Occurrence of viral nervous necrosis in hatchery-reared barfin flounder.
Watanabe, K, Yoshimizu, M., Ishima, M., Kawamata, K. & Ezura, Y.
Bull. Fac. Fish. Hokkaido Univ.
Mass mortalities occurred in hatchery-reared barfin flounder Verasper moseri juveniles. Diseased fish showed abnormal swimming with hemorrhaging of eyes and brain. Brain tissue was stained by fluorescent antibody technique using an anti-SJNNV (striped jack Pseudocaranx dentex nervous necrosis virus) rabbit serum. Vacuolations were recognised in nervous tissues and viral particles ranging from 27 to 28 nm in size were observed by electron microscopy. Presence of the nodavirus was also detected by PCR. Detection rates of nervous necrosis virus gene from egg fluids were increased with repeating egg collection during spawning period.