Otolith Sr:Ca ratio and morphometry as indicators of habitat of a euryhaline species: the case of silverside Odontesthes bonariensis

ESTEBAN AVIGLIANO; PAOLA VILLATARCO; ALEJANDRA VANINA VOLPEDO

CIENCIAS MARINAS

INST INVESTIGACIONES OCEANOLOGICAS, U A B C, APARTADO POSTAL 423

Lugar: Ciudad de México; Año: 2015 vol. 41 p. 189 - 202

0185-3880

The silverside (Odontesthes bonariensis) is an euryhaline species native of South America that represents a very important fishing resource for the Plate Basin (Argentina and Uruguay). This study compares Sr:Ca ratio of water as well as Sr:Ca ratio and morphometry of the sagittae otolith of the Silverside present in different environments (one lake, two dams of freshwater, one lagoon and one estuary) in order to evaluate the use of these variables as markers of habitat. The pattern of Sr:Ca ratio of the water agrees with the one found in the otoliths, showing a positive relationship with the conductivity of the water. Univariate and multivariate analyses of variance (ANOVA and MANOVA) indicated significant differences (p<0.05) among localities studied for the morphometric indices. The discriminating analysis provided a high percentage of individuals rightly classified for a salty water environment (100%), lentic water bodies and estuary (60-80%), being circularity and formfactor the morphometric variables most relevant. These results indicate that the Sr:Ca ratio and otolith morphometry  are good markers of habitat for this important resource.