Facts, Truths and Myths about SPF Shrimp

/ 10:40 PM
Shrimp domestication and genetic improvement programs began in the late 1980s, in the United States of America, under the United States Marine Shrimp Farming Program (USMSFP), using the Pacific whiteleg shrimp Penaeus vannamei.  The USMSFP was based on proven concepts from the livestock and poultry industries and began with establishing a specific pathogen-free (SPF) shrimp stock.  The original shrimp stock was obtained using rigorous screening of captured wild shrimp for selection of individuals naturally free of major shrimp pathogens.  Although the concept of SPF animals was well defined for terrestrial animals, it was relatively new for aquaculture, and it took some time to be adopted by the aquaculture community.  In the early 1990s, parallel to USMSFP, several other programs on genetic improvement of shrimp were initiated in Latin America.  Subsequently, several new terminologies and products, such as specific pathogen resistant (SPR) shrimp, specific pathogen tolerant (SPT) shrimp and even ‘all pathogen exposed’ (APE) shrimp, entered the shrimp industry vocabulary and became commercial.  This led to confusion in the shrimp industry about the meaning, relationship and significance of these new terms with respect to SPF.
SPF Mother Shrimp
The concept of specific pathogen-free (SPF) animal stocks and the technology to create and manage them evolved primarily in the Western hemisphere (the United States and Europe).  It originated in the early 1940s and lies within the scope of laboratory animal medicine.  Specifically, SPF chicken eggs were developed for the culture and propagation of live organisms for vaccine production.  Thereafter, over the subsequent 30–40 years, SPF technology was adopted, developed and applied to commercial poultry, and in the 1960s, extended to swine and other domestic animal production systems.  It was also used in veterinary applications for the production and maintenance of standardized and genetically inbred animal stocks to serve as ‘white mice’ for medical and veterinary research.

The United States Marine Shrimp Farming Program (USMSFP) of the United States Department of Agriculture (USDA) was formed in 1984, made up of several institutions in different States in the USA with the objective of increasing local production of marine shrimp while decreasing the reliance on importation.  The response of USMSFP, after having its breeding program hit by a disease outbreak, was a paradigm shift towards designing, developing and implementing an integrated SPF herd health, infectious disease management program that would thereafter be applied to all the USMSFP participant institutions and eventually be commercialized in the USA shrimp industry.  Consequently, the first commercial program for domestication and genetic improvement of penaeid shrimp was initiated under the USMSFP using Pacific whiteleg shrimp (Penaeus vannamei) in 1989.  The primary objective of the program was to produce broodstock, free of specific pathogens, that could be bred and produce postlarvae that could be raised in biosecure production facilities and systems, to reduce mortality and increase production.

Basically, the USMSFP program adopted the breeding and selection concepts from the livestock and poultry industries to establish specific pathogen-free (SPF) stocks of shrimp that would provide high health and genetically improved postlarvae.  The stocks were obtained by rigorous screening of captured, wild shrimp for selection of individuals naturally free from a list of known and easily detectable shrimp pathogens that it would be possible to permanently exclude from the stock under strict quarantine conditions in a nucleus breeding center (NBC) housing many founder families.  These stocks could then be subjected to a domestication and genetic improvement program, where better-performing families from each generation could be used to produce postlarvae destined to become SPF broodstock in an adequately biosecure broodstock multiplication center (BMC).  The broodstock would be supplied to commercial hatcheries where postlarvae would be produced for farmers to stock in ponds.

In parallel, several breeding and selection programs were carried out with P. vannamei in Latin America.  In Venezuela, a mass selection program began in 1990 to produce shrimp adapted to the local rearing conditions.  Similarly, in Colombia commercial producers mass selected TSV resistant shrimp in the early 1990s.  These early efforts later developed into fully-fledged family selection breeding programs that resulted in some improved populations for the local industry.  The programs in Latin America were based on the concept that the populations should be well adapted to local conditions and should be resistant or tolerant to the major disease problems endemic in the region.  Thus, a major dichotomy in breeding strategies emerged in the 1990s, with selection, maintenance and multiplication of populations in essentially disease-free conditions under the SPF protocols of the USMSFP while other programs used populations selected in the presence of multiple disease pressures that are common in commercial production.

