# Pyganodon grandis > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Pyganodon_grandis > Markdown URL: https://mediated.wiki/source/Pyganodon_grandis.md > Source: https://en.wikipedia.org/wiki/Pyganodon_grandis > Source revision: 1330252322 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Species of bivalve This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations. (January 2023) (Learn how and when to remove this message) Pyganodon grandis Conservation status Least Concern (IUCN 3.1)[1] Secure (NatureServe)[2] Scientific classification Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: Unionida Family: Unionidae Genus: Pyganodon Species: P. grandis Binomial name Pyganodon grandis (Say, 1829) Synonyms[3] List Anodonta grandis Say, 1829 Anodonta grandis subsp. grandis Say, 1829 Anodonta grandis subsp. simpsoniana Lea, 1861 Anodonta grandis subsp. corpulenta Cooper, 1834 Anodonta lugubris Say, 1829 Anodonta inflata Rafinesque, 1831 Anodonta stewartiana Lea, 1834 Symphynota benedictensis Lea, 1834 Anodonta corpulenta Cooper, 1834 Anodonta plana Lea, 1834 Anodonta declivis Conrad, 1834 Anodonta gigantea Lea, 1838 Anodonta ovata Lea, 1838 Anodonta salmonia Lea, 1838 Anodonta decora Lea, 1838 Anodonta pepinianus Lea, 1838 Anodonta harpethensis Lea, 1840 Anodonta footiana Lea, 1840 Anodonta maryattana Lea, 1840 Anodonta globosa Lea, 1841 Anodonta virens Lea, 1852 Anodonta linnaeana Lea, 1852 Anodonta opaca Lea, 1852 Anodonta lewisii Lea, 1857 Anodonta danielsii Lea, 1858 Anodonta gesnerii Lea, 1858 Anodonta texasensis Lea, 1859 Anodonta kennicottii Lea, 1861 Anodonta simpsoniana Lea, 1861 Anodonta leonensis Lea, 1862 Anodonta dallasiana Lea, 1863 Anodonta bealei Lea, 1863 Anodon subangulata J.G. Anthony, 1865 Anodon subinflata J.G. Anthony, 1865 Anodon imbricata J.G. Anthony, 1865 Anodon micans J.G. Anthony, 1865 Anodon opalina J.G. Anthony, 1865 Anodon mcnielii J.G. Anthony, 1866 Anodon subgibbosa J.G. Anthony, 1866 Anodon inornata J.G. Anthony, 1866 Anodon nopalatensis Sowerby, 1867 Margaron benedictii Lea, 1870 Anodonta sulcata Küster, 1873 Anodonta somersii Call, 1880 Anodonta houghtonensis Currier in DeCamp, 1881 Anodonta grijalvae Morelet, 1884 Anodonta tabascensis Morelet, 1884 Anodonta dakota Frierson, 1910 Anodonta dakotana Utterback, 1915 Anodonta inflata subsp. viridis Rafinesque, 1831 Anodonta inflata subsp. fuscata Rafinesque, 1831 Anodonta inflata subsp. zonalis Rafinesque, 1831 Wikimedia Commons has media related to [Pyganodon grandis](https://commons.wikimedia.org/wiki/Category:Pyganodon_grandis). ***Pyganodon grandis***, or the **giant floater**, is a [species](/source/Species) of [freshwater mussel](/source/Freshwater_mussel), an [aquatic](/source/Aquatic_animal) [bivalve](/source/Bivalve) [mollusk](/source/Mollusk) in the family [Unionidae](/source/Unionidae), the river mussels. This species is fast-growing, large, and has a short lifespan. It is variable and widespread[4] across the [United States](/source/United_States) and southeastern [Canada](/source/Canada). Original description (Say 1829): "Shell very large, subovate; disk unequally wrinkled and undulated transversely, dark yellowish brown; umbo elevated; beak slightly elevated, with generally, two or three small sinuous, acute undulations; hinge margin slightly arquated, sometimes nearly rectilinear, somewhat angulated at its anterior termination, thence the edge descends by a nearly rectilinear, or slightly concave line to the anterior margin, which is considerably narrowed; sinus of the hinge margin concave; posterior margin widely rounded; within white margined, particularly before, with dusky." ## References 1. **[^](#cite_ref-1)** Cummings, K.; Cordeiro, J. (2012). ["*Pyganodon grandis*"](https://www.iucnredlist.org/species/189102/1919024). *[IUCN Red List of Threatened Species](/source/IUCN_Red_List)*. **2012** e.T189102A1919024. [doi](/source/Doi_(identifier)):[10.2305/IUCN.UK.2012-1.RLTS.T189102A1919024.en](https://doi.org/10.2305%2FIUCN.UK.2012-1.RLTS.T189102A1919024.en). Retrieved 8 June 2023. 1. **[^](#cite_ref-NS_2-0)** [NatureServe](/source/NatureServe). ["*Pyganodon grandis*"](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.117497/). *NatureServe Explorer*. Arlington, Virginia. Retrieved 30 December 2025. 1. **[^](#cite_ref-3)** ["*Pyganodon grandis* (Say, 1829)"](https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=568179). [Integrated Taxonomic Information System](/source/Integrated_Taxonomic_Information_System). Retrieved 8 June 2023. 1. **[^](#cite_ref-4)** ["MUSSELp | Mussel of the Month"](https://mussel-project.uwsp.edu/motm/2007/07-09.html). *mussel-project.uwsp.edu*. Retrieved 2023-08-03. - Binney, W.G. 1858. The complete writings of Thomas Say on the conchology of the United States. Bailliere Publ. NY - Haag, W. R. (2012). *North American Freshwater Mussels: Natural History, Ecology, and Conservation*. Cambridge University Press. [ISBN](/source/ISBN_(identifier)) [978-0521199384](https://en.wikipedia.org/wiki/Special:BookSources/978-0521199384) - Say, T. 1829. Descriptions of some new terrestrial and fluviatile shells of North America. New Harmony Disseminator of Useful Knowledge, New Harmony, Indiana. (see the description also in Binney's summary of Say's writing, 1858). This article incorporates text from this source, which is in the [public domain](/source/Public_domain). Taxon identifiers Pyganodon grandis Wikidata: Q3795937 BOLD: 30982 CoL: 4QNGF GBIF: 2287951 iNaturalist: 130983 IRMNG: 10460625 ISC: 110540 ITIS: 568179 IUCN: 189102 NAS: 2240 NatureServe: 2.117497 NCBI: 96932 Observation.org: 944640 Open Tree of Life: 2851599 WoRMS: 857389 Anodonta grandis Wikidata: Q3794955 BOLD: 642081 CoL: 7Q4XZ EoL: 449653 GBIF: 2287925 IRMNG: 11259624 ITIS: 79936 WoRMS: 571956 This Unionidae-related article is a stub. You can help Wikipedia by adding missing information. - [v](https://en.wikipedia.org/wiki/Template:Unionidae-stub) - [t](/source/Template_talk%3AUnionidae-stub) - [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Unionidae-stub) --- Adapted from the Wikipedia article [Pyganodon grandis](https://en.wikipedia.org/wiki/Pyganodon_grandis) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Pyganodon_grandis?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.