Collaborative Research: RUI: THE EVOLUTION OF SALINITY TOLERANCE IN MONOGONONT ROTIFERS

University Of Tennessee Chattanooga, Chattanooga TN

Investigators

Abstract

Biodiversity faces threats from fluctuating salinity levels, influenced by climate shifts and human activities such as water extraction, agricultural runoff, and pollution. These changes pose significant challenges to aquatic ecosystems, stressing and endangering resident species. However, some organisms exhibit remarkable resilience to varying salinity levels through physiological adaptability and genetic mechanisms. How do these species thrive in fluctuating salinity conditions, and what can studying their evolutionary, genetic, and physiological processes reveal about resilience and adaptation in changing environments? This project will investigate these questions using microscopic invertebrates—monogonont rotifers, whilst nurturing a new generation of scientific experts in this ecologically important yet often understudied group of invertebrates. This project will support a postdoctoral associate, a Ph.D. student, two M.S. students, and 15 undergraduates, primarily recruited from underrepresented groups. Additionally, 40 undergraduate students will participate in hands-on research activities through two summer programs. Researchers will engage the public through collaborations with universities, university museums, and the Tennessee Aquarium, promoting a broader understanding and appreciation of the challenges biodiversity faces in a changing world through the lens of rotifer evolutionary ecology. Monogonont rotifers play critical roles in aquatic ecosystems by influencing bioturbation, bacterial denitrification, and the transfer of energy from producers to larger consumers. Their short generation times and varying salinity tolerances within the same clade, make them ideal subjects for studying ecological, physiological, and evolutionary processes related to salinity tolerance. This project will: (1) enhance understanding of rotifer taxonomy and ecological distribution by sampling across various salinities using an integrated taxonomic approach. Despite extensive documentation of marine biodiversity in the United States, there is no formal survey of saltwater rotifers from the Southeast U.S. Focusing on this area is particularly relevant due to significantly increasing coastal flooding, sea-level rise and salinification interacting with dense human populations; (2) investigate genomic and transcriptomic differences among salinity-tolerant species through common garden experiments, revealing differential genomic arrangements, gene expression patterns, and phenotypic responses to changing environments; (3) utilize phylogenomic methods and advanced phylogenetic comparative methods to determine ancestral habitat preferences among targeted genera, assess niche conservatism impacts on current species distributions, and analyze rates of adaptation for salinity-tolerant traits. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.