Synergic effect between temperature and ultraviolet radiation on aquatic

PATRICIA E., GARCIA; DIEGUEZ, M. C.; ZAGARESE, H. E.

Lake Placid, Florida (U.S.A)

Workshop; Gleon 6 Workshop; 2008

GLEON (Global Lake Ecological Observatory Network)

It is well known that the increase in solar irradiance threatening both ecosystems and organisms of mid inhabiting mid and high latitudes of the earth. At the organism level,different mechanisms and strategies provide protection to endure life at high irradiance and particularly, to cope with high ultraviolet radiation (RUV) levels. The accumulation of  Photoprotective compounds (PPCs), such as carotenoids and mycosporine-like aminoacids (MAAs) has been shown to improve the survivorship of aquatic organisms exposed to high levels of RUV. In this study we analyzed the variability of carotenoidsand MAAs in a calanoid copepod in relation to temperature and RUV. The crustaceans  were collected from the shallow pond “Los Juncos” (North Patagonia, Argentina). Theresults of laboratory incubation show up that PPCs (both MAAs and Carotenoids) were highest at 16ºC in the presence of visible light (PAR + UV-A). Remarkably thesurvivorship of the copepod decrease with increasing temperature and in the presence of visible light. This may be related to the fact that Boeckella species are cold-adapted and as reflected by they  occurrence at mid and lower latitudes during cold months. Thus, Boeckella may be vulnerable to the increase in temperature which could condition their occurrence resulting in changes in geographical distribution as has been observed in several different animal and plant.