?Comparing species detection success between molecular markers in DNA metabarcoding of coastal macroinvertebrates

DNA metabarcoding has great potential to improve marine biomonitoring programs by providing a rapid and accurate assessment of species composition in zoobenthic communities. However, some methodological improvements are still required, especially regarding failed detections, primers efficiency incompleteness databases. Here we assessed the two different marker loci (COI 18S) three primer pairs detection through macrozoobenthic communities colonizing types artificial substrates (slate, PVC granite), sampled between 3 15 months deployment. To accurately compare success markers, also compared representativeness detected public databases revised reliability taxonomic assignments. Globally, recorded extensive complementarity each marker, with 69% exclusively either 18S or COI. Individually, recovered, at most, 52% all on samples, showing abilities amplify specific groups. Most have reliable reference sequences their respective (82% for COI 72% 18S), meaning that when was one not other, it most likely due faulty amplification, lack matching database. Overall, results showed impact applied ability indicated that, currently, if only single pair is employed zoobenthos metabarcoding, fair portion diversity may be overlooked.