UV radiation effects and bioaccumulation of UV-absorbing compounds in Artemia persimilis larvae

Abstract

The aims of this study were to determine if larvae of Artemia persimilis (Crustacea: Branchiopoda) can bioaccumulate ultraviolet radiation (UVR) absorbing compounds like mycosporine-like aminoacids (MAAs) through the diet and the probable protective role of this compounds on larvae of shrimp. Metanauplii II-metanauplii VII of Artemia were feeding with microalgae to produce UV absorbing compounds like Thalassiosira fluviatilis and Chaetoceros gracilis previously irradiated with UVR. Additionally, were studied if this irradiation affects their ingestion rate, survival and growth. Microalgae grown in F/2 media during 20 days in semi-continuous cultures, under two radiation treatments: 1) PAR (400-700nm): with an average irradiance of 300 μmol quanta m-2 s-1 for photosynthetically active radiation and 2) UVR+PAR (280-700 nm): with an average irradiance of 300 μmol quanta m-2 s-1 for PAR plus an average irradiance of 20 W m-2 simulating natural conditions. Only for those specimens fed with UVR-irradiated algae, a peak of absorption (334 nm ~ 0.13 OD/n) in the UVR range was observed. There were no significant differences in Ingestion rate (192 ±10 and 176±7 µL ind-1 h-1) and growth (400 y 370 %) between no irradiated and UV-irradiated treatment, respectively. After exposition to UVR stress for 48 hours those individuals fed PAR-treated algae showed mortality rates ~50 %; whereas those fed UVR-irradiated algae present survival rates ~90%. The results implies that larval stages of A. persimilis can bioaccumulate UV-absorbing compounds through their diets, supporting the idea that this compounds plays an important role by protecting against UVR stress.