How fermentation helps on proliferation of beneficial bacteria in shrimp farming?

Hello everyone:

    Today we will see about the use of fermented probiotics application in shrimp farming.

    I already posted in my blog about aerobic, anaerobic bacteria uses in shrimp pond and definition about probiotics and it uses.

Fermented probiotics application before stocking:

     If you are doing shrimp culture, then you definitely know about this fermented probiotics application in your pond. 

      Different farmers uses different ingredients in the fermentation medium. Before that I tell about benefits of yeasts.

Note: Prebiotics+ Probiotics = Synbiotics.

If your applied the fermented probiotics with the help of prebiotics like ricebran then the final product called Synbiotics. 

We can't separately use prebiotic sources because some of them needs breakdown process through fermentation. We can't directly add probiotics because before adding we have to activate and proliferate the amount of beneficial bacteria.

For this reason only, we are going to fermentation and it is called Synbiotics and it have very good results compare to the separate use of prebiotics and probiotics.

Yeasts:

       It is a unicellular eukaryotic organism. Nowadays, many research going on that, how to utilize the use of yeasts in shrimp farming. Yes, it has various capabilities. Yeast can bring the chemical changes very fastly. It have high metabolic rate than bacteria and have rapid growth. It have good beneficial activity on animal gut also.

Fermentation of yeast with rice bran then adding probiotics into the medium gives very good results in shrimp pond.

      During fermentation, yeast produces valuable compounds and extracellular enzymes like amylase, cellulase, protease. The enzymes produced by the yeast is helpful for the probiotic bacteria for breakdown the compounds into simple molecules. Oligosaccharides are not digested by the intestine, by this process bacteria can breakdown these compounds into simple molecules. Yeast fermented in aerobic method gives good results, it produces end products such as carbon dioxide and water.

        Yeast can also tolerate the acidic environment. But specific strains only gives benefits. Mostly used species is saccharomyces cerevisiae.

   

It is one type of fermentation,

                        Rice bran 

(Used as a energy source for yeast and probiotic bacteria)

                       Yeast

 (Produces protein, phenolic compounds, bioactive compounds, antioxidants, antimutagenic compounds, anti inflammatory compounds, antimicrobials etc..)

                       Probiotic bacteria

(Specific strains like Bacillus, streptomyces)

           Aerobic fermentation for 18-24 hrs.

Fermentation for more than 12 hours gives best results.

Fermentation is nothing but the action of enzymes. If any reaction influenced by enzyme and produce any chemical changes, then it is called fermentation. In this preparation, bacteria utilize the energy source from prebiotics and with enzymatic changes happens inside the medium.

Ricebran:

    In this application, better to use defatted and deoiled ricebran for the better reaction. It contains good protein about 18-20%. High amount of sucrose and starch. It also contains vitamin B and minerals. It is a good food source for bacteria proliferation.

    Sometimes the oils content in the ricebran cause deterioration. Hydrolysis( chemical reaction in the presence of water) and oxidation of oil can be prevented by using defatted and deoiled ricebran.

Method:

    Heat the water to prevent the unwanted microorganism and add prebiotics sources like ricebran (also can use jaggery, soyabean meal and many other ingredients in the water),  and then add yeast (if you want) and add probiotics bacteria and give aeration for the complete process. In this process, yeast breakdown the ricebran and produce some valuable bioactive compounds from ricebran. Then the probiotic bacteria present in the medium also grows well by utilizing the energy and it also produce certain compounds. This is the simple narration of the process.

Combination of fermentation of ricebran and yeast give good results.

Uses in shrimp pond:

        If we applied to the pond water, the beneficial bacteria present in the medium spread into the pond and prevents the growth of harmful bacteria in that environment.

       Application of fermented juice will cause the formation of small flocs in the aquatic environment. It is used as the food source of the stocking species.

        The carbon source and other nutrients present in the fermented juice will increase the growth of zooplanktons like copepods in the pond ecosystem. 

         It also combines with other aggregates and forms microbial proteins which can used as food for shrimp. It cleans the harmful microorganisms  and converts the any organic matter present in the pond ecosystem.

         The beneficial compounds like antioxidants and immune supporting compounds etc.. are present in the end product of fermentation.

          These are the various use of fermented juice application in pond water. It will create perfect environment for shrimp growth. I just narrate the happening of reaction in the medium. Different farmers use different ingredients based on the guidence of technical supporter.

P.Dhivagar BFSc,

Technical executive - Growel feeds

9384346193

        

Blue green algae in shrimp pond.

Hello everyone:

   Today we will see about occurance and effect of blue green algae in shrimp pond.

What is blue green algae?

