How temperature plays major role in shrimp farming.(Water quality series - 1)

Hello everyone:

     Today we will see the importance of temperature in shrimp culture. What are the problems will come due to the temperature variance in shrimp pond.

     Most of the persons who doing shrimp farm must know about the things what happened during temperature Change.

     Shrimp grows very fastly, but we can't culture throughout the year. Why?

    If you are doing intensive or super intensive system means no problem. But you are doing the culture of shrimp on outside means you have to fix the culture days based on climate change(keep in mind). Ok let's jump into topic.

Temperature:

      Most of the farmers doing in outer earthern pond. So in these situations, temperature plays important role in growth of our shrimp. We all focus only on ammonia, nitrite, H2S, but indirectly temperature plays very crucial role.

        Heat is produced in water due to sunlight. Because sunlight have some energy in the form of photons , when it comes to contact with water then it transfers heat . It gives rise to increase in temperature.

         In other ways, solar radiation determines the temperature of water and air temperature also determines the temperature of water. Air is fastly heated than water. 

         For Penaeus vannamei can grows well in the optimum temperature range from 28-32 degree Celsius. Optimum temperature only gives good growth. Growth occurs in the organism by metabolic process and some biochemical process occured in the body.

         If temperature increases then it will increase the chemical reaction of water. If temperature increases then it cause evaporation and increase the salinity.(if water have 5ppt then high temperature causes evaporation of water and the salinity increase, because at the particular salinity, the water content is reduced and the excess salt remains in the remaining water).

          If you are not properly runs the aerator then it cause the formation of stratification layer in water. If the layer is formed then it prevents mixing. 

          Yes, oxygen only produced in the upper layer of water and not moves to bottom. It causes deficiency of oxygen in bottom of the pond. It prevents the decomposition process. In anaerobic condition there is a chance for occurs of various problems.

          Increase in temperature causes increases in reaction of chemicals. Any chemical like lime or any fertilizer will dissolves quickly. It is not effective. There is some chemical, these only better at high temperature application.

         Warmer water holds low dissolved oxygen

         Colder water holds more dissolved oxygen.

If temperature increases then it increases the respiratory rate of all aerobic organism that present in the pond include animals and planktons and also microorganisms.

If temperature increases then it increases the photosynthetic activity of planktons. Then it allows planktons to take excess co2, if no co2 available then it takes source from carbonates. It will decrease the alkalinity.

Temperature has indirect proportional to density.

Temperature increases - density decrease.

Temperature decrease - density increase.

If your pond have some algal blooms at higher temperature. It will prevents the entry of sunlight into deep. So the upper water is more heated . It causes the decrease in density of the upper layer. If density low in upper region means, it can't move to down and there is no chance for mixing of water and Dissolved oxygen into the bottom.

       

Pathogens:

       Some pathogens can proliferate well in high temperatures. So temperature also the chance of reason for pathogenic proliferation.

High temperature affects fluidity:

        High temperature causes the cells of the animal becomes more fluid. At this time fatty acids present in the cell is more rigid and allows the movement of all other compounds through the cell.

       By this movement, the cells become damage and leads to cell death. It mainly affect the lipid layer of the cell.

Affects the solubility of oxygen:

        Imagine this our pond water is a solution which contains solutes and solvent.

        Solution - solutes (salts) + solvent (water).

       Under high temperature causes low solubility of dissolved oxygen in water. Increase in temperature causes increases kinetic energy then the molecules from the solvent escape and return to gas. There is lots of chance of escaping of oxygen into out. 

       This the reason why colder water hold high dissolved oxygen than warmer water.

Increase in temperature also causes increases the solubility of ammonia.

Sometimes high temperature causes decrease the pH in water. It is not the meaning of acidity of water. In general,if the temperature of water is high, it increases the dissociation of Hydrogen ions from  waek acids that present in water. So it is the reason for that.

Several studies shows increases in temperature of pond will increase the FCR of the culture. This is due to increase temperature then increases the metabolic rates and enzymatic reaction in shrimp body. Normally some energy is required for the metabolic activity of the shrimp. If temperature increases then needs high energy then needs high feed, so FCR will increases.

Temperature causes major problems in shrimp growth. At particular temperature its growth and FCR is very good. Temperature increases then feed intake increases and reduced the growth rate of shrimp. 

Proper aeration is very important in shrimp farming. Proper mixing, proper aeration to all the region of the pond will prevents the all major problems in aquaculture.

I posted about impact of temperature in shrimp metabolism. Pls refer this in my blog.

                   Thank you 😊.

P.Dhivagar BFSc,

9384346193.

dhivagarfcri2000@gmail.com.