Diagnosis of Viral Epidermal Hyperplasia of Japanese Flounder Larvae by Fluorescent Antibody Technique

Abstract

The first occurrence of “viral epidermal hyperplasia” of Japanese flounder larvae was recorded in Hiroshima Prefecture in 1985, and since then the same disease has been prevailing in hatchery-reared flounder in various districts of Japan. In the present study, we applied fluorescent antibody technique (FAT) to the disease as a diagnostic procedure. Electron microscopy and transmission experiments revealed that 4 out of 5 cases examined were due to viral epidermal hyperplasia. FAT test, using a rabbit antiserum against virus particles collected from epithelial cells of affected flounder larvae, exhibited a positive reaction on only the epidermis of the fish in the above 4 epizootics. Thus, the FAT method proved to be useful for rapid diagnosis of the present disease.