Abstract
The South American silver croaker, Plagioscion squamosissimus, holds significant importance for the artisanal fisheries operating in the sub-middle and lower courses of the São Francisco River, located in northeastern Brazil. Its complex horizontal movement patterns and habitat-use preferences are not fully understood in the waters of hydroelectric dam reservoirs, raising important questions for the rational and sustainable management of this species. This study aimed to identify the habitat use of P. squamosissimus individuals captured in three fishers’ associations (Olho D’água do Casado, Petrolândia and Rodelas). Individuals were collected between September 2023 and March 2024. A selection of 25 individuals per location from the same age group (+2 years) was used, following annual age estimation based on existing growth curves. Element-to-calcium (element/Ca) ratios in the otolith cores and edges were determined using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The data were analyzed using univariate and multivariate statistics to assess the degree of separation between individuals in relation to natal origin (otolith cores) and time of capture (otolith edges) from the three sampling sites. Significant differences in element/Ca ratios between core and edges of the otolith were observed for Ba/Ca, Mg/Ca, Mn/Ca and Sr/Ca ratios. These results indicate an ontogenetic change in the habitat use, in which similarity in core signatures suggests a common natal origin, likely influenced by shared environmental conditions of the individuals investigated in this study.
Author Contributions
Conceptualization, F.d.L.F. and A.T.C.; Methodology, F.d.L.F., A.M.V. and A.T.C.; formal analysis, F.d.L.F. and A.T.C.; investigation, F.d.L.F. and A.T.C.; resources, N.S.P. and A.T.C.; data curation, R.M.S. and P.B.P.; writing—original draft preparation, F.d.L.F.; writing—review and editing, N.S.P. and A.T.C.; visualization, F.d.L.F. and A.T.C.; supervision, N.S.P. and A.T.C.; project administration, N.S.P.; funding acquisition, N.S.P., J.P.C. and A.T.C. All authors have read and agreed to the published version of the manuscript.
Funding
A.T.C was funded by national funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., and by the European Commission’s Recovery and Resilience Facility, within the scope of UID/04423/2025 (https://doi.org/10.54499/UID/04423/2025), UID/PRR/04423/2025 (https://doi.org/10.54499/UID/PRR/04423/2025), and LA/P/0101/2020 (https://doi.org/10.54499/LA/P/0101/2020). This work is also a result of the project ATLANTIDA II (ref. NORTE2030-FEDER-01799200).
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
Available upon request.
Conflicts of Interest
The authors declare no conflicts of interest.
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