Mortality caused by the streptococcal disease of cultured yellowtail at fish farms in Kitaura Bay, Miyazaki Prefecture was investigated.
The results obtained were as follows :
1) It has been found that a severe damage of the streptococcal disease of cultured yellowtail occurred at central areas in the fish farms.
2) It was demonstrated that a change of damage the streptococcal disease of cultured yellowtail has been closely related to a fluctuation of a haul catch of a sardine which are using as the feed of cultured yellowtail.
From above mentioned results, it was concluded that an occurrence of the streptococcal disease of cultured yellowtail has been originally caused on the fish culturing technique.
