Abstract
Excystation in vitro ofBucephaloides gracilescens metacercaria is a two-stage event. An initial, passive phase of peptic digestion for 1 h at pH 2 removes much of the outer, fibrous and cellular capsule of host origin. The second, active phase is triggered by a rise in environmental pH (to pH 7.2) which stimulates muscular activity in the metacercaria resulting in excystation within 5 min. Angler bile, the bile salts sodium taurocholate and sodium glycocholate, or the bile salt mixture, and sodium tauroglycocholate increase the rate and percentage of successful excystation. Cysts from the orbit and nasal regions of whiting have thicker walls than those from the auditory capsules and cranial fluid of the brain and require a longer period (2 h) of pepsin digestion for optimal excystation. Trypsin, reducing agents, or a CO2-atmosphere play no apparent role in excystation.
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Johnston, B.R., Halton, D.W. Excystation in vitro ofBucephaloides gracilescens metacercaria (Trematoda: Bucephalidae). Z. Parasitenkd. 65, 71–78 (1981). https://doi.org/10.1007/BF00926555
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DOI: https://doi.org/10.1007/BF00926555