A fish nodavirus associated
with mass mortality in hatchery-reared red drum, Sciaenops ocellatus
Myung-Joo Oh, Sung-Ju Jung, Suk-Ryul Kim, K.V.
Rajendran, Young-Jin Kim, Tae-Jin Choi, Hyeung-Rak Kim, Jin-Do Kim-2002
Aquaculture, 211(1-4): 1-7
Abstract:
A nodavirus was detected in the larval stages of red
drum, Sciaenops ocellatus, from Korea. The fish suffered heavy
mortality (80-90%) and the principal signs of the disease included darkening
of the body, anorexia, whirling movement, spinal deformity and enlarged swim
bladder. Histological findings revealed vacuolation and necrosis in the
nerve cells of brain, spinal cord and retina. Electron microscopic
observation showed the presence of spherical, non-enveloped viral particles,
measuring 30 nm in diameter in the cytoplasm of nerve cells. Samples from
dead and moribund fish were subjected to RT-PCR using SJNNV primers and a
426-bp product was detected by agarose gel electrophoresis. The results of
the present investigation indicated that the causative agent of the outbreak
was a nodavirus, and this forms the first record of NNV in red drum.
(Department of Fish Pathology, Yosu National
University, Yosu 550-749, South Korea, Fax: +82-61-659-3173, e-mail: ohmj@yosu.ac.kr)