Watersnake Eats Fish (image) University of California - Davis Caption Southern watersnakes eat many different freshwater fish species such as this Sunfish. A UC Davis study shows the non-native snakes are invading California waters, posing a threat to already imperiled native fish, amphibians and reptiles. Credit J.D. Willson/University of Arkansas Usage Restrictions Provide photo credit. 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.