Research on Quantitative Analysis Technology for Pacific White Shrimp Density Based on Environmental DNA

Litopenaeus vannamei is one of the most essential farmed shrimp species globally, yet disease outbreaks during cultivation continue to hinder industry development. Accurate biomass estimation is critical for optimizing feeding, maintaining water quality, and preventing disease. This study developed a quantitative method for environmental DNA (eDNA) using real-time fluorescence quantitative PCR with L. vannamei as the model species. Species-specific primers were designed and validated to ensure detection specificity. Temperature significantly influenced eDNA degradation, with higher temperatures accelerating decay; eDNA remained detectable in water for over a month at 26°C. A strong linear correlation was observed between eDNA concentration and shrimp biomass, highlighting eDNA's potential for biomass assessment. eDNA release per unit body weight varied with growth stage, following the pattern "small > medium > large," while short-term feeding had no significant effect. The method was validated in both indoor recirculating systems and outdoor ponds, where eDNA levels correlated positively with final yield. This study establishes a robust eDNA-based framework for monitoring shrimp biomass, enabling precise, dynamic management in aquaculture.