Exploring the capacity of aquatic biofilms to act as environmental DNA samplers: Test on macroinvertebrate communities in rivers

Aquatic biofilms are heterogeneous assemblages of microorganisms surrounded by a matrix extracellular polymeric substances (EPS). Recent studies suggest that aquatic can physically act as sorptive sponges DNA. We took the opportunity from already available samples stone and macroinvertebrates specimens collected in parallel at same sites to test capacity DNA samplers macroinvertebrate communities streams. Macroinvertebrate usually studied with metabarcoding using extracted their bodies bulk samples, which remains time-consuming approach involves destruction all individual samples. The ability capture was explored on 19 rivers tropical island (Mayotte Island, France). First, were identified based morphological characteristics. Second, biofilms, targeted standard COI barcode. resulting molecular inventories compared. They provided comparable structures diversities for when one is working unassigned OTU data. After taxonomic assignment data, diversity richness no longer correlated. ecological assessment derived conserved also showed biofilm method allows detect higher some organisms (Cnidaria), hardly accessible method. results this study exploring signal captured natural encouraging. However, more detailed integrating replicates comparing biodiversity both will be necessary. Better understanding how represents given sampling site necessary before considering its use bioassessment applications.