paddlefish

fish family

Also known as: Polyodontidae, duckbill cat

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Last updated

July 23, 2026

Quick Summary

Paddlefish are archaic freshwater fish belonging to the family Polyodontidae. They are characterized by a paddle-shaped snout, a wide mouth, smooth skin, and a cartilaginous skeleton, making them relatives of the sturgeon.1

The American paddlefish (Polyodon spathula) is greenish or gray, averaging about 18 kg (40 pounds) but capable of reaching up to 2.2 meters (7.2 feet) and 90.7 kg (200 pounds). It inhabits the Mississippi River basin and parts of southern Canada. This species is classified as vulnerable by the IUCN.1

The Chinese paddlefish (Psephurus gladius) was larger, reaching up to 3 meters (9.8 feet) and weighing 300 kg (661.4 pounds). It inhabited the Yangtze River basin and was declared extinct in 2020.1

Paddlefish feed by gaping their mouths open, using their gill rakers to strain plankton from the water. Their roe is used to make caviar.1

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chondrostean
>paddlefishes (family Polyodontidae) in the order Acipenseriformes. Some taxonomies also include the bichirs and reedfish of Africa (order Polypteriformes), but this remains a subject of much debate. Many taxonomists argue that the subclass Chondrostei is a paraphyletic group—that is,
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>paddlefishes (family Polyodontidae) in the order Acipenseriformes. Some taxonomies also include the bichirs and reedfish of Africa (order Polypteriformes), but this remains a subject of much debate. Many taxonomists argue that the subclass Chondrostei is a paraphyletic group—that is,
Read More

paddlefish
…paddlefish makes up the family Polyodontidae in the order Acipenseriformes. A paddlefish feeds with its mouth gaping open and its gill rakers straining plankton from the water through its gills.
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…paddlefish makes up the family Polyodontidae in the order Acipenseriformes. A paddlefish feeds with its mouth gaping open and its gill rakers straining plankton from the water through its gills.
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chondrostean
Annotated classification
Polyodontidae (paddlefishes)Snout greatly elongated, paddle-shaped, and supported by stellate ossicles. In Polyodon the skin is smooth except for a few scales at the base of the tail. Psephurus additionally has tiny deeply embedded scales all over the body. The mouth is subterminal but large. The…
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Polyodontidae (paddlefishes)Snout greatly elongated, paddle-shaped, and supported by stellate ossicles. In Polyodon the skin is smooth except for a few scales at the base of the tail. Psephurus additionally has tiny deeply embedded scales all over the body. The mouth is subterminal but large. The…
Read More