Snails can serve as intermediate hosts to parasites that infect fish. The parasites life cycle involves snails, fish, and fish eating birds. Take snails out of the equation and your fish have fewer parasites to deal with.

http://www.bassresource.com/fish_biology/fish_parasites.html

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The "black spot" parasite has the same general life cycle, using snails and fish as intermediate hosts, but after leaving a snail it penetrates the skin and scales of fish and encysts itself in the skin of the fish, appearing as black specks or spots on the fish's skin. When the fish is eaten by a fish-eating bird, such as a kingfisher, the life cycle starts anew.


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Here's the bottom line. Parasites come, they go. Pond managers observe parasites from time to time, but rarely need to take action. When parasites make their way into sportfish, it's not necessarily a problem. But, to lower the incidence of parasites, one (or more) hosts need to be managed or eliminated. The most common practice is to manage excessive aquatic plants, which house snails, or to use red ear sunfish to eat snails. Or, both. Remember, balancing a pond and its life is key to success. Dealing with parasites is also a balancing act.



Last edited by Shorty; 07/23/12 09:30 AM.