They are one of the most diverse groups with 48,248 extant species and can be found everywhere except Antarctica 4, 5. Spiders are an ancient group of arthropods with their fossil records dating back to the Devonian period (~400 million years ago) 1, 2, 3. These data show that DNA barcoding is a valuable tool for specimen identification and species discovery of Indian spiders. Additionally, we reinstate the original combination for Linyphia sikkimensis based on both morphology and DNA barcoding. Two morphologically distinguished species ( Plexippus paykulli and Plexippus petersi) showed intra-individual variation within their DNA barcode data. Further, shallow genetic distances were detected in Cyrtophora cicatrosa, Hersilia savignyi, Argiope versicolor, Phintella vittata, and Oxyopes birmanicus. The intraspecies distances which were as large as our proposed delimitation threshold were observed in Pardosa sumatrana, Thiania bhamoensis, and Cheiracanthium triviale. Cryptic diversity was detected in Pardosa pusiola, Cyclosa spirifera, and Heteropoda venatoria. We detected more than one MOTU in 11 morphospecies with discrepancies in genetic distances and tree topologies. The multiple species delimitation methods (BIN, ABGD, GMYC and PTP) revealed a total of 107 molecular operational taxonomic units (MOTUs) for 101 morphospecies. The estimated delimitation threshold of the Indian spiders was 2.6% to 3.7% K2P corrected pairwise distance. A total of 489 barcodes was generated and analyzed, among them 85 novel barcodes of 22 morphospecies were contributed to the global database. ![]() This study is the first large scale attempt on DNA barcoding of spiders from India with 101 morphospecies of 72 genera under 21 families, including five endemic species and holotypes of three species. To overcome these obstacles, DNA barcoding plays a pivotal role in spider identification throughout the globe. Identification of this group is challenging due to their cryptic behavior, sexual dimorphism, and unavailability of taxonomic keys for juveniles. Spiders are mega diverse arthropods and play an important role in the ecosystem.
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