Fig. 69. Module Disease of the Cills in a one-siunmer Carp, 

 Purina sized, white cysts between the rows of gill lamellae. 



Fig. 70. One-year Rainbov; Trout with Hotary Disease, 

 Shortened jaw, curvature of the spinal column and black 

 coloration of the tail from the vent onward. (According to 

 Schaeperclaus, 1931.) 



'■'.Tiirling Disease . The instigator of this most dangerous and economically most 

 important disease of the brood of rainboiv and brook trout, Lentospora cerebralis, is a 

 ver^' small sporozoa, whose spores have a diameter of about 8 mu. In contrast to the 

 previously mentioned sporozoa which occurs preponderantly on the skin and gills, 

 Lentospora is parasitic only in the interior and especially in the juvenile cartilages 

 of the entire skeletal system. If the disease is once introduced, the bottoms and 

 v.'ater of all ponds in which rotary diseased trout were formerly kept, become infected 

 by the spores which are easily carried about by the water and are resistant to dryness 

 and frost. Once the disease has been introduced it is extremely difficult to eradicate 

 again. 





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