Establishment and Optimization of Environmental DNA Detection Techniques for Assessment of Fenneropenaeus chinensis Biomass

Abstract:

In recent years, environmental DNA (eDNA) technology has developed rapidly as a new method for investigation of aquatic organisms and has been widely used in the field of aquatic ecosystem research for species detection, biodiversity evaluation, and biomass assessment. However, few studies have specifically evaluated the effects of different eDNA enrichment and extraction methods on the results of the eDNA technology operation process to establish a set of optimal eDNA technology operation procedures for specific research subjects. In addition, because of differences in living habits between species, the amount of DNA released from different species and the size of DNA fragments are different. Therefore, different eDNA enrichment and extraction methods should be adopted for different research subjects. In this study, Fenneropenaeus chinensis was used as the research object, and eDNA was enriched by the membrane method, and eDNA was extracted by combining a blood and tissue DNA extraction kit. A filter membrane with a diameter of 47 mm, a nitrocellulose membrane, a polycarbonate membrane, and a nylon membrane were used, and each membrane was set to 0.45 μm, 0.8 μm, 1.2 μm, and 5 μm according to pore size. With 4 gradients, the sampling water volume was set to three gradients of 500 ml, 1 L, and 2 L. The experimental results showed that the membrane material size, pore size of the membrane, and the volume of the sampled water had certain influences on the qualitative and quantitative analysis of F. chinensis. The 0.45 μm glass fiber membrane filter and 2 L water sample detected the greatest DNA copy number. Based on this, a set of operational procedures for F. chinensis prawn eDNA technology was established to improve the detection rate of F. chinensis, which provided the basis for subsequent distribution monitoring and biomass assessment of F. chinensis.