FISH HEALTH MANAGEMENT 



321 



Trichodina on warmwater fish can be controlled with any of the following 

 treatments: 



(1) Copper sulfate as an indefinite pond treatment at whatever concen- 

 tration can be used safely in the existing water chemistry. 



(2) Potassium permanganate at 2 parts per million as an indefinite pond 

 treatment. 



(3) Formalin at 15-25 parts per million as an indefinite pond treatment. 



(4) Formalin at 125-250 parts per million, depending on water tempera- 

 ture and species and size of fish, for up to 1 hour. 



To control Trichodina on salmonids, formalin at 167-250 parts per mil- 

 lion for up to 1 hour usually is successful. If salmonids are sensitive to for- 

 malin, a 2-4 parts per million treatment of Diquat for one hour should be 

 tested. 



AMBIPHRYA 



Ambiphrya (Scyphidia) can occur in large numbers on the skin, fins, and 

 gills of freshwater fish. 



The organism has a barrel-shaped body with a band of cilia around the 

 unattached end and around the middle of the body, and a ribbon-shaped 









Figure 92. Epistylis, lOOx magnification. (Courtesy G. H. Hoffman, Fish Farm- 

 ing Experimental Station, Stuttgart, Arkansas.) 



