Résumé
The gastropod Terebralia palustris is found in mangroves from the Indo-Pacific, where it plays important ecological roles and is exploited by humans. As such, it reflects interactions occurring with the socio-ecosystem, yet our understanding of its distribution and ecological niche are still scarce. Understanding the relative importance of factors of the mangrove socio-ecological system (MSES) on the realized niche of T. palustris may be used to better define the three dimensions of the niche (abiotic, biotic and accessibility). We studied the distribution of T. palustris at the scale of Mayotte Island (France, Indian Ocean) through the prism of MSES, including local ecological knowledge and environmental memory held by population. To this end, a survey campaign of the 29 mangroves of Mayotte made it possible to finely map its occurrences and correlate the spatial patterns to a variety of factors of the MSES related to three dimensions of the niche, including societal and ecological components. Questionnaire interviews were conducted to highlight potential relationships between current and past distribution of the species. Mangrove characteristics constrain the realized niche of T. palustris at the scale of the island. The gastropod is found on large and wide mangroves where the habitat is heterogeneous. Instead, societal variables had little influence on the distribution of the species. Our study showed that dealing with both ecosystem and societal subsystems and their involvement in each dimension of the niche concept therefore is a promising way of understanding the distribution of a species in anthropized systems.