Concentration of Flavobacterium psychrophilum in the Ovarian Fluid and Milt of Cultured Salmonids

Abstract

We measured the concentration of F. psychrophilum in the ovarian fluid and milt of six species of salmonids that were collected from freshwater fish farms in Japan. We detected the bacteria in 39 of 61 groups of female fish (544 of 3,276 fish) and 21 of 42 groups of male fish (248 of 1,434 fish). The concentration of F. psychrophilum ranged from 10 to 10^7.7 CFU/mL (mean 10^2.0 CFU/mL) in the ovarian fluid and from 10 to 10^4.5 CFU/mL (mean 10^2.1 CFU/mL) in the milt. Our data suggest that the bacteria are widely distributed, and are present at high levels, throughout Japan.