A DNA barcode reference library and ecoregion analysis of North American wolf spiders (Araneae: Lycosidae)

Gergin A. Blagoev, Jeremy R. deWaard, and Paul D.N. HebertCentre for Biodiversity Genomics, University of Guelph

Poster ID: 800

AbstractSpecies diversity on our planet follows complex patterns governed by historical, physical and biological parameters, resulting in the classificationof well-defined ecoregions usually dominated by specific plant communities. As spiders are predators, they are not directly dependent on plantsfor nutrition but may have similar distributional patterns. Until now, comprehensive analysis of these patterns has been prohibited by arduousspecimen identification and a high incidence of cryptic species. However, DNA barcoding can circumnavigate many of these barriers bydelineating species and accelerating specimen identification. We utilize this method to build a DNA barcode reference library for Nearctic wolfspiders (Araneae: Lycosidae), the fifth largest spider family in North America, and investigate distribution patterns across the Nearctic ecoregions.

AcknowledgementsFinancial support was provided by the Ontario Ministry of Research and Innovation and by thegovernment of Canada through Genome Canada and the Ontario Genomics Institute in supportof the International Barcode of Life project. We are extremely grateful to colleagues whoprovided specimens for analysis (Charles Dondale, Chris Buddle, Claudia Copley, Darren Copley,Pat Miller, Robb Bennett, Tom Mason). We are very grateful to John Waithaka and other staff atParks Canada for supporting collection programs in national parks across Canada.

ReferencesBlagoev, G.A., deWaard, J.R., Ratnasingham, S., deWaard, S.L., Lu, L., Robertson, J., Telfer,

A.C. & Hebert, P.D.N., 2016. Untangling taxonomy: a DNA barcode reference library forCanadian spiders. Molecular Ecology Resources, 16, 325–341. https://doi.org/10.1111/1755-0998.12444

Commission for Environmental Cooperation, 1997. Ecological Regions of North America:Toward a Common Perspective. Montreal, Quebec. 71 pp.

Foelix, R., 2011. Biology of Spiders (Third Edition). Oxford University Press. 432 pp. ISBN:9780199734825

World Spider Catalog, 2017. World Spider Catalog. Natural History Museum Bern, online athttp://wsc.nmbe.ch, version 18.5, accessed on {date of access}. doi: 10.24436/2.

With 2486 species from 124 genera, the family Lycosidae isranked fifth in size among spiders (World Spider Catalog, 2017).Wolf spiders are abundant in almost all terrestrial ecosystems(Foelix, 2011), and live mainly on the ground surface. This studydevelops a reference barcode library for wolf spiders acrossCanada and the continental United States, which comprises14% of the Earth's surface (Fig. 1) and 14 different ecozones(Commission for Environmental Cooperation, 1997).

Introduction

Fig. 1. Locality map of all sequenced wolf spiders in the correspondingNorth American ecozones.

More than 95% of the spider specimens used in this study werecollected by members of CBG through various projects in theterritories of Canada and the United States. However, collectionsat the Royal BC Museum (Victoria) and the Lyman EntomologicalMuseum (Montreal) provided a small proportion of specimens.All specimens were identified or verified by the first authorthrough the genitalic examination of all adults when they wereavailable. COI sequence analyses were performed at theCanadian Centre for DNA Barcoding (CCDB; www.ccdb.ca)employing standard protocols outlined in Blagoev et al. (2016).

Methods

We present a comprehensive DNA barcode reference library forover two-thirds of the Nearctic wolf spider fauna. The resultsconfirm that DNA barcodes are an effective tool for theidentification of Nearctic wolf spiders. With the exception of severalcases of potentially cryptic species, BINs and species correspondwell, suggesting that rapid and accurate estimates of spider diversityare possible with this approach. It has also permitted the firstattempt to resolve the distributional pattern for this large family ofspiders in North America. However, if most BIN splits reflect cryptictaxa (Fig. 2B), the true species count for North American wolfspiders could be 40–50% higher than currently recognized.

Conclusion

In total, 7394 DNA barcode sequences were generated from170 morphologically-identified species (70% of the NearcticLycosidae), representing 241 Barcode Index Numbers (BINs)(Table 1). Adult specimens were not available for 19 BINs, thusinterim names were assigned.

There was a perfect correspondence between BIN membershipand a known species in 109 cases, while