Molecular taxonomy and phylogeny of orb weaving spiders araneae araneidae in Kerala

Abstract

The family Araneidae, commonly known as orb-weaving spiders, represents the third-largestspider family in the world and the second-largest in India. These spiders inhabit a wide range ofecosystems and are distributed across all landmasses except Antarctica. Ongoing revisions arenecessitated by challenges such as extreme sexual size dimorphism, colour polymorphism, andabdominal variability among conspecifics, as well as the existence of cryptic species. This studypresents a focused investigation on the araneids of Kerala, aiming to make a substantialcontribution to the taxonomy, molecular data, and phylogenetic understanding of the group.Detailed morphological examination and barcoding of COI and H3 genes have resulted in anupdated checklist of araneids in Kerala, including 59 species belonging to 23 genera.Leviaraneus viridiventris and Chorizopesoides orientalis were reported from India for the firsttime. A total of 109 barcodes were generated, among these, 38 were new additions to GenBank.Species identity of certain morphologically challenging species and the existence of colourmorphs in Nephila pilipes were confirmed. Three pairs of cryptic species were identified.Phylogenetic trees were reconstructed using different methods such as Neighbour Joining,Maximum Parsimony, Maximum Likelihood and Bayesian Inference. The placement andmonophyly of nephilines and zygiellines were confirmed. The monophyletic origin of Acusilas,Arachnura, Argiopinae, Bijoaraneus, Araneilla, and Plebs was revealed. The genera Araneusand Cyclosa exhibited polyphyly. The study is the first comprehensive, successful attempt todate the divergence of araneids. The present study underscores the effectiveness of COIbarcoding in species-level identification and demonstrates the value of incorporating multiplegenetic markers to resolve phylogenetic relationships.