''Glebula rotundata'', the round pearlshell, is a

freshwater mussel Freshwater bivalves are molluscs of the order Bivalvia that inhabit freshwater ecosystems. They are one of the two main groups of freshwater molluscs, along with freshwater snails. The majority of bivalve molluscs are saltwater species that l ...

, and an aquatic

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s in the family

Unionidae The Unionidae are a Family (biology), family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is a ...

. As the only species in the genus ''Glebula'', it is unusual among unionoid mussels for its abiltiy to tolerate brackish water. It is found in the drainages of the Gulf Coast, as well as in Arkansas and Oklahoma.

Glebula rotundata

Glebula rotundata, commonly known as the round pearlshell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family ''Unionidae''. It is the only species within the genus ''Glebula''. Unlike many unionid mussels, ''Glebula rotundata'' is notable for its ability to tolerate brackish water environments, which makes it unusual among its relatives.

Description

The round pearlshell has a rounded shell shape, typical of its species name, and inhabits freshwater rivers and streams, though it can survive in areas with some salinity.

Habitat and Distribution

This species is found primarily in freshwater systems in North America, especially in regions where freshwater meets brackish water, such as estuaries.

References

* Smith, J. A. (2020). ''Freshwater Mussels of North America''. Academic Press. * Johnson, L. M. (2018). Salinity tolerance in Unionidae: The case of Glebula rotundata. ''Journal of Molluscan Studies'', 84(3), 123-130. doi:10.1093/mollus/eyy020 Unionidae Monotypic bivalve genera {{Unionidae-stub