LIGHT AND ELECTRON-MICROSCOPIC STUDIES ON MYXOBOLUS-COTTI EL-MATBOULI AND HOFFMANN, 1987 INFECTING THE CENTRAL-NERVOUS-SYSTEM OF THE BULLHEAD (COTTUS-GOBIO)

Myxobolus cotti (Myxozoa: Myxosporea) is described as found in the central nervous system of the bullhead (Cottus gobio) caught in the Alpine lake Königssee and in a brook in the Bavarian Forest, Federal Republic of Germany (El-Matbouli and Hoffmann 1987). Aggregations of spores and polysporoblastic trophozoites compressed and replaced large areas of the white and grey matter of the brain and spinal cord. These aggregations may be surrounded by a thin, connective tissue capsule; in a few cases they were associated with loose infiltrates of glial cells. Neither conspicuous tissue reactions nor inflammatory responses were evident. No other organs were seen to be infected with M. cotti. Mature spores are oval, with a tapering anterior end, and the pyriform polar capsules are nearly equal in size. Fresh spores measured 8.9-15.1 μm in length (mean, 12.4 μm) and 8-12.4 μm in width (mean, 9.6 μm); polar capsules were 4.3-9 μm long (mean, 6.4 μm); and 2-3.8 μm wide (mean, 2.9 μm). Light microscopy, the ultrastructure of pansporoblasts, sporogenesis and mature spores are described. © 1990 Springer-Verlag.