Figure 1.
Study sites at Paranapanema sub-basin (São Paulo State): Itaúna stream (ITA) (Itatinga city); and Tibagi sub-basin (Paraná State): Preto stream (PRE) (Mauá da Serra city), Iapó stream (IAP) (Castro city) and Quebra Perna stream (QPE) (Ponta Grossa city).
Figure 2.
Results from the Principal Components Analysis (PCA) from the different sampling areas (ITA, PRE, IAP, and QPE) according to abiotic factors: pH, Ec (Conductivity), Turb (Turbidity), Temp (Temperature), Chl (Chlorophyll). The canonical axes explained 78.9 % of the variation. ITA: Itaúna stream, PRE: Preto stream, IAP: Iapó stream, QPE: Quebra Perna stream.
Figure 3.
Isotopic biplot of variation in mean δ13C and δ15N (‰) values calculated for juveniles and adults of Aegla castro at Itatinga from São Paulo State (ITA: Itaúna stream, Paranapanema sub-basin) and Mauá da Serra (PRE: Preto stream, Tibagi sub-basin), Castro (IAP: Iapó stream, Tibagi sub-basin) and Ponta Grossa (QPE: Quebra Perna stream, Tibagi sub-basin) in Paraná State.
Figure 4.
Variation in δ13C and δ15N for Aegla castro at Itatinga from São Paulo State (ITA: Itaúna stream, Paranapanema sub-basin) and Mauá da Serra (PRE: Preto stream, Tibagi sub-basin), Castro (IAP: Iapó stream, Tibagi sub-basin) and Ponta Grossa (QPE: Quebra Perna stream, Tibagi sub-basin) in Paraná State. Median values are represented by horizontal lines inside boxes (first and third quartiles); vertical lines represent minimum and maximum values. Differences between samples are indicated by different letters (Tukey test, p < 0.05). In C3 plants, the value of δ13C ranges from -22 ‰ to -34 ‰ (light gray), in C4 plants from -9 ‰ to -16 ‰ (gray), and intermediate values between C3 and C4 (white) (Vogel, 1993Vogel, J.C. 1993. Variability of carbon isotope fractionation during photosynthesis. p. 29-46. In: J.R. Ehleringer; A.E. Hall and G.D. Farquhar (eds), Stable Isotopes and Plant Carbon: Water Relations. San Diego, Academic Press.; Boutton, 1996Boutton, T.W. 1996. Stable carbon isotope ratios of soil organic matter and their use as indicators of vegetation and climate change. p. 47-82. In: T.W. Boutton and S.I. Yamasaki (eds), Mass spectrometry of soils. New York, Marcel Dekker.; Ducatti et al., 2011Ducatti, C.; Martins, C.L.; Arrigoni, M.B.; Martins, M.B.; Vieira Jr., L.C. and Denadai, J.C. 2011. Utilização de isótopos estáveis em ruminantes. Revista Brasileira de Zootecnia, 40: 68-75. ). δ15N values considered to come from human and animal origins are indicated by the orange bar (Heaton, 1986Heaton, T.H. 1986. Isotopic studies of nitrogen pollution in the hydrosphere and atmosphere: a review. Chemical Geology, 59: 87-102. ; McClelland and Valiela, 1998McClelland, J.W. and Valiela, I. 1998. Linking nitrogen in estuarine producers to land-derived sources. Limnology and Oceanography, 43: 577-585. ; Hoffman et al., 2012Hoffman, J.C.; Kelly, J.R.; Peterson, G.S.; Cotter, A.M.; Starry, M.A. and Sierszen, M.E. 2012. Using δ15N in fish larvae as an indicator of watershed sources of anthropogenic nitrogen: Response at multiple spatial scales. Estuaries and Coasts, 35: 1453-1467. ).
Figure 5.
Biplots of stable isotopes using the mean for δ13C and δ15N (± SD). Calculated values for Aegla castro and potential food sources from ITA (Itaúna stream), PRE (Preto stream), IAP (Iapó stream), and QPE (Quebra Perna stream).