Challenging species delimitation in Collembola: cryptic diversity among common springtails unveiled by DNA barcoding

Abstract

Collembola is one of the major functional groups in soil as well as a model taxon in numerous disciplines. Therefore the accurate identification of specimens is critical, but could be jeopardised by cases of cryptic diversity. Several populations of six well characterised species of springtails were sequenced using the COI barcode fragment as a contribution to the global Collembola barcoding campaign. Each species showed high intraspecific divergence, comparable to interspecific sequence divergence values observed in previous studies and in 10 congeneric species barcoded here as a reference. The nuclear marker, 28S, confirmed all the intraspecific lineages found with COI, supporting the potential specific status of these entities. The implications of this finding for taxonomy and for disciplines relying on species names, such as evolution and ecology, are discussed.

A quantitative protocol for DNA metabarcoding of springtails (Collembola)

“…Even for species that had been barcoded at other sites, their sequences were different from those collected from identical morphological species at the study site (i.e., <90% of sequence similarity). These results support the huge and hidden diversity in Collembola shown in previous studies (e.g., Porco et al 2012aPorco et al , 2012bCicconardi et al 2013) and suggest the need for generating more reference sequences of this group, more extensively at our study site as well as in various other geographic regions. At present, the construction of a locally collected database for mtCOI and mt16S genes will be needed to identify collembolan species from metabarcoding data.…”

“…While >3% of difference in COI sequence (i.e., <97% of identity) has been usually considered to indicate distinct species in various taxa (Hebert et al 2003), greater than 3% difference within morphological species has been previously reported in Collembola (e.g., Porco et al 2012aPorco et al , 2014Anslan and Tedersoo 2015) and was found in the present study. As distributions of inter-and intraspecific sequence similarities overlapped (Fig.…”

“…As the size of our database was limited, published sequence data were combined with our data to conduct this and the following analyses. We used mtCOI sequence data from Porco et al (2012a), who revealed sequence divergences between cryptic species within cosmopolitan morphospecies of Collembola; reproductively isolated lineages found in their study were regarded as different species (in total 188 sequences from 28 (crypto)species from 16 morphospecies). For mt16S data, sequences from published complete collembolan mitogenomes (10 sequences from 9 species; see later subsection for the accession numbers) were combined because no other sequence deposited in a public database completely overlapped the region utilized in our metabarcoding method.…”

Biological Invasions, Climate Change, and Genomics

“…Mostly, the aim has been to characterize the diversity of an assemblage and identify alien species among its members in a given recipient area, or to verify whether given populations are from species thought to be nonindigenous (e.g. Scheffer et al 2006;Smith and Fisher 2009;Porco et al 2012Porco et al , 2013Fern andezAlvarez and Machordom 2013;Zhang et al 2013a). Such approaches nonetheless are subject to the same kinds of problems as those facing DNA barcoding generally (see review by Taylor and Harris 2012).…”

Molecular Identification and Barcoding of Two Shrimp Species (Parapenaeopsis Sculptillis and Parapenaeopsis Hardwikii) Collected From Gorai Creek of Mumbai, West Coast of India

“…The amplified products showed approximately 700bp ( Figure 2). Several studies have been reported that sequence diversity in a ~650 bp region near the 5' end of the MT-COI gene provides strong species-level resolution for varied animal groups, including birds [1,12], fishes [7,30], springtails [5,24], spiders [5,6] and moths [16,20]. It has been reported that the primer pair, (LCO_MT1_NC101214 and LCO_MT2_NC021214) was not so ''universal'' as thought before, as it would still fail to amplify some taxa [21,28].…”