Host-influenced geochemical signature in the parasitic foraminifera Hyrrokkin sarcophaga

• Published in: Biogeosciences
• Main Authors: N. Schleinkofer, D. Evans, M. Wisshak, J. V. Büscher, J. Fiebig, A. Freiwald, S. Härter, H. R. Marschall, S. Voigt, J. Raddatz
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Ecology; QH540-549.5; Life; QH501-531; Geology; QE1-996.5; Lophelia pertusa
• Online Access: https://doi.org/10.5194/bg-18-4733-2021; https://doaj.org/article/887fdace03a44f51ae1c2ccc002b03bd

Hyrrokkin sarcophaga is a parasitic foraminifera that is commonly found in cold-water coral reefs where it infests the file clam Acesta excavata and the scleractinian coral Desmophyllum pertusum (formerly known as Lophelia pertusa) . Here, we present measurements of the trace element and isotopic composition of these parasitic foraminifera, analyzed by inductively coupled optical emission spectrometry (ICP-OES), electron probe microanalysis (EPMA) and mass spectrometry (gas-source MS and inductively-coupled-plasma MS). Our results reveal that the geochemical signature of H. sarcophaga depends on the host organism it infests. Sr <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="1b4178c77ca0d4bfee6c9ddd864f3a43"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-18-4733-2021-ie00001.svg" width="8pt" height="14pt" src="bg-18-4733-2021-ie00001.png"/></svg:svg> Ca ratios are 1.1 mmol mol −1 higher in H. sarcophaga that infest D. pertusum , which could be an indication that dissolved host carbonate material is utilized in shell calcification, given that the aragonite of D. pertusum has a naturally higher Sr concentration compared to the calcite of A. excavata . Similarly, we measure 3.1 ‰ lower δ 13 C and 0.25 ‰ lower δ 18 O values in H. sarcophaga that lived on D. pertusum , which might be caused by the direct uptake of the host's carbonate material with a more negative isotopic composition or different pH regimes in these foraminifera (pH can exert a control on the extent of CO 2 hydration/hydroxylation) due to the uptake of body fluids of the host. We also observe higher Mn <math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math> <svg:svg ...