Effects of short time UV-A exposures on compound eyes and haematological parameters in Procambarus clarkii (Girad, 1852)

The amount of ultraviolet radiation (UVR) reaching the Earth's surface has been increasing as a result of an increasingly thinner ozone layer. The UV-A component of the UVR is able to generate oxidative stress in the compound eye and haemolymph of Procambarus clarkii when the latter was exposed for as little as 15 min daily for one week to UV-A. Changes in the eye involved corneal material, crystalline cones, pigments in cone stalks and retinula cells, rhabdom integrity, haemocyte infiltration, and haemal spaces. UV-A had significant impacts on haemolymph iron and glucose, whereas Ca ions were unaffected. Total protein and Cu-ions showed only insignificant changes following UV-A radiation. Involvement of lipid peroxidation and DNA fragmentation was significant with regard to the tissue damage cause by the UV-A. UV-A furthermore induced biological effects on serum electrophoretic patterns: some fractions either increased in size or others decreased. The described changes can be used as reference guidelines in evaluations of UV-A induced stress effects in P. clarkii