Mussel of the

Page last updated
30 July 2007

Mussel of the Month

The August 2007 Mussel of the Month is Popenaias popeii. Popenaias is generally a Central American genus found from Honduras north to Texas.

Popenaias popeii
USNM 85895. Rio Salado, Nueva Leon, Mexico. Berlandier! (type)

Popenaias popeii is the only species of the genus to be found as far north as the United States. The other two species of the genus are known from Mexico and further south in Mesoamerica. In general, Central American species in the Unionidae are currently treated as belonging to genera endemic (13) to that area, but Popenaias is one of the few (5) genera to straddle the Nearctic and Neotropical regions. Other Mesoamerican species have closer affinities to South America and are classified in the family Mycetopodidae.

Popenaias is generally similar (shells and soft-parts) to Elliptio, but the former has a distinct breeding period, spawning in the boreal winter rather than the summer. Winter breeding among members of the Pleurobemini caused quite a problem for early classifications that relied heavily on the "brooding period" as a taxonomic character.


Phylum Mollusca
Class Bivalvia
Subclass Palaeoheterodonta
Order Unionoida

Superfamily UNIONOIDEA Rafinesque, 1820

Family UNIONIDAE s.s.
Subfamily AMBLEMINAE Rafinesque, 1820
Tribe PLEUROBEMINI Hannibal, 1912

Genus Popenaias Frierson, 1927

Species Popenaias popeii (Lea, 1857)

For more information about Popenaias and breeding period, check out:
  • Ortmann, A.E. 1912. Notes upon the families and genera of the najades. Annals of the Carnegie Museum 8: 222-385.
  • Heard, H.H. & R.H. Guckert. 1970. A re-evaluation of the Recent Unionacea (Pelecypoda) of North America. Malacologia 10(2): 333-355.
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