Although the concept of SPF animals was well defined for terrestrial animals that could be grown out in isolated installations, it was relatively new for aquaculture where it is difficult to isolate the animals in the aquatic environment.  A major impetus for eventual wide adoption of the SPF shrimp concept was the emergence and spread of whitespot disease (WSD) of shrimp caused by whitespot syndrome virus (WSSV) in the mid-1990s.  At that time, Penaeus monodon was the main cultivated shrimp species in Asia, and it was soon realized that the major source of WSSV in shrimp growout ponds was infected postlarvae derived from captured WSSV-carrying broodstock and that PCR monitoring was not sufficiently effective to minimize the level of WSSV in PLs to acceptable levels for sustainable shrimp production.  As pointed out in 2005, the main reason behind the importation of P. vannamei into Asia was the perceived poor performance, slow growth rate and disease susceptibility of the major indigenous cultured shrimp species, P. chinensis in China and P. monodon virtually everywhere else.  These were the consequences of using infected broodstock that would transmit pathogens to their offspring.  The availability of SPF stocks of P. vannamei together with pathogen exclusion biosecurity strategy was very effective and rapidly led to it becoming the dominant cultivated shrimp species in Asia.

Because of the benefits of using domesticated and genetically improved SPF stocks of P. vannamei to produce healthy PLs for farmers to use in stocking their ponds, the term SPF in Asia began to be related to stocks with higher disease resistance or tolerance.  The opposite situation occurred in Latin America where SPF shrimp were stocked in ponds with no pathogen exclusion biosecurity leading to mass mortalities and leading to farmer perception that SPF status implied higher disease susceptibility.  This perception was incorrect.  SPF only indicates the sanitary status of a stock and gives no indication of its susceptibility, resistance or tolerance to infection and disease.

This dichotomous approach resulted in the creation of new terms such as specific pathogen resistant (SPR) stocks and specific pathogen tolerant (SPT) stocks that led to confusion in the shrimp industry regarding the meaning, relationship and significance of these new terms with respect to SPF.  While mistaken perceptions of SPF and SPR have long been recognized, the paramount need for SPF domesticated shrimp stocks and SPF as a novel and emerging technology that will support sustainable shrimp aquaculture were emphasized during the Global Conference on Aquaculture 2010.

The objective of this position paper is to clarify these concepts and terminologies and to reconfirm the importance and the benefits of developing and maintaining domesticated, healthy, shrimp stocks that are effectively free from major pathogens and make shrimp farming more profitable and sustainable.  This paper reflects the outcome of an expert meeting convened by the Food and Agriculture Organization of the United Nations (FAO) in Bangkok, Thailand (May 26 to 28, 2016).  The authors would like to acknowledge the Food and Agriculture Organization of the United Nations for supporting the expert group meeting that paved the way for deliberations and consensus on the subject of SPF shrimp in aquaculture.

