DNA barcoding of Naididae (Annelida, Oligochaeta), based on cytochrome C oxidase gene and ITS2 region in China

Abstract

Exploring the effectiveness of DNA barcoding in species identification is a prerequisite for biodiversity conservation and environmental monitoring. Aquatic oligochaetes could serveas excellent indicators in aquatic monitoring programmes. However, few studies haveexamined the effectiveness of DNA barcoding in these specific organisms. Themitochondrial cytochrome C oxidase (COI) gene of 83 specimens belonging to 40 speciesof 18 genera were sequenced in this study. The results showed that there was a barcodegap between species of Naididae and the intraspecific genetic distances of each specieswere smaller than interspecific genetic distances. The classification results of ABGD(Automatic Barcode Gap Discovery) were consistent with those of morphologicalidentification, except for Tubifex tubifex and Lumbriculus variegatus. All species weresuccessfully distinguished in the phylogenetic tree, based on the ITS2 region, which wascoincident with the morphological result. Our results provided evidence that DNA barcodingcan be used as an effective and convenient tool for species identification of the familyNaididae and even for other aquatic oligochaetes