An update on the effects of ultraviolet radiation on marine crustaceans

MARCOVAL MARIA ALEJANDRA; FENUCCI JORGE L

Cordoba

Simposio; 16th International Congress on Photobiology; 2014

The depletion of the ozone layer is constantly increasing. This atmospheric lack in protection against UV radiation (UVR) generates several impacts on marine organisms, including phyto- and zooplankton communities, rendering them particularly vulnerable to projected climate changes. Planktonic species may nonetheless show several strategies for protection against enhanced solar UV stress, such as vertical migration, as well as the synthesis of screening substances (e.g. carotenes) or UV-absorbing compounds (e.g. mycosporine-like amino acids, MAAs). The literature is extense regarding UV-absorbing compounds in zooplankton, which may be obtained from their algal diet or through symbiotic associations. However, when it comes to studies on marine crustaceans from coastal Argentina, the information is scarce. This paper reviews the effects of UVR on planktonic larvae of the Argentine red shrimp, Pleoticus muelleri, as our model organism. Larval stages of marine organisms are key study models for the evaluation of the deleterious effects of UVR on growth and survival, since they are more vulnerable to solar UV than the later stages; these effects translate into adult populations. Feeding P.muelleri larvae with different UV-irradiated microalgal diets, we found that UV- absorbing compounds synthesized by Chaetoceros sp. and Pavlova sp. are bioaccumulated in tissues of P. muelleri larvae. Moreover, larval growth, survival and development are dependent upon the concentration of these UV-absorbing compounds. This results in a dietary photo-protective effect under UVR stress, which might allow P. muelleri to acclimate to long-term UVR exposure. Additionally, preliminary data on antioxidant activity from UV-irradiated larvae point to MAAs accumulation as an effective protection strategy against UVR in P. muelleri larvae. Understanding the underlying mechanisms of sublethal and lethal stress factors, and the differences within and among species in their abilities to respond to these stressors, projections can be made about their success or failure to cope with climate change.