Australian prawn production, forecast at 24 kilotonnes in 2014/15, is valued at >$310 million. The prawn fishery is an important natural resource that supports a substantial export industry. Prawn aquaculture is a significant industry in northern Australia and accounts for approximately 20% of the total volume of Australian production. Of the YHV-complex of viruses, YHV1 is exotic to Australia, is an OIE-listed pathogen and can cause 100% mortality in 3-5 days. The endemic GAV (YHV2) occurs commonly in P. monodon in Australia and has been associated with Mid-Crop Mortality Syndrome (MCMS). The pathogenicity of the newly detected YHV-complex genotypes to Australian prawns is unknown. While YHV7 was detected in diseased P. monodon its role in the disease is unknown. YHV8 and YHV10 were detected in imported commodity prawns from China. These prawns were released from quarantine as only YHV1 requires risk management according to the prawn IRA (BAA 2009/25). The pathogenicity and potential impact of YHV8 and YHV10 to Australian prawns is unknown and the risk associated with these imported genotypes needs to be clarified. This project will generate knowledge regarding the susceptibility of Australian farmed P. monodon and P. merguiensis to the newly discovered enzootic YHV7 and exotic YHV8 and YHV10 genotypes. This information is critical for policy-makers, regulators, managers and producers to implement appropriate biosecurity measures. The Project aligns with Key Research Area 6.2.1 of the FRDC AAHS R&D Plan “Knowledge about new and emerging infectious diseases” and value-adds to the FRDC 2103/036 TRF project.

1. Determine the susceptibility of P. monodon and P. merguiensis to YHV-complex Genotype 7 (YHV7)

2. Determine the susceptibility of P. monodon and P. merguiensis to YHV-complex Genotype 8 (YHV8)

3. Determine the susceptibility of P. monodon and P. merguiensis to YHV-complex Genotype 10 (YHV10)

4. Transfer protocols and controls for diagnostic tests to state diagnostic laboratories