Aphanomyces Infection in Dwarf Gourami(Colisa lalia).

Abstract

A disease due to lower fungus was found in pet fish, dwarf gourami (Colisa lalia). In almost all cases, swelling of the abdomen due to swollen internal organs without accumulation of ascitic fluid was characteristic external sign of infected fish. Histopathological examination showed fungal hyphae and many granulomas present in the internal organs and musculature. Fungi were isolated from the lesions and were identified as a member of the genus Aphanomyces. The fungus had high pathogenicity to goldfish (Carassius auratus). No oogonia were produced in hemp seed cultures. This fungal infection closely resembled in pathology the mycotic granulomatosis which is known in cultured ayu in Japan.下等菌に起因する疾病がドワーフグラミーに発生した. 病魚の多くは腹部膨満を呈したが, 腹水の貯留は認められなかった. 筋肉および内臓諸器官の圧扁標本中に無隔で分枝した菌糸が存在した. 病理組織学的に内臓諸器官および筋肉内に菌に起因する肉芽腫が多数観察された. 病魚からの菌の分離は困難なことが多いが, これは体内では菌がすでに死滅していることが多いためと推察された. 分離菌はすべて Aphanomyces sp. に同定された. 本菌の各種性状はアユの真菌性肉芽腫症原因菌, A. piscicida に類似したが, 若干の差異も見られた.