Salinity effect on freshwater fishes

Done by: Sumaiah AlghamdiHind alsubeie

Submitted to T: Alanood

Content

• Introduction • Material and methods• Result • Discussion • References

Introduction • Salinity is one of the important environmental

factors affecting survival, growth and distribution of many aquatic organisms optimal salinity levels for growth, survival and reproduction competence are often species–specific (1)

• In this study we try to find out the ability of freshwater fishes in adaptation for salinity by measuring different concentration of salinity which affect the physiological function of the fishes bodies.

Material and methods

Material :• 3 aquarium in each one 2 fishes .• The first one is control • The second one with 5% salt in

1000 ml water + 150 g NACL salt • The last one with 15% sal in 1000

ml water + 50 g NACL salt Method:• Watch the experience every day

with and write the changes and deaths in each aquarium during 7 days.

Result

Day and date

Aquarium 15% Nacl

Aquarium 5%Nacl Control Note

  D L D L D L  Day 1 2   2      2  

Day 2              

Day3              

Result

Physiological changes• Low energy• Rigidity in the body• Loss of scales• Secretion of substances from the body• Death

Result

Discussion • As the result showed that some Changes in

salinity can effect biota in freshwater directly or indirectly .

• the major limiting factor affecting the survival of freshwater fishes is seawater and  exposure to salinities greater than about 9% is Absence of efficient  efficient branchial and renal mechanisms osmotic stress which increase osmotic pressure and deterioration of cell function  also this   effect accompanied by changes in Na+ K+ ATPase activity ,Co2 level and acid-base balance(3)

Any question

Thank you

References

• Effect of salinity on survival and growth of giant freshwater prawn Macrobrachium rosenbergii (de Man)B.K. Chanda, R.K. Trivedib, S.K. Dubeyb,∗, S.K. Routb, M.M. Bega, U.K. DasbaDirectorate

• Effect of increasing salinity on freshwater ecosystem in Australia . D.L .Nielsen ,M.A.Brock , G.N.Rees and D.S.Baldwin

• Effects of salinity on freshwater fishes in coastal plain drainages in the southeastern U.S Mark .S.Peterson . Michael .R.Meador