Paddlefish

American paddlefish, Polyodon spathula

Paddlefish are a family of ray-finned fish belonging to the order Acipenseriformes. There are 8 genera in total, the two main species being the American and Chinese paddlefish, and the other 5 being fossil genera.

Aside from the American paddlefish, there is a hypothetical extinct species called "Polyodon" tuberculata, but there's not a lot of information about it.

Description

Just like sturgeons, paddlefish have a cartilaginous skeleton. They also have a unique feature; their notochord is still there despite growing up.

Classification

• Family Polyodontidae Bonaparte, 1838 (paddlefish)
  • Genus †Protopsephurus Lu, 1994
  • Genus †Paleopsephurus MacAlpin, 1941a
  • Genus †Pugiopsephurus Hilton et al., 2023
  • Genus †Parapsephurus Hilton et al., 2023
  • Subfamily Polyodontinae Grande & Bemis, 1991 non Pflugfelder, 1934
    • Genus †Crossopholis Cope, 1883
    • Genus Polyodon Lacépède, 1797 (American paddlefish)
    • Genus †Psephurus Günther, 1873 (Chinese paddlefish)

Habitat

Chinese paddlefish, Psephurus gladius

P. spathula

See the main article: American paddlefish

The American paddlefish (Polyodon spathula) once lived in oxbow lakes, big rivers, and more. However, it is now limited to the Mississippi possibly due to overfishing.

P. gladius

See the main article: Chinese paddlefish

The Chinese paddlefish (Psephurus gladius) lived in the Yangtze and Yellow Rivers while it was still alive, but now, it's extinct.

Gallery

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  Restoration of Crossopholis

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  Holotype of Parapsephurus, note that the snout is separated

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  An American paddlefish swimming

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  Restoration of the Chinese paddlefish

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  Fossil of Protopsephurus

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  Restoration of Protopsephurus along with other fishes of the Yixian Formation

Paddlefish Media

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  General morphology of paddlefish

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  Closeup of the head, showing the presence of electrorecepting organs (ampullae of Lorenzini)

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  Restoration of the Cretaceous †Protopsephurus

References

1. "Chinese paddlefish, one of world's largest fish, declared extinct". Animals. 8 January 2020.
2. Grande, Lance; Jin, Fan; Yabumoto, Yoshitaka; Bemis, William E. (2002). "Protopsephurus liui, a well-preserved primitive paddlefish (Acipenseriformes: Polyodontidae) from the Lower Cretaceous of China". Journal of Vertebrate Paleontology.
3. "†Crossopholis Cope 1883". Paleobiology Database.