Polyodon spathula, commonly known as the American paddlefish, is an ancient freshwater species found in the Mississippi River basin. Notable for its long, paddle-shaped snout, it uses electroreceptors to detect plankton, its primary food source. The species is a filter feeder and plays a crucial role in maintaining aquatic ecosystems.

Polyodon spathula, commonly known as the American paddlefish, is native to the Mississippi River Basin in the United States. This includes major rivers such as the Mississippi, Missouri, and Ohio rivers, as well as their tributaries. The geographical distribution extends across states like Louisiana, Missouri, Illinois, and Kentucky.

The American paddlefish inhabits large, slow-moving rivers with abundant plankton. It prefers open waters in river channels, backwaters, and oxbows. These environments are typically characterized by turbid waters, moderate to slow currents, and a substrate composed of mud, sand, or gravel.

Polyodon spathula is primarily a filter feeder, using its gill rakers to strain zooplankton and phytoplankton from the water. This ecological niche is crucial as it helps maintain the balance of plankton populations in its habitat. The paddlefish's long snout, or rostrum, is believed to play a role in detecting prey through electroreception, aiding its survival in turbid waters.