    Blue green is also known as cyanobacteria. Yes it is a type of bacteria. There many confusion in which kingdom it goes.. it is a prokaryotic (no nucleus). It is a photosynthetic organism and have various pigments like ...

Chlorophyll a - You saw green colour in this algae. This green colour is due to this pigment.

Blue pigment - phycobilin. 

It is called as Blue green algae.

Some have red pigments and carotenoids.

How we find in pond?

      You can easily observe the blue green algae by visual appearance. It have dark green in colour. It forms a mate at corner of the pond(at initial stage). Then it will spread to the entire pond.

Looks like green paint.

Examples:

      Microcystis, nostoc, oscillatoria, anabaena etc...

(Microcystis mostly found).

Did you know?

    Blue green algae have the capability of making mutual relationship with others. Ex: Anabaena make relationship with azolla.

   It reproduced by asexual (binary fission, fragmentation)

    Some filamentous species of blue green algae have the capability of spore formation.

Where bluegreen algae present?

     It is present in the surface of the water. This algae have some gas vesicles on its inner side. This has vesicles helps to float this algae always on surface region.

When it will appear?

      It is observed that more growth of blue green algae occurs in high temperature. Because high temperature causes formation of thermal  stratification layer on water. It prevents the mixing of nutrients. At that time this algae can easily compete with other planktons and prevents other planktons growth.

       It also appears when excess of nutrient loads is present in the water. If excess of nutrient like nitrogen and phosphorus present means it does not get out of your pond easily.

      Maintain proper usage of feed in your pond. 

It will not get out of your pond until the proper maintenance happens.

                  Improper pond management

                    Improper pond preparation

                         Wastage of feed

                 Loading of excess nutrients

      Chance for occurance of Blue green algae

                  Takes oxygen at night 

                   Affects shrimp health

                        Death of algae

                        Produce toxins

            Died algae moves to pond bottom

        Excess oxygen required for degradation

                       Increases BOD.......

So many bad things happens if you are not properly maintaining. Then waste of money..

Toxins:

     Bluegreen algae can produce toxins and it affects the shrimp. Toxins produced by cyanobacteria is called cyanotoxins. Some species release toxins at even alive. Some species release toxins after death. It require so many days to deactivate the toxins which is produced by bluegreen algae.

Microcystis produces microsystin toxin. Heavily occurance of bloom will produce this type of toxin.

Some species produce neurotoxin.

If it produces toxin means then it will affect the hepatopancreas of the shrimp. It leads to other diseases. Toxins does not kills the species easily but if the algae is eaten by the shrimp then it gives some bad odour. It is accumulated in the body of the animal.

Note: if not any feed available, at rare situation only shrimp eats bluegreen algae.

How to prevent in shrimp pond?

      Proper aeration required. Because aeration causes proper mixing of pond water. Avoid excess loading of organic wastes and other nutrients in pond. Properly maintain pH of the pond. Some earthern pond have huge phosphate accumulation, so it also leads to bloom. We have to check it. Properly disinfect the pond water. Good preparation method must be followed during preparation.

What will do if I found bluegreen algae in my pond?

     Cool.. we can control it. It is better to exchange about 25% of the pond water. Yes it is very better...keep it in mind..

     Try to manually removes the bloom.

     We have to prevent the nutrients , so use soil probiotics in pond and use sludge pump if any excess organic matter found in your pond.

     Increase the aeration in your pond.

      If you prevents the excess nutrients that is available for bluegreen algae, then it automatically destructed from pond.

     If these are not working then go for applying hydrogen peroxide at low concentration. There is a huge involvement of Hydrogen peroxide in killing bluegreen algae. But careful before application because excess application of Hydrogen peroxide leads to killing of other planktons in your pond.

     I will tell the reason of using Hydrogen peroxide in killing of blue green algae.

    You can also use copper sulphate to prevent this.

If your pond is affected by bluegreen algae. Properly prepare the pond for the next culture. Because if the bluegreen algae dies then this will release toxins , this toxins in active form for some days upto 2 months also. 

Proper maintenance leads to good culture...

                 Thank you 😊.

P.Dhivagar BFSc,

9384346193.

dhivagarfcri2000@gmail.com.

    

How and why white feces syndrome occurs in shrimp pond?

Hello everyone:

  Today we will see about white feces syndrome occurance and what are the major cause of white feces disease in shrimp.

In most of the cases white feces syndrome is not occurs alonely in pond. It is a one type of additional disease. If any infection comes to shrimp hepatopancreas then it will leads to the white feces disease. You can note that if your shrimp affected by EHP and Vibrio then later white feces disease comes. We prevents the disease only by improving the hepatopancreas strength.

It occurs when the hepatopancreas of the Shrimp severely affects. 

