottingpapilliform, filiform, spiniform and blade-likepaper and used for scanning and transmission electronmicrotriches that are restricted to particular regions ofmicroscopic studies.scolex and strobila. The central to peripheral regionsof the scolex are covered with papilliform and filiform