The Known and Potential Hosts of Texas Mussels: Implications for Future Research and Conservation Efforts

Abstract

North America is home to the most diverse freshwater mussel fauna (Mollusca: Unionidae) in the world; however, at least 70% of native mussel species are considered imperiled to some degree. Texas has 52 currently recognized mussel species, and many of these have experienced significant population declines. These declines are anticipated to worsen as the population and water demands continue to grow throughout the state. The life history of unionids includes a unique reproductive strategy involving an obligate ectoparasitic larval stage; therefore, suitable host organisms are required for a mussel population to remain viable. Because of this relationship, the identification of host organisms is an important component for successful mussel conservation efforts. Data on host organisms are often difficult to locate or may be incomplete or completely lacking. We performed a comprehensive literature review to compile the known and/or potential host species for the mussels of Texas. Data was organized by mussel species and information including the total number of hosts identified in the literature review, type of host study methodology, and whether the mussel and/or host is a state or federally listed species was incorporated into a reference table. Identified host species were grouped by family, and the percentages for each host family were then compared for each mussel species using a chi-square goodness of fit analysis. The information compiled during this literature review exposes areas in need of future research and should be considered during the development of future mussel management and conservation protocols within Texas.