1. Prepared By Abeer Alhabash

2. Fresh water has little salt concentration, organism can live in this water and adapt cells on the concentration of medium salt level. Prepared by Abeer Alhabash

3. Freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 0.05%.fresh waterriverslakessalinity These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations.physiologicaladaptations Prepared by Abeer Alhabash

4. Aim of work An experiment how can it adapt in different concentration of salt and effect on Physiological response of fish. Prepared by Abeer Alhabash

5. Identify ability some fresh water fish can accliumatized in differ of concentration of salt

6. Materials Goldfish large beaker Concentration of salt (5%, 15% and 60% and fresh water). Prepared by Abeer Alhabash

8. 1.Carefully remove a fish from the tank and place it in a beaker that is half filled with the water from the tank that held the fish. 2.Preparation of solutions ( 5%, 20% and 60% of salt) and fresh water (Control). 3. Placed in each basin fixed number of fish. 4. Experience relay daily and recorded the number of death in each concentration. Prepared by Abeer Alhabash

9. Solution 60% Solution 15% Solution 5% ControlDay LDLDLDLD1 2 3 4 5 6 D= death L=Live Prepared by Abeer Alhabash