Tag - virus

Characterization of a new member of Iridoviridae, Shrimp hemocyte iridescent virus (SHIV), found in white leg shrimp (Litopenaeus vannamei)

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A newly discovered iridescent virus that causes severe disease and high mortality in farmed Litopenaeus vannamei in Zhejiang, China, has been verified and temporarily specified as shrimp hemocyte iridescent virus (SHIV). Histopathological examination revealed basophilic inclusions and pyknosis in hematopoietic tissue and hemocytes in gills, hepatopancreas, periopods and muscle. Using viral metagenomics sequencing, we obtained partial sequences annotated as potential iridoviridae. Phylogenetic analyses using amino acid sequences of major capsid protein (MCP) and ATPase revealed that it is a new iridescent [...]

9 May
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What do we know about EHP?

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• Tissue specific for HP unlike most other microsporidians which affect muscle • Transmitted orally between shrimp with no need for an intermediate vector very unusual and very worrisome • Very difficult to visualize with normal histology • Requires practice and patience • Once spores are in ponds very difficult to eradicate HP with EHP spores Control of EHP • Two fold approach to possible control – Broodstock carriers shed spores in feces which contaminate egg and nauplii surfaces. – Farmed animals shed spores into ponds which in [...]

4 May
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Strong year for Indonesia

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Indonesia is coming off a year of head-on production of between 300,000t-350,000t, but growth is likely to slow in 2015, said an executive with a processor, not wishing to be quoted by name. Around 50,000t of this is now going for domestic use, he said. “This number is much different from official number, normally I don’t want to dispute the number, but from what we can see import data in US, Japan and EU, you can total Indonesia number is about 120,000t-125,000t of finished [...]

1 May
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Aquatic Animal Disease Report

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1. White Spot Disease (WSD) Pathogen: White spot syndrome virus (WSSV) Species affected: Penaeus monodon and Litopenaeus vannamei (10-85 DOC) Name of affected area: reported in 18 provinces (total area 7,279 ha) including Hai Phong, Quang Ninh, Nghe An, Ha Tinh, Quang Tri, Quang Binh, Quang Ngai, Thua Tien Hue, Phu Yen, Binh Dinh, Ho Chi Minh, Long An, Tien Gang, Ben Tre, Tra Vinh, Soc Trang, Bac Lieu and Ca Mau. Mortality rate: average to high, 100% in some cases within 10 d. Clinical signs: lethargic or moribund shrimps aggregated [...]

1 May
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How can you control Vibrio bacteria?

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After Dr. Lightner confirmed its virulence using Koch’s postulate, it was found that some strains of Vibrio parahaemolyticus that is the cause of EMS in Asia. Most recently it has also been found to cause EMS in Mexico, which is far away from Asia. It is possible that someone brought brooder shrimp from an Asian country where EMS is prevalent into Mexico for breeding purposes and the weak postlarvae got EMS, or perhaps they used very fast-growing breeding stock [...]

1 May
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Mineral Extract Reduces EMS, White Spot Impacts In Pacific White Shrimp

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Summary: In the search for suitable alternatives to antibiotics and chemical therapeutics for disease treatment and prevention in shrimp, a promising control method is to strengthen non-specific defense mechanisms in crustaceans. The authors recently performed a study to evaluate immunity to white spot syndrome virus and virulent Vibrio parahaemolyticus in shrimp treated with a new mineral extract additive in pelletized feeds. Compared to control animals, shrimp fed the treated diets had significantly higher survival after challenge by injection with the pathogens.   Plastic tanks with 2-m diameters were [...]

1 May
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India – Broodstock Shortage

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The All-India Shrimp Hatcheries’ Association has urged the Centre to set up multiplication centres to meet the excess demand for brood stock for shrimps and provide quality seed. Steps should also be taken to regularise and regulate the unauthorised shrimp hatcheries, according to L Satyanarain (alias Tikku), President of All-India Shrimp Hatcheries’ Association. “Otherwise, the whole industry will be affected and every one will suffer,” he said. Quality seed holds the key for sustainable shrimp culture. Therefore, proliferation of hatcheries and production of seed without the requisite safeguards [...]

1 May
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PH shrimp trade good, but laggard in Asia

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DAGUPAN CITY—The country’s shrimp industry is beginning to bounce back, although it is still way behind leading shrimp producers in Asia, aquaculture experts and scientists here said. Leobert de la Peña, a crustacean pathologist of the Southeast Asian Fisheries Development Center, said the local shrimp industry’s biggest problem is still the white spot syndrome virus (WSSV), which can wipe out a pond’s shrimp population in seven to 10 days. De la Peña was here on Sunday to witness the graduation of [...]

1 May
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CENIACUA Develops WSSV-Resistant Shrimp In Colombia

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Summary: The 1999 appearance of white spot syndrome virus (WSSV) in white shrimp caused high mortality at shrimp farms in Colombia. To combat the disease, Corporación Centro de Investigación de la Acuacultura de Colombia (CENIACUA) initiated a selective-breeding program to develop WSSV resistance in shrimp. After initially poor survival and slow growth in resistant animals, more recent trials involving segregated and mixed populations of selected and non-selected shrimp, CENIACUA achieved populations much more resistant to WSSV than populations not [...]

30 Apr
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Early Mortality Syndrome: Changing the Way We Farm

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Early Mortality Syndrome (EMS) has wreaked devastation across Asian shrimp farms over the past few years but now key research by Dr George Chamberlin, Global Aquaculture Alliance, and Dr Donald Lightner, University of Arizona, among others, is helping farmers adapt to living with and preventing EMS, writes Lucy Towers, The FishSite Editor. EMS is a bacterial disease of shrimp, characterised by an empty stomach, pale hepatopancreas and an empty midgut, which rapidly results in mass mortalities. The mass mortality caused by [...]

28 Apr
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