India, Oct. 4 -- Hawaii just wanted to control mosquitoes. So, in 1905 it thought of a simple solution. It introduced a small fish from Texas to Oahu, the western mosquitofish, to eat mosquito larvae. What happened next is described in a 1999 paper by researcher Ronald Englund in the Journal of Insect Conservation. The fish was supposed to solve one problem; it may have caused another one.

The western mosquitofish is tiny. It only reaches a size of about 2 inches. However, it consumes a variety of small water organisms, not only the mosquito larvae. That's a pretty big appetite for such a small fish. It could survive in both freshwater and saltwater and eventually found its way to the other Hawaiian islands. It was introduced to many oth...