Abstract
The fine structure of embryonic envelopes of a linstowiid cestode,Oochoristica anolis, was studied by transmission electron microscopy. Eggs are contained individually within specialized uterine capsules. Despite the added protection of the uterine capsule and modified medullary parenchymal myocytons, each oncosphere is enclosed by the full complement of embryonic envelopes characteristic of most other cyclophyllideans. The embryonic capsule is slightly thickened by deposition of uterine lumenal material on its surface. The syncytial outer envelope contains numerous lipid droplets similar to those of the medullary parenchyma in which the uterine capsules are distributed. Prominent nuclei, mitochondria, ribosomes and glycogen are also present. A bilayered embryophore occupies the distal region of the syncytial inner envelope, which also contains nuclei and numerous ribosomes, but few lipid droplets. One or, more frequently, two oncospheral membranes lie between the inner envelope and oncosphere. These observations suggest that linstowiid embryonic envelopes are formed in a manner similar to those of other cyclophyllideans.
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Conn, D.B. Fine structure of the embryonic envelopes ofOochoristica anolis (Cestoda: Linstowiidae). Z. Parasitenkd. 71, 639–648 (1985). https://doi.org/10.1007/BF00925597
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DOI: https://doi.org/10.1007/BF00925597