Either of two species (family Polyodontidae) of archaic freshwater fishes with a paddlelike snout, wide mouth, smooth skin, and cartilaginous skeleton.
It feeds with mouth gaping open, gill rakers straining plankton from the water. The American paddlefish, or spoonbill ( Polyodon spathula ), is greenish or gray and averages 40 lbs (18 kg); it lives in the open waters of the Mississippi basin. The other known species ( Psephurus gladius ), a larger fish with a more slender snout, inhabits the Chang (Yangtze) River basin. The flesh of both species resembles catfish ; the roe can be made into caviar .