Mussels (Bivalvia, family Unionidae) known from the Caddo River. This is an incomplete list as some specimens are still being identified.
| Actinonaias ligamentina | mucket |
| Alasmidonta marginata | elktoe |
| Amblema plicata | threeridge |
| Cyprogenia aberti | western fanshell |
| Elliptio crassidens | elephantear |
| Elliptio dilatata | spike |
| Fusconaia flava | Wabash pigtoe |
| Lampsilis hydiana | Louisiana fatmucket |
| Lampsilis powellii | Arkansas fatmucket |
| Lampsilis satura | sandbank pocketbook |
| Lasmigona costata | flutedshell |
| Ptychobranchus occidentalis | Ouachita kidneyshell |
| Strophitus undulatus | creeper |
| Villosa lienosa | little spectaclecase |