Fusarium disease is an infectious condition that occurs in the cultivation of kuruma shrimp ( Penaeus japonicus ), primarily presenting as lesions in the gills. These lesions contain proteolytic enzymes of likely bacterial origin. This is the first study to demonstrate fungal–bacterial mixed infection in gill lesions of Fusarium‐infected kuruma shrimp. Tenacibaculum spp. showing proteolytic activity were isolated from the lesi...