The American paddlefish (Polyodon spathula) is a smooth-skinned ray-finned freshwater fish that is the only living species of the paddlefish family. The fish is often considered a relict species as it retains some morphological traits of its early ancestors, including a mostly cartilaginous skeleton and a paddle-shaped rostrum extending from its cranium for roughly one-third its body length. It is also considered a highly derived fish due to its novel adaptations, such as filter feeding. The planktivorous fish averages 5 ft (1.5 m) in length, and has a heterocercal tail fin resembling that of sharks. It is native to the Mississippi River basin, with a range extending to the Great Lakes, but is now considered vulnerable due to overfishing, poaching, habitat destruction, and pollution, and its naturally occurring populations have died off in most of its peripheral range, including New York and Pennsylvania. (Full article...)