Taxonomy and molecular phylogeny of long Jawed spiders (Araneae: Tetragnathidae) in Kerala

Abstract

The family Tetragnathidae, commonly known as long jawed spiders, is distributed inthe tropical and subtropical areas of the world. The present study is the first tosystematically investigate the taxonomy and molecular phylogeny of tetragnathids inKerala with the purpose of delimiting species boundaries and understandinginterrelationships between them. The study documented a total of 27 tetragnathidsunder eight genera from the state of Kerala, which constitutes 48% of the Indiantetragnathid fauna. A new six-eyed Dolichognatha species, D. chimminiensis sp.nov., described during the study represents the third of the genus from India.Tetragnatha cochinensis, T. viridorufa, Tylorida flava, and Atelidea sp. wererecorded as endemic to India. This is the first to record T. lauta, T. squamata, T.serra, T. jaculator and a silvery spider, Leucauge rubromaculata from India. Malesof L. fastigata and Tylorida flava were recorded for the first time in India and this isthe first to describe the latter species with an exhaustive account of its bodymorphology and genitalic characters. Furthermore, T. chamberlini was proposed asthe junior synonym of T. javana and T. andamanensis was synonymized with T.hasselti. Since the taxonomic accounts of many of the tetragnathids wereinadequate, T. cohinensis, T. geniculata, and T. serra were rigorously redescribedand the former species was revised after a century. The barcode data generatedduring the current study were satisfactorily concordant with the traditionalmorphological characters. The concatenated nucleotide sequences of CO1 and 18Sfairly resolved the evolutionary relationship between tetragnathids by employingNeighbour Joining (NJ), Maximum Parsimony (MP), Maximum Likelihood (ML),and Bayesian Inference (BI) approaches. The monophyly of the familyTetragnathidae was evident with the clustering of four subfamilies, such asTetragnathinae, Leucauginae, Metainae, and Nanometinae.