Renal sphaerosporosis in cultured grouper Epinephelus malabaricus.
Histological and electron-microscopical techniques revealed a heavy Sphaerospora infection in the kidneys of cage-cultured grouper E. malabaricus from sites in the Songkla and Satun provinces of Thailand. Kidney tubule lumens contained mature spores and developing stages adhering to the brush border of the tubules. Renal corpuscles were also affected. No pathogenic bacteria or viruses were identified as causative agents of the disease. This is the first report of sphaerosporosis in brackish water fish cultured in South East Asia.