An effective white spot syndrome virus challenge test for cultured shrimp using different biomass of the infected papilla

White spot syndrome virus (WSSV) is one of the most virulent pathogens of cultured penaeid shrimp. Several control strategies are used commonly to mitigate the economic losses caused by the pathogen, such as application of antiviral products at farm level. One of the most practical method for the screening of potential anti-WSSV products is through challenge tests. Therefore, it is essential to develop simple, reproducible and effective bioassays able to simulate specific mortality levels. The purpose of this study was to develop a simple and reproducible bioassay that simulate different mortality levels by varying the proportion of WSSV-infected and noninfected shrimp tissues administered to susceptible shrimp during a per os challenge test. This method mimics one of the natural transmission routes of WSSV infection in shrimp and could be applied to identify potential antiviral products to different cultured shrimp species susceptible to WSSV. Here we report: • A simple and economic method to evaluate therapeutic antiviral products against WSSV through a challenge test, that uses different biomass amounts of WSSV-infected papilla. • Allows to simulate a wide and reproducible range of mortalities observed in shrimp farms. • A challenge test that simulates one mode of natural WSSV infection in shrimp.