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Aquatic Animal Health Subprogram: the production of nodavirus-free fish fry and the nodaviruses natural distribution

Project number: 2002-043
Project Status:
Completed
Budget expenditure: $222,356.00
Principal Investigator: Ian Anderson
Organisation: Department of Primary Industries (QLD)
Project start/end date: 29 Jun 2002 - 30 Jul 2008
:

Need

Nodavirus in wild barramundi populations

* There is a need to address concerns about the effect of stocking hatchery-reared barramundi on the level of unapparent nodavirus infections (that is, the prevalence) in wild barramundi.
* The first step is to determine the prevalence of nodavirus in wild populations of barramundi (that is to say the natural level of nodavirus-carrier status – an infection without disease).
* The baseline nodavirus prevalence data will permit:
- comparison of barramundi populations in areas where stocking has or has not occurred,
- assessment of changes in prevalence of nodavirus in future years,
- effective decisions about appropriate sources of replacement broodstock for breeding programs.

Nodavirus in freshwater fishes

* There is a need to address concerns about the risk of possible lethal transmission of barramundi nodavirus to freshwater fishes.
* Recent investigations have shown a possible susceptibility of freshwater fishes to barramundi nodavirus and that nodaviruses naturally occur in species other than barramundi in Australia, including the freshwater species, sleepy cod.
* There is a need to determine if there are nodaviruses in freshwater fishes as a risk analysis for translocation should include disease-status information in the receiving population.

Are the nodaviruses found in freshwater fishes related to barramundi nodavirus?

* If nodaviruses are detected in freshwater fish an analysis of relatedness (sequence analysis of PCR products) could indicate an association to previous stocking in that area of hatchery-reared barramundi. This information would support effective risk analysis for future translocation considerations.

A testing protocol for hatchery production of nodavirus-free fish fry.

* Broodstock screening protocols to identify nodavirus-free broodstock have been described from overseas but the detection tests used then are not as sensitive as the two-step or nested RT-PCR, and the protocols include a requirement for egg/water disinfection and repeat testing of larvae.
* There is a need to evaluate and validate the sensitivity of the two-step or nested RT-PCR to identify nodavirus-free broodstock and to determine if one or more tests are required to confirm the nodavirus-free status.
* There is a need to confirm in barramundi that larvae/fry become infected by nodavirus through the vertical transmission route (ie., from their parent(s)).
* There is a need to determine if fry can become infected via nodavirus-contaminated water once they are stocked into nursery systems.
* If the vertical infection route is the same for all fish species, the information on the testing protocol required to produce nodavirus-free barramundi fry will be a model testing protocol applicable to all fish species in breeding programs in Australia.

Objectives

1. To determine the natural level of nodavirus infection in wild barramundi.
2. To determine the presence or absence of nodavirus infections in freshwater fish species.
3. To describe the relatedness of any nodaviruses isolated from freshwater fishes.
4. To define the best testing protocol in barramundi hatchery production systems to ensure nodavirus-free fry production.

Final report

ISBN: 978-0-7345-0405-0
Author: Ian Anderson
People
PROJECT NUMBER • 2002-652
PROJECT STATUS:
COMPLETED

Aquatic Animal Health Subprogram: enhancement of the emergency disease management capability in Victoria - developing a Victorian Control Centres Management Manual

AQUAVETPLAN and its associated manuals, and in particular the ‘AQUAVETPLAN Control Centres Management Manual’ provide the necessary framework for the development of a Victorian management/operational manual that would meet the planning needs in relation to aquatic animal diseases. The...
ORGANISATION:
Agriculture Victoria
Environment
PROJECT NUMBER • 2004-091
PROJECT STATUS:
COMPLETED

Aquatic Animal Health Subprogram: further research and laboratory trials for diagnostic tests for the detection of A invadans (EUS) and A astaci (Crayfish Plague)

Crayfish plague and epizootic ulcerative syndrome are two fungal diseases that affect freshwater crayfish and freshwater finfish, respectively. Crayfish plague, which is caused by Aphanomyces astaci, is exotic to Australia, but is capable of causing massive stock losses of up to 100% which would be...
ORGANISATION:
Murdoch University
Industry
PROJECT NUMBER • 2019-086
PROJECT STATUS:
COMPLETED

Development of a national sector-specific biosecurity plan guideline and template for the farmed freshwater native finfish industry of Australia

These guidelines were developed as part of Fisheries Research and Development Corporation (FRDC) project number 2019-086: Development of a national sector-specific biosecurity plan guideline and template for the farmed freshwater native finfish industry of Australia and in accordance with: •...
ORGANISATION:
Freshwater Native Fish Association (FNFA)
TAGS
Environment
PROJECT NUMBER • 1999-205
PROJECT STATUS:
COMPLETED

The effect of barramundi Nodavirus on important freshwater fishes

This project has confirmed the knowledge that management of barramundi translocations outside their natural range requires fisheries authorities take into account the risk that barramundi nodavirus may lethally infect native freshwater fishes. The project has shown barramundi nodavirus can...
ORGANISATION:
Department of Primary Industries (QLD)
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