*2.2. Polarized and Brightfield Microscope Analysis*

For each species, permanent slides were observed with both types of lighting in an Olympus BX 51 microscope (Olympus, Tokyo, Japan) and photographs obtained with Image Pro Plus 7.1 software (Media Cybernetics, MD, USA) to characterize the morphology and distribution of biominerals in the different tissues of the three regions studied (Figure 1). Additionally, photographs of isolated biominerals from each tissue were also obtained with the two types of lighting.
