Figure 2.

The independent and interactive effects of chronic exposure to UV-B and predatory chemical cues (PCC) on (a) burst swimming performance (i.e. the average swimming velocity (mm s⁻¹) over 100 ms) and (b) survival time (min) in a predator environment of L. peronii tadpoles. LUV and HUV denote low and high UV-B levels, respectively, and PCC⁻ and PCC⁺ denote PCC absence and presence, respectively. In (a), n = 40, 35, 29 and 29 for LUV PCC⁻, LUV PCC⁺, HUV PCC⁻ and HUV PCC⁺, respectively. In (b), n = 41, 33, 37 and 37 for LUV PCC⁻, LUV PCC⁺, HUV PCC⁻ and HUV PCC⁺, respectively. Data represent means ± s.e. Exposure to high UV-B did not affect the burst swimming performance (p = 0.97) of tadpoles, but reduced their survival time in a predator environment (p = 0.02). Exposure to PCC significantly increased the burst swimming performance of tadpoles (p = 0.03), and increased their survival time in a predator environment (p = 0.03). There was no interaction between UV-B and PCC for burst swimming performance (p = 0.45), nor survival time in a predator environment (p = 0.58). Open bars, PCC⁻; filled bars, PCC⁺.