Abstract
This study compared the histopathology of young striped jack Pseudocaranx dentex experimentally infected with the dematiaceous fungus Ochroconis humicola NJM 0472 with that of spontaneously infected fish. Moribund and freshly dead fish from both groups showed similar histopathology, and appeared to have been killed due to hyphae penetrating the visceral organs. Fish that survived the infection appeared to be able to suppress the fungal growth by well-established inflammatory reaction involving mycotic granulomas and granulation tissues. The results suggested that two types of O. humicola infection occur in young striped jack: an acute type infection, which is characterized by penetrating hyphae that cause direct tissue destruction and a chronic type infection, which is characterized by severe inflammatory reaction that causes functional disorders of the affected organs.
