Effects of sudden salinity changes on short-term hematological and biochemical responses in Mudskipper Periophthalmus waltoni Koumans 1941 (Gobiidae: Perciformes)

The present study investigates and reports the effects of sudden salinity changes on short-term hematological and biochemical responses in Walton's mudskipper, Periophthalmus waltoni. For this purpose, mudskippers caught from coastal area of Persian Gulf (Bandar Khamir, Hormozgan Province, Iran) were acclimated and fed with frozen blood worms (Chironomus) for one month prior to the start of experiments. After acclimation, groups of 15 individuals were fully submerged in either dechlorinated tap water (fresh water; Group A), 50% seawater (SW) (17‰ salinity; Group B), or 100% SW (35‰ salinity; Group C) during a period of 24 hours. Fish which were free to be in or out of 50% SW served as controls. Statistical analysis showed a significant influence of salinity levels on erythrocyte, haemoglobin, haematocrit, leucocytes, lymphocytes, neutrophils, monocytes and on all biochemical parameters tested during the study. It seems that the changes recorded in haematological and biochemical parameters were the best strategy that the Walton's mudskipper has to adapt itself to an environment with different salinity levels.