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Vulnerability of the paper Nautilus (Argonauta nodosa) shell to a climate-change ocean: potential for extinction by dissolution.
- Source :
-
The Biological bulletin [Biol Bull] 2012 Oct; Vol. 223 (2), pp. 236-44. - Publication Year :
- 2012
-
Abstract
- Shell calcification in argonauts is unique. Only females of these cephalopods construct the paper nautilus shell, which is used as a brood chamber for developing embryos in the pelagic realm. As one of the thinnest (225 μm) known adult mollusc shells, and lacking an outer protective periostracum-like cover, this shell may be susceptible to dissolution as the ocean warms and decreases in pH. Vulnerability of the A. nodosa shell was investigated through immersion of shell fragments in multifactorial experiments of control (19 °C/pH 8.1; pCO(2) 419; Ω(Ca) = 4.23) and near-future conditions (24 °C/pH 7.8-7.6; pCO(2) 932-1525; Ω(Ca) = 2.72-1.55) for 14 days. More extreme pH treatments (pH 7.4-7.2; pCO(2) 2454-3882; Ω(Ca) = 1.20-0.67) were used to assess tipping points in shell dissolution. X-ray diffractometry revealed no change in mineralogy between untreated and treated shells. Reduced shell weight due to dissolution was evident in shells incubated at pH 7.8 (projected for 2070) after 14 days at control temperature, with increased dissolution in warmer and lower pH treatments. The greatest dissolution was recorded at 24 °C (projected for local waters by 2100) compared to control temperature across all low-pH treatments. Scanning electron microscopy revealed dissolution and etching of shell mineral in experimental treatments. In the absence of compensatory mineralization, the uncovered female brood chamber will be susceptible to dissolution as ocean pH decreases. Since the shell was a crucial adaptation for the evolution of the argonauts' holopelagic existence, persistence of A. nodosa may be compromised by shell dissolution in an ocean-change world.
- Subjects :
- Animal Shells chemistry
Animal Shells radiation effects
Animals
Calcification, Physiologic radiation effects
Female
Hydrogen-Ion Concentration
Microscopy, Electron, Scanning
Minerals analysis
Nautilus chemistry
Nautilus radiation effects
Paper
Temperature
X-Ray Diffraction
Animal Shells physiology
Climate Change
Extinction, Biological
Nautilus physiology
Oceans and Seas
Subjects
Details
- Language :
- English
- ISSN :
- 1939-8697
- Volume :
- 223
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- The Biological bulletin
- Publication Type :
- Academic Journal
- Accession number :
- 23111135
- Full Text :
- https://doi.org/10.1086/BBLv223n2p236