- Autor(in)
- Seitenbereich
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209 - 214
- Zusammenfsg.
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The marine, tropical surgeonfish Naso tuberosis contains the ciliated protozoan Balantidium jocularum as an intestinal symbiont. Some specimens of this ciliate are host to a rod shaped Gram-positive bacterium residing in the ciliate's macronucleus. These bacteria were studied by transmission electron microscopy. The largest bacterium measured about 4 mu m long and 0.6 mu m wide. Many contained an internal compartment that could be an endocyst. Thus far, nucleoids have been observed only in the cytoplasm outside this compartment. In one end of the cytoplasm are vesicular structures. The inner compartment has different appearances in different bacterial specimens, from structureless and very electron opaque to somewhat reticular and subdivided into two zones of different texture and electron opacity. If the relationship is parasitic is not known. It is speculated that this bacterium may be phylogenetically related to the recently described and unusual Gram-positive bacterium Epulopiscium. The latter resides ''freely'' in the intestines of N. tuberosis and other surgeonfishes.