A large mainly freshwater fish related to the sturgeon, with an elongated snout.
The plankton-feeding Polyodon spathula of the Mississippi basin, and the fish-eating Psephurus gladius of the Yangtze River, the only surviving members of the family Polyodontidae‘American paddlefish are mainly freshwater fish but can survive in brackish water.’
- ‘Since sturgeons and paddlefish have lost many traits of most bony fish - they lack scales and have a cartilaginous skeleton - their fossil records are very sparse.’
- ‘Within the Chondrostei, only sturgeons, bichirs and paddlefishes survive today, and many are threatened.’
- ‘The tail fin of most ray-finned fish, with the exception of sturgeons and paddlefish, is homocercal, nearly symmetrical about the midline.’
- ‘Within bony fishes, non-neopterygians (bichirs, paddlefish, and sturgeons) have relatively smaller brains than those in the vast majority of teleosts.’