Sources: 1. Reviews in Aquaculture.  Facts, Truths and Myths About SPF Shrimp in Aquaculture.  Victoria Alday-Sanz (National Aquaculture Group, P.O. Box 20, 21961, Al Lith, Saudi Arabia), James Brock, Timothy W. Flegel, Robins McIntosh, Melba Bondad-Reantaso, Marcela Salazar and Rohana Subasinghe.  Early View Online Version of Record before Inclusion in an Issue.  Received by Reviews in Aquaculture on April 22, 2018; accepted October 2, 2018; and first published online on November 10, 2018.  2. Bob Rosenberry, Shrimp News International, November 17, 2018.
Shrimp domestication and genetic improvement programs began in the late 1980s, in the United States of America, under the United States Marine Shrimp Farming Program (USMSFP), using the Pacific whiteleg shrimp Penaeus vannamei.  The USMSFP was based on proven concepts from the livestock and poultry industries and began with establishing a specific pathogen-free (SPF) shrimp stock.  The original shrimp stock was obtained using rigorous screening of captured wild shrimp for selection of individuals naturally free of major shrimp pathogens.  Although the concept of SPF animals was well defined for terrestrial animals, it was relatively new for aquaculture, and it took some time to be adopted by the aquaculture community.  In the early 1990s, parallel to USMSFP, several other programs on genetic improvement of shrimp were initiated in Latin America.  Subsequently, several new terminologies and products, such as specific pathogen resistant (SPR) shrimp, specific pathogen tolerant (SPT) shrimp and even ‘all pathogen exposed’ (APE) shrimp, entered the shrimp industry vocabulary and became commercial.  This led to confusion in the shrimp industry about the meaning, relationship and significance of these new terms with respect to SPF.
SPF Mother Shrimp
The concept of specific pathogen-free (SPF) animal stocks and the technology to create and manage them evolved primarily in the Western hemisphere (the United States and Europe).  It originated in the early 1940s and lies within the scope of laboratory animal medicine.  Specifically, SPF chicken eggs were developed for the culture and propagation of live organisms for vaccine production.  Thereafter, over the subsequent 30–40 years, SPF technology was adopted, developed and applied to commercial poultry, and in the 1960s, extended to swine and other domestic animal production systems.  It was also used in veterinary applications for the production and maintenance of standardized and genetically inbred animal stocks to serve as ‘white mice’ for medical and veterinary research.

The United States Marine Shrimp Farming Program (USMSFP) of the United States Department of Agriculture (USDA) was formed in 1984, made up of several institutions in different States in the USA with the objective of increasing local production of marine shrimp while decreasing the reliance on importation.  The response of USMSFP, after having its breeding program hit by a disease outbreak, was a paradigm shift towards designing, developing and implementing an integrated SPF herd health, infectious disease management program that would thereafter be applied to all the USMSFP participant institutions and eventually be commercialized in the USA shrimp industry.  Consequently, the first commercial program for domestication and genetic improvement of penaeid shrimp was initiated under the USMSFP using Pacific whiteleg shrimp (Penaeus vannamei) in 1989.  The primary objective of the program was to produce broodstock, free of specific pathogens, that could be bred and produce postlarvae that could be raised in biosecure production facilities and systems, to reduce mortality and increase production.

Basically, the USMSFP program adopted the breeding and selection concepts from the livestock and poultry industries to establish specific pathogen-free (SPF) stocks of shrimp that would provide high health and genetically improved postlarvae.  The stocks were obtained by rigorous screening of captured, wild shrimp for selection of individuals naturally free from a list of known and easily detectable shrimp pathogens that it would be possible to permanently exclude from the stock under strict quarantine conditions in a nucleus breeding center (NBC) housing many founder families.  These stocks could then be subjected to a domestication and genetic improvement program, where better-performing families from each generation could be used to produce postlarvae destined to become SPF broodstock in an adequately biosecure broodstock multiplication center (BMC).  The broodstock would be supplied to commercial hatcheries where postlarvae would be produced for farmers to stock in ponds.

In parallel, several breeding and selection programs were carried out with P. vannamei in Latin America.  In Venezuela, a mass selection program began in 1990 to produce shrimp adapted to the local rearing conditions.  Similarly, in Colombia commercial producers mass selected TSV resistant shrimp in the early 1990s.  These early efforts later developed into fully-fledged family selection breeding programs that resulted in some improved populations for the local industry.  The programs in Latin America were based on the concept that the populations should be well adapted to local conditions and should be resistant or tolerant to the major disease problems endemic in the region.  Thus, a major dichotomy in breeding strategies emerged in the 1990s, with selection, maintenance and multiplication of populations in essentially disease-free conditions under the SPF protocols of the USMSFP while other programs used populations selected in the presence of multiple disease pressures that are common in commercial production.

