Salinity adaptation and sea water tolerance are vital and energy demanding process in the life history of anadromous species such as kuttum fish. As a results of this phenomenon the blood electrolytes fluctuation would be prevented. Evaluation on feed deprivation in ion changes of kuttum fish is the aim of this study. Kuttum juveniles with average weight of 0.5 gram were divided into the couple groups. One group considered as a control and were fed ad libitum during over the experiment and fishes from another group were left fasted. Both groups were exposed to the salinity challenge for 7 days and sampling was done in second, third, fourth and seventh days after challenge initiation. Consequently Na+K+ATPase activity, monovalent (sodium, potassium and chloride) and divalent (calcium) ions were evaluated. Results showed significant decrease in NaKATPase activity as a result of fasting. Some ions (Ca and K) were also decreased significantly. On the other hand, Sodium and chloride were increased in the feed deprived kuttum fish. Based on obtained results we can conclude that feed deprivation may have a disruptive effect on success in seawater adaptation. Therefore more attention should be considered about feeding as an important factor in kuttum recruitment policy.