Avigliano E. auteur aut IRD Pouilly Marc auteur aut IRD Silva N. auteur aut IRD Sanchez S. auteur aut IRD text journalArticle eng text/pdf born digital access Oxydoras kneri and Hemisorubim platyrhynchos are catfish species of high ecological and commercial relevance from the Parana River (La Plata Basin, South America) whose life history remains unknown. The aim of this study was to reveal the nursery areas and describe the habitat use throughout the ontogeny of both catfish species from the Parana River using the otolith Sr-87/Sr-86 ratio. Otolith core-to-edge Sr-87/Sr-86 analyses were measured using a LA-MC-ICPMS system. A Quadratic Discriminant Analysis (Wilks' Lambda = 0.029, p < 0.0001) based on the water Sr-87/Sr-86 baseline of the La Plata Basin was run to infer the natal origin using the core Sr-87/Sr-86 ratio as an independent variable. Oxydoras kneri was classified as originating from Paraguay (35.7%), middle Parana (57.1%), and upper Parana (7.1%) rivers, while H. platyrhynchos was classified as originating from the middle (56.3%) and upper (43.7%) Parana River. Otolith Sr-87/Sr-86 time series suggested a high complexity in the stock structure of both species from upper Parana River, with a significant contribution of specimens originating in other areas. Both species showed isotopic variations in their otoliths compatible with short- and medium-scale movements between different reaches of the Parana and Paraguay rivers that could exceed 200 km. specialized Otolith microchemistry Freshwater migration Strontium isotopes Oxydoras kneri Hemisorubim platyrhynchos PARAGUAY ARGENTINE BRESIL BOLIVIE 034 040 [Early access] [12 p.] 2023 0378-1909 https://www.documentation.ird.fr/hor/fdi:010086916 10.1007/s10641-023-01390-5 0378-1909 [F B010086916] https://www.documentation.ird.fr/hor/fdi:010086916 https://www.documentation.ird.fr/intranet/publi/2023-03/010086916.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2023-03-08 2023-03-08 fdi:010086916 fre