Although the concept of SPF animals was well defined for terrestrial animals that could be grown out in isolated installations, it was relatively new for aquaculture where it is difficult to isolate the animals in the aquatic environment.  A major impetus for eventual wide adoption of the SPF shrimp concept was the emergence and spread of whitespot disease (WSD) of shrimp caused by whitespot syndrome virus (WSSV) in the mid-1990s.  At that time, Penaeus monodon was the main cultivated shrimp species in Asia, and it was soon realized that the major source of WSSV in shrimp growout ponds was infected postlarvae derived from captured WSSV-carrying broodstock and that PCR monitoring was not sufficiently effective to minimize the level of WSSV in PLs to acceptable levels for sustainable shrimp production.  As pointed out in 2005, the main reason behind the importation of P. vannamei into Asia was the perceived poor performance, slow growth rate and disease susceptibility of the major indigenous cultured shrimp species, P. chinensis in China and P. monodon virtually everywhere else.  These were the consequences of using infected broodstock that would transmit pathogens to their offspring.  The availability of SPF stocks of P. vannamei together with pathogen exclusion biosecurity strategy was very effective and rapidly led to it becoming the dominant cultivated shrimp species in Asia.

Because of the benefits of using domesticated and genetically improved SPF stocks of P. vannamei to produce healthy PLs for farmers to use in stocking their ponds, the term SPF in Asia began to be related to stocks with higher disease resistance or tolerance.  The opposite situation occurred in Latin America where SPF shrimp were stocked in ponds with no pathogen exclusion biosecurity leading to mass mortalities and leading to farmer perception that SPF status implied higher disease susceptibility.  This perception was incorrect.  SPF only indicates the sanitary status of a stock and gives no indication of its susceptibility, resistance or tolerance to infection and disease.

This dichotomous approach resulted in the creation of new terms such as specific pathogen resistant (SPR) stocks and specific pathogen tolerant (SPT) stocks that led to confusion in the shrimp industry regarding the meaning, relationship and significance of these new terms with respect to SPF.  While mistaken perceptions of SPF and SPR have long been recognized, the paramount need for SPF domesticated shrimp stocks and SPF as a novel and emerging technology that will support sustainable shrimp aquaculture were emphasized during the Global Conference on Aquaculture 2010.

The objective of this position paper is to clarify these concepts and terminologies and to reconfirm the importance and the benefits of developing and maintaining domesticated, healthy, shrimp stocks that are effectively free from major pathogens and make shrimp farming more profitable and sustainable.  This paper reflects the outcome of an expert meeting convened by the Food and Agriculture Organization of the United Nations (FAO) in Bangkok, Thailand (May 26 to 28, 2016).  The authors would like to acknowledge the Food and Agriculture Organization of the United Nations for supporting the expert group meeting that paved the way for deliberations and consensus on the subject of SPF shrimp in aquaculture.

Sources: 1. Reviews in Aquaculture.  Facts, Truths and Myths About SPF Shrimp in Aquaculture.  Victoria Alday-Sanz (National Aquaculture Group, P.O. Box 20, 21961, Al Lith, Saudi Arabia), James Brock, Timothy W. Flegel, Robins McIntosh, Melba Bondad-Reantaso, Marcela Salazar and Rohana Subasinghe.  Early View Online Version of Record before Inclusion in an Issue.  Received by Reviews in Aquaculture on April 22, 2018; accepted October 2, 2018; and first published online on November 10, 2018.  2. Bob Rosenberry, Shrimp News International, November 17, 2018.
Continue Reading
One of Okinawa’s most popular products on the Japanese mainland is kuruma tiger shrimp (Penaeus japonicus, locally called kuruma ebi) produced by Epoch Prawn Farms in mineral-rich, deep-sea water pumped to the surface by the Okinawa Deepsea Water Research Institute.


