Mussel of the

Page last updated
3 February 2022

Mussel of the Month

The February 2022 Mussel of the Month is Anodontites patagonica. Anodontites is a genus of 26 species distributed from Central America to southern South America.

USNM 86609. Uruguay River, South America (type of Anodonta wymanii Lea).

In August of 2010, we featured Anodontites crispata as the Mussel of the Month. Back then, we didn’t have much to say about it, except to lament that Anodontites was an understudied, “garbage pail” genus. By that, we meant that it was a rich group of species of uncertain phylogenetic affinities in dire need of revision. Almost 12 years later, that assessment holds.

While the species of Anodontites have been listed multiple times recently — in various more-lumped or more-split arrangements (Haas, 1969; Simone, 2006; Graf & Cummings, 2007, 2021; Pereira et al., 2014; Mansur et al., 2020) — no more than 2 of 26 species of Anodontites have ever been included in a phylogenetic analysis (e.g., Bogan & Hoeh, 2000; Guerra et al., 2019; Huang et al., 2019).  And, in the most recent analyses, the phylogenetic positions of those two species do not support the monophyly of genus. This is well documented on the Anodonties Cladomics page on this site.

Hopefully, a thorough phylogenetic analysis that tests the monophyly and sister-relationships of Anodontites species was someone’s New Year’s Resolution this year!


Phylum Mollusca
Class Bivalvia
Subclass Palaeoheterodonta
Order Unionoida

Superfamily ETHERIOIDEA Deshayes, 1830
Family MYCETOPODIDAE Gray, 1840
Subfamily ANODONTITINAE Modell, 1942

Genus Anodontites Bruguière, 1792

Species Anodontites patagonica (Lamarck, 1819)
[+ Anodonta wymanii Lea, 1860]

To find out more about Anodontites and the classification of Neotropical freshwater mussels, check out:
  • Bogan, A. E. & W. R. Hoeh. 2000. On becoming cemented: evolutionary relationships among the genera in the freshwater bivalve family Etheriidae (Bivalvia: Unionoida) [in] E. M. Harper, J. D. Taylor & J. A. Crame, eds., The Evolutionary Biology of the Bivalvia. Geological Society, London, Special Publications, vol. 177. The Geological Society of London, London. pp. 159-168.
  • Graf, D.L. & K.S. Cummings. 2007. Review of the systematics and global diversity of freshwater mussel species (Bivalvia: Unionoida). Journal of Molluscan Studies 73: 291-314.
  • Graf, D.L. & K.S. Cummings. 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 (36 pp.).
  • Guerra, D., M. Lopes-Lima, E. Froufe, H.M. Gan, P. Ondina et al. 2019. Variability of mitochondrial ORFans hints at possible differences in the system of doubly uniparental inheritance of mitochondria among families of freshwater mussels (Bivalvia: Unionida). BMC Evolutionary Biology 19 (229): 1-22.
  • Haas, F. 1969. Superfamilia Unionacea. Das Tierreich, Leif. 88. Walter de Gruyter and Co., Berlin. 663 pp.
  • Huang, X.-C., J.-H. Su, J.-X. Ouyang, S. Ouyang, C.-H. Zhou & X.-P. Wu. 2019.Towards a global phylogeny of freshwater mussels (Bivalivia: Unionida): Species delimitation of Chinese taxa, mitochondrial phylogenomics, and diversification patterns. Molecular Phylogenetics and Evolution 130: 45-59.
  • Mansur, M.C.D., I.C. Miyahira, J.O. Arruda, T.N. Antoniazzi & D.M. Pimpão. 2020. Key to Unionida. [in] Damborenea, Rogers & Thorp, eds. Freshwater Invertebrates — Keys to Neotropical and Antarctic Fauna (4th edition) 5: 409-430.
  • Pereira, D., M.C.D. Mansur, L.D.S. Duarte, A.S. de Oliveira, D.M. Pimpão et al. 2014. Bivalve distribution in hydrographic regions in South America: historical overview and conservation. Hydrobiologia 735: 15-44.
  • Simone, L.R.L. 2006. Land and Freshwater Molluscs of Brazil: An Illustrated Inventory of the Brazilian Malacofauna, Including Neighboring Regions of South America, Respect to the Terrestrial and Freshwater Ecosystems. EGB. Fapesp. São Paulo. 390 pp.

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