Feasibility of Elemental and Microstructural Differentiation of Land Snail Eggs from Bradybaena ravida and Cathaica fasciola

Although species identification is crucial for land-snail eggs, limited effort has been made to identify the species responsible for producing the eggs. In this study, we used laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) to measure 54 elements in both the eggshells and adult shells of Bradybaena ravida and Cathaica fasciola and we used scanning electron microscope (SEM) to analyze the microstructure of the eggshells of the two species. Our results reveal that while the concentrations of Sr, Na, Mg, P, and Ba in the adult shells of the two species are not distinct, they are distinct or partially distinct between their eggshells, indicating that these elements have the potential to differentiate the eggs of the two species. Moreover, the eggshells of C. fasciola exhibit a blocky morphology without cavities, whereas those of B. ravida, while also blocky, contain irregular cavities. These distinct elemental and microstructural characteristics enable the effective differentiation of the eggs of B. ravida and C. fasciola. Our study demonstrates the feasibility of a critical microscopic methodology for identifying land-snail eggs at the genus/species level, thereby facilitating deeper exploration of their value in understanding biological, climatic, and ecological changes.