Before cooking, you can differentiate kuruma shrimp from other tiger shrimp by the distinct blue in their tails. The prawns are nearly translucent with stripes that give them their English name tiger shrimp.

The shrimp are initially hatched at a centralized location near the research institute before being distributed to several farms. The shrimp are active at night and spend their days buried in the sand on the bottom of the growout ponds.

In June, at Epoch Prawn Farms, the water is drained from the tanks and the sand at the bottom is exchanged with new sand, and any shrimp that were not harvested the previous year are collected. Exchanging the sand is a difficult and expensive process, but important for producing high-quality shrimp. If the sand is not replaced, the shrimp have a softer color and less flavor.

The shrimp eggs near the deep-sea water institute hatch in September. They are cultured through their larval stages and then transferred to the shrimp farms. Around 400,000 postlarvae are stocked in each pond. Epoch has three ponds.

The prawns grow slowly during the cold winter months, but they have a better taste and more amino acids than prawns grown in the summer, when they grow more quickly.

To ensure the highest quality, Epoch feeds the shrimp daily with a proprietary mix of vitamins, squid, ground fish and other ingredients imported from mainland Japan. The feed is expensive, but ensures that the shrimp develop the right color. Every day, divers patrol the pools to ensure the shrimp are eating and that no debris has entered the tanks from the sea. Water is exchanged daily.

Utilizing lights and bait, shrimp are trapped at night because that’s when they are active. A simple funnel net allows the shrimp to enter the trap and keeps them from escaping. Small shrimp can easily escape from the traps. In the morning, the shrimp are transferred to cold-water containers and transported directly to a processing facility.

At Epoch, the shrimp are sorted by size and then the shrimp with no damage to their appendages are separated for live shipment. About 1% of the shrimp has soft shells, which are very popular. Once sorted, the shrimp are weighed and boxed. They can live two to three days if kept cold, and can be shipped live all over Japan.

Most Okinawa tiger shrimp are sent to Tokyo and other large cities in Japan, where high-end restaurants purchase them at auctions. Some shrimp are also flash frozen for distribution during non-peak seasons. Shrimp are especially popular as gifts (esebo), given at the end of the year.

Epoch Tiger Prawns produces high-quality shrimp. Many farms throughout Okinawa also produce tiger shrimp, but the close proximity to deep-sea water and careful control allow Epoch to produce truly superior shrimp. Depending on size, its shrimp sell for between $31 and $45 a pound.

Source: The Ultimate English Guide to Kumejima [Okinawa]. Tiger Prawns [車エビ]. No date, discovered on May 21, 2013.
The antibiotics most frequently used in aquaculture to combat bacterial diseases are oxytetracycline, florfenicol, sarafloxacin and enrofloxacin. Globally, other antibiotics such as chlortetracycline, quinolones, ciprofloxacin, norfloxacin, oxolinic acid, perfloxacin, sulfamethazine, gentamicin and tiamulin are used.

Illustration: Antibiotics in shrimp farming
Even though they are frequently used on shrimp farms, information related to residues of oxytetracycline and enrofloxacin in Litopenaeus vannamei tissue is very scarce.

In an unpublished study performed at the Research Center for Food and Development, Hermosillo, Sonora, México, they administered a diet medicated with enrofloxacin at a level of 200 mg kg-1 for 14 days in an attempt to determine the accumulation and elimination of enrofloxacin and its metabolite ciprofloxacin in a crop of Litopenaeus vannamei. Subsequently, a diet without the antibiotic was administered for 16 days. The study was carried out under controlled laboratory conditions and on a farm. In the lab study, using high-performance liquid chromatography to analyze our results, enrofloxacin reached maximum concentrations in the tail and hepatopancreas of 0.54±0.26 μg g-1 and 3.52±1.9 μg g-1, respectively. For ciprofloxacin, levels of 0.18±0.13 μg g-1 and 1.05±0.20 μg g-1 were reached in the tail and hepatopancreas, respectively.

