data_Terebralia_habitat

The epigean gastropod <i>Terebralia palustris</i> is an engineer species of the mangrove ecosystem widely distributed in the Indo-Pacific. Nevertheless, existing knowledge on its distribution remains quite contradictory and suggests highly context-dependent responses. It is found either only in the landward mangrove or in the whole mangrove depending on the location throughout its range. In Mayotte (France, Indian Ocean), a very heterogeneous presence has been observed within the landward mangrove of 13 mangroves out of 29 in 2022. We therefore aimed to understand the distribution of <i>T. palustris</i> in Mayotte in relation to environmental factors and to characterize the habitat heterogeneity from the species’ point of view. To this end, we studied environmental conditions related to feeding, shading, soil quality, and moisture comparing sites of species presence and absence during both dry and wet seasons. Results indicate the landward mangrove is in fact a heterogeneous habitat expressed into five microhabitats differentiated by their vegetation structure, soil organic matter content and elevation on the shore. These microhabitats host the species in varying proportions (density and size). <i>T. palustris </i>is found here because the vegetation provides the shade necessary to avoid desiccation, in particular due to the density and height of the trees. This improved definition of the realized niche of <i>T. palustris</i> makes it possible to understand which habitat must be preserved to ensure the persistence of this species. The species was not always found where these characteristics exist: further studies should explore the reasons for its absence, whether natural (competition/predation) or anthropogenic (pollution/overexploitation).