White feces syndrome - white to yellow brown of feces strings floats on the surface of water or found in check tray. It have good buoyant capacity for floating.

Shrimp bottom have various wastes and various types of pathogens present. If shrimp eats from the bottom then all types of microorganisms present in the bottom will enter into the shrimp gut. So we have maintain good microflora in the shrimp gut.

AHPND or Early mortality syndrome:

It is mainly caused in shrimps due to the bacteria and also by some parasites. Vibrio also causes this disease. In this disease , the pathogen first affect the hepatopancreas in the body. Then it multiplies and causes severe death. Types of worm like vermiform and parasite called gregarine are the major cause for the disease.

You have to properly check the seed before buying.

Relation between AHPND and white feces syndrome:

    It is the important factor of white feces disease. In hepatopancreas, if the vermiform and gregarine infects more then it cause the sloughing of cells.

It is called aggregated transformed microvilli which is sloughed with the epithelial cells in the hepatopancreatic tubule.

Aggregated transformed microvilli

Sloughing of cells

Hepatopancreatic tubule

Everyone knows about microvilli - it majorly involves in absorptive function in hepatopancreas.

These gregarine, worm and bacterial infection will affect the microvilli. Then it also leads to the death of hepatocytes in the hepatopancreas. Then the hepatopancreas in white colour due to loss of pigmentation. These highly white coloured death cells moves via gut and shows white in colour and leads to white gut disease. Then the fecal matters comes out from the body in white colour. We called it is white feces disease.

Death hepatocytes in hepatopancreas

Moves via gut (white colour)

White feces

When the concentration of bacteria,worm and gregarine infection increases they take nutrients from host. ATM (aggregated transformed microvilli) concentration determines the white feces. 

Symptoms:

 Decrease in feed consumption, decrease in growth rate , white gut(necrosis of epithelial mucosa and haemocytic enteritis, movement of cell via gut shows white gut). It sometimes causes lesions in hepatopancreas. Floating of white or yellow fecal mates in pond.

White feces occurs if any damage in hepatopancreas and other hepatopancreatic related disease. In some early post larvae hepatopancreas functions may suddenly changes due to any parameters. We have to properly maintain it.

We can prevent by giving proper gut probiotics to the shrimp from earlier culture days. Quality of feed is very important.  Some protists also present as host for that worms and gregarine parasites. So proper pond preparation is very important for good culture. Some of research also going about the proper reasons for white feces.

Hepatopancreas is very important for shrimp. It is doing important function in shrimp likes digestive and absorptive function. It releases digestive enzymes. It stores nutrients for the animal. It provides energy for metabolism, molting, reproduction. Different types of cells in hepatopancreas doing various function. We will see briefly about hepatopancreas colour and different cells in the organ and how to improve the hepatopancreas function in next blog.

P.Dhivagar, BFsc, Tamilnadu.

Email: dhivagarfcri2000@gmail.com

ph: 9384346193

What happens to the Moulted shells in shrimp pond?

Hello everyone:

  Today we will see some intresting topic. Anyone think about this? What happens to the Moulted shells and what reaction happens inside the shrimp pond.

Some interesting things happens.... Come on lets jump into the topic......

Exoskeleton:

      Shrimp is a crustacean which have exoskeleton for an protective cover of the body. It gives protection to the shrimp from disease and predations etc..

Shrimp have a moulting cycle. It occurs on the interval based on the body weight of the Shrimp.

In early stages moulting happens daily. 

Composition:

 The exoskeleton of the shrimp mainly consist of chitin and minerals. Chitin is a aminosugar compound(modified polysaccharide) which means it majorly contains carbohydrates and some nitrogen compounds. 

Many of people thinks , chitin is a protein but it is not right.

The major minerals present in the shell is calcium, phosphorous and also sodium, zinc , carbonates also present in the shell.

After moulting:

 After moulting the shells moves into the bottom and does not floats on the surface. The shells have some more density than water. Two main reaction happens in the pond environment,

Deproteinization and Demineralization (which means removal of protein and mineral.)

Chitin is the majorly decomposed by heterotrophic bacteria in the pond bottom. Some species like Pseusomonas, Bacilus, Flavobacterium etc. These microbes can use chitin for the growth.

                       Chitinolytic bacteria

                         Chitinase enzyme

                       Breakdown of chitin

                   Used as a energy source

How?

    Microbes uses carbon source from the chitin as the energy source. The remaining nitrogen also used for the energy source of beneficial bacteria. It is very intresting ,

Exoskeleton plays one of the important role in maintaining carbon and nitrogen source in pond ecosystem. Yes, but many of people don't know about this.

By the Demineralization process, minerals from the shells also released to the pond.

