Critically Endangered
Pallid sturgeon
Scaphirhynchus albus
The pallid sturgeon is an endangered species of ray-finned fish, endemic to the waters of the Missouri and lower Mississippi River basins of the United States.
Appearance
Pallid sturgeon are much paler in coloration with grayish white backs and sides, while shovelnose sturgeon are brown. Pallid sturgeon turn whiter as they age and younger specimens are easily confused with adult shovelnose sturgeon since they are similar in color. Like the shovelnose sturgeon, their tails are heterocercal, with the top tail fin being longer than the bottom fin, though this is more pronounced in pallid sturgeon.
Although visually similar, the shovelnose sturgeon is much smaller and usually weighs no more than 5 pounds (2.3 kg). Named for its pale coloration, it is closely related to the more common shovelnose sturgeon (Scaphirhynchus platorynchus), but is much larger, averaging between 30 and 60 inches (76 and 152 cm) in length and 85 pounds (39 kg) in weight at maturity.
Range and habitat
The pallid sturgeon's historical range spanned the entire Missouri River and into the Mississippi River. Historically, the species was rare to nonexistent in the upper Mississippi, probably due to a lack of proper habitat. Currently, the species is considered imperiled throughout its entire range.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Breeding
One study of nine females indicated that they begin egg development between the ages of 9 and 12 years, but do not reach reproductive maturity until they are 15 years old. Reproduction does not take place every year. The average interval between spawnings is three years, although other studies suggest an interval as long as 10 years.
Spawning usually takes place May to July. Prior to the construction of dams on the Missouri, pallid sturgeon migrated hundreds of miles upstream to spawn, and sought out rocky or hard surfaces to deposit hundreds of thousands of eggs.
In crisis
Fish and Wildlife Service placed the pallid sturgeon on its endangered species list because few young individuals had been observed in the preceding decade and sightings had greatly diminished. The species is now rarely seen in the wild. It was the first fish species in the Missouri River drainage area to be listed as endangered, and a loss of its habitat is thought to be responsible for its decline. Efforts to prevent the species from becoming extinct have had modest success.
Even though never believed to be common, pallid sturgeon populations rapidly declined during the late 20th century and the species was listed as endangered on September 6, 1990. The U.S. Government and most of the states with pallid sturgeon populations have commenced restoration efforts to save the species from extinction.
CITES lists this taxon on Appendix II. Confirm the current appendix on the CITES checklist.
Pallid sturgeon is Critically Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Pallid sturgeon, Wikidata item Q921461. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
