Unionoida cum Grano Salis

Page last updated
9 August 2018

Unionoida cum Grano Salis

Update History

The Unionoida cum Grano Salis pages are occasionally updated to reflect taxonomic progress. The purpose of this page is to record the changes that were made to the pages with each update.
9 August 2018

Another 4 months go by, and there are more important changes to incorporate. Among a few others, three key works have driven this update:

Updates to Nearctic Richness. — A single new species was described, Cyclonaias necki. Regional richness increased from 309 to 310 species.

Updates to Indotropical Richness. — Three species of Scabes (S. anceps, S. mandarinus, and S. scobinatus) and Pseudobaphia persculpta were elevated from synonymy. Harmandia munensis was synonymized another newly elevated species, Trapezoideus comptus. Lamprotula similaris was sunk in Gibbosula polysticta. Five gains and 2 losses raised regional richness by 3, to 246 species.

There were no changes to species richness in other regions.

The biggest change to the Unionoida was splitting of Margaritifera into three genera (Margaritifera, Cumberlandia, and Pseudunio) and tranferring Gibbosula from the Unionidae to the Margaritiferidae.

In all, with this update we have gained four species, bring the global species richness of freshwater mussels to 927 species.


30 March 2018

It was only about 4 months ago that we did the 1st update in more than 3 years, but the pace of freshwater mussel revisions has sped up, and we have been motivated to try and keep up. This updated follows a few key works:

Updates to Nearctic Richness. — In addition to gaining some new genera (Cambarunio, Leaunio, Paetulunio, and Sagittunio) and raising at least one genus from synonymy (Pseudodontoideus), five new species were described (Cambarunio hesperus, Leaunio pataecus, Sagittunio ortmanni, Strophitus pascagoulaensis, and S. williamsi) and two were resurrected (C. dactylus and C. jonesii). These seven species raises the known Nearctic richness from 302 to 309.

Updates to Palearctic Richness. — Four species were raised from synonymy (Anodonta exulcerata, Sinanodonta calipygos, S. japonica, and S. lauta), raising the known richness from 61 to 65.

Updates to Indotropical Richness. — Cuneopsis kiangsiensis has never been included on our list of valid species before because it had been overlooked by previous workers. Eight more species are resurrected from synonymy (Lanceolaria, fruhstorferi, L. laevis, S. elliptica, S. jourdyi, and S. lucida), and three introduced Nearctic species are recognized in the Yangtze (Amblema plicata, Potamilus alatus, and Reginaia ebena).

There were no changes in species richness in the other regions.

In all, we have gained 17 species of Unionidae, increases our current tally from 906 to 923. There are no updates to the known richness of the other five families at this time. However, we know of additional changes that will be published this year, so expect another update in summer 2018!

4 December 2017

There have been a number of big changes to the species- and genus-level taxonomy of freshwater mussels, and we have updated the MUSSEL Project Database accordingly. There have been several key publications over the last couple years.

Updates to Nearctic Richness. — There was no change in overall richness. The total number of species before this update was 302, and it still is. However, That is because the 13 species that have been synonymized away (Anodonta dejecta, Elliptio cylindracea, E. errans, E. hepatica, E. judithae, E. raveneli, E. waccamawensis, Fusconaia askewi, F. lananensis, Lampsilis fullerkati, Pleurobema altum, Toxolasma mearnsi, Villosa perpurpurea) were exactly match by 12 species added to the list. Those 13 include Reginaia apalachicola, which we had previously labeled as "fossil", and 12 former synonyms now recognized as valid (Anodontiodes denigrata, Cyclonaias archeri, C. mortoni, Epioblasma aureola, E. curtisii, E. gubernaculum, E. perobliqua, E. walkeri, Fusconaia chunii, Lampsilis brittsi, Venustaconcha troostensis, Villosa sima).

Updates to Neotropical Richness. — 217 species, no change.

Updates to Afrotropical Richness. — 79 species, no change.

Updates to Palearctic Richness. — Species richness increased from 57 to 61 species. Six former synonyms were elevated to valid species (Potomida acarnanicus. P. semirugata, Unio bruguierianus, U. elongatulus, U. foucauldianus, U. ionicus), but two other species were sunk into synonym (Margaritifera togakushiensis & Unio terminalis).

