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

AVIGLIANO, ESTEBAN; VILLATARCO, PAOLA,; VOLPEDO, ALEJANDRA

CIENCIAS MARINAS

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

Lugar: Ciudad de México; Año: 2015 vol. 41 p. 1 - 14

0185-3880

The silverside (Odontesthes bonariensis) is an euryhaline species native of South America that represents a very important fishing resource. In this work it was compared the relation Sr:Ca of the water and otoliths as well as the morphometry of the sagittae otolith of the Silverside in different environments (one lake and two dams of fresh water, 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, having a positive relationship with the conductivity of the water. Univariate and multivariate analyzes of variance  (ANOVA and MANOVA) showed significant differences (p<0.05) for the morphometric indices among the study sites. The discriminating analysis showed a high percentage of individuals well 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.Odontesthes bonariensis) is an euryhaline species native of South America that represents a very important fishing resource. In this work it was compared the relation Sr:Ca of the water and otoliths as well as the morphometry of the sagittae otolith of the Silverside in different environments (one lake and two dams of fresh water, 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, having a positive relationship with the conductivity of the water. Univariate and multivariate analyzes of variance  (ANOVA and MANOVA) showed significant differences (p<0.05) for the morphometric indices among the study sites. The discriminating analysis showed a high percentage of individuals well 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.