Teichert N. auteur aut IRD Tabouret H. auteur aut IRD Lagarde R. auteur aut IRD Grondin H. auteur aut IRD Ponton Dominique auteur aut IRD Pecheyran C. auteur aut IRD Bareille G. auteur aut IRD text journalArticle eng text/pdf born digital access Otolith microchemistry can provide crucial information to address gaps of knowledge in spatio-temporal ecology of fish species. However, understanding the seasonal variability of water chemistry and its effect on otolith signatures is needed to interpret fish movements. Otolith multi-elemental signatures were used to examine the diadromous migration and small-scale movements of a tropical goby (Sicyopterus lagocephalus) within a watershed in La Reunion Island, Indian Ocean. The elemental ratios Sr:Ca, Ba:Ca and Sr:Ba recorded monthly in the water of nine sampling sites varied between localities and were correlated with otolith signatures, whereas the Mg:Ca signature was not. The incorporation of some trace elements in otoliths was influenced by the size of fish and site where they were caught, reflecting an effect of endogenous and exogenous factors. Despite these sources of variation, the elemental signatures did not overlap for three river sections distributed along the 26-km-long watershed. The diadromous migration and fish lifetime movements between these river sections were reconstructed using an original process based on random forest analysis. This approach revealed distinct migratory behaviours after fish entered in the river, with some individuals progressing slowly in the watershed whereas other rapidly reached the upper localities. As adults, S.lagocephalus showed a restricted exploratory behaviour and a strong site fidelity to a particular part of the watershed. The detection of adult movement was typically only between adjacent locations and is possibly explained by shifts in local intraspecific hierarchies and/or displacement during extreme discharge caused by cyclones. specialized habitat discrimination individual life histories movement patterns otolith chemistry random forest river networks water chemistry REUNION 036 034 27 3 834-846 2018 0906-6691 https://www.documentation.ird.fr/hor/fdi:010073099 10.1111/eff.12396 0906-6691 [F B010073099] https://www.documentation.ird.fr/hor/fdi:010073099 https://www.documentation.ird.fr/intranet/publi/2018/06/010073099.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2018-07-03 2023-07-11 fdi:010073099 fre