Updates to Indotropical Richness. — Species richness gained 15 species overall, up to 234 from 219. Eleven new species were described (Anemina ussuriensis, Gibbosula nanningensis, Lamellidens brandtii, Lanceolaria bogani, Parreysia canefrii, Pseudodon bogani, P. manueli, Radiatula mouhoti, Scabies songkramensis, Trapezoideus nesemanni, T. panhai) and 8 more were elevated from synonymy (Lamellidens savadiensis, Nodularia nuxpersicae, Parreysia vulcanus, Radiatula myitkyinae, Trapezidens dolichorhynchus, Trapezoideus foliaceus, T. peguensis, T. subclathratus). Four formerly valid species were demoted to synonyms (Lamellidens indawgylensis, Parreysia mandelayensis, Physunio ferrugineus, P. micropteroides).

Updates to Australasian Richness. — 30 species, no change.

Since 15 November 2014 the world acquired 39 freshwater mussel species that weren't on our list, and taxonomic research led to 21 species being removed from our tally. That is a net increase of 18 species, from 888 to 906.

15 November 2014

During the summer and fall of 2014, our effort was spent on getting all of our taxonomic data into shape for submission to the ITIS database. The nuts and bolts of most of this work had been completed during the previous year, but the results of a couple new publications had to be incorporated.

Updates to Nearctic Richness. — The region gained a single species by elevating Quadrula nobilis from synonymy. This increased the total richness from 301 to 302.

Updates to Neotropical Richness. — Neotropical species richness increased from 185 to 217 (+32 species). Species from several genera were pulled from synonymy and are now recognized as valid: Castalia crosseana, C. nehringi, C. orinocoensis, Castaliella quadrata, C. schombergiana, 21 species of Diplodon, Anodontites ihering, A. lucida, A. schombergianus, A. solenidea, Monocondylaea costulata, M. franciscana, M. juspidea, M. parchappii, and Tamsiella schoteriana. However, three formerly recognized species were demoted to synonymy: Anodontites napoensis, Rhidipidodonta demeraraensis, and R. guayanensis. In fact, all the Rhipidodonta were moved to Diplodon.

Updates to Afrotropical Richness. — 79 species, no change.

Updates to Palearctic Richness. — The number of Palearctic freshwater mussel species increased from 56 to 57 by removing Nodularia mongolica from the synonymy of Unio crassus.

Updates to Indotropical Richness. — Our new assessment of the Indotropics had a net 6 fewer species, dropping from 225 to 219. Although five newly described species were added (Acuticosta jianghanensis, Lamprotula linae, Lanceolaria yueyingae, Sinanodonta qingyuani, and Solenaia neotriangularis) and three more were pulled from synonymy (Aculamprotula grandidens, Lamellidens rhadinaeus, and Parreysia viridula), 14 more were subtracted through synonymy: Acuticosta ovata, Arconaia huaihensis, A. mutica, Lamprotula microstricta, L. leleci, L. mansuyi, Lepidodesma aligera, Chamberlainia paviei, Physunio semialatus, Pseudodon solidus, Scabies chinensis, S. longata, Solenaia oleivorus, and Unionetta fabagina.

Updates to Australasian Richness. — Australasia lost three species, dropping to 30. Both Cucumerunio websteri and Echyridella lucasi were synonymized with other valid species, and Velesunio ovatus was removed outright as a nomen dubium.

Overall, the world gained 25 new freshwater mussels between 11 August 2013 and 12 November 2014, increasing the global species richness from 862 to 887. Most of the increases came from South America and China.

11 August 2013

During the summer of 2013, we endeavored to prepare our taxonomic data for inclusion in the ITIS database. This resulted in an update of the data in the MUSSELpdb and an overdue over-haul of these Unio cum Grano Salis pages. Some of the works that precipitated the changes listed below are:

  • Campbell, D.C. & C. Lydeard. 2012. The genera of the Pleurobemini (Bivalvia: Unionidae: Ambleminae). American Malacological Bulletin 30: 19-38.
  • Graf, D.L. & K.S. Cummings. 2011. Freshwater mussel (Mollusca: Bivalvia: Unionoida) richness and endemism in the ecoregions of Africa and Madagascar based on comprehensive museum sampling. Hydrobiologia 678: 17-36 + supplemental material.
  • Inoue, K., D.M. Hayes, J.L. Harris & A.D. Christian. 2013. Phylogenetic and morphometric analyses reveal ecophenotypic plasticity in freshwater mussels Obovaria jacksoniana and Villosa arkansasensis (Bivalvia: Unionidae). Ecology and Evolution doi: 10.1002/ece3.649: 14 pp.
  • Ouyang, J., X. Wu, S. Ouyang, S. Li & D. Zhao. 2011. Phylogenetic analysis of some Chinese freshwater Unionidae based on mitochondrial COI sequences. Journal of Conchology 40(5): 543-548.
  • Williams, J.D., R.S. Butler & J.M. Wisniewski. 2011. Annotated synonymy of the Recent freshwater mussel taxa of the families Margaritiferidae and Unionidae described from Florida and drainages contiguous with Alabama and Georgia. Bulletin of the Florida Museum of Natural History 51(1): 1-84.

