Pathogen	Candida sake
Taxonomy	Anamorphic fungi, Hyphomycetes
Hosts	Salmonid fishes
Disease name	Tympanites ventriculi
Infection site	Stomach
Clinical signs	Abnormally swollen abdomen is observed (Fig. 1).
Fungiology	Candida sake is a yeast whose body is oval (3-4×3.5-6 μm) or elongate (2-3×6-15 μm) (Hatai and Egusa, 1975; Hatai, 2006). It forms hyphal cells (pseudomycelium).
Pathology	A distended stomach filled with gas bubbles and flimsy gastric wall are observed in the diseased fish. The gastric mucosa is erosive (Awakura and Kimura, 1972). The fish becomes lethargic, and finally dies due to the impairment of feeding and swimming (Hatai, 2006).
Health hazard	Since this fungus is not infectious to human, it is harmless in food hygiene.
Diagnosis	Check the yeast in the stomach.
Other information	Because this disease cannot be experimentally reproduced, the disease mechanisms are unknown.
References	Awakura, T. and T. Kimura (1972): A gastric dilatation found in pond-cultured Oncorhynchus masou. Fish Pathol., 6, 121-124. Hatai, K. and S. Egusa (1975): Candida sake from gastro-tympanites of amago, Oncorhynchus rhodurus. Bull. Jap. Soc. Sci. Fish., 41, 993. Hatai, K. (2006): Tympanites ventriculi. New atlas of fish diseases (ed. by Hatai, K. and K. Ogawa), Midori Shobo, p. 32. (In Japanese)

(Photo by T. Awakura)

Fig. 1. Masu salmon showing tympanites vebtriculi