Carp

Carp are the swarming, splashing beggars of Hemenway Harbor.

The popcorn-gobbling pets who crowd around docks at Lake Mead Marina are a popular tourist staple, but they don't do much else for Lake Mead.
The overgrown gray goldfish have multiplied to an abundance since their introduction in the Colorado River more than 100 years ago — to the point that they now make up a large part of the lake's ecosystem.