Study of osmoregulation ability in rainbow trout juvenile (Oncorhynchus mykiss) after move to the Caspian Sea

Subject Areas : New Technologies in Aquaculture Development

Received: 2021-02-02 Accepted : 2021-02-02 Published : 2013-05-22

Keywords: Oncorhynchus mykiss, Osmoregulation, Keywords: Rainbow trout, Osmolarity, Brachish water,

Abstract :

Abstract[1] In this study, changes in osmolarity of blood serum in 150 fingerlings of rainbow trout with a average weight of 20.01±1.33, in order to determine the compatibility with different salinities for fish farming in brackish water. Fish were studied in different salinity levels including 7 ppt, 11ppt, and 0ppt (fresh water). Blood sampling was performed from caudal vein at times 0, 24, 48, 72 and 240 hours after the beginning of experiment. After centrifugation and separation of blood plasma, osmotic pressure was measured by osmometer. The results showed that osmolarity at 0 salinity (freshwater) was 313.7±18.5 mosm/L and after 10 days experiment, this value in 7ppt salinity was 331. 7±7.7mosm/L. In this salinity levels and time no significant difference was found with time 0. After 10 days in 11ppt salinity, the osmolarity value was 367.6±15.5 mosm/L. At this time a significant statistical difference was observed with time 0. Therefore, according to the results, osmotic pressure changes within 10 days showed capability of osmoregulation in tested fish in 7ppt salinity. But fish which were in 11 ppt salinity did not manage to regulate their blood osmolarity.   * Corresponding Authors; Email: [e-mail]