Figure 2. Isotopic signature of sources, invertebrates and fish in three rivers of the Iténez basin (Amazon, Bolivia).

Biplots display mean values (± sd in error bars) of δ¹³C and δ¹⁵N values for sources (A,B,C) POM =  Particulate organic matter, Litt =  Leaf litter, Peri =  Periphyton; C3 =  C3 aquatic macrophytes and TVeg =  Terrestrial Vegetation; and invertebrates groups (D,E,F): Ephe =  Ephemeroptera, Odo =  Odonata, Dec =  Decapoda, Col =  Coleoptera and Gas =  Gasteropoda. (G,H,I) represented mean values (± sd in error bars) of δ¹³C and Trophic Position (derived from δ¹⁵N) of fish species: detritivore (1 =  Curimatella cf. alburna, 2 =  Psectrogaster sp.), herbivore (3 =  Schizodon fasciatus), insectivore (4 = Triportheus angulatus) and piscivore (5 = Pseudoplatystoma sp., 6 = Pygocentrus nattereri, 7 = Hoplias malabaricus and 8 = Acestrorhynchus sp.). In biplots (A,B,C), C4 aquatic marcophytes (δ¹³C : −12.3 to −13.2‰; δ¹⁵N : 2 to 2.2‰) were not plotted and δ¹³C and δ¹⁵N values of detritivore (1, 2) and herbivore (3) fish species were reported.