The fanshell (Cyprogenia stegaria) is a species of aquatic bivalve mollusk in the family Unionidae. This clam is native to the United States, where breeding populations remain in only three rivers. It is a federally listed endangered species of the United States.[2][3]

Fanshell
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Unionida
Family: Unionidae
Genus: Cyprogenia
Species:
C. stegaria
Binomial name
Cyprogenia stegaria
(Rafinesque, 1820)
Synonyms[4]
List
  • Cyprogenia irrorata (Lea, 1828)
  • Cyprogenia irrorata irrorata (Lea, 1828)
  • Cyprogenia irrorata pusilla Simpson, 1900
  • Obovaria stegaria Rafinesque, 1820
  • Unio irroratus Lea, 1828
  • Obovaria stegaria tuberculata Rafinesque, 1820
  • Obovaria stegaria fasciolata Rafinesque, 1820
  • Unio verrucosus albus Hildreth, 1828

This clam is known to be reproducing in the Clinch River in Tennessee and Virginia, and the Green and Licking Rivers in Kentucky. There may be a small reproducing population in the Tennessee River. There also may be some small populations remaining in several states, but these are not reproducing.[5]

This species is threatened by the loss and degradation of its habitat.[3]

Reproduction

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All Unionidae are known to use the gills, fins, or skin of a host fish for nutrients during the larval glochidia stage. Cyprogenia stegaria release into the water a conglutinate mimicking an Oligochaeta worm which contains the mussel's young. When a fish bites into the conglutinate lure, the young glochida are released and latch onto the fish's gills for nutrients.[5]

References

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  1. ^ Bogan, A.E. (1996). "Cyprogenia stegaria". IUCN Red List of Threatened Species. 1996: e.T6184A12566234. doi:10.2305/IUCN.UK.1996.RLTS.T6184A12566234.en. Retrieved 17 November 2021.
  2. ^ a b "Fanshell (Cyprogenia stegaria)". Environmental Conservation Online System. Retrieved 18 April 2023.
  3. ^ a b c 55 FR 25591
  4. ^ "Cyprogenia stegaria (Rafinesque, 1820)". Integrated Taxonomic Information System. Retrieved 18 April 2023.
  5. ^ a b Jones, J. W. and R. J. Neves. (2002). Life history and propagation of the endangered fanshell pearlymussel, Cyprogenia stegaria Rafinesque (Bivalvia:Unionidae). Journal of the North American Benthological Society 21(1) 76–88. doi:10.2307/1468301 JSTOR 1468301