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The guppy is a small fish that people often keep in bowls or tanks in their homes. In their bowls, guppies are harmless, but in the wild, the story is different. When some guppy owners in Nevada grew tired of their fish, they threw them in a small lake. The guppies then multiplied rapidly and ate all the food in the lake, so that there was none left for the native fish, which disappeared. The same thing has happened in a number of other lakes in the western United States, and now at least one species of fish-the white river spring fish-is almost extinct. Thus, even a little fish like the guppy ●●●●.