Spiny Water Flea (IMAGE) University of Wisconsin-Madison Caption The invasive spiny water flea is a voracious predator of native zooplankton in Lake Mendota. Originally from Russian lakes, it made its way to the Great Lakes in the ballast water of cargo ships. Its long tail helps keep it safe from smaller fish. Credit Jake Walsh/UW-Madison Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.