obligate, intracellular parasites, mostly of fish, belonging to the class Microsporidea.
occurs in the muscles of eels and causes body deformities when muscles atrophy.
produces large cysts that protrude from the body wall of affected fish.
found in the skeletal muscles of aquarium fish causing 'neon fish disease'. The muscles are patchily transparent and the fish lose their balance and the fins degenerate.
causes the development of cysts and tumors in the muscles of marine fish.
infects the ovaries of minnows causing infertility.
infects the gills of trout causing clubbing and fusion.