Early Mortality Syndrome Outbreaks: A Microbial Management Issue in Shrimp Farming?

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A recent disease of farmed Penaeid shrimp, commonly referred to as “early mortality syndrome” (EMS) or more technically known as “acute hepatopancreatic necrosis disease” (AHPND), was first reported in southern China in 2010 and subsequently in Vietnam, Thailand, and Malaysia [1]. The EMS/AHPND disease typically affects shrimp postlarvae within 20–30 days after stocking and frequently causes up to 100% mortality. The Global Aquaculture Alliance [2] has estimated that losses to the Asian shrimp culture sector amount to USD 1 [...]


Aquaculture Feed Composition Helps Define Potential For Water Pollution

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Summary: A study found that feed for salmon and trout had higher organic carbon concentrations than did catfish, shrimp and tilapia feeds. Nitrogen and phosphorus concentrations were similar among salmon, trout and shrimp feeds, and higher than those in catfish and tilapia feeds. Whole body concentrations of organic carbon were greater in salmon and trout than in the other species. Salmon and shrimp had the highest whole body nitrogen concentrations. Phosphorus concentrations were greater in catfish and tilapia than [...]


The immune system of shrimp

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Introduction Penaeid shrimp aquaculture is an important economic activity worldwide. Nevertheless, shrimp production has been seriously affected by diseases, mostly those caused by viruses (Flegel, 2006) and Vibrio bacteria (Bachère, 2000). Shrimp resistance to invading organisms is strongly influenced by its immune status. The defense mechanisms of crustaceans is less developed than that in finfish and other vertebrates (Figure 1). More specifically, crustaceans have no adaptive memory. In other words, they do not have the ability of producing immunoglobulins, so that [...]


Dietary supplements of aquatic animals

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An important key to culture of any fed species is the development of sustainable, cost-effective and nutritionally complete feeds, along with efficient feed management systems. Emerging technologies for improving the gut environment are being rigorously studied and are beginning to be applied in aquaculture feeds. Use of probiotics in feeds, although successful in human and animal nutrition, is not well accepted in aquaculture. Improved delivery methods and better understanding of gut microflora of aquatic animals could change this in the future (Balcázar et [...]


Species, Pond Size Define Aeration Approaches

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Summary: Each type of aerator has advantages and disadvantages. The combination of paddlewheel aerators and propeller-aspirator-pump aerators can be particularly effective in deep ponds. Diffused-air systems are most appropriate for small ponds. The amount of aeration can be increased as feeding rate increases to conserve energy. Aeration in shrimp ponds usually can be reduced from mid-morning until early evening. Research has demonstrated that considerable energy can be saved by using aerator automation systems. Claude E. Boyd, Ph.D., School of Fisheries, [...]


Pond Bottom Dryout, Liming – Part I. Disinfection in Semi-Intensive Shrimp Ponds

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Summary: The main pond bottom soil management practices used in semi-intensive culture are pond dryout and liming between crops. These practices accelerate organic matter decomposition, neutralize soil acidity and destroy unwanted organisms. Since most soils become too dry for microbial decomposition of organic matter within three weeks, there is little need to dry pond bottoms more than that period. Where bottom sediment is deep, remove it to facilitate dryout. Ponds with soil pHs below 7.5 should be limed to enhance decomposition. Li Li, Ph.D., [...]


Developing Live Bacterial Vaccines By Selecting Resistance To Antibacterials

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Summary: As wide use of antibiotics has led to antibiotic resistance in fish pathogens, vaccines present an alternative control method to prevent bacterial diseases. The authors conducted a study to determine whether the natural compound gossypol, the antibacterial disinfectant proflavine hemisulfate, or the antibiotics novobiocin or ciprofloxacin was effective in attenuating bacteria for the purpose of vaccine development. Although the chemical treatments did yield attenuated isolates to varying degrees, only a few isolates provided safe, efficacious protection in tilapia [...]


Applications of Probiotics in Aquaculture

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The need for sustainable aquaculture has promoted research into the use of probiotics on aquatic organisms. The initial interest was focused on their use as growth promoters and to improve the health of animals; however, new areas have been found, such as their effect on reproduction or stress tolerance, although this requires a more scientific development. 4.1. Growth Promoter Probiotics have been used in aquaculture to increase the growth of cultivated species, in reality it is not known whether these products increase the [...]


Use of Probiotics in Aquaculture

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The growth of aquaculture as an industry has accelerated over the past decades; this has resulted in environmental damages and low productivity of various crops. The need for increased disease resistance, growth of aquatic organisms, and feed efficiency has brought about the use of probiotics in aquaculture practices. The first application of probiotics occurred in 1986, to test their ability to increase growth of hydrobionts (organisms that live in water). Later, probiotics were used to improve water quality and control of bacterial infections. Nowadays, there [...]


What are Bacteria?

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Whenever we hear the word bacteria we assume that something is dirty, our food is rotten, or someone is sick, but this is not always true! While there are many types of bad bacteria that can harm us by sneaking into our water and food, there are also many good types of bacteria that help us each and every day! There are bacteria in our stomachs that help us digest the food our body can’t, and there are bacteria [...]