FN Archimer Export Format PT J TI Structure of small tropical island freshwater fish and crustacean communities: A niche‐or dispersal‐based process? BT AF Lagarde, Raphael Teichert, Nils Valade, Pierre Ponton, Dominique AS 1:1,2;2:3;3:4;4:5; FF 1:;2:;3:;4:; C1 Centre de Formation et de Recherche sur les Environnements Méditerranéens UMR 5110 Université de Perpignan Via Domitia Perpignan ,France Centre de Formation et de Recherche sur les Environnements Méditerranéens UMR 5110 CNRS Perpignan ,France UMR 7208 BOREA (Biologie des Organismes et Ecosystèmes Aquatiques) Sorbonne Université MNHN CNRS UMPC Université Caen IRD – Station Marine de Dinard – CRESCO University of Antilles Guadeloupe ,France OCEA Consult’ La Réunion, France ENTROPIE IRD Université de La Réunion CNRS Université de la Nouvelle‐Calédonie – Ifremer Institut Halieutique et des Sciences Marines (IH.SM) Université de Toliara Toliara, Madagascar C2 UNIV PERPIGNAN, FRANCE CNRS, FRANCE MNHN, FRANCE OCEA CONSULT’, FRANCE IRD, FRANCE UNIV TOLIARA, MADAGASCAR UM ENTROPIE IN WOS Cotutelle UMR copubli-france copubli-univ-france copubli-int-hors-europe copubli-sud IF 2.867 TC 7 UR https://archimer.ifremer.fr/doc/00654/76587/77859.pdf LA English DT Article DE ;abundances;diadromy;environmental gradients;migration;taxonomic richness;western Indian Ocean AB Determining the relative importance of niche‐ and dispersal‐based processes in the structuring of animal communities is central in ecology. Freshwater fish and crustacean communities of small tropical islands can bring new insights for understanding these processes as all their species present a pelagic larval stage which gives them important dispersal capacities. Consequently, we hypothesized that dispersal‐based process may be preponderant for structuring these communities from the regional to the local, that is, survey site, scales. Gradient forest analyses allowed us to model the effect of 12 environmental variables on freshwater taxa abundances in two southwestern Indian Ocean islands: Mayotte (26 taxa) and Reunion (21). A total of 153 surveys in Mayotte and 266 in Reunion were used for building the models. Despite the strong heterogeneity of environmental conditions between the two islands, the main factors structuring freshwater fish and crustacean communities in both islands were the elevation and the slope of the sites. The observed structure appeared more pronounced for predatory species than for primary consumers and omnivores. As predators generally have limited locomotor capacities, it is concluded that dispersal‐based process structures these communities not only at large geographical scales but also at the intra‐watershed scale, by limiting the inland penetration (or dispersion) of species in relation to their locomotor capacities. However, more knowledge concerning ecological traits and taxonomic status of many species is needed to confirm this assumption. Abstract in French is available with online material PY 2021 PD JAN SO Biotropica SN 0006-3606 PU Wiley VL 53 IS 1 UT 000585270800001 BP 243 EP 254 DI 10.1111/btp.12865 ID 76587 ER EF