The green sunfish (Lepomis cyanellus) is a species of freshwater fish in the sunfish family (family Centrarchidae) of order Perciformes. It is native to a wide area of North America east of the Rocky Mountains, from the Hudson Bay basin in Canada to the Gulf Coast in the United States and northern Mexico.
Green Sunfish are found in many waters and uptain a yellowish color, though can be a blueish black. can be anywhere from 3 to 12 inches some are very large.
http://en.wikipedia.org/wiki/Green_sunfish