Mussel of the

Page last updated
1 May 2009

Mussel of the Month

The May 2009 Mussel of the Month is Germainaia geayi. Germainaia is a possibly bogus genus of one species reported from Madagascar.

Germainaia geayi
MNHN 1704. Madagascar (lectotype).

We described Germainaia as a new genus last month (Graf & Cummings, 2009). As we said on our project page about the freshwater mussels of Madagascar:

"Germainaia geayi is known only from 2.5 specimens with the vague locality "Madagascar." The species was originally described as "Unio (Nodularia) geayi" by Germain (1911). Most subsequent treatments, however, have put G. geayi in the genus Coelatura. Unio, Nodularia, and Coelatura are all genera assigned to the family Unionidae. However, we aren't completely convinced that the available material actually belongs to that family.

Hyridella depressa"Upon first inspection of the type when we were in Paris in 2006, that specimen struck us as more similar to a hyriid, like one might find in Australia or New Zealand (such as Hyridella depressa). While members of the Unionidae and the Hyriidae can be readily distinguished based upon their soft-anatomy, we have had trouble when it comes to family-level shell synapomorphies.

"Given the scanty material available for G. geayi and the conflicts it presents to going biogeographical hypotheses, we regard Germainaia as incertae sedis at the family level."


Phylum Mollusca
Class Bivalvia
Subclass Palaeoheterodonta
Order Unionoida

Family UNIONIDAE ?? Rafinesque, 1820
[incertae sedis]

Genus Germainaia Graf & Cummings, 2009

Species Germainaia geayi (Germain, 1911)

For more information about Germainaia and the freshwater mussels of Madagascar:
  • Germain, L. 1911. Les Unionidae de Madagascar. Bulletin du Muséum National d'Histoire Naturelle, 17: 136-140.
  • Graf, D.L. & K.S. Cummings. 2009. Actual and alleged freshwater mussels (Mollusca: Bivalvia: Unionoida) from Madagascar and the Mascarenes, with description of a new genus, Germainaia. Proceedings of the Academy of Natural Sciences of Philadelphia 158: 221-238.
NSF icon MUSSEL icon
"Making the world a better place, one mollusk at a time."