Some other chitinolytic bacterias like Aeromonas, streptomyces, Bacillus also have an capability of chitin disintegration. Some of these bacteria can lives both in aerobic and anaerobic conditions.

Some enzymes from zooplankton and fungi also have the capability of degrade this shells. I think now you understand the importance of microbial colonies in pond ecosystem. If your pond have huge sludge and organic matters means it refers to improper management of beneficial microbial colonies in the pond ecosystem. So pls use probiotics to your culture system for better management.

                                    Thank you.

Contact: dhivagarfcri2000@gmail.com

Mbl: 9384346193

How zeolite works on ammonia absorption in shrimp pond?

Hello everyone:

Everyone knows, In shrimp ponds, if ammonia increases then add zeolite to reduce ammonia. Everyone tells zeolite removes ammonia. But we must know the reaction for better clarification. 

Zeolite:

We can tell it is the type of mineral which contains sodium, aluminium, silicate. It has special function called adsorption (உறிஞ்சுதல்).

Zeolite have tetrahedral shape, it has a entry channels for adsorption. Zeolite can adsorbs 30% from their body weight. Imagine it can adsorbs how much? It is in powdered form.

Zeolite have pores for absorbing gases. It is mainly works on cationic exchange. 

How it works?

We don't directly apply zeolites granules to the water because if we applied directly means, there is chance for absorbing water and atmospheric air or other things through the pore size in zeolite in shrimp pond. So it make competition for absorbing ammonia.Our aim is for removing Ammonia. If we make some small balls or mixed the with sand and make balls is better for application. Because at this time if we make balls means there is less chance for contact with air . Then it will moves down to the pond and it's work will start.

Zeolites leaves it's negative charges on its surface. It attracts the positive ammonium ions and some other toxic metals. In the high concentration of ammonium ion, it absorbs this ion and leaves it's sodium to the water(cationic exchange process).

It is also used for the softening of water.

Zeolites functions based on salinity.

High salinity - reduces the ammonia adsorption.

Low salinity - increases the ammonia adsorption.

Why salinity affects adsorption?

Because high salinity have high concentration of minerals and cations. If the concentration of ammonium is lower than the minerals then the minerals make compete for the adsorption.

In this the zeolite will take some of minerals also due to their high concentration. It leads to reduce the level of minerals in water.

Less than 1 ppt Salinity have high adsorption of 9gm of ammonia per kilogram zeolite. Salinity increases then we have to add more zeolite.

                      Zeolite

                 Applied in water

            Sodium ions released

   Ammonia and toxic metals adsorbed

After adsorption of ammonia in water, zeolite makes the tight bond with ammonia and other toxic metals. It doesn't release it in water, then after some time it leached out very slowly and decomposed. I hope it will clears your doubt. 

Next blog will come with intresting topic.

I would like to thank the people who reads my blog from 22 different countries. Your reading gives some energy to me.

                               Thank you😊.

Mail: dhivagarfcri2000@gmail.com

Mbl: 9384346193

Complete details about EHP in shrimp pond.

Hello everyone:

        Today we will see about important disease occurs in shrimp farming called EHP. EHP, white spot syndrome, Vibrio, white gut, white fecal disease. These are incurable.

        Hepatopancreatic microsporidiosis is a disease caused by Enterocytozoan hepatopenaei, we called it as EHP. It is a microsporidian parasites and have intracellular action on host cell. It penetrates into the host cell and start multiplication.

          It is first discovered in P.monodon in Thailand in 2004, but it causes severe loss and wide spread from 2009.

Symptoms:

          By physical observation, we can't detect EHP in shrimp. We thought like, yes our shrimp grows well, no problem, but EHP shows it's work after some DOC. If your shrimp affected with EHP means, huge size variation occurs on the population. Shrimp grows very slowly. Farmers have a general doubt, before stocking we checked EHP for the seeds, at the time negative results came but how it affects? How it is possible?

            Remember that, in certain early stages of shrimp, this parasites does not proliferate in certain amount. So the PCR results is negative. EHP will detected on certain later stages of shrimp. This is the main problem. So we have check some often times for the presence of EHP in shrimps after stocking. If the shrimps affected with EHP, it increases the FCR. Lot of chance for feed wastage. It leads to affect in another water quality like Ammonia,pH and nitrite. Empty gut, soft shells also occurs in shrimps.

 How EHP enters into the pond?

Improper pond preparation.(if previous crop is affected by any disease, we have properly dry and disinfect the pond for next crop).

Improper biosecurity in farm.( Remember that biosecurity is the important one in farm).

Improper checking the quality of seeds during purchasing.

How it enters into hatchery?

    In broodstock management, we give high protein feed with polychaetes, clams to the shrimp.

