Summary
The ultrastructure of the oral sucker of the cercaria of Schistosoma mansoni was investigated using stereoscan and transmission electron microscopy. Secretions of the penetration glands are released through ducts which open at the bases of a series of raised tegumentary folds on the anterior tip of the oral sucker and not through hollow spines. These tegumentary folds may serve to protect the duct apertures during the free swimming period of the cercaria. During penetration into the final host the folds may act as a “rasp” to break down the host skin and in addition help to confine the enzymatic activity of the glandular secretions to a particular area. A series of sensory structures, in close proximity to the duct openings, probably enable the cercaria to test the host surface which results in the selection and penetration of a suitable site.
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Robson, R.T., Erasmus, D.A. The ultrastructure, based on stereoscan observations, of the oral sucker of the cercaria of Schistosoma mansoni with special reference to penetration. Z. F. Parasitenkunde 35, 76–86 (1970). https://doi.org/10.1007/BF00259532
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DOI: https://doi.org/10.1007/BF00259532