Devil & Deep Creek 12/24/07

[BrianID]

Based on everything I've read, black spot disease isn't anything to worry about. I wouldn't hesitate to eat a fish with a few black spots but I still wouldn't eat a fish that looked like this.



Here is what Jim Fredricks had to say about black spot disease. Jim Fredricks is the F&G's Upper Snake Region fisheries manager.
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[#000000][i]The causal agent for black-spot disease is a digenetic trematode whose larvae burrow into the skin of fish. ("Digenetic" refers to the need for several animal hosts, including fish, to complete its life cycle and "Trematode" is a class of parasites that includes flukes or flatworms.) The adult worm inhabits the gut of the definitive host, a fish-eating bird (e.g. kingfishers, gulls, and herons). Droppings from the bird carry eggs into the water where they hatch into miracidia, which attack several species of snail - the first intermediate host. From the snail, enormous numbers of cercariae emerge which infect several species of fish - the second intermediate host. The cercariae burrow directly into the skin and encyst as metacercariae or larvae. The fish surrounds this cyst with dark melanin pigment giving rise to the black spots (about 1-2 mm in diameter) in the skin, fins, and gills. If a fish is heavily infected, a condition known as popeye appears, in which the eyes bulge out from their sockets. The infected fish is eaten by a bird, which completes the life cycle. [/#000000][#000000]Although black-spot disease is aesthetically unpleasant to anglers, there's little evidence that it can affect wild fish populations (though at extremely high levels of infection, it is possible). The disease poses no known health threats to humans after cooking the infected fish. [/#000000]

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