Vilcot M. auteur aut IRD Keggin T. auteur aut IRD Albouy C. auteur aut IRD Donati G. F. A. auteur aut IRD Acosta-Chaparro A. auteur aut IRD Borrero-Pérez G. H. auteur aut IRD Cheutin M. auteur aut IRD Corredor J. D. G. auteur aut IRD Hocdé Régis auteur aut IRD Juhel J. auteur aut IRD Marques V. auteur aut IRD Mouillot D. auteur aut IRD Mutis-Martinezguerra M. auteur aut IRD Polanco F. A. auteur aut IRD Vermeij M. J. A. auteur aut IRD Pellissier L. auteur aut IRD Manel S. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Habitat configuration governs the movement of organisms across landscapes, thereby shaping both population structure and community assembly. While theoretical and empirical studies have assessed how habitat connectivity simultaneously influences intra- and interspecific diversity, direct comparisons across contrasting biogeographic regions remain limited. Here, we investigate patterns of genetic and species beta-diversity in tropical reef fishes across two ocean basins with distinct spatial configurations: the Caribbean Sea and the Western Indian Ocean. Using a comparative framework based on species occurrence data from five fish families and single nucleotide polymorphism (SNP) data from 19 species, we detected significant isolation by distance at both population and community levels in the Western Indian Ocean, but only at the community level in the Caribbean Sea. Additionally, genetic and species beta-diversity were positively correlated among species in the Western Indian Ocean, but not in the Caribbean Sea. Together, these results suggest that the shorter inter-reef distances of the Caribbean Sea promote higher connectivity, leading to a decoupling of intra- and interspecific beta-diversity patterns. specialized connectivity isolation by distance marine fish species-genetic diversity correlation beta-diversity OCEAN INDIEN MER DES ANTILLES 036 082 16 6 e73760 [12 ] 2026 2045-7758 https://www.documentation.ird.fr/hor/fdi:010097400 10.1002/ece3.73760 2045-7758 [F B010097400] https://www.documentation.ird.fr/hor/fdi:010097400 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2026-07/010097400.pdf IRD - Base Horizon / Pleins textes 2026-07-09 2026-08-05 fdi:010097400 fre