associated with the disinfection of trout eggs as these are readily 

 accessible (see particularly The Progressive Fish-Culturist ) and are 

 being revised from time to time. 



Acriflavine has been suggested by several authors as a suitable 

 disinfectant of trout eggs (Blake 1930^ Atkinson 1932, Funmculosis 

 Committee 1933, Smith 1939, 1940, 1942, 1944, O'Donnell 1944). Eggerth 

 (1926) shCTTed that the bactericidal action of acriflavine was greatly 

 reduced in neutral and acid solution. Smith (1942) found that only those 

 solutions (500 p. p.m.) at pH 7.0 and above killed B. salmo nicida in 

 20 minutes and at pH 5,5 the bacteria survived for over 50 minutes. By 

 using acriflavine (500 p. p.m.) at pH 7.7, Smith (1942) found the 

 organism was killed in less than 20 minutes. No abnormalities in fish 

 resulted from this treamtnet (Smith 1942). Smith (1944) gathered data 

 which indicated that for B. salmonicida organisms in the lag phase and 

 logarithmic death phase are more resistant to the action of 500 p. p.m. 

 alkaline acriflavine solution at 1° C. than are bacteria in the phase 

 of logarithmic growth. 



The recommended dilution of acriflavine is 1:2000 (approximately 

 500 p. p.m.) (Blake 1930, Atkinson 1932, Furunculosis Committee 1933, 

 Smith 1940, O'Donnell 194/J. Either eyed or "green" ova m.ay be 

 disinfected mth safety, but idth "green" ova treatment should be carried 

 out on the day of fertilization, or a fev/ hours after that process is 

 completed (Blake 1930). 



Ova to be treated should first be washed with clean water, then 

 drained and placed in suitable vessels such as enamelled basins (Blake 

 1930), A solution of acriflavine (1:2000) in well-aerated water should 

 be poured over them in the proportion of at least three and a half fluid 

 ounces to each 1000 ova. The quantity of germicide does not increase 

 the mortality among ova and the volume mentioned may be increased 

 without danger, but it should not be diminished, or there will not be 

 sufficient to ensure disinfection. The disinfectant should be left in 

 contact -.Tith the ova for 20 minutes as a minimum and treatment may be 

 prolonged to 30 minutes (Blake 1930, O'Donnell 1944). After treatment, 

 ova should be washed in clean water. 



Information regarding precautions to be observed while 

 disinfecting trout eggs and regarding the necessary details for the 

 disinfection of eggs with acriflavine, is given in a recent article by 

 O'Donnell (1944). Snieszko and Friddle (1948) also give instructions on 

 cleanliness while disinfecting trout eggs. 



Turning to sulfo-merthiolate Gee and Sarles (1942) foiind that 

 better results were obtained mth this germicide than with acriflavine. 

 Snieszko and Friddle (1948) showed that trout eggs in all stages of 

 development could be disinfected safely with sulfo-merthiolate. 



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