Quadrula couchiana (Lea, 1860)

Rio Grande monkeyface



Taxonomy & Nomenclature

Synonym/s: Unio couchianus Lea, 1860 (original combination); Amphinaias couchiana (Lea, 1860)


Amphinaias was elevated from subgenus to genus by (Graf & Cummings, 2007). However, Williams et al. (2017) consider the species valid as Q. couchiana.


Conservation Status


Last record: 1898 (NatureServe, 2014)

IUCN RedList status: Critically Endangered



Texas, USA


Biology & Ecology










Bogan, A. E. (1996). Amphinaias couchiana. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. ( Downloaded on 12 June 2011.

Graf, D. L. and Cummings, K. S. (2007). Review of the systematics and global diversity of freshwater mussel species (Bivalvia: Unionoida). Journal of Molluscan Studies 73: 291-314.

Graf, Daniel L. and Cummings, Kevin S. (2021). A ‘big data’ approach to global freshwater mussel diversity (Bivalvia: Unionoida), with an updated checklist of genera and species. Journal of Molluscan Studies 87(1): eyaa034.

Haag, Wendell R. (2009). Past and future patterns of freshwater mussel extinctions in North America during the Holocene, pp. 107-128. In: Turvey, Samuel T. (ed.). Holocene Extinctions. Oxford, UK & New York, USA: Oxford University Press. xii + 352 pp.

Howells, R. G. (1996). Distributional surveys of freshwater mussels bivalves in Texas: progress report for 1995. Texas Parks and Wildlife Department, Management Data Series 125: Austin, Texas.

Howells, R. G. (2004). Last stand for mussels of the Rio Bravo? Eye on Nature (Texas Parks and Wildlife), spring, 2004: 2.

Howells, R.G., C.M. Mather, and J.A.M. Bergmann. (1997). Conservation status of selected freshwater mussels in Texas. Pages 117-126 in K.S. Cummings, A.C. Buchanan, C.A. Mayer, and T.J. Naimo (eds.). Conservation and Management of Freshwater Mussels II: Initiatives for the Future, Proceedings of a UMRCC Symposium, 16-18 October, 1995, St. Louis, Missouri. Upper Mississippi River Conservation Committee, Rock Island, Illinois.

Howells, R. G., R.W. Neck, and H.D. Murray. (1996). Freshwater Mussels of Texas. Texas Parks and Wildlife Press: Austin, Texas. 218 pp.

Johnson, R. I. (1999). Unionidae of the Rio Grande (Rio Bravo del Norte) system of Texas and Mexico. Occasional Papers on Mollusks, 6(77): 1-65.

NatureServe. (2014). NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available (Accessed: January 27, 2015).

Neck, R. W. (1984). Restricted and declining non-marine mollusks of Texas. Texas Parks and Wildlife Department Technical Series, 34: 1-17.

Turgeon, D.D., J.F. Quinn, Jr., A.E. Bogan, E.V. Coan, F.G. Hochberg, W.G. Lyons, P.M. Mikkelsen, R.J. Neves, C.F.E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F.G. Thompson, M. Vecchione, and J.D. Williams. (1998). Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland: 526 pp.

Williams, James D., Bogan, Arthur E., Butler, Robert S., Cummings, Kevin S., Garner, Jeffrey T., Harris, John L., Johnson, Nathan A. and Watters, G. Thomas. (2017). A revised list of the freshwater mussels (Mollusca: Bivalvia: Unionida) of the United States and Canada. Freshwater Mollusk Biology and Conservation 20: 33-58.


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