Abstract
Yearling masu trout Oncorhynchus masou were experimentally infected by Argulus coregoni and effects of the infection on the host blood _parameters were examined 24 hours and 10 days after infection. Plasma glucose concentration increased in the infected group after 24 hours. After 10 days, 1) erythrocyte and leucocyte counts, hemoglobin concentration and hematocrit value decreased in the infected group; 2) plasma total protein, total cholesterol and calcium concentrations in the infected group decreased more than those in the uninfected; 3) immature erythrocyte count was remarkably high in some infected fish; and 4) there was no distinct difference in the glucose level between the infected and uninfected group. No significant differences were observed in thrombocyte count and plasma phosphate concentration.
