Abstract
The silverside Odontesthes bonariensis is a euryhaline species native of South America and represents a very important fishing resource for the Plata Basin (Argentina and Uruguay). This study compares the Sr:Ca ratio of water as well as the Sr:Ca ratio and morphometry of the sagittal otolith of the silverside present in different environments (one salt lake, two freshwater dams, one lagoon, and one estuary) in order to evaluate the use of these variables as markers of habitat. The pattern of the Sr:Ca ratio in 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 indicated significant differences (P < 0.05) among the localities studied for the morphometric indices. The discriminant function analysis provided a high percentage of correctly classified individuals for the saltwater environment (100%) and the lentic water bodies and estuary (60–80%), circularity and form factor being the most relevant morphometric variables. These results indicate that the Sr:Ca ratio and otolith morphometry are good markers of habitat for this important resource.
Highlights
The Argentinian silverside, Odontesthes bonariensis (Valenciennes 1833), is one of the most important fishery resources in estuaries and rivers of southwestern South America
Low values were recorded for the Plata estuary and Los Alisos Dam waters, and there were no differences between these two sites (Kruskal–Wallis, P > 0.05)
There were no significant differences between the Sr:Ca ratios of the silverside otoliths from the Cabra Corral Dam and Plata estuary (ANOVA, P < 0.05)
Summary
The Argentinian silverside, Odontesthes bonariensis (Valenciennes 1833), is one of the most important fishery resources in estuaries and rivers of southwestern South America. Ciencias Marinas, Vol 41, No 3, 2015 feeds primarily on plankton, whereas during the adult stage, it ingests other organisms such as gastropod molluscs and crustaceans (Escalante and Grosman 2001); in lotic water bodies where plankton is relatively scarce, such as the Plata River estuary, the silverside’s diet is mainly based on molluscs and fish (Escalante and Grosman 2001). Sexual maturity is attained between the first and second year of life (total length of ~140 mm), depending on the region (Barco 1986)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
