Fluvio-marine travelers from South America: Cyclic amphidromy and freshwater residency, typical behaviors in Genidens barbus inferred by otolith chemistry

摘要: Abstract Catfish Genidens barbus is a commercially fished species from the south-western Atlantic Ocean. Overfishing of this during last few years has caused collapse fisheries and in turn led to ban its exploitation. In order identify migratory patterns four migration corridors South America, we determined Sr:Ca Ba:Ca ratios otoliths, by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). range between 0.90 9.83 mmol/mol (mean ± standard deviation: 3.86 ± 1.05 mmol/mol) 0.00013 0.10 mmol/mol (mean ± SD: 0.0094 ± 0.0160 mmol/mol), respectively. Three types amphidromous cyclical (annual) that include use freshwater, estuarine marine environments are detected. Resident freshwater fish (6.5%) found only Patos Lagoon. Depending on study site, 18 45% analyzed population were spawned while rest waters. The change-point analysis shows positive correlation changes transects (r = 0.63, p = 0.0001), whereas Kruskal-Wallis test no significant differences number ratio sampling sites (H = 2.1, p = 0.53). Only for Lagoon analyses show significantly higher (H = 9.1, p = 0.03). data indicate average movements among similar corridors. appears be more variable relation ratio, indicating former could sensitive environmental changes. conclusion, work describes first time, annual migrations dependence different fluvial-marine systems. understanding habitat will help design estuarine-specific management actions with ultimate goal recovering fisheries.