Population structure and ontogenetic habitat use of Micropogonias furnieri in the southwestern Atlantic Ocean inferred by otolith chemistry

ESTEBAN AVIGLIANO; ALVES, NADIA MARINA; M. RITA RICO; RUARTE, CLAUDIO; LUCIANA D' ATRI; ANA MÉNDEZ; JORGE PISONERO; ALEJANDRA VOLPEDO; BORSTELMANN CLAUDIA

FISHERIES RESEARCH

ELSEVIER SCIENCE BV

Año: 2021 vol. 240 p. 1 - 10

0165-7836

The whitemouth croaker Micropogonias furnieri is a demersal sciaenid fish widely distributed inAtlantic coasts and estuaries from Mexico to Argentina. In the South Atlantic (33°- 41°S), there aretwo stocks: Río de la Plata (RDP) and El Rincón (ER), respectively. Studies based on genetic, ageand size structure data suggested that RDP stock would be composed of two different populations,one estuarine-dependent (estuarine type) and the other with oceanic spawning sites (oceanic type).The hypothesis of segregation between the estuarine and oceanic types, and between these and theER stock was tested by using the otolith chemistry in the edge (adult stage) and core (early stage) offish. Li/Ca, Na/Ca, Mn/Ca, Cu/Ca, Ba/Ca, and Pb/Ca ratios were determined by LA-ICP-MS.Several ratios were significantly different between sampling sites for edge and core (p<0.05). Foredge, PERMANOVA showed significant differences (p<0.05) between all sampling sites, while thequadratic discriminant analyses showed a mean jackknifed classification of 83% (87% for Uruguay,76% for RDP and 86% for ER). This supports the hypothesis of differentiation of the RDP stock intooceanic and estuarine-dependent groups. The non-metric multidimensional scaling and clusteranalysis based on the core chemistry suggested that there would be at least two large chemicalsignatures in the early stage. The elemental ratio time series showed a potential endogenous effect onthe incorporation of various elements (e.g. Ba, Mn, Li) in the early stages, while Sr/Ca time seriessuggested a general migratory behavior between estuarine and marine habitats throughout ontogeny.