    EHP is a parasite, it is mostly found in these live organism which is used as a feed in hatchery. There may be a one of the chance for contamination. So, it is better to give the food after heating or prevents the use of live animal for feed or frozen the food or radiate the food before application. It may reduce the parasite. The news told Artemia, mollusks, polychaetes are positively reported for EHP. Like vibrio, EHP also well proliferate in high saline condition. The Marine water must properly disinfected.

How it spread to other shrimps?

    EHP is generally enters into host by oral and fecal matter or directly affect the hepatopancreas. In hepatopancreas, it causes lesions and reduce the activity. In hatchery, if an animal is affected with EHP, the fecal matters released by the affected animal causes infection to other shrimps.

EHP is a spore forming parasite.

           Spores enters into the target host cell.

       Insert it's spore into target host cells cytoplasm

         New spores matures inside the cytoplasm by   nucear division.

     Spore cells matures, bursts, release the matured spores.

Infect the other cell... likewise spread into all cell...

Spores also excreted through fecal matter of the affected shrimp. It easily affect the entire population.

But in different salinities may affect the duration of spore formation of EHP. High saline and high hardness condition is favourable for EHP. Because, Ca is important for conducting cell events in EHP.

Low infection does not cause mortality or lesions.

EHP also associate with other disease like AHPND and white feces syndrome in vannamei.

In high proliferated condition causes other opportunistic bacterias to grow. By this triggeration also leads to WFD.

High pH also promotes faster extrusion of spores.

In hatchery, we have to properly maintain biosecurity measures, proper cleaning and disinfecting the eggs. It prevents the vertical transmission of disease. If you are maintains nursery, before going to stock in growout , you have to check the EHP one time.Proper pond management, proper biosecurity measures, proper sampling, proper selection of seeds, proper pond preparation is the important thing to prevent this infection.

        

Complete details about vibrio in shrimp pond.

Hello everyone:

         Nowadays, vibrio is a major threat to the shrimp farms mainly due to improper management of pond quality. It will leads to sudden mortality of all shrimps and huge economic loss occurs. If you are know about shrimp farming, definitely you often heard the word about vibrio.vibrio..vibrio..

          We have all the things for shrimp farming, we must ensure to have sufficient knowledge and proper maintenance of shrimp culture..

Vibriosis:

          It is a disease causes by the vibrio species. It is aquatic microorganism. We can't completely remove or eradicate the vibrio from pond. We have to do maintenance and controlling the proliferation of the bacteria.

         Vibrio is a gram negative and rod shaped bacteria. It is a facultative anaerobes (live with or without oxygen),but in high oxygenated condition it can produce high ATP for their survival.

           We often heard that, vibrio is majorly found in the shellfishes and cause poisoning. Yes, it is mostly present in the Crustacean shells. It is well proliferate in high saline condition. In pond preparation we very well aware about the presence of any shells or parasites.

            In high saline,cone shells also found and reproduce vigorously. We have to maintain good pond condition.

           Vibrio is opportunistic pathogen.

What is opportunistic pathogen?

           Opportunistic pathogen are not cause disease to the animal in normal condition, but if the animal is wounded or infected with other disease or reduced immune response occurs,, at that time vibrio cause disease to the animals. However various types of vibrio species found. Among them certain species such as Vibrio harveyi, V.parahaemolyticus,           V.alginolyticus are the majorly cause disease in shrimp farming. But one species Vibrio campbellii is related with wssv.

     Vibriosis causes tail necrosis, black shell disease, red disease and leads to loose shell syndrome, white gut disease, causes red colouration in pleopods and sides of the body. By this red colour appearance on the pleopods and sides of the body, we can conclude and immediately check vibrio count in lab. It causes yellowing of gill tissues. If the shrimp is infected with Vibrio harveyi means, we can detect by appearance of greenish lumniscence in the tail of the shrimp.

        Vibrio proliferate well at high salinity and high temperature conditions. It produce some quorum sensing and produces toxins. Some research told Vibrio alginolyticus can share and exchange the toxins to the other bacteria (under certain extreme conditions). Some species has the ability to alter the genome and produce variants and strains at certain conditions( like Corona virus ). At that time it is difficult to control.

 

       In lab we detect vibrio colonies using TCBS agar. This agar prevents the growth of other enterobacteriace such as E.coli, salmonella. Oxygall present in the medium prevents the growth of gram positive bacteria. Vibrio requires high alkaline Condition for the growth.

Sucrose - for metabolism.

Thymol blue and bromo thymol blue - indicates the pH changes. These are the important things present in the plating medium.

Some vibrio produces yellow colonies and some produce green colonies.

