Horizontal migration of Acartia pacifica Steuer (copepoda) in response to UV-radiation

It is known that zooplankton migrate vertically to avoid UV-radiation (UVR 280-400 nm) but little is known if such avoidance happens horizontally Here we showed that the copepod Acartia pacifica avoided UV irradiated fields horizontally Exposure of A pacifica to PAR or PAR + UV-A for 30 min did not make any difference in the horizontal distribution of the individuals However addition of UV-B radiation that is PAR + UV-A + B resulted in uneven distributions among the treatments with significant less individuals compared to the PAR or PAR + UV-A treatments More carotenoids and UV-absorbing compounds were found in the A pacifica individuals that chose to stay under the radiation treatments with UV It is concluded that A. pacifica can migrate horizontally to avoid UV-related harms and those contains more protective compounds were less sensitive to UVR (C) 2010 Elsevier B V All rights reservedNational Basic Research Programs of China [2009CB421207]; National Non-profit Institutes [2008M15]; State Key Laboratory of Marine Environmental Science Xiamen University [MEL-RS0919