This paper provides the first detailed description of a Tetracapsuloides species, Tetracapsuloides vermiformis n. sp., with vermiform stages in the bryozoan host, Fredericella sultana, and its experimental transmission from F. sultana to Cyprinus carpio. The suitability of morphological, biological and 18S rDNA sequence data for discrimination between malacosporean species is reviewed and recommendations are given for future descriptions. Presently, malacosporean species cannot be differentiated morphologically due to their cryptic nature and the lack of differential characters of spores and spore-forming stages in both hosts. We examined biological, morphological and molecular characters for the present description and for revising malacosporean taxonomy in general. As a result, Buddenbrockia plumatellae was split into two species, with its sac-like stages being ascribed to Buddenbrockia bryozoides n. comb. In addition to ribosomal DNA sequences multiple biological features rather than morphological characters are considered essential tools to improve malacosporean taxonomy in the future according to our analysis of the limited traits presently available.
- MeSH
- Bryozoa parazitologie MeSH
- interakce hostitele a parazita MeSH
- kapři MeSH
- Myxozoa genetika fyziologie MeSH
- nemoci ryb parazitologie MeSH
- organismy bez specifických patogenů MeSH
- parazitární nemoci u zvířat parazitologie přenos MeSH
- RNA ribozomální 18S genetika MeSH
- stadia vývoje MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
We undertook a detailed ultrastructural investigation to gain insight into the early stages of development of the vermiform myxozoan, Buddenbrockia plumnatellae Schröder, 1910 in two bryozoan hosts. Early cell complexes arise in the peritoneum after division and migration of isolated cells in the host body wall. The development of cell junctions linking the outer (mural) cells of the complex then produces a sac enclosing a mass of inner cells. Elongation to the vermiform stage (myxoworm) occurs during multiplication and reorganisation of the inner cells as a central core within the single-layered sac wall. The core cells develop into muscle and sporogonic cells separated from the mural cells by a basal lamina. Myogenesis occurs along the length of the myxoworm from cells that differentiate from the central core, and is independent of elongation. Four primary sporogonic cells maintain positions close to the basal lamina, between muscle cells, while giving rise to secondary sporogonic cells that eventually become free in the central cavity. At least some secondary sporogonic cells undergo meiosis. In view of the recent confirmation of the phylogenetic affinity of Buddenbrockia with the Cnidaria, we postulate how features observed in Buddenbrockia may be homologous with cnidarian structures. Finally we propose a new family name, Buddenbrockiidae, to replace Saccosporidae which was proposed previously in breach of the International Code of Zoological Nomenclature.
