Quantifying the freshwater mussel - fish host relationship to inform conservation

Abstract

Among the many global cases of drastic declines in faunal biodiversity, the North American freshwater mussel fauna represents an extreme case. This project first examined the potential host relationships between mussels native to the Apalachicola-Chattahoochee-Flint river basin (ACF) and a single species, the Gulf sturgeon. Amblema neislerii (fat threeridge) alone was found to successfully metamorphose (3.5%) on Atlantic sturgeon, the sister subspecies to Gulf sturgeon. This project second examined the physiological aspect of the mussel-fish host relationship via investigation of the effects of exogenous cortisol on larval metamorphosis. This investigation found that administration of cortisol to potential host fish can affect mussel metamorphosis in many ways: increased initial glochidial attachment, increased proportion of successful metamorphosis, higher number of juveniles produced, and a protracted time period of juvenile production. These findings contribute to basic research into the physiological mechanisms underlying the mussel-fish host relationship and applied research in captive propagation techniques.