Tag Archives: fish health

Genetics roadmap to develop more resilient farmed fish

WorldFish will embark on new research to create more resilient fish with characteristics such as disease resistance and more effective feed utilization. Based on a roadmap developed with world experts at a WorldFish-hosted fish breeding workshop on 23–24 May at The Roslin Institute in Edinburgh, the research will use advanced techniques such as genomic selection to introduce these characteristics into its improved tilapia strains.

Since 1988, WorldFish has used selective breeding to develop and manage the fast-growing Genetically Improved Farmed Tilapia (GIFT) strain. The strain has been disseminated to at least 16 countries, mostly in the developing world, and is grown by millions of small-scale fish farmers for food, income and nutrition across the globe.

Harvested GIFT Tilapia (Credit: Worldfish)

Harvested GIFT Tilapia (Credit: Worldfish)

Use of genomic selection tools, which enable the selection of animals based on genetic markers, will allow WorldFish to expand its GIFT research beyond a growth-only focus and introduce selection for characteristics that are otherwise difficult to measure, such as resilience and feed efficiency. Genomic selection has enabled a step change in the rate of genetic improvement of terrestrial livestock, and has the potential to do the same in fish.

Expansion of GIFT research is a key part of the CGIAR Research Program on fish (FISH) and supports WorldFish efforts under its sustainable aquaculture program to increase the productivity of small-scale aquaculture to meet growing global demand for fish.

John Benzie, Program Leader, Sustainable Aquaculture, WorldFish: “Incorporating new traits in the breeding program for GIFT will help fish farmers prepare for future challenges such as climate change and increasing evidence of disease risks. This will particularly benefit farmers in Africa and Asia, where tilapia is critical for food security yet farmers often have limited access to improved fish breeds suited to local conditions.”

Ross Houston, Group Leader, The Roslin Institute: “Aquaculture production needs to increase by 40 percent by 2030 to meet global demands for fish. Nile tilapia (Oreochromis niloticus) is arguably the world’s most important food fish, and plays a key role in tackling rural poverty in developing countries. The innovations in genetic improvement mapped out in this workshop are an important step toward achieving these ambitious goals.”

Attendees of the workshop included experts from WorldFish’s Malaysian and Egyptian bases, The Roslin Institute, the Swedish University of Agricultural Sciences, The University of Stirling’s Institute of Aquaculture, the Earlham Institute, CIRAD and the Animal Breeding and Genetics group of Wageningen University and Research.

The roadmap will feed into a strategy for the genetic improvement and dissemination of GIFT seed in Africa, the further development of which will take place at the Genetics Network meeting being hosted by WorldFish at the World Aquaculture 2017 conference in Cape Town on 26–30 June.

For more information or to request an interview contact:

Toby Johnson, Head of Communications
Mobile Tel: +60 (0) 175 124 606
Email: t.johnson@cgiar.org
Web: worldfishcenter.org
Photography: flickr.com/photos/theworldfishcenter/

About WorldFish
WorldFish is an international, nonprofit research organization that harnesses the potential of fisheries and aquaculture to reduce hunger and poverty. Globally, more than one billion poor people obtain most of their animal protein from fish and 800 million depend on fisheries and aquaculture for their livelihoods. WorldFish is a member of CGIAR, a global research partnership for a food-secure future.

About CGIAR
CGIAR is a global research partnership for a food-secure future. Its science is carried out by the 15 research Centers that are members of the CGIAR Consortium in collaboration with hundreds of partners.

Tilapia lake virus (TiLV): What to know and do?

Tilapia lake virus is a newly emerging virus that is associated with significant mortalities in farmed tilapia. With cases reported across Africa, Asia and South America, the virus represents a huge risk to the USD 7.5 billion global tilapia industry. All countries with a tilapia industry must be vigilant and act quickly to investigate cases of mortalities in farm.
Published by the CGIAR Research Program on Fish Agri-food Systems.

Scientists net virus behind tilapia die-offs in Israel and Ecuador

An international scientific team led by researchers at Columbia University’s Mailman School of Public Health and Tel Aviv University has identified and characterized a novel virus behind massive die-offs of farmed tilapia in Israel and Ecuador, which threatens the $7.5 billion global tilapia industry. A paper in the journal mBio describes tilapia lake virus (TiLV) and provides information needed to fight the outbreak.

Known in its native Middle East as St. Peter’s fish and thought to be the biblical fish that fed multitudes, tilapia provides inexpensive dietary protein. The world’s second most farmed fish, tilapia is also the basis of aquaculture employment in developing countries in Asia, Latin America, and the Middle East. (The United States is the leading tilapia importer globally.) Since 2009, Israel has seen precipitous declines in tilapia, with annual yields plummeting as much as 85 percent–highly unusual considering the fish is known to be relatively resistant to viral infections. Similar die-offs have been seen in Ecuador and Colombia.

Diseased tilapia

Tilapia diseased from tilapia lake virus infection, Ecuador. Photo: Hugh Ferguson.

The scientists used high-throughput sequencing to determine the genetic code of the virus from tissue taken from diseased fish in Israel and Ecuador. This process would normally be sufficient to identify the culprit, but in this case, the resulting DNA sequences didn’t match any known virus, with the exception of a small genetic segment, that only remotely resembled a virus associated with the reproduction of influenza C.

Undeterred, the researchers employed other tools from their scientific tackle box, providing ample evidence that the genetic material was the same as the implicated virus dubbed TiLV. They used mass spectroscopy to characterize the proteins in cells growing the virus, which matched those they expected to see based on the genetic sequence. By analyzing the structure of viral DNA, they went on to observe 10 gene clusters with complementary endpoints, suggesting a circular form associated with a common type of viral reproduction involving a protein called a polymerase.

