Mussel of the

Page last updated
6 July 2017

Mussel of the Month

The June 2017 Mussel of the Month is Virgus beccarianus. Virgus is a monotypic genus endemic to New Guinea.

Virgus beccarianus
AMS 126464. Brown River, 35 mi from Port Moresby, Papua New Guinea.

Once again, our Mussel of the Month is classified in a monotypic genus. This has been a pattern this year (e.g., Plectomerus, Pseudodontopsis, Protunio, Elliptoideus) as we work our way through the genera we have not yet covered. The classification of Virgus has actually been pretty straight-forward. Simpson (1900) introduced the genus with Unio beccarianus as the type species, and everyone since then has agreed (e.g., McMichael, 1956; McMichael & Hiscock, 1958; Haas, 1969; Graf & Cummings, 2007; Walker et al., 2014). But, that is about the extent of our knowledge: there is a mussel from New Guinea that goes by that name. We know of fewer than 20 museum lots (including the types in Italy, which we haven’t handled), and there is no IUCN Red List assessment for this species.

V. beccarianus is one of eleven species (in seven genera) of freshwater mussels found on New Guinea and nearby islands. Two of the species, in the genus Haasodonta, are currently regarded as unionids, but the rest are classified in the family Hyriidae. Haasodonta, Microdontia, and Virgus are endemic to New Guinea (and adjacent islands), but the genera Alathyria, Hyridella, Velesunio, and Westralunio are also represented on Australia. In fact, two species (see table below) are shared between New Guinea and Australia.

species eastern western New Guinea
Alathyria pertexta X   X
Haasodonta fannyae     X
Haasodonta vanheurni     X
Hyridella guppyi     X + Solomon Ids.
Hyridella misoolensis     X + Misool Id.
Microdontia anodontaeformis     X
Velesunio sentaniensis     X
Velesunio wilsonii X X X
Virgus beccarianus     X
Westralunio albertisi     X
Westralunio flyensis     X



Phylum Mollusca
Class Bivalvia
Subclass Palaeoheterodonta
Order Unionoida

Family HYRIIDAE Swainson, 1840
Subfamily HYRIINAE s.s.
Tribe HYRIDELLINI McMichael, 1956 (1934)

Genus Virgus Simpson, 1900

Species Virgus beccarianus (Tapparone Canefri, 1883)

To find out more about Virgus and the freshwater mussels of New Guinea, check out:
  • 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.
  • Haas, F. 1969. Superfamilia Unionacea. Das Tierreich, Leif. 88. Walter de Gruyter and Co., Berlin. 663 pp.
  • McMichael, D.F. 1956. Notes on the freshwater mussels of New Guinea. Nautilus 70(2): 38-48.
  • McMichael, D.F. & I.D. Hiscock. 1958. A monograph of the freshwater mussels (Mollusca: Pelecypoda) of the Australian region. Australian Journal of Marine and Freshwater Research 9(3): 372-508.
  • Simpson, C.T. 1900. Synopsis of the naiades, or pearly fresh-water mussels. Proceedings of the United States National Museum 22: 501-1044.
  • Walker, K.F., H.A. Jones & M.W. Klunzinger. 2014. Bivalves in a bottleneck: Taxonomy, phylogeography and conservation of freshwater mussels (Bivalvia: Unionoida) in Australasia. Hydrobiologia 735: 61-79.
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