Molecular characterization of ‘tubifex worms’ based on 16S rRNA and cytochrome c oxidase subunit I

Abstract

‘Tubifex worms’ encompass extensive cryptic diversity that requires molecular characterization to confirm the species commonly found in Bangladesh including their lineages. Therefore, this study focused on the molecular characterization and phylogeny analysis at lineages level by sequencing the fragment of 16S rRNA and cytochrome c oxidase subunit I (COI) genes through standard cloning and sequencing techniques followed by phylogenetic characterization. All six isolates, belong to the genus Limnodrilus that is confirmed into two different species (L. hoffmeisteri and L. claparedianus-cervix) of the tubifex. The phylogenetic analysis estimated that the resident worms are under the same clade although transmissions from other countries might likely occur through different aquatic routes and birds. The drawbacks were the use of a complex colony rather than a single worm and taking representative isolates instead of all the positive amplicons for sequencing. However, this study is the first report of genetical confirmation of the genus Limnodrilus at lineage level from Bangladesh. Keywords: Tubifex, Phylogeny, Cytochrome oxidase, 16S rRNA, Bangladesh