• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Coastal Prairie ChapterCoastal Prairie Chapter
  • Home
  • Join Us
    • Become a Texas Master Naturalist™!
    • Spring 2025 Training Class Information and Registration
    • Frequently Asked Questions
    • Transfer Your Membership to the TMNCPC
  • About Us
    • Contact Us
    • TMN State Webpage
    • All About the Texas Master Naturalist Logo
    • Certification pins and Service Pins
  • Newsletter
  • Calendar
    • All Events
    • Public Outreach Events
  • Seabourne creek
  • Volunteer
    • VSP – Signature Projects
    • Seabourne Creek Nature Park
    • Fort Bend County Fair “AgTivity Barn”
    • Chapter Administration
    • Coastal Prairie Conservancy & Other Prairie Organizations
    • Recycling Local Facilities
    • “Citizen Scientist”
    • Texas State Parks
    • Nature Trackers with TPWD
  • Learn
    • TMNCPC Nature Brochures
    • Animal and Plant ID Guides & Apps
    • Native Plant and Prairie Gardens Support Wildlife
    • Planting for Pollinators
    • Links to Other Websites
    • Green Home and Garden Tips
    • Beneficial Insects Flyer
  • Members
    • Members Only
    • VMS Log-in Page
    • How to Use VMS to Log in your hours
    • SignUpGenius
Search

Mussels: Texas’ Biofilters

January 23, 2023 by Shannon Westveer

During Spring Training 2022, Dr. Charles Randklev of Texas A&M National Resources Institute Dallas asked a class of TMNCPC members a critical question regarding the generally unseen mussels occurring in our state: Why care? 

Trainees learned of the role freshwater mussels provide in structural habitat, stabilizing streams in high flow events, biofiltering and recycling nutrients while they clean the water. At 5-140 liters per mussel per day of filtration capacity, these ‘habitat engineers’ have been likened to wastewater treatment facilities. They are important members of Texas aquatic systems!

They are branded with names like ‘pistolgrip,’ ‘pigtoe,’ ‘healsplitter,’ and ‘fatmucket.’ Sessile creatures, they don’t move around much; it’s because of this that many species have seen steep declines. Changes in hydrology (adequate flow, damming, flooding), degradation of water quality, and increased siltation and sedimentation all diminish their ability to thrive. Mussels are ectothermic like other aquatic animals; summer heat will kill those not thermally buffered with sufficient water depth. 

Loss of fish populations are adversely affecting their reproductive life cycles. Many species require specific host fish species onto which their larvae, glochidia (glo-KID-ee-uh), can attach, maturing in parasitic fashion until dropping off elsewhere as juveniles, then populating new places along the bottoms of our many rivers and streams as biofiltering adults.

In Texas, human development disturbs natural aquatic systems; our thirst for clean water necessitates conservation efforts and attention to these creatures! One of the most vulnerable groups of animals today, 15 species are now threatened in Texas, and 12 are being considered for the Endangered Species Act. Nationwide, 37 species of freshwater mussels are already presumed extinct (Master et al. 2000). The Texas Hornshell (Popenaias popeii), along the Pecos water system with confluence into the Rio Grande River, is already listed as endangered. 

Video by The Partnership for the Delaware Estuary

About the Header Image

(Photo credit: Shannon Westveer) The giant floater mussel (Pyganodon grandis) inhabits low velocity habitats in streams, rivers, lakes, and reservoirs, and is most often found in fine substrates such as silt and sand (Cummings and Mayer 1992; Downing et al. 2000; Whaley et al. 2004; NatureServe 2015). More tolerant of lower oxygen concentrations than most other mussels, it might explain why it is the most observed species in both Fort Bend County and in Texas according to Research Grade observations recorded through iNaturalist.

Learn More About Mussels

  • iNaturalist.org | Research Grade Freshwater Mussels in Texas
  • Texas A&M Natural Resources Institute Dallas | Mussels Research
  • The Partnership for the Delaware Estuary | Side-by-Side Filtration Time Lapse Video

Filed Under: Blog Tagged With: freshwater mussels, giant floater, invertebrate, tamu nri, texas waters

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Top Posts & Pages

Texas Red Winged Black Birds
Texas "Climax Forests"
Purple Martins!
Medicinal Plants of Texas
Texas Armadillos
Texas Falcons

Share This Page!

Texas Master Naturalist Coastal Prairie Chapter

1402 Band Road, Ste 100, Rosenberg,TX 77471
(832) 225-6936

© 2025 Texas A&M University. All rights reserved.

  • Compact with Texans
  • Privacy and Security
  • Accessibility Policy
  • State Link Policy
  • Statewide Search
  • Veterans Benefits
  • Military Families
  • Risk, Fraud & Misconduct Hotline
  • Texas Homeland Security
  • Texas Veterans Portal
  • Equal Opportunity
  • Open Records/Public Information