Abstract
Median lethal doses (LD50) of Aeromonas salmonicida on Amago salmon, Oncorhynchus rhodurus were studied by three different infection routes.
LD50 of the bacteria on Amago salmon by intramuscular injection, intraperitoneal injection and bathing method (water-borne injection) were estimated as 4.3-5.1 × 100 CFU/fish, 3.0-4.5 × 103 CFU/fish and 2.2-2.7 × 106 CFU/ml, respectively.
The fluctuations of LD50 obtained in the each duplicate experiments were ignorable. This suggests the advantage of using genetic isolated stocks of fish for the experimental animal.
