FISH HEALTH MANAGEMENT 335 



Masoten at 0.25 part per million active as a pond treatment, repeated 

 four times at weekly intervals, gives good control of anchor worms. How- 

 ever, inconsistent results are obtained when water temperatures exceed 

 80°F or when the pH is 9 or higher. During summer months, Masoten 

 treatment should be applied early in the morning and it may be necessary 

 to increase the concentration to 0.5 part per million active for best results. 



Packing and Shipping Specimens 



Several state agencies have laboratories with biologists trained in the diag- 

 nosis of fish diseases. In addition, several fish- disease laboratories and a 

 number of trained hatchery biologists in the United States Fish and 

 Wildlife Service are available for help in disease diagnosis. In recent years 

 private consulting biologists also have set up practices in disease diagnosis. 



Correct diagnosis depends upon accurate and detailed information re- 

 garding the fish and the conditions under which they were raised, and 

 especially upon the proper preparation of material that will be shipped to a 

 fish- disease laboratory. The more information that is available, the more 

 likely that the diagnosis will be correct. 



If, after a preliminary diagnosis in the hatchery, some treatment already 

 has been started, specimens and information nevertheless should be sent to 

 a disease laboratory for verification. Although the symptoms may seem typ- 

 ical, another disease may be present. It is not uncommon to have two 

 disease conditions present at the same time, one masking the other. 

 Although treatments may be effective for one condition, the other disease 

 may still be uncontrolled. Hatchery personnel should furnish the laboratory 

 with correctly collected and handled material, including all available infor- 

 mation, at the earliest possible date. // the required information is not fur- 

 nished with specimens, conclusive diagnosis may not be possible. 



To facilitate the packing and shipping of proper specimens and informa- 

 tion, a comprehensive checklist, such as the Diagnostic Summary Informa- 

 tion form (Figure 106), should be included. All instructions and questions 

 should be read carefully. All questions should be answered. If an answer 

 cannot be furnished, or a question is not applicable, this should be indicat- 

 ed in each case. When disease breaks out, specimens should be collected 

 and preserved before any treatment is given or started. Only a few fish 

 should be sent for examination, but these should be collected with the ut- 

 most care. Dead fish or fish that appear to be normal are nearly worthless. 

 The most desirable fish are those that show most typically the sings of the 

 disease in question. Moribund, but still living, fish are the best for diagnostic 

 purposes. 



