Effects of hypoxia and non-lethal shell damage on shell mechanical and geochemical properties of a calcifying polychaete
Calcification is a vital biomineralization process where calcifying organisms construct their calcareous shells for protection. While this process is expected to deteriorate under hypoxia, which reduces the metabolic energy yielded by aerobic respiration, some calcifying organisms were shown to...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-06-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/15/3267/2018/bg-15-3267-2018.pdf |
| Summary: | Calcification is a vital biomineralization process where calcifying organisms
construct their calcareous shells for protection. While this process is
expected to deteriorate under hypoxia, which reduces the metabolic energy
yielded by aerobic respiration, some calcifying organisms were shown to
maintain normal shell growth. The underlying mechanism remains largely
unknown, but may be related to changing shell mineralogical properties,
whereby shell growth is sustained at the expense of shell quality. Thus, we
examined whether such plastic response is exhibited to alleviate the impact
of hypoxia on calcification by assessing the shell growth and shell
properties of a calcifying polychaete in two contexts (life-threatening and
unthreatened conditions). Although hypoxia substantially reduced respiration
rate (i.e., less metabolic energy produced), shell growth was only slightly
hindered without weakening mechanical strength under unthreatened conditions.
Unexpectedly, hypoxia did not undermine defence response (i.e., enhanced shell
growth and mechanical strength) under life-threatening conditions, which may
be attributed to the changes in mineralogical properties (e.g., increased
calcite / aragonite) to reduce the energy demand for calcification. While more
soluble shells (e.g., increased Mg ∕ Ca in calcite) were produced under
hypoxia as the trade-off, our findings suggest that mineralogical plasticity
could be fundamental for calcifying organisms to maintain calcification under
metabolic stress conditions. |
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| ISSN: | 1726-4170 1726-4189 |