Spinning Tilapia (ST) - Viral Infections In Fish

Spinning Tilapia (ST)

Syndrome

CAUSATIVE AGENT:

Iridovirus (110-140 nm)

SPECIES AFFECTED:

Oreochromis mossambicus, O. aureus, O. niloticus, and Sarotherodon galilaeus

GROSS SIGNS:

Affected tilapia fry and fingerlings swim in a spiral pattern, sink to the bottom then rise and hang at a 45 degrees angle just under the water surface, gasping for air. They do not feed and are darker in color.

EFFECT ON HOST:

Tilapia manifesting the spinning syndrome die within 24 h of onset. Up to 100% mortality in affected population of Tilapia fry has been reported. Histo-pathologically, the renal tubules are shrunken, hemorrhaging and infiltrated with eosinophilic granular cells. In addition, focal myolysis develops in the muscles.

DIAGNOSIS:

The disease is detected by signs of the disease, EM, isolation/identification of the virus.