Occurrence of trypanosomiasis in net-cage cultured groupers (Cromileptes altivelis and Epinephelus fuscoguttatus) in Nanshan port of Sanya, Hainan province, China

In the present study, reported was an unidentified trypanosome that caused massive mortalities of cultured humpback grouper, Cromileptes altivelis (Valenciennes, 1828) and brown-marbled grouper, Epinephelus fuscoguttatus (Forsskal, 1775) in the net-cages in Sanya, China, and some general pathological features of E. fuscoguttatus after experimental infection of the trypanosome. Before dying in the net cages of diseased fish, listlessness and anorexia were the observable symptoms. The blood of the diseased fish was light-coloured in comparison with that of healthy one. E. fuscoguttatus experimentally infected with this trypanosome are with different degrees of engorgement in gill lamella, liver, spleen and kidney. Tissue lesion and necrosis were observed in liver and spleen of diseased fish.