PFOS (perfluorooctane sulfonate) is one of the perflourinated organic compound, which persist as a residual compound in the coastal environments. Intertidal mud crab Macrophthalmus japonicus mainly inhabits in coastal and bay ecosystems in Indo-Pacific region including Korea and reflects to environmental changes. In the present study, M. japonicus were exposed to different concentrations of PFOS and various ecotoxicological end-points such as survival rate,
elimination of appendages, changes of the crust and internal organ color changes were investigated. Interestingly, the PFOS exposure showed concentration-dependent decrease of survival rate. High PFOS exposure (30 μg L-1) showed a low survival rate of 24% at 168 hours. Further, in comparison with the controls, the rate of elimination of appendages was also considerably increased in a time dependent manner upon PFOS exposure. Notably, with progression of time, an increased exposure to PFOS, test species showed whitening effect in a concentration-dependent manner, whereas the crab crust color was unchanged in the control. In addition, change in internal organs color and their visibility (clarity) observed in PFOS exposed crabs compared to control. Taken together, we suggest, eco-toxicology end-points of M. japonicus exposed to PFOS gave important biological information which could be useful to identify toxic contamination in the marine benthic environments.