Small changes make big progress: A more efficient <scp>eDNA</scp> monitoring method for freshwater fish

Comprehensive and accurate assessments of fish composition diversity are essential for understanding ecology resource management. Traditional surveys generally involve capturing organisms, which is invasive the biological community under study conflicts with original intention biodiversity conservation. Environmental DNA (eDNA) metabarcoding has become an integrated method monitoring species without disturbing ecosystems. However, due to serious nonspecific amplification primers in eDNA-based monitoring, many non-fish sequences, usually human also amplified, results data wastage increase costs. We designed new universal freshwater by analyzing whole mitochondrial genome Chinese fish. The performance was compared using silico polymerase chain reaction, followed vitro analysis eDNA from Yangtze River, third largest river world harbors species. found that 12S region most suitable gene marker both other minor change at 3?-end primer can greatly reduce improve effectiveness metabarcoding. Even small changes may have qualitative quantitative effects on detected biodiversity, should be considered experimental design interpretation. These will help selection surveys, consequently support conservation biodiversity.