Reason for the white spot formation and yellow colour on exoskeleton of vannamei....

Hello everyone:

            Today we will see about the white spot formation in vannamei.. 

Reason for white spot formation in carapace of vannamei. 

        Sometimes,  we can observe the white spots present on the molted carapace shell. It's absolutely looks like the spot which occured by white spot syndrome virus. But there is significant difference present between these white spots. 

# Possibilities of occuring. 

     1. It may be due to white spot virus. If it is white spot virus. Shrimp showing less feed intake, lethargic swimming, and mortality occurs heavily within 3-5 days. If these are not happens means, your shrimp have no white spot virus..... 

  

     2. Second possibility is the important one.. Most of the farmers using bore water for their culture. It have more alkalinity content. When you are culturing water goes more than 8.3 pH, then there is a less chance for mineral dissolution in water. It can't dissolved in water, it will deposit on the bottom... 

       That time these minerals also deposits on carapace of the shrimp. When moulting will occurs then it will be lost. The exoskeleton of the shrimp have different layers. 

              

              Epicuticle

             Exocuticle

            Endocuticle 

             Epidermis. 

  The calcium present in the exoskeleton reacts with excess carbonates in the pond and get deposited like white spots in surface of the exoskeleton... 

This conditions mostly occurs in farming side when the pH and alkalinity of the water is high. 

       High minerals application doesn't give good results, it will create improper environment in pond. Excess minerals also cause yellow colour deposition on the exoskeleton. The minerals applications must be based on the ratio and deficiency..  Contact for more info and consultacy services... 

                   Thank you... 

Better feeding frequencies for P.vannamei.......

Hello everyone:

            Most of the farmers doing different feeding frequencies in their farm. Is it working? What are the advantages, disadvantages in changing feeding and feeding frequency for vannamei... We will see in detail. 

Shrimp digestion:

            Vannamei has short intestine and the digestion process also held fast. Most of the omnivore and carnivore species have short intestine compared to herbivore species. It also takes less than 3 hrs for digestion. The food materials passes via oesophagus and get into stomach (Foregut - Midgut - Hindgut).The digestion started in stomach and most of the nutrients absorbed into hepatopancreas and other regions. 

Common thought :

            Most of the farmers thought that the more frequency of feed increases the growth of the shrimp. But it is not fully true.. 

* Shrimp roam more in the night time comparing to daytime. 

* The increasing the frequency of feed will increase the secretion of more enzymes for digestion and absorption and leads to imbalance production of enzymes. If shrimp fed with more frequency of feed in daytime then it use more energy at the night time for physical activities. 

Enzymatic activity:

      Researchers analysis the best feeding frequency for vannamei.. 

1- Shrimp fed with more frequency in daytime have secreting more amylase enzymes at night time. 

              

2- Shrimp fed with less frequency (2-3 times) secretes less amylase enzymes at night time. 

  * This amylase enzymes is  used to breakdown the carbohydrates. This enzyme secretion denotes more energy spending at night time. This states more physical energy spending on night time by giving more feeding frequency. 

Better results:

        Feeding shrimp with 2,3 and 4 meals per day shows good results in survival, FCR, water quality.... 

But... If your pond has affected with any disease or if you want to boost your shrimp health, that time you can give extra functional feed to the shrimp. 

There is no significant change in growth for the shrimp which is fed with more frequency of feeding. 

Main disadvantages:

      If you increasing the feeding frequency then you have to increase the gut health of the shrimp. Otherwise more feeding will affects gut health and leads to gut related disease. 

     Improper pond environment with pathogenic bacterial population - results in gut related disease. 

     

We have to focus on........ PRIMARY PRODUCTIVITY of the pond. 

Earlier DOC - Shrimp must be fed with high nutritional feed and Planktons. The maintenance of zooplankton will leads to good culture. Grow out with 2-4 frequencies is better for shrimp. 

Is night feeding working? 

        Most of the researches tells night feeding is not successful in earthern systems. Because various water quality, behaviour of shrimp will plays important barrier during night feeding. We will see in next blog. 

                       Thank you🙏. 

Reason for the foam formation in pond water....

Hello everyone:

       Today we will see about the reason for the foam formation in aquaculture pond... 

       Many persons seeing in the early morning or evening time, when the aerators running, at that time more foam will forms on the water surface and spreads to the entire water column. 

Reason:

     1, If you applied any hydrophobic agents to the pond, then the foam will come for certain hours. 

    2, Sometimes plankton crash causes little amount of foam on the edges of the pond. 

     If you are not applied any agents but foam come means, then what is the reason?... 

      It may be due to the presence of dissolved organic nutrients in your pond. If you are using high protein feed or doing culture with high stocking density are the important reason and also due to improper management will leads to accumulation of organic load in the pond.. 

      In this organic matters most of them are hydrophobic in nature. When the aerators creates oxygen that time they accumulate on the bubbles in airwater interface.. More formation of air- water interface will leads to more accumulation of organic compounds on the bubbles. 

       These organic compounds present on the edges of the foam and create more foam when the organic nutrients is more in pond water. 

In biofloc.... 

          You can see this type of foam in biofloc culture.... Excess foam means excess nutrients... Partial water exchange and feed the fish based on body weight is the solution. 

          After breakdown of the bubbles, again the nutrients will go into the water and leads to change in water quality parameters... These are the important reason for the excess white foam in pond water.. There may be due to the other reasons also... We can tell based on pond conditions... 

For more info and technical services pls contact me...  Thank you...