V.harveyi, V.parahaemolyticus - green colonies( not ferment the sucrose )

V.alginolyticus - yellow colonies ( fermented the sucrose in the medium and produce acids, it reduces the pH and yellow colour appears).

 

There is certain limit for the occurance of the vibrio. Yellow - less than 500 cfu/ml. Green - less than 50 cfu/ml in water.

In animal - yellow - less than 100 cfu/gm, Green - less than 50 cfu/ gm.

If the shrimp in stress condition, it leads to affect immune response and leads to increase in Vibrio.

Prevention:

            Source of water for the culture. The source of water is sea or Creek or river , it must be disinfect with chlorine. Because chlorine invades the vibrio in few minutes. If it is borewater ,we don't need to disinfect but we have to detect the presence of other toxic metals in the water. Proper preparation of the pond. Proper biosecurity measures. Use the gut probiotics to shrimp at the proper time reduce harmful bacteria in the animal.

             Prevents the accumulation of sludge in the pond. Properly maintains and give soil Probiotics to the pond. The beneficial bacteria numbers increases it prevents the other bacterial growth. It grows by the competition. Beneficial bacteria utilize the all nutrients and makes nutrient not available for harmful bacteria. So probiotics is very very important. Maintain proper biosecurity measures in pond and prevent disease and get profit... Vibrio present in all the times, but way of pond management leads to prevent the proliferation.

                               Thank you 😊.

    

       

Why quicklime is mostly used in soils? Why it is not used during culture?

Hello everyone:

Today we will see about reaction of quick lime in soil and it's importance in aquaculture. Instead of lime other materials also used such as dolomite etc. Particularly we see about quick lime.

Burnt lime(Cao)

If we treated burnt lime with water, it forms calcium hydroxide ( hydrated lime or slaked lime). Slaked lime is prepared by hydration with water.

Quick lime (Cao):

   It is also called as burnt lime or unslaked lime. It is named as burnt lime because of its method of  production.

    Everyone know that before going for stocking, we have to do liming and also heard that all persons use quick lime to the soil preparation. I am right?

    If it is a new pond or previously cultivated pond, anything it may be. But liming is important. If it is previously cultured pond means, there is lot of sludge,it is in acidic conditions and contains toxic ions, sulfur compounds. We want to correct it.

     Generally clayey pond bottom have acidic conditions with lot of Hydrogen and Aluminum ions. This cause the pH of the soil in lower level.

Lime has a reacting capacity with acids. By the reaction they neutralize the acidity. Hydroxides of lime produce carbonates by the reaction with carbon dioxide. It increases pH and alkalinity and hardness.

     If quick lime applied to the soil, it replace the bad ions present in the surface of the soil and make the soil free and increase the load bearing capacity of the soil.

Example: clayey soil have some of silica, alumina. After application of lime, Ca present in the lime reacts with these silica and alumina, it forms (Ca silicate hydrate) and (Ca aluminate hydrate.) These compounds increase the soil strength.

Calcium oxide is more reactive compared to other lime. Calcium oxide produce lot of heat when it applied with water and also suddenly increase the pH compared to other lime. If we applied this quick lime into the cultured pond means it may cause any stress to the cultured organism due to its heat producing capacity and sudden increasing in pH. So we use the Quick lime in soil only. Quick lime have high melting point. 

Lime increases the pH, alkalinity, hardness and calcium present in the lime promotes plankton production.

Note: Low pH leads to phosphorus deficiency in water.In low pH, phosphorus is tightly bound to bottom soil by irons and Aluminum. It causes the nutrient deficiency to plankton. By application of lime we can overcome this. Phosphorus is the limiting nutrient in freshwater.

Application rate of lime to the pond is generally based on the pH of the soil and Neutralizing efficiency of the lime. In water lime dissolves slowly. Lime also disinfect the harmful microorganisms present in the soil. By sudden increase in pH, microorganisms cannot able to tolerate and die. But in aquaculture, some of the researches told , we cannot completely kills vibrio by lime application. But we can control it. Lime is an disinfectant, it kills parasites and other small organism present in the pond soil. The reaction of lime also depends on its fineness and it's size. Limestones are not used in water because of its slow solubility. After application of lime in soil, it will take sometimes to complete the reaction. It also depends on the lime efficiency.

White is the colour of this lime . If we observed any other colour like brownish etc..We can conclude that there is a impurities in this lime. Early morning is better for application of lime. At this time the pH also low. 

                       Thank you 😊.

Which water is best for vannamei farming?

Hello everyone:

In this topic, we will see the small overview about which water is best for vannamei culture.

All are know , P.vannamei is highly cultured species in India due to its adoptability to various salinity of water. Yes, it adopt to various salinity and have good survival in high stocking densities. Good international market value. SPF seeds also available. So everyone likes to culture vannamei.

