Scanning electron microscopic revision of common species of the genus Chloromyxum (Myxozoa: Myxosporea) infecting European freshwater fishes

• Main Authors: Lom, J., Dyková, I.
• Format: Other/Unknown Material
• Language: English
• Subjects: Myxosporea; Chloromyxum; surface structures; fish parasites; Pacific; Lota lota; lota
• Online Access: https://kramerius.lib.cas.cz/view/uuid:fead10ed-ea22-4e87-9f84-30e3be4241ef

Seven species of the genus Chloromyxum Mingazzini, 1890 infecting freshwater fishes in the Czech Republic arc redescribed using scanning electron microscopic (SEM) observation of surface structures of their spores, and one is described as a new species. The pattern of ridges on the spore surface is in most cases difficult if not impossible to observe and illustrate exactly by means of light microscopy. However, the features are clearly visible with SEM. In fact, this method becomes a prerequisite for any well based description of Chloromyxum species. C. reticulatum from the gall bladder of Lota lota is the only Chloromyxum species revealing button-like projections on the shell valves Instead of characteristic ridges found on the spores of all other species. Ridges of different shapes were characterized on the spore surface in C. lenorae from the urinary system of Lota lota, in C. thymalli from the gall bladder of Thymallus thymallus, and ill C. trutlae from the gall bladder of Salmo trutta fario. C. cristatum from the gall bladder of various cyprinids has conspicuously developed ridges; several other species are designated as junior synonyms of C. cristatum. C. fluviatile from the gall bladder of various cyprinids has an unusual variability in the surface patterns of its spores; its junior synonyms are designated. A new species, C. paulini sp. n. from the gall bladder of Alhurnus alhurnus has spores covered by a pattern of meridional or whirling ridges. A species found in the urinary tract of Salmo trutta fario is identified tentatively as C. cf. majori, known from salmonids of the American Pacific coast.