Name of the condition: Myofibrogranuloma

Cause of disease: Virus

What does it look like? Fish look normal on the outside but certain areas of the fillet look semi-translucent, or yellowish brown with knotted muscle fibers. The tissue has a very dry freezer burn appearance. Other areas of the fillet may be even granular with mineral deposits or opaque.

Myofibrogranuloma Myofibrogranuloma

Fish species affected:

This condition is only seen in walleye.

Life cycle:

The condition is not infectious. Genetic and environmental stressors may play a role in the development of the disease.

Where is the disease is found?

Can be found in lakes in Minnesota, Wisconsin, North Dakota and South Dakota.

Is it safe to eat?

Due to a lack of concrete scientific knowledge about the spread of the disease, consumption is not recommended.

How can I prevent the spread?

There are no known methods of preventing this condition.

Disposal of unused portions:

Dispose of unused portions by burying or with household waste. Fish entrails should never be discarded back into the lake.