Studies on Visceral Mycosis of Salmonid Fry一I. : Histopathology

1. サケ科魚類稚魚の内臓真菌症を病理組織学的に検討した。 2. その結果2種の真菌感染が認められた。S.diclina感染症ではカビ菌糸は胃幽門部の胃壁から侵入し,その周囲の内臓諸器や腹腔内に伸長していた。未同定糸状真菌感染症ではカビ菌糸は鰾内で多量に発育し, 標壁から侵入して周囲の内臓諸器官に伸長していた。Histopathological observation was made on 20 diseased rainbow trout fry and 5 amago Salmon fry (O.rhodurus f. macrostomus). 1) Saprolegnia diclina i infection : Fungal hyphae grew in the lumen of the pyloric region of the stomach. Hyphae extended from the gastric epithelium into the muscle layers in which they grew markedly. Further hyphae extended out from the stomach wall into the pancreas, pyloric caecae, spleen, abdorninal cavity, abdominal musculature and visceral blood vessels in which hyphal emboli were formed frequently. 2) Infection with an unidentified fungus which had thin septate hyphae : Fungal hyphae markedly grew in the swim bladder. They invaded the wall of the anterior region of the swim bladder and extended into the liver, gall bladder, kidney, wall of the esophagus and the cardiac region of the stomach, body musculature and into the visceral blood vessels