Contact Us Newsletter Home Myxobolus cerebralis is a metazoan parasite that penetrates the head and spinal cartilage of fingerling trout where it multiplies very rapidly, putting pressure on the organ of equilibrium. Those that survive until the cartilage hardens to bone can live a normal life span, but are marred by skeletal deformities.
Fish can, however reproduce without passing on the parasite to their offspring.
The minute organism, native to the Eurasian continent, was introduced into North American waters in the late 1950s. So far its severe damage has been primarily to wild rainbow populations, although many other salmonid species can become infected, with or without clinical disease. Brown trout, also a European import, become infected by M.cerebralis , but rarely suffer clinical disease. Under some circumstances infected browns suffer some mortality, but they always insure the survival of the parasite. Regardless of species, when each infected fish dies, many thousands to millions of the parasite spores are released to the water.