Mussels of Texas

Unionid freshwater mussels (hereafter mussels) are a fascinating group of aquatic animals that evolved from marine mollusks over 400 million years ago. Mussels due to their cryptic morphology are often inconspicuous and can appear as passive bystanders to their environment. Despite their lackluster appearance, these fascinating animals play a vital role in freshwater ecosystems. Like most bivalves, mussels are filter feeders that eat algae, bacteria, and other material suspended in the water. Because of this mussels can influence how energy is exchanged between living and non-living components within streams, rivers and lakes. Mussels live on the stream bottom, often completely buried, making them difficult to see. In good habitat, mussels can form dense beds, which can provide and enhance habitat for other aquatic species, and serve as forage for animals such as fish, birds, mammals and even humans.

Mussels possess a unique reproductive life history, which includes a larval stage (glochidia) that is typically parasitic on the gills and/or fins of fish. Adult mussels move very little on their own and so their host-fish is the only means by which they can move long-distances, particularly upstream. Depending on the species, the nature of the mussel-host fish relationship can range from very specific (only certain types of fish are used) to general (multiple types of fish are used). Finally, mussels can be long-lived (some up to 100 years or more), but for species in Texas longevity is likely less than this.

Of the approximately 297 mussel species known to occur in North America, nearly three-quarters are considered imperiled. In Texas the fauna is but a shadow of its former splendor. Of the 51 species known to reside within the state 15 are considered state-threatened and of these 11 are now being reviewed for listing under the U.S. Endangered Species Act. 

So why Mussels of Texas? The accurate identification of freshwater mussels or any other species for that matter, and understanding their distribution is essential for not only enjoying them in nature but also for aiding in their conservation and management. For mussels, accurate identification is challenging due to similarities in shell morphology between species. Similarly, information on the distribution of mussels in Texas has been largely unavailable or based on small datasets that have not accurately portrayed the true distribution of a given species.

To that end, MoTX is an interactive database that includes distribution and species information for all 51 species in Texas to assist the general public, resource managers, and scientists/conservationists, with appreciating, managing and protecting this fascinating and important resource.

MoTX, to include all content and database are under a license, and the copyrights are owned by NRI, therefore users should use the following citation whenever using content or data from this website/database other than contributed data:

Randklev C.R., C. Robertson, C.H. Smith, A.H. Kiser, N.B. Ford, M. Hart, J. Khan, M. Fisher, and R. Lopez. (2023). Mussels of Texas Project Database, Version 2.0.