UV-absorbing compounds acquired through the diet are not enough for a marine mesoherbivore to cope with solar ultraviolet radiation

VALIÑAS, M.S.; HELBLING, E.W.

Granada

Encuentro; 2015 Aquatic Sciences Meeting Aquatic Sciences: Global And Regional Perspectives ? North Meets South; 2015

Association for the Sciences of Limnology & Oceanography

One way by which animals could obtain protection against ultraviolet radiation (UVR) is from their diet, by acquiring photoprotective compounds (UVabsorbing compounds, UVAC) synthetized by primary producers. We evaluated the potential impacts of solar UVR and diet quality on newborn carrying females of the marine amphipod Amphitoe valida, a key secondary producer from Patagonia coasts (Argentina). Amphipods were exposed to two radiation treatments: visible light + UVR and only visible light, and three diets: poor in UVAC (Ulva rigida), rich in UVAC (Porphyra columbina), and mixed (both macroalgae). Females showed higher food consumption rates and higher UVAC content when fed on diets containing P. columbina, and preferred this macroalgae over U. rigida. Moreover, individuals exposed to UVR accumulated more UVAC than those exposed only to visible light, suggesting the existence of a mechanism to differentially accumulate UVAC depending on the radiation type. Despite this differential accumulation, mortality was higher in the presence of UVR, which indicated that UVAC cannot provide full photoprotection in A. valida females, at least after a short feeding period with diets containing these compounds.