1. Aquaculture activities at the Laboratory of Virology Faculty of Veterinary Medicine, UGent <2002 ≥2002

2. White spot syndrome in shrimp - Aggressive and devastating disease, characterized by lethargy, lack of appetite and reddish to pink body discoloration, presence of white spots on exoskeleton - Infects many crustaceans, including most cultured shrimp species - Mortalities of up to 100% within 3-10 days - Cause of huge losses (billions of US$ per year) Etiology: White spot syndrome virus (WSSV) - Family of the Nimaviridae, genus whispovirus - Rod-shaped double stranded DNA virus - Virion has envelope with a tail-like appendage and measures 275 nm X 120 nm

3. Realisations (2002-2011) a)production & titration of WSSV in shrimp a)standardized IM inoculation model pathogenesis virulence/pathogenicity of ≠ strains susceptibility (≠ species; ≠ genetic lines; ≠ ages) treatments (antivirals, T°, immunomodulating molecules) effect of moulting/cuticula damage c) defence -> haemocytes culture in attachment culture in suspension particle uptake particle destruction -> haemolymph

4. T0’ T120’ T24h T48h T72h P. vannamei M. rosenbergii Haemocyte culture in attachement

5. T0’ T10’ T30’ T60’ T120’ T24h P. vannamei M. rosenbergii T48h Haemocyte culture in suspension

6. Particle uptake and inactivation Beads 200nm Bacteri a Beads 1µm WSSV? SOP virus purification! Vibrio ? Co-infections?

7. Future work (> 2011) a)standardized PO/PR inoculation model pathogenesis virulence/pathogenicity of ≠ strains susceptibility (≠ species; ≠ genetic lines; ≠ ages) treatments (antivirals, T°, immunomodulating molecules) effect of moulting/cuticula damage role of peritrophic membrane how to strengthen barrières (feed, water quality, flora) b) new defence mechanisms -> haemocytes uptake/inactivation ≠ viruses/bacteria/… aggregation/coagulation particle catching/isolation system outside haemocyte activation -> haemolymph ? genetic determinants?