Applicability and Advantage of Mitochondrial Metagenomics and Metabarcoding in Spider Biodiversity Survey

Abstract

Spiders are an extraordinary animal group with extremely high diversity in species, morphology, and behavior. Accurate estimation of species diversity and community composition is essential in spider ecological studies as well as applications of biodiversity surveys and monitoring. However, spider biodiversity surveys still largely utilize the morphology-based approach, which is often time-consuming and highly dependent on taxonomic experts. In this study, we tested the applicability of mitochondrial metagenomic and metabarcoding methods in the biodiversity survey of spiders. Local mitogenome and barcode databases of 62 reference species were built using next-generation sequencing and Sanger sequencing technologies. The performances of mitochondrial metagenomics, metabarcoding, and morphological methods were compared for five plot samples of spiders. The results show that the molecular methods (mitochondrial metagenomics and metabarcoding) have a higher species detection rate compared with the traditional morphological biodiversity method, which is largely due to their capability of incorporating the large proportion of immature specimens in each plot into the biodiversity assessment. Our study demonstrates the great potential of molecular approaches in advancing spider biodiversity and community ecology studies and suggests that by combining both mitochondrial metagenomic and metabarcoding methods we could provide more accurate and reliable biodiversity assessment for spiders.