Variability of &amp;#948;13C and &amp;#948;15N in three zooplankton species from the Upper Paraná River floodplain

Ana R A Santana,Fabio Amodêo Lansac-Tôha,Evanilde Benedito

doi:10.1590/s1984-46702009000400017

Variability of &#948;13C and &#948;15N in three zooplankton species from the Upper Paraná River floodplain

Ana R A Santana, Fabio Amodêo Lansac-Tôha + Show 1 more

Open Access

https://doi.org/10.1590/s1984-46702009000400017

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Journal: Zoologia (Curitiba)	Publication Date: Dec 1, 2009
Citations: 4	License type: cc-by

Affiliation: Universidade Estadual de Maringá

Abstract

This study evaluated the isotopic composition of three zooplankton species - Notodiaptomus amazonicus (Wright, 1935), Moina minuta Hansen, 1899 and Bosmina hagmanni Stingelin, 1904 - from the Upper Parana River floodplain. We predicted that there would be isotopic variability among species in the different sampled environments. Samplings were conducted in three lakes from the Baia subsystem and in two lakes from the Parana subsystem. At each location, some abiotic variables were measured, and zooplankton (3 to 4) and phytoplankton (3) samples were taken. The species sampled did not present significant differences between subsystems; however, they were different among the lakes, with variations of about 10.8‰ for δ13C and 5.8‰ for δ15N. The isotopic values found for phytoplankton also did not differ significantly among sampling stations, presenting variations of about 9.3‰ for δ13C and 7.4‰ for δ15N. These results indicate that the isotopic values of species varied among the lakes, and that they are dependent on isotopic signals from phytoplankton.

Highlights

Ecologists usually quantify the niche through analyses of stomach content and the feeding behavior of consumers (KLING et al 1992)
This study evaluated the isotopic composition of three zooplankton species – Notodiaptomus amazonicus (Wright, 1935), Moina minuta Hansen, 1899 and Bosmina hagmanni Stingelin, 1904 – from the Upper Paraná River floodplain
The isotopic values found for phytoplankton did not differ significantly among sampling stations, presenting variations of about 9.3‰ for ␦13C and 7.4‰ for ␦15N. These results indicate that the isotopic values of species varied among the lakes, and that they are dependent on isotopic signals from phytoplankton

Summary

Introduction

Ecologists usually quantify the niche through analyses of stomach content and the feeding behavior of consumers (KLING et al 1992). To add to information generated by the carbon stable isotope analysis, the 15N isotope indicates the species’ trophic position because of the enrichment of 15N between the adjacent trophic levels by approximately 3.4‰ (VANDER-ZANDEN et al 1997, VANDER-ZANDEN & RASMUSSEN 2001, POST 2002) Studies using this technique with zooplankton generally consider these organisms to be at the level of higher taxonomical groups. Considering that zooplankton is the principal link in energy transfer to the other trophic levels, it is extremely important to study it using isotopic variability Besides their high productivity, the floodplains are characterized by the input of organic matter due to the high levels of sedimentation in these environments (JUNK et al 1989). In this paper we test the hypothesis that there is isotopic variability among zooplankton species, in keeping with the isotopic variation observed in phytoplankton in the different environments from the Upper Paraná River floodplain

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