Assessing the use of two southwestern Atlantic estuaries by different life cycle stages of the anadromous catfish Genidens barbus (Lacépède, 1803) as revealed by Sr:Ca and Ba:Ca ratios in otoliths

ESTEBAN AVIGLIANO; GONZALO VELASCO; ALEJANDRA VANINA VOLPEDO

JOURNAL OF APPLIED ICHTHYOLOGY-ZEITSCHRIFT FUR ANGEWANDTE ICHTHYOLOGIE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015

0175-8659

The objective of this study was to asses the long-term patterns of estuarine and estuarine-to-continental shelf use by Genidens barbus in two estuaries in the southwestern Atlantic Ocean, using Sr:Ca and Ba:Ca ratios in otoliths. Adult fish (total length: 54.0-78.1 cm) were caught in Lagoa dos Patos estuary (Brazil) and the De la Plata River estuary (Argentina-Uruguay) (total length: 64.0-79.2 cm) during October 2012. A New Wave UP193FX (193 nm excimer laser) LA system was coupled to an Agilent 7500ce Quadrupole ICP-MS in order to determine the chronological variation of 88Sr, 138Ba and 43Ca throughout ontogeny. G. barbus showed high plasticity in its displacement patterns in the southwestern Atlantic Ocean. Present results suggest the occurrence of different fish groups in that area, each one with a particular migratory behavior: some specimens may undertake large migrations between the estuaries and the platform while others may have higher degree of estuarine dependence. Such plasticity may be influenced by the environmental conditions and food availability in the different areas frequented by the species.