Seawater:

P.vannamei is cultured from varied salinity (0-35ppt).

Seawater is mainly composed of various ions like chloride, sodium, Magnesium, potassium, calcium.

These are the important ions which is required for the proper shrimp growth and development.

These ions very essential for osmoregulatory functions. In early stages of shrimp (post larvae) it must present in high saline water. Above PL 10 is best for altering salinity for adoptations. 

Seawater has the ability to prevent and control the solubility of gases such as carbon dioxide and other toxic gases. It also controls oxygen so aeration must present in proper manner at seawater culture. So there is less chance for decreasing pH in Seawater. It also have good alkalinity, so it have good buffering action against acidic pH. During culture, seawater does not requires high minerals, but freshwater or low saline water must requires high minerals throughout the culture.if we use borewater or Creek water, We must analyse the proper minerals composition present in that water. We must check hardnes, alkalinity, pH, presence of ionic compositions in the bore water. It may various between region to region.

In some researches told, low amount of ammonia and nitrite accumulation is found in Seawater compared to freshwater. In Seawater there is less chance for bloom compared to freshwater. But proper aeration required throughout the culture in Seawater under high stocking densities. High saline water is best for the vannamei farming. You must treat the water before use. Because it may contains various toxins or toxin producing algaes, parasites, insects. Sometimes alkalinity also less in freshwater compared to Seawater. If nitrification process occurs means, the alkalinity of the water gradually reduces to buffer the acidic pH. 

Main difficulties in shrimp farming is operational cost. Feed is a major operational cost. Aeration, current is another one. Minerals, probiotics is another one.. if we find low cost ,high efficiency feed , then shrimp farming is easily started in low investment. Do your research to make this possible. Thank you 😊.

Algal blooms and crashes in shrimp pond.

Hello everyone:

    Today we will discuss about the occurance of algal blooms and crashes in shrimp pond.

    These are the planktons, they are microscopic and survive by the process of photosynthesis in pond. They use inorganic nutrient and convert them into energy for their growth.

   We all know the limiting nutrients in freshwater and marinewater.

   Nitrogen - Marine water.

   Phosphorus - Freshwater.

The main reason for the algal bloom is increased nutrient concentration in pond water. In shrimp ponds, we apply many nutrient and use high protein feed. There is lot of possibilities in feed wastage and accumulation in bottom.

Nitrogen and phosphorus accumulation in the pond bottom is the main reason for the bloom formation.

If any imbalance between the microbial colonies or improper feed management can lead to increases in nitrogen concentration.

Phosphorus occured mainly by fertilizer application and runoff waters. Because phosphorus is accumulated in the soil. If runoff occurs,it leads to increase in concentration and also improper preparation of pond bottom also leads to increase in phosphorus accumulation in soil and liberate into water and leads to bloom formation.

Some of blue green algae formed in the blooms causes severe effect to the pond. It dominates the other species and high chance for producing toxins in water and affect the shrimp health.

If bloom forms, it prevents the entry of sunlight into the pond bottom. It affects the pH of the water. Heavy blooms can choke the gills of the organism and causes death.

If lined shrimp pond means we can easily manage the nutrient accumulation in the pond bottom. If it is earthern pond means , we must take care about heavy nutrient loading in pond bottom.

Some Farmers taken water from creeks and rivers, at this time we must properly treat the water to prevent the entry of toxic algaes into the pond. We must treated and  filtered with 2-3 nets in inlet pipe. 

Algal crash means sudden death of algae in pond system. Sometimes, We can observe the brownish colour with foams in pond edges. But soon after it moves into the pond bottom. Various reasons for the algal crash, sudden increase in temperature and sudden fluctuations in salinity, nutrient deficiency, absence of sunlight, will leads to crash of an algae. 

                           Death algae

                   Moves to pond bottom

            Need high energy for disintegration 

        Increased oxygen consumption ( by bottom               bacteria to disintegrate the death algaes)

               It affects the pH of the water.

So, many harmful effects behind the algae death. 

Treatment: 

  First don't use any chemicals. Manual removal  is the best method. Control the excess nutrients accumulation in the pond bottom. Increase beneficial microbial colonies. Use soil probiotics at the time of algal crash. If it possible means, partially exchange the pond water. Algal crash also leads to some turbid condition in water. Many persons uses fishes such as tilapia to control the organic matter present in pond bottom. 

These are the various problems and reason for algal bloom and crash in pond water.

I will post lot of informations about shrimp farming. if you want any specific topic means you can comment. Shrimp farming is growing sector. I hope the posts will gives you some little ideas. Share to your friends those who are interested in aquaculture. Thank you 😊.

