Oncogenic stress alters predator-prey interactions between a globally invasive and a native planaria species.

Oncogenic pressures, factors that increase tumor risk, are intensifying with human-driven environmental change, yet their ecological effects remain mainly unquantified. We examined how UVB-induced oncogenic stress affects interactions between two Australian freshwater planaria: the globally invasive predator Girardia tigrina and the native prey Cura pinguis. We hypothesized that DNA damage could either heighten prey vulnerability or impair predator performance. Native planaria showed less UVB-induced DNA damage, likely due to darker pigmentation, while damage in G. tigrina reduced predation rates, suggesting energetic costs of DNA repair. UVB also reduced movement in both species, with partial recovery in the invasive species but prolonged immobility in the native. Additionally, UVB strongly suppressed asexual reproduction in G. tigrina, indicating trade-offs between DNA repair and proliferation. These results reveal that oncogenic stress can reshape species interactions and invasion dynamics, underscoring the need to integrate cancer ecology into conservation and invasion biology.