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Spiders (Araneae) of Churchill, Manitoba: DNA barcodes and morphology reveal high species diversity and new Canadian records.

Blagoev GA, Nikolova NI, Sobel CN, Hebert PD, Adamowicz SJ - BMC Ecol. (2013)

Bottom Line: As well, one probable new species of Alopecosa (Lycosidae) was recognized.This study provides the first comprehensive DNA barcode reference library for the spider fauna of any region.The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biodiversity Institute of Ontario, University of Guelph, Guelph, Ontario N1G 2W1, Canada. gblagoev@uoguelph.ca.

ABSTRACT

Background: Arctic ecosystems, especially those near transition zones, are expected to be strongly impacted by climate change. Because it is positioned on the ecotone between tundra and boreal forest, the Churchill area is a strategic locality for the analysis of shifts in faunal composition. This fact has motivated the effort to develop a comprehensive biodiversity inventory for the Churchill region by coupling DNA barcoding with morphological studies. The present study represents one element of this effort; it focuses on analysis of the spider fauna at Churchill.

Results: 198 species were detected among 2704 spiders analyzed, tripling the count for the Churchill region. Estimates of overall diversity suggest that another 10-20 species await detection. Most species displayed little intraspecific sequence variation (maximum <1%) in the barcode region of the cytochrome c oxidase subunit I (COI) gene, but four species showed considerably higher values (maximum = 4.1-6.2%), suggesting cryptic species. All recognized species possessed a distinct haplotype array at COI with nearest-neighbour interspecific distances averaging 8.57%. Three species new to Canada were detected: Robertus lyrifer (Theridiidae), Baryphyma trifrons (Linyphiidae), and Satilatlas monticola (Linyphiidae). The first two species may represent human-mediated introductions linked to the port in Churchill, but the other species represents a range extension from the USA. The first description of the female of S. monticola was also presented. As well, one probable new species of Alopecosa (Lycosidae) was recognized.

Conclusions: This study provides the first comprehensive DNA barcode reference library for the spider fauna of any region. Few cryptic species of spiders were detected, a result contrasting with the prevalence of undescribed species in several other terrestrial arthropod groups at Churchill. Because most (97.5%) sequence clusters at COI corresponded with a named taxon, DNA barcoding reliably identifies spiders in the Churchill fauna. The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group.

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Ultrametric neighbour-joining trees (K2P) showing shallow sequence divergence among COI sequences for two sibling species groups: A) four Pardosa species (P. dromaea, P. groenlandica, P. podhorskii, P. furcifera) of the P. modica group, and B) three Erigone species (E. arctica, E. arctophylacis, E. dentigera). Bootstrap values are based on 500 replications.
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Figure 13: Ultrametric neighbour-joining trees (K2P) showing shallow sequence divergence among COI sequences for two sibling species groups: A) four Pardosa species (P. dromaea, P. groenlandica, P. podhorskii, P. furcifera) of the P. modica group, and B) three Erigone species (E. arctica, E. arctophylacis, E. dentigera). Bootstrap values are based on 500 replications.

Mentions: Although different species usually show more than 2% interspecific divergence, lower levels of sequence divergence should occur in young species, and they have been detected in many groups[87,88]. In some extreme cases, valid species pairs differ by only a single bp in the barcode region[89] or not at all[73]. Two cases of young species assemblages were detected in this study involving species of Pardosa and Erigone (FigureĀ 13).


Spiders (Araneae) of Churchill, Manitoba: DNA barcodes and morphology reveal high species diversity and new Canadian records.

Blagoev GA, Nikolova NI, Sobel CN, Hebert PD, Adamowicz SJ - BMC Ecol. (2013)

Ultrametric neighbour-joining trees (K2P) showing shallow sequence divergence among COI sequences for two sibling species groups: A) four Pardosa species (P. dromaea, P. groenlandica, P. podhorskii, P. furcifera) of the P. modica group, and B) three Erigone species (E. arctica, E. arctophylacis, E. dentigera). Bootstrap values are based on 500 replications.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4222278&req=5

Figure 13: Ultrametric neighbour-joining trees (K2P) showing shallow sequence divergence among COI sequences for two sibling species groups: A) four Pardosa species (P. dromaea, P. groenlandica, P. podhorskii, P. furcifera) of the P. modica group, and B) three Erigone species (E. arctica, E. arctophylacis, E. dentigera). Bootstrap values are based on 500 replications.
Mentions: Although different species usually show more than 2% interspecific divergence, lower levels of sequence divergence should occur in young species, and they have been detected in many groups[87,88]. In some extreme cases, valid species pairs differ by only a single bp in the barcode region[89] or not at all[73]. Two cases of young species assemblages were detected in this study involving species of Pardosa and Erigone (FigureĀ 13).

Bottom Line: As well, one probable new species of Alopecosa (Lycosidae) was recognized.This study provides the first comprehensive DNA barcode reference library for the spider fauna of any region.The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biodiversity Institute of Ontario, University of Guelph, Guelph, Ontario N1G 2W1, Canada. gblagoev@uoguelph.ca.

ABSTRACT

Background: Arctic ecosystems, especially those near transition zones, are expected to be strongly impacted by climate change. Because it is positioned on the ecotone between tundra and boreal forest, the Churchill area is a strategic locality for the analysis of shifts in faunal composition. This fact has motivated the effort to develop a comprehensive biodiversity inventory for the Churchill region by coupling DNA barcoding with morphological studies. The present study represents one element of this effort; it focuses on analysis of the spider fauna at Churchill.

Results: 198 species were detected among 2704 spiders analyzed, tripling the count for the Churchill region. Estimates of overall diversity suggest that another 10-20 species await detection. Most species displayed little intraspecific sequence variation (maximum <1%) in the barcode region of the cytochrome c oxidase subunit I (COI) gene, but four species showed considerably higher values (maximum = 4.1-6.2%), suggesting cryptic species. All recognized species possessed a distinct haplotype array at COI with nearest-neighbour interspecific distances averaging 8.57%. Three species new to Canada were detected: Robertus lyrifer (Theridiidae), Baryphyma trifrons (Linyphiidae), and Satilatlas monticola (Linyphiidae). The first two species may represent human-mediated introductions linked to the port in Churchill, but the other species represents a range extension from the USA. The first description of the female of S. monticola was also presented. As well, one probable new species of Alopecosa (Lycosidae) was recognized.

Conclusions: This study provides the first comprehensive DNA barcode reference library for the spider fauna of any region. Few cryptic species of spiders were detected, a result contrasting with the prevalence of undescribed species in several other terrestrial arthropod groups at Churchill. Because most (97.5%) sequence clusters at COI corresponded with a named taxon, DNA barcoding reliably identifies spiders in the Churchill fauna. The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group.

Show MeSH
Related in: MedlinePlus