Figure 5.

Difference in the isotopic signature of non‐symbiotic and symbiotic organisms. In non‐symbiotic organisms, the light isotopes are removed first during the processes of respiration and excretion, leaving the heavy isotopes in the tissue. The tissue will thus be enriched by ca. 3‰ in ¹⁵N and 1‰ in ¹³C at each trophic step. In symbiotic associations, nutrients are continuously recycled within the association, and the isotopic signature of the symbiosis will be a mix between the different food sources