| Autor: |
Gey, Christoph J., Thielen, Frankie, Pfister, Laurent, Hissler, Christophe, Türk, Guilhem, Baier, Sven, Schöne, Bernd R. |
| Zdroj: |
Marine & Freshwater Research; 2023, Vol. 74 Issue 13, p1129-1144, 16p |
| Abstrakt: |
Context: The ultrastructure of marine bivalve shells, specifically the thickness of nacre tablets has recently been identified to be related to water temperature. Aims: This study investigates whether the nacre tablet thickness (NTT) of freshwater pearl mussel shells can serve as a proxy for stream water temperature. Methods: Laboratory-grown juvenile and adult Margaritifera margaritifera from three streams were analysed using scanning electron microscopy to determine the relationship between NTT and water temperature. Key results: Neither laboratory-grown juvenile nor adult specimens from the field revealed consistent NTT trends with temperature. Conclusion: The NTT of M. margaritifera is largely uncoupled from stream water temperature. Presumably, fluctuations in stream water pH caused physiological stress and forced the animal to allocate more energy to homeostasis than to shell growth. The absence of a coupling between NTT of juvenile mussels and temperature is likely to be due to stronger physiological control on nacre tablet morphology during early stages of ontogeny, favouring thinner tablets with a larger proportion of organics v. CaCO3, which increases the fracture resistance of the shell. Implications: Therefore, only if ambient pH remains stable, NTT of freshwater mussels beyond the age of five may serve as a temperature proxy, albeit being associated with a large error. Assessing the effects of climate change on aquatic ecosystems requires water-temperature data from the pre-instrumental era. This information can be reconstructed from the morphology of biominerals in shells of some marine bivalves. However, the thickness of nacre tablets in freshwater pearl mussels is an unreliable temperature indicator, likely owing to pH fluctuations causing physiological stress that affects biomineralisation processes. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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