Ammonia and Nitrite formation in shrimp pond. Why salts used to reduce nitrite toxicity in low saline water?

Hello everyone:

 Today we will see about ammonia and nitrite formation in shrimp pond and will see the reason why salts added to reduce nitrite in shrimp pond.

Before that ... We must know about osmoregulation.

Yes, Osmoregulation is a physiological process that occurs in aquatic organism to maintain the fluid in equilibrium. It said as salt and water balance of an organism. It happens in every aquatic organism.

 Freshwater fish - high salt in body than the surrounding medium.

 Marinewater fish - low salt in the body than the environment.

Usually the osmosis is the movement of water from low to high concentrated solution. kidney and gills do osmoregulation process.Through the skin and gills the exchange of water and salt takes place.

In Marine fishes have low concentration of salt in body compared to the environment. You imagine the Marine fish lives in the water with high salt content. The water present in the fish body moves into the environment through skin. This process is osmosis.( because water moves from low to high concentration). 

If this process happens means there is a problem of  loss of water in Marine fish occurs. To prevent this problem Marine fish drinks excess amount of water compared to freshwater and also it's excreted concentrated urine. Because if the urine is diluted means there is water loss occurs. So the modification of glomeruli in kidney of Marine fish retains the water inside of the body.

(Diffusion- movement of chemicals from high to low concentration.)

 I hope you understand about osmoregulation😊.

We will move into main topic. Pls continue the reading.......

Ammonia is present in two forms in water unionized ammonia and ionized form(Ammonium).

In this, unionized ammonia is very toxic and leads to change in water quality.

Ammonia is excreted as a metabolic waste of protein in shrimp body. vannamei is cultured in different salinity of water.

But there is many problems will be faced during low saline culture because of absence of much minerals in water.

High saline water prevents the solubility of toxic gases in water compared to freshwater.

High saline water maintains proper osmoregulatory function of the animal.

Ammonia is mainly excreted through gills and excreted through fecal matter by the shrimp that is present in the pond. We know that, shrimp requires high protein feed in the diet. 100 gm protein contains 16 gm of nitrogen. So there is a high chance for ammonia accumulation in pond. It also forms by wastage of feed and decomposition of any other solid particles like leaf ... It also leads to chance for producing ammonia in water. Ammonia has the capability of diffusing in the animal body by the process of diffusion.

Dead planktons settled on the bottom of the water. It also leads production of ammonia.

Ammonia - Nitrite - Nitrate ( nitrification process).

This process is accompanied by nitrifying bacterias that present in the pond bottom.

If any imbalance between these bacterias , it will affects the entire process.

Unionized ammonia is highly toxic in low DO condition. In low DO condition there is lot of possibilities of occuring denitrification process. So DO must be maintained in the constant level in water.

Nitrate - nitrite - nitrous oxides - nitrogen gas ( denitrification).

 Nitrite is the intermediate product of the both process. If nitrite toxicity increases, it enters into the blood and affects the oxygen binding capacity of the shrimp. Haemocyanin is present in shrimp. If nitrite enters into blood stream it reacts with haemocyanin and form methaemocyanin and causes hypoxic condition in body tissue.

It will affects the gills of the shrimp and reduce metabolism and leads to death of the shrimps.

After sudden increase in ammonia there is sudden increase in nitrite occurs.

In general, Ammonia causes reducing the osmoregulatory function of the Shrimp.

It causes stress condition to the shrimps.

Ammonia increases means automatically nitrite also increases. In this we prevents the nitrite toxicity by applying salts or giving proper nitrifying bacterias.

If we give salts, there is increases in chloride content of the salt increases salinity and reduce the solubility of toxic gases in pond. In stressed Condition, shrimp excreted excess of ammonical matter in the pond. If we applied salt into the pond, it regularise the osmosis and decrease the excretion of ammonical waste from the shrimp.

Increased chloride ion decreases nitrite toxicity. It also reduces the excretion of Ammonia from gill.

Salinity have the inverse relationship with nitrite toxicity.

Salinity increase -- nitrite toxicity decreases.

This is the main function of salt in the prevention of nitrite toxicity in the pond water. High pH, high temperature increases the toxic nature of ammonia. If Ammonia accumulated in the pond, it affect entire body of the Shrimp. Reduced feed consumption, sudden moulting, poor growth, affects the immune system of the Shrimp and nitrite toxicity affects the gills of the Shrimp.

If we maintain the proper feed in the pond system, we can reduce the Ammonia formation in the pond. Proper removal of bottom sludge, proper pond preparation and maintenance of proper bacterial colonies in the pond system can leads to good culture.....😊🦐