American Paddlefish

Polyodon spathula

The American paddlefish (Polyodon spathula) is a large ancient fish of the Mississippi River basin and connected rivers and reservoirs. Its long paddle-shaped rostrum is packed with sensory organs that help it detect tiny prey in open water. Unlike many big river fish, adult paddlefish feed mainly by swimming with the mouth open and filtering zooplankton. The body is smooth and mostly scaleless, with a cartilaginous skeleton and a deeply forked tail that give it a sharklike outline.

Human management includes regulated sport harvest, hatchery propagation, restocking, and aquaculture for meat and roe. Paddlefish need large volumes of clean, oxygen-rich water and access to plankton or carefully developed feeds, so they are not practical home aquarium fish. Dams that block spawning migrations, channel alteration, and overharvest for caviar have shaped many recovery plans. Hatcheries often collect broodstock, incubate eggs, and release young fish into suitable river systems while agencies track harvest limits and population age structure.