In this study, cultures of neural stem-progenitor cells (NSPC) from the brain of green terror cichlid Aequidens rivulatus were established and various NSPCs were demonstrated using immunocytochemistry. All of the NSPCs expressed brain lipid-binding protein, dopamine- and cAMP-regulated neuronal phosphoprotein 32 (DARPP-32), oligodendrocyte transcription factor 2, paired box 6 and sex determining region Y-box 2. The intensity and localisation of these proteins, however, varied among the different NSPCs. Despite being intermediate cells, NSPCs can be divided into radial glial cells, oligodendrocyte progenitor cells (OPC) and neuroblasts by expressing the astrocyte marker glial fibrillary acidic protein (GFAP), OPC marker A2B5 and neuronal markers, including acetyl-tubulin, βIII-tubulin, microtubule-associated protein 2 and neurofilament protein. Nevertheless, astrocytes were polymorphic and were the most dominant cells in the NSPC cultures. By using Matrigel, radial glia exhibiting a long GFAP or DARPP-32 fibre and neurons exhibiting a significant acetyl-tubulin process were obtained. The results confirmed that NSPCs obtained from A. rivulatus brains can proliferate and differentiate into neurons in vitro. Clonal culture can be useful for further studying the distinct NSPCs.

A disease outbreak with 71% (cumulative) mortality was reported in a freshwater hybrid sturgeon farm located in Hualien County, Taiwan. The moribund¯sh showed signs of lethargy, anorexia, di®use external hemorrhages around mouth and anus, and on the base of¯n and abdomen surface accompanied with abdomen swelling. Post-mortem examination revealed multiple red patches ranging from 1 to 5 cm in size on the liver. The histopathology revealed extensive coagulative to lique¯ed necrosis of various sizes in the liver and spleen. Focal necrosis of kidney was also evident. The lesions were positive with Ziehl-Neelsen acid fast staining. A rapid growth of nontuberculous mycobacteria (NTM) was isolated from liver of moribund sturgeon and the polymerase chain reaction (PCR) studies using primer sets derived from Mycobacterium sp. suggested this NTM was closely related to Mycobacterium marinum. There was only one bacterial colony been isolated in brain heart infusion agar (BHI Agar) and been identi¯ed as Streptococcus iniae. These¯ndings suggest that a bacterium identi¯ed as belonging to M. marinum might cause heavy mortality.