Epioblasma metastriata

Epioblasma metastriata, commonly known as the upland combshell, is a freshwater mussel species endemic to the Tennessee River system in the southeastern United States. This bivalve mollusk was historically found in medium to large rivers with stable gravel and sand substrates. Like other freshwater mussels, it has a complex life cycle that requires fish hosts for larval development, with the larvae (glochidia) attaching to specific fish species to complete their metamorphosis. The upland combshell is currently classified as Critically Endangered by the IUCN, representing one of North America's most imperiled freshwater mussel species. The primary threats to this species include habitat degradation from dam construction, water pollution, sedimentation, and changes in water flow regimes. The impoundment of rivers has fundamentally altered the flowing water habitats that this species requires, while agricultural and urban runoff has degraded water quality. Additionally, the decline of suitable host fish populations has further compromised reproduction and recruitment. The species has experienced severe population declines and range reductions, with many historical populations now extirpated. Conservation efforts focus on habitat restoration, water quality improvement, and captive breeding programs. Research continues on identifying suitable host fish species and developing propagation techniques to support population recovery. Protection of remaining habitat and restoration of river connectivity are critical for the species' long-term survival.