In the farm study, maximum concentrations of enrofloxacin reached 0.36±0.17 μg g-1 and 1.60±0.82 μg g-1 in the tail and hepatopancreas, respectively. For ciprofloxacin, the numbers were 0.03±0.02 and 0.36±0.08 μg g-1 in the tail and hepatopancreas, respectively. When the feeding of the medicated diets was suspended, enrofloxacin and ciprofloxacin residues in the tissues began to decrease, requiring four to ten days for both antibiotics to reach undetectable levels in the tail and six to fourteen days for elimination from the hepatopancreas.

Oxytetracycline, another of the widely used antibiotics, was studied at a shrimp farm. Shrimp (Litopenaeus vannamei) were treated for 14 days with feed that contained a theoretical oxytetracycline concentration of 5,000 mg kg-1. Next, an antibiotic-free diet was administered for 16 days. The shrimp were sampled every third day. Vibrio bacteria were isolated at the molecular level from the tail and hepatopancreas, counted and expressed as CFUs (colony-forming units).

The results show an average maximum concentration for oxytetracycline in the tail of 31.32±3.44 μg g-1 and in the hepatopancreas of 274.81±62.35 μg g-1. The withdrawal times necessary for the oxytetracycline residues to be eliminated were ten days for the hepatopancreas and sixteen days for the tail. Under lab conditions, a diet was administered to Litopenaeus vannamei shrimp that contained 5,000 mg Kg-1 of oxytetracycline for 14 days. The levels of maximum concentration for oxytetracycline were 33.54±11.19 μg g-1 in the tail, 194.37±16.11 μg g-1 in the hepatopancreas and 18.79±5.87 μg mL-1 in the hemolymph. The elimination time for oxytetracycline was six to ten days for all tissues.

The most frequent administration route for antibiotics is in the feed. It is important that the antibiotic be contained within a pellet to maintain its stability and protect it from leaching and binding to trivalent and divalent cations in the pond. It is very important that the shrimp eat all the medicated feed; otherwise the environment will be contaminated and the emergence of bacterial resistant strains will be favored. Also, water temperature is a critical factor when using medicated feeds because it affects maximum concentration, distribution volume and the rate of elimination. Oxygenation, pH, salinity, stage of disease, the weather and presence of natural food in the ponds are other factors that affect antibiotic therapies.

An estimated 15 to 40 percent of medicated diets are not ingested by the shrimp and remain in the pond. Another fraction of the medication is not absorbed during its passage through the intestinal tract of the shrimp and returns to the environment in fecal matter. The amount of antibiotic transferred to the environment varies from 1% for chloramphenicol to 90% for oxytetracycline. Approximately 70-90% of the antibiotic used in the therapy of shrimp ends up in the environment and sediment, and a high percentage of it exhibits antibacterial activity. It has been reported that residues of oxolinic acid and oxytetracycline are very persistent under certain conditions, with half-lives exceeding 100 days.

International regulations regarding the use of antibiotics in aquaculture have established a list of prohibited products. The strongest restrictions are on the use of chloramphenicol, dimetridazole, furazolidone, nitrofurazone, other nitrofurans and fluoroquinolones, none of which should be used at any stage of the shrimp production process.

Source: Health and Environment in Aquaculture. Editors: Edmir Daniel Carvalho, Gianmarco Silva David and Reinaldo J. Silva. Chapter Eight, The Use of Antibiotics in Shrimp Farming. M.C. Bermúdez-Almada and A. Espinosa-Plascencia. Research Center for Food and Development, Hermosillo, Sonora México

A breeding population of giant tiger shrimp (Penaeus monodon) may be established off the southeastern coast of the United States and in the Gulf of Mexico.

