In Texas, the USFWS is currently reviewing 11 mussel species for ESA protection and several of these species (e.g., Cyclonaias petrina, Texas Pimpleback, and Lampsilis bracteata, Texas Fatmucket) have been the primary focus of controlled propagation by several federal hatcheries. To date, information on genetic diversity within and across known populations for these species is incomplete and so the justification for their controlled propagation is unclear, and a genetic management plan to guide propagation activities does not exist. These unknowns raise serious questions about whether any of the 11 proposed species are truly in need of and would benefit from controlled propagation. The overall goal of this project is to provide guidance on genetic considerations that should be addressed prior to implementing controlled propagation. The completion of these tasks will provide information that can be used to inform species-specific genetic management plans and help operationalize controlled propagation, if needed. The specific objective of this study is to conduct a range-wide survey of genetic variation in Potamilus metnecktayi, Salina Mucket, Truncilla cognata, Mexican Fawnsfoot, and Truncilla macrodon, Texas Fawnsfoot, that will allow identification of distinct populations and demographic history that have influenced the genetic diversity of these species.