The continuous trend towards increased stocking densities increases the risk and impact of disease, such as outbreaks of White Spot Syndrome Virus (WSSV) that cause 8-15 billion USD of losses per year. Pacific White Shrimp Litopenaeus vannamei has been shown to exhibit consistent acoustic behavior when feeding, and there have been several studies that show behavioral recognition and feeding monitoring is possible from acoustic data. However, as of yet, no study has investigated how disease affects shrimp activity from an acoustic analysis perspective. We attempt to address this gap by recording and analyzing the acoustic signals generated by L. vannamei in response to a WSSV disease challenge.
We set up a rearing tank for shrimp at the University of Arizona Aquaculture Pathol- ogy Laboratory. We initially introduced 15 4-week-old shrimp in an approximately 1000 L tank as a baseline level. After two weeks, we added an additional 20 shrimp to increase the stocking density. The tank was con- stantly aerated and checked daily to replace fouled airstones. For 4 weeks, the shrimp were fed commercial diet at regular inter-
vals to provide a baseline for behavior. At the end of the 4th week, they were chal- lenged with WSSV by feeding infected tis- sue at 2.5% body weight. During the entire study period, we deployed an Aquarian AS-1 hydrophone in the tank and recorded audio at 96 kHz sample rate.
Four days post-infection, maximum fre- quency and duration of the clicks signifi- cantly lowered by 13 kHz and 11.6 ms, re- spectively. The overall shape of the sound emission spectra also changed substantially. This suggests that acoustic monitoring may be effective in detecting WSSV infection.
This work was produced together with the University of Arizona Aquaculture Pathology Laboratory2, and was supported in part by the National Science Foundation (No. 2329826)