Elemental distribution in cephalopod statoliths: NanoSIMS provides new insights into nano-scale structure

Abstract

We have applied the novel analytical method NanoSIMS to cephalopod statoliths for the first time in order to analyse their chemical microstructure, using a spatial resolution of 400 nm. This technique makes it possible to analyse in situ nano-scale chemical variations between increment layers. In statoliths of the boreoatlantic armhook squid Gonatus fabricii, we found distinct concentration patterns indicating a periodicity in strontium and sodium distributions. Sr and Na show a negative relation, both elements showing alternating patterns where the increments vary in width between approximately 1 and 5 lm. Results suggest, that aragonite deposited during the night is rich in Na and poor in Sr, while aragonite deposited during the day is rich in Sr and poor in Na. This study demonstrates the excellent suitability of NanoSIMS for nano-scale microchemical analyses of aragonite, providing new information on calcification processes and individual life histories. Possible future fields of application include not only cephalopod statoliths, but also virtually all biomineralized tissues in aquatic organisms like fish otoliths, gastropod statoliths, bivalve shells, foraminifers and corals.

Micro-scale geochemical and crystallographic analysis of Buccinum undatum statoliths supports an annual periodicity of growth ring deposition

“…It was concluded that these cycles corresponded with daily growth rate changes as a result of a diurnal feeding cycle and were inversely correlated to Sr/Ca ratios. The findings from this study and those of Zumholz et al (2007c) have demonstrated and confirmed the suitability of high sensitivity, high resolution techniques such as SIMS and nanoSIMS for studying the geochemistry of small biogenic carbonate structures.…”

“…something that B. undatum has been shown to display from ageing studies (Shelmerdine et al, 2007;Hollyman, 2017). No literature could be found relating to the incorporation of Na into gastropod statoliths, however, Zumholz et al (2007c) found putative daily cycles of Na/Ca in the statoliths of the squid Gonatus fabricii using nanoSIMS. It was concluded that these cycles corresponded with daily growth rate changes as a result of a diurnal feeding cycle and were inversely correlated to Sr/Ca ratios.…”

In Situ Imaging of Metals in Cells and Tissues

“…658 NanoSIMS has also been applied to biologically related geochemistry studies, for example, in elemental mapping and tracer studies of Archean fossils, 659 natural calcium carbonate samples, 660 and statoliths. 661 Calcification of soft tissues occurs during pathological conditions and has important clinical implications. Although calcification occurs mainly in extracellular matrices, 662 calcium phosphate mineral can also deposit intracellularly.…”

Advances in Imaging Secondary Ion Mass Spectrometry for Biological Samples

“…NanoSIMS has also been used to characterize microbially mediated geochemical processes using isotopic tracers (27), natural abundance stable isotopes (28), and organic nitrogen detection and mapping in mineral aggregates (77). Other biologically related geochemistry studies include elemental mapping and tracer studies on reef-building corals (20,75), statoliths (118), coccoliths (36,92), diatoms (2), and fossil organic mapping (79).…”