Diseases, Parasites, and Special Problems 

 in Handling Fishes 



FISHES SUFFER from numerotis diseases and par- 

 asites. In many cases, determining the cause of a par- 

 ticular problem or ailment is a time-consuming job 

 and may require special equipment and trained 

 technicians. This is especially true of bacterial infec- 

 tions. Diagnosis based on gross symptoms is not satis- 

 factory in many cases. Its reliability is related to the 

 experience of the investigator, but, unfortunately, a 

 great deal of experience is needed to insure even a 

 reasonable degree of accuracy. Frequently one disease 

 or parasite repeatedly gives trouble, and it becomes 

 evident that considerable work in identification of 

 the pathogen is warranted. While some treatments are 

 effective against a number of different pathogens and 

 thus it is possible to utilize a "shotgun" approach 

 (e.g., formahn is effective against a number of external 

 parasites), in some cases specific treatments are re- 

 quired. Ichthyophthirius is an external, protozoan 



