Low temperature suppresses mantle-mediated shell biomineralization in freshwater invasive golden mussels

The hematoxylin-eosin-stained mantle exhibited progressive histopathological damage, including epithelial disorganization, fold deformation, inflammatory cell infiltration, and significant reductions in epithelial indentation height. Carbonic anhydrase and tyrosinase contents decreased significantly under low-temperature exposures, whereas reactive oxygen species, superoxide dismutase, and catalase increased. Transcriptomic and metabolomic analyses further revealed coordinated changes in biomineralization-, stress response-, immune regulation-, and membrane-related genes and pathways.

Together, these results show that low temperature suppresses mantle-mediated shell biomineralization in L. fortunei and suggest that impairment of this costly functional trait may represent an important physiological cost of low-temperature response, thereby helping explain how low temperature may constrain the invasion success of freshwater bivalves to high-latitude habitats.</p>