polyodon

Polyodon is a genus of paddlefishes in the family Polyodontidae, order Acipenseriformes. The genus has one living species, Polyodon spathula, commonly known as the American paddlefish. Paddlefishes are ancient ray-finned fish characterized by a long, flat rostrum and a broad, fusiform body.

Polyodon spathula has an elongated body with a distinctive paddle-shaped rostrum that can extend over a third of its body length. It possesses a small mouth on the underside and relies on filter feeding to capture zooplankton. The rostrum contains dense electroreceptors that help detect prey in turbid water. The fins include a large dorsal fin near the tail and a forked caudal fin.

The American paddlefish is native to North American river systems, especially the Mississippi River basin and its tributaries. It inhabits large, slow-moving rivers and freshwater reservoirs with abundant plankton, typically in deeper channels or backwaters.

Life history and ecology: Paddlefish are long-lived and reach reproductive maturity after several years. They are broadcast-spawners, migrating upriver to spawn in spring when conditions improve. Eggs are released into the current and hatch into free-swimming larvae that feed on zooplankton.

Conservation and human use: Overfishing for meat and eggs and habitat modification have reduced populations; many states regulate harvest; aquaculture and hatchery programs support industry.