[Coincidental appearance of PKD and Sphaerospora sp. (Myxosporidia) in stock of Salmo gairdneri (Osteichthyes)].

For the first time in Europe simultaneous occurrence of PKX and Sphaerospora sp. is recorded in Salmo gairdneri. Myxosporidian (?) forms hitherto not described have been observed in the kidney interstitium and the epithelium of the renal tubules, sporadically also in the swimbladder wall and the intestinal wall, besides the typical PKX organism in the kidney interstitium. Sporogonic stages and spores of a Sphaerospora species have been found in the lumen of the renal tubules. Neither the exact identification of the Sphaerospora species has been possible, nor the final proof, whether the luminal form, the hitherto undescribed extraluminal forms and PKX belong to one another.