2.7. Elemental composition of the exhumed nauplii.
Fine anatomical structures and elemental composition of the carcasses were studied under SEM (Zeiss EVO-50) and associated SEM⁄EDX (energy dispersive X-ray spectroscopy INCA Oxford 350). To prepare the samples for SEM analysis, the nauplii were rinsed of salts and sediment particles, as described in Naimark et al., 2018c. SEM imaging was performed on glass supports, and SEM⁄EDX point analyses on copper supports to allow for measurement of Al, Si, and Fe. We analyzed separately the adhered mineral particles and the surface tissues of the carcasses (free of bacteria and visible adhered mineral particles). This allowed us to distinguish between the tissue intake of dissolved elements and mere adhesion of minerals.