In 1988, nearly 300 tiger shrimp (Penaeus monodon) were collected off the coasts of South Carolina, Georgia and Florida after an accidental release of roughly 2,000 animals from the Waddell Mariculture Center in South Carolina.  It’s doubtful if this release has had anything to do with the increase in P. monodon catches that began in 2006 when six monodon were collected in USA waters.  In 2007, four were collected, in 2008 (21), in 2009 (47), in 2010 (32)—and in 2011 (273)!  Monodon has now been found from North Carolina to Texas.  The first documented collections in Mississippi and Texas occurred in 2009 and 2011, respectively.
In order L. Vannamei can grow optimally, it needs a place to live that can provide state physics, chemistry, and biology is optimal. Physical environmental conditions are including temperature and salinity. While the chemical conditions is including pH, dissolved oxygen (DO), nitrate, orthophosphoric, and the presence of plankton as natural feed. Should be noted that environmental conditions can inhibit the growth of shrimp, shrimp can be deadly, such as the emergence of toxic gases and pathogenic microorganisms.
Paddle wheel Aerator (PWA) for Increase dissolved oxygen
Temperature is one factor controlling the speed of biochemical reactions. This is because the temperature can determine the metabolic rate of shrimp and other aquatic organisms. Low temperatures will result in a lower metabolic system in contrast to the high temperatures will spur a more rapid metabolism. In order for the cultivation of L. Vannamei to work well, pond waters temperature range suggested is between 28 - 32o C.

Water transparency values ​​for shrimp cultivation are recommended between 30-60 cm. The value of transparency associated with the color of water caused by the content and the amount of plankton contained therein. If the pond water green leaves of 35 cm brightness figures, when the dark green water color and brightness 20 cm of water when a blackish brown color brightness range between 60-80 cm.

The influence of pH is harmful to the shrimp are usually caused by the mechanism of increasing the concentration of toxic or poisonous substances, such as an increase in anionic ammonia (NH3) at pH above 7. Whereas in waters with low pH will cause an increase in the fraction of anionic sulfide (H2S) and the toxicity of nitrite, as well as physiological disorders shrimp. In the long term, low pH conditions would result in the release of sodium into the water body. On shrimp culture, the pH level will change from day to day and tended to decrease during the growing season the shrimp, because the accumulation of organic acids and nitrification of ammonia. Optimal pH range 7.5 to 8.3 for prawn growth.

Concentration of dissolved oxygen (DO) in the pond waters affects the physiology of the shrimp. Oxygen levels is the most important environmental factor in shrimp ponds. Decreasing DO in the water, would result in shrimp stress and susceptible to disease. Shrimp growth will be slow because the rate of feed consumption decreases with decrease in dissolved oxygen concentration. In ponds with dissolved oxygen concentration 1.0 mg / l cause shrimp can’t eat. The dissolved oxygen concentration of 1.0 -1.4 mg / l causes the shrimp do not grow, while the DO below 5mg / l causes the shrimp has limited growth.

Nitrate and orthophosphoric is a necessary nutrient in the growth of phytoplankton. Both types of nutrients can be directly utilized by phytoplankton. Nitrogen compounds as waste products of digestion of proteins can accumulate to dangerous levels in the pond. Shrimp using nitrogen component of the protein that has been digested (the amino group NH2) to form the protein itself, but its metabolism is not able to convert nitrogen into energy. An ammonia level from 0.02 to 0.05 mg / l was able to inhibit the growth of aquatic animals in general, whereas the levels of 0.45 mg / l can inhibit growth of 50% shrimp. Later in the levels of 1.29 mg / l has resulted in the death of the shrimp.
Mangrove Forest
One function of mangrove forests as a buffer to maintain the shoreline in order to remain stable. Mangrove Forests can prevent sea erosion due to its ability in accelerating the expansion of land. On the other hand, the mangrove forest is also the most productive coastal ecosystems to be used as shrimp ponds. Especially for traditional pond.

