Identification of earthworms (Clitellata, Oligochaeta) from Kottayam district in Southwestern India: an integrated traditional and barcoding approach

Earthworms from various land uses in the Kottayam district of Kerala, part of the Western Ghats hotspot in India, were studied using an integrative approach that involved morphoanatomical methods and cytochrome c oxidase I (COI) barcoding techniques for the first time here. The study unveiled the presence of nine earthworm species: Drawida ghatensis Michaelsen, 1910; Moniligaster julkai Narayanan and Paliwal, 2022; Glyphidrilus annandalei Michaelsen, 1910; Pontoscolex corethrurus (Müller, 1857); Eukerria kuekenthali (Michaelsen, 1908); Dichogaster bolaui (Michaelsen, 1891); Megascolex cochinensis Stephenson, 1915; M. konkanensis Fedarb, 1898; and Lampito mauritii Kinberg, 1867, belonging to eight genera. The COI sequences of all nine species were deposited in GenBank. Notably, M. julkai and E. kuekenthali are novel additions to the GenBank barcode database. The Bayesian phylogram and maximum-likelihood indicated that the species M. julkai in this study exhibited a closer relationship to D. ghatensis than to other Moniligaster species. This study provides detailed descriptions and illustrations of all nine species, supplemented by their DNA barcodes, to facilitate future species identification.