| Abstrakt: |
The morphology of two isolates of the parasitic ciliate Cryptocaryon irritansobtained from wild fish from S-E Queensland, Australia, was examined by observation of live parasites, silver impregnation (protargol, silver carbonate, silver nitrate), scanning (SEM) and transmission (TEM) electron microscopy. Trophonts of both isolates were characterised by an apical cytostome and a post-oral groove readily visible in silver carbonate impregnations and SEM. The groove consisted of three membranous folds which extended from the cytostome posteriorly for one third to one half the length of the trophont. Some possible functions for the groove are hypothesised. Similar structures have not been described previously from trophonts of other C. irritansisolates. The circumoral cirri of trophonts and theronts were composed of dikinetids. Each circumoral cirrus was associated with a rib-like structure in the precytostomal depression and was aligned with a meridional row of somatic monokinetids. The number of somatic kinetid rows was related to trophont diameter. Theronts were densely ciliated with a subapical, slit-like cytostome. The morphology of the two isolates appeared identical. The simple oral apparatus, uniform somatic ciliation, and ultrastructure of its cytopharynx indicates C. irritanshas affinities with pros tome ciliates. |
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