image: Guppies, Poecilia reticulata, are an example of an invasive fish species, and they now outnumber the endangered Mexican fish, Zoogoneticus tequila, by 6 to 1 in the pond where the last remaining population is found. This image relates to an article that appeared in the Sept. 4 issue of Science, published by AAAS. The study, by Dr. A.E. Magurran at University of St. Andrews in St. Andrews, UK, was titled, "Threats to Freshwater Fish." view more
Credit: Image © <i>Science</i>/AAAS