Nearctic. — Overall, North America lost 1 species, bringing the total richness down to 301. However, this net change obscures a number of changes. Epioblasma rangiana, Elliptio occulta and Truncilla cognata were added, and Elliptio buckleyi, Elliptio waltoni, Obovaria jacksoniana and Anodontoides denigrata were removed from the list of Nearctic taxa. In addition, Villosa arkansasensis and V. choctawensis moved to the genus Obovaria, Pleurobema gibberum moved to Pleuronaia, and Quincuncina mitchelli moved to Fusconaia. All of these taxa belong to the family Unionidae.

Neotropical. — Cental and South America had a net gain of one species, to 185. Anodontites depexus and A. pittieri were added, and Truncilla cognata was removed to the Nearctic region. Anodontites belongs to the family Mycetopodidae.

Afrotropical. — Aspatharia mabillei, A. tawaii and A. tristis were removed from the Africa list, bringing the species richness down to 79. The genus Aspatharia belongs to the Iridinidae.

Palearctic. — The Palearctic region held steady at 56 species. Microcondylaea bonellii is now listed as M. compressa.

Indotropical. — The Indotropical region had a net gainfive species, up to 225. Lamprotula leleci, Solenaia carinatus, S. oleivorus, S. rivularis, and Lamellidens mainwaringi were pulled from the syonymy of other Indotropical freshwater mussel species. Lanceolaria bilirata was split from L. oxyrhyncha (now restricted to the Palearctic region). All of these species belong to the Unionidae.

Australasia. — No change, 33 species.

There was a net gain of 3 species (859 + 3 = 862) to our tally of the global diversity of freshwater mussels. In addition, we made 17 corrections to spelling, publication dates, species order, etc. that didn't change the tallies.

4 October 2011

The occasion of updating the classification used on this site led to an update of Unionoida cum Grano Salis. The two major works that led to the latest changes are:

  • Khalloufi et al. 2011. The unionids of Tunisia: taxonomy and phylogenetic relationships, with description of Unio ravoisieri Deshayes, 1847 and U. durieui Deshayes, 1847. Journal of Molluscan Studies 77: 103-115.
  • Whelan, N.V., A.J. Geneva & D.L. Graf. 2011. Molecular phylogenetic analysis of tropical freshwater mussels (Mollusca: Bivalvia: Unionoida) resolves the position of Coelatura and supports a monophyletic Unionidae. Molecular Phylogenetics and Evolution 61: 504-514.

Nearctic. — Gained 1 species because of the introduced Sinanodonta woodiana, up to 302.

Neotropical. — Went from 183 to 184 with the addition of the introduced Sinanodonta woodiana.

Afrotropical. — No change (82).

Palearctic. — Gained 1, up to 56. Unio durieui was added to Europe, as was the introduced Sinanodonta woodiana (known before from elsewhere in the Palearctic).

Indotropical. — No change (220).

Australasia. — No change (33).

5 January 2011

We have updated our results to reflect progress published since our original checklist (Graf & Cummings, 2007). Some of the key works include:

  • Araujo, R., J. Reis et al. 2009. Las náyades de la península Ibérica. Iberus 27: 7-72.
  • Bogan, A.E. 2010. Mollusca-Bivalvia Checklist. Freshwater Animal Biodiversity Project. [This website lists all the freshwater bivalves tallied in Bogan (2007). The freshwater mussels list largely follows our checklist (Graf & Cummings, 2007).]
  • 2010. Fauna Europa.
  • Kondo, T. 2008. Monograph of Unionoida in Japan (Mollusca: Bivalvia). Special Publication of the Malacological Society of Japan (3). 69 pp.
  • Williams, J.D., A.E. Bogan, J.T. Garner. 2008. Freshwater Mussels of Alabama and the Mobile Basin in Georgia, Mississippi and Tennessee. University of Alabama Press, Tuscaloosa. 908 pp.

Nearctic. — Lost a net 1 species, dropping from 302 to 301.

Neotropical. — Lost 3, dropping from 186 to 183.

Afrotropical. — No change.

Palearctic. Gained 7, jumping from 48 to 55.

Indotropical. — Gained 1, going from 219 to 220.

Australasian. — no change.

Overall, there was a net gain of four species since the last update, raising the total to 858.

  • Bogan, A.E. 2007. Global diversity of freshwater mussels (Mollusca, Bivalvia) in freshwater. Hydrobiologia 595: 139-147.
  • 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.
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