No abstract

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 microns in length (mean, 12.4 microns) and 8-12.4 microns in width (mean, 9.6 microns); polar capsules were 4.3-9 microns long (mean, 6.4 microns) and 2-3.8 microns wide (mean, 2.9 microns). Light microscopy, the ultrastructure of pansporoblasts, sporogenesis and mature spores are described.

The effects of the herbicide atrazine (2-Chlor-4-ethyl-amino-6-isopropyl-amino-s-triazine) on the kidney of rainbow trout (Oncorhynchus mykiss) were studied by exposing them to sublethal concentrations of 1.4 and 2.8 mg atrazine per liter of water for 96 h (acute exposure) respectively to 5, 10, 20, 40, and 80 micrograms/L for a period of 28 days (chronic exposure). Alterations of the different components of renal corpuscles and of renal tubules, as well as an increase in cells with mitotic figures in renal hemopoietic interstitium were constant features at lower chronic (5, 10, 20, 40 micrograms/L) exposure; necrosis of endothelial cells and renal hemopoietic tissue were prominent at concentrations of 80 micrograms/L, and 1.4 and 2.8 mg/L atrazine.

Abstract. Rainbow trout (Oncorhynchus mykiss) developed a post-infectious chronic membranous glomerulonephritis 15 months after they had been experimentally infected with Renibacterium salmoninarum. Histologically, peritubular and periglomerular fibrosis, hypercellular glomeruli with occluded Bowman's space, and partial or complete adhesion to Bowman's capsule were constant features. Electron microscopy revealed thickened glomerular basement membranes with spikes accompanied by finely granular electron-dense deposits at the epithelial side and dense material in the mesangial matrix. Indirect immunofluorescence indicated linear immunoglobulin deposits along the glomerular basement membrane. The presence of R. salmoninarum was demonstrated by culture and by indirect immunofluorescence. Low serum hemagglutination-inhibiting antibody titers were demonstrated.

Hoferellus carassii is a common parasite of goldfish Carassius auratus and gibel carp C. auratus gibelio. Early trophozoite stages of H. carassii were found intracellularly, in epithelial cells of renal tubules. Plasmodial stages, however, had a coelozoic way of life, inhabiting the lumen of renal tubules, ureters and preferentially the urinary bladder. Spores were produced mostly in the latter site. No strict seasonality in development was established. In general, early stages were found during summer and autumn months, while spores occurred primarily from autumn to spring. In natural waters H. carassii infection of gibel carp passed without symptoms and only minor degenerations were recorded in kidney and urinary ducts. In goldfish from a pet fishpond, however, hoferellosis induced kidney enlargement disease, severe cystic transformation of tubules, and degeneration of the renal interstitium. Renal damage was caused by trophozoites invading the epithelial cells of renal tubules.