Isolated patches of mangrove growing in semi-permanent saltwater. Source: https://www.avianreport.com/mangrove-forest/
In order for the construction of shrimp ponds can run and preservation of mangrove forests can be maintained it would require the construction of shrimp farms are environmentally sound. In selecting the location of the pond, things to note is the knowledge about the type of beach area that will serve as the location of shrimp farms.

Broadly speaking, land aquaculture can be divided into two fishponds are influenced by tidal (intertidal) and land ponds that are not influenced by tidal (supratidal). The hallmark of the intertidal area of ​​the flooded area during high tide would otherwise be bronzed and dry at low tide.

Intertidal Area
Intertidal area is generally covered by mangrove forest primary. If you want to build shrimp farms in the intertidal area, it is highly recommended in locations that are still brackish water. Despite the low productivity potential, but if its management is done well, especially the improvement of hydrological, then it can turn into a potential pond area.

Excess use of intertidal areas for pond construction site is in terms of income and expenditure of water that can be done by gravity. Especially for traditional farms that still use simple technology. When the tide, the water put into storage by opening the floodgates. Then at low tide gate was closed so that water can be accommodated for the flood embankment.

Supratidal Area
Supratidal area is an area that is not influenced by tides, but still can reach the highest high tide which usually happens once a year. Use of land for development in the region supratidal ponds require relatively high cost due to putting water into the pond needed additional equipment (pumps).

Cultivation is applied to this area should be done intensively in order to cover production costs are high. Intertidal area has the advantage on the clay soil texture, clay, and slightly sandy or a combination of all three. So when making this area of ​​the pond is completed, fry can be stocked directly without any risk of leakage.
IMNV (Infectious Mionecrosis Virus) is a disease found in the white shrimp. The disease was first discovered in Brazil and the coast of South America in 2003. When first attacked, productivity white shrimp in Brazil declined very sharply. Over time IMNV disease a scourge that was greatly feared by the white shrimp farmers worldwide.
IMNV on White Shrimp. Source: http://gis.bkipm.kkp.go.id/edis/upload/20150225114758imnv.jpg
Dispersal and Disease Transmission
IMNV disease primarily spread by the host who had previously been carrying the virus IMNV. Recent research states that the IMNV is a type of virus R-NA. The nature of the R-NA is much simpler than the D-NA makes this virus can survive without a host for 60 days; compared with Whitespot (WSSV) which can only live for 3 hours if without a host. Diameter size of this virus is 40 nm, 1 / 8 times smaller than the Whitespot.

IMNV infected shrimp that have been marked with white as cotton in the third or fourth segment, will now grow up to the sixth segment. If you have severe then most of the affected segment of the shrimp will look red and cause death.

Trigger factors of IMNV
Based on experience, IMNV vicious attack in the pond if the water quality is not stable. Highly fluctuating temperature changes was allegedly a major cause of the spread and transmission of the IMNV. Ponds with stable quality will be more resistant to attack IMNV than ponds with an unstable water quality.

Disease prevention and handling of IMNV
Shrimp that have been stricken with the disease will usually be pulled over to the edge of the pond and is characterized by the onset of the color white as cotton in the 3rd segment. The most effective way to prevent the occurrence of disease IMNV is to implement a good Biosecurity. The selection and fries stocking of disease-free is one way to minimize the incidence of IMNV.

 Disinfection of water going into the pond should always be done in order to kill the host which may spread IMNV, due to its extremely small size, then the double filtering with a filter having a size smaller than 40 nm are also required to be done. Given this IMNV free living virus could reach 60 days it is expected that the already disinfected water is collected in ponds reservoirs as long as possible before it is released into the pond.

Increased endurance shrimp with extra vitamins and immunostimulants application can be done to reduce stress factor. Good water quality management and water quality carefully in order to remain stable is a key factor in order to prevent attacks IMNV disease. The last way is to reduce the stocking density. By reducing the stocking density of solid means give more space to live on the shrimp so that it will reduce stress factors. Conversely, when densely stocking the higher the risk of stress on the larger shrimp will thus be more susceptible to disease attack.