Sex-dependent effects of ultraviolet radiation on the marine amphipod Ampithoe valida (Ampithoidae)

•The effects of ultraviolet radiation and diet on males and females of a marine amphipod were evaluated.•Females preferred diets rich in UV-absorbing compounds (UVAC), and accumulated more under UVR.•Males did not show preference for any food type.•Mortality due to UVR was detected only for females, with highest values in poor UVAC diet.•Differential response depending on the sex of organisms must be consider in future studies.

The combined effects of solar radiation and diet on the marine amphipod Ampithoe valida were investigated exposing individuals to two solar radiation treatments: PAB (>280 nm, PAR + UV-A + UV-B) and P (>400 nm, only PAR), and three diets: poor (Ulva rigida) and rich (Porphyra columbina) in UV-absorbing compounds (UVAC), and mixed diet: (U. rigida + P. columbina). Females of A. valida showed higher food consumption rates when diets contained P. columbina, and preferred this macroalgae rather than U. rigida, resulting in a higher content of UVAC in their bodies. Moreover, the content of UVAC increased in the PAB treatment, thus suggesting the existence of a mechanism to accumulate these compounds under UVR. Although UVR affected the survival, the highest mortality rates were found in those females fed with poor-UVAC diets, which evidence that UVAC provided partial protection against UVR. Males preferred mixed diet, and did not show preference for any particular macroalgae. No differences in mortality were observed between radiation treatments, indicating that UVR did not affect the survival of males, independently if they accumulated UVAC or not. The vulnerability of females to UVR would be partially determined by the type of food consumed, which in turn would be closely related to the macroalgae composition of the intertidal they inhabiting. These effects could be even more pronounced under a global change scenario.