Finally and conclusively, healthy fish were exposed to TiLV cultured in a laboratory, resulting in disease that matched with what was seen in those countries: in Israel, the fish had swollen brains; in Ecuador, liver disease. In the coming weeks, the researchers will publish on the link between the TiLV and an outbreak of disease among tilapia in Colombia.

“The TiLV sequence has only minimal similarity in a small region of its genome to other viruses; thus, the methods we typically use to identify and characterize viruses through sequencing alone were insufficient,” says first author Eran Bacharach, a molecular virologist at Tel Aviv University.

“It appears to be most closely related to a family of influenza viruses called orthomyxoviruses; however, we still don’t understand much about its biology,” adds Nischay Mishra, associate research scientist at the Center for Infection and Immunity at Columbia’s Mailman School.

Importantly, the findings provide the genomic and protein sequences necessary for TiLV detection, containment, and vaccine development.

“We are shifting our focus now to implementing diagnostic tests for containment of infection and to developing vaccines to prevent disease,” says Avi Eldar of the Kimron Veterinary Institute in Bet Dagan, Israel.

The team of 18 researchers represent five institutions in four countries: the Center for Infection and Immunity and the New York Genome Center in the U.S., Tel Aviv University and Kimron Veterinary Institute in Israel; the University of Edinburgh, Scotland; and St. George’s University, Grenada, West Indies.

“The New York Genome Center was excited to join in characterizing this novel virus and contribute to this important environmental and globally impactful research,” says Toby Bloom, the Center’s deputy scientific director.

“Gumshoe epidemiology, molecular gymnastics and classical microbiological methods were required to link this new virus to disease,” says Ian Lipkin, senior author, director of the Center for Infection and Immunity and John Snow Professor of Epidemiology at the Mailman School. “Resolution of this mystery was only possible through the concerted efforts of this talented group of international collaborators.”

While best known for identifying viruses behind human disease, the Center for Infection and Immunity, pinpointed the virus beyond a disease that decimated salmon farms in Europe in 2010. They have done similar work with seals, sea lions, and Great Apes.

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The current research was supported by grants from the United States-Israel Bi-National Agricultural Research & Development Fund (BARD IS-4583-13), the Israel Ministry of Agriculture & Rural Development Chief Scientist Office (847-0389-14), U.S. National Institutes for Health (AI109761), USAID PREDICT, and a fellowship to J.E.K.T. from the Manna Center Program in Food Safety and Security at Tel Aviv University. The authors declare no conflicts.

Aquaculture Symposium to Focus on Infectious Diseases of Tilapia & Strip Catfish

Aquaculture Symposium taking place on 24 of March all day at Meeting Room 2 (3rd floor) of SECC in Ho Chi Minh City Vietnam which focus on Infectious diseases of Tilapia & Strip catfish invite 4 Fisheries experts from Veterinary Pathobiology, Faculty of Veterinary Science, Chulalongkorn University Bangkok, Thailand and the specialist in Tilapia from Vietnam to join the session.

The interesting topics are Franciscellosis, Streptococcosis, Columnaris disease in Tilapia and Strip catfish and Concurrent infection & Miscellaneous diseases, Antibiotic resistance in Aquaculture, Vaccine for Tilapia and Strip catfish and close session with Viral Nervous necrosis in Tilapia. This class is special for fish farmer to understand and study how to solve the infectious diseases of Tilapia and strip catfish in Vietnam. FAVA believe that this class will create the valuable knowledge for all delegate and the 120 seats are limited.

All conference program, please visit here

For more information of ILDEX Vietnam 2016, please visit www.ILDEX-VIETNAM.com

Aquaponics Workshop Offered at University of the Virgin Islands

University of the Virgin Islands, Albert A. Sheen Campus
St. Croix, USVI

Program – 3-day course that will provide in-depth knowledge of the principles and practical application of the aquaponic system that has been developed at the University of the Virgin Islands. Participants will be introduced to the system design that maintains water quality by hydroponic plant culture (aquaponics), Fish production instruction will be conducted using both the Nile tilapia (Oreochromis niloticus) and red tilapia. Hydroponic plant production will focus on vegetables, culinary herbs and ornamental flowers.

Instruction – Each day will include a half-day of classroom lecture and a half-day of hands-on field work. Participants will learn the technology through presentation of the theory and practical skill development. Each student will be given a USB Flash Drive of reference materials and course content. Water quality labs will cover the methods of analysis and the use of water quality test kits. Field work will include fish handling, vegetable production and system operation.

Fee – Registration is required.  The course fee is $600.  Your registration will be confirmed by email upon receipt of payment.  The number of participants is limited and early registration is recommended.  The course fee does not include transportation to St. Croix, lodging, meals or local transportation.

Facilities – UVI is located in the heart of beautiful St. Croix. The Aquaculture Program operates fifteen research-scale systems (six aquaponic and nine biofloc) as well as commercial-scale aquaponic and biofloc systems, a fry sex-reversal system, a recirculating system for fingerling rearing and a purge system. The program annually produces about 20,000 lbs. of tilapia and a variety of vegetables.

Topics

Aquaponic system Plant production
   System design and management    Seedling production
   Components    Disease and insect control
   Construction techniques    Harvesting and packaging
Operation Economics
   Water quality    Capital budgeting
   Fish production    Operations plan
   Stocking rates    Marketing
   Feeding, growth and survival Fingerling production
   Harvesting and processing    Brood stock management
   Breeding/Fry sex reversal

Upcoming Workshop Dates:

  • February 27 – March 1, 2013
  • April 3 – 5, 2013
  • May 8 – 10, 2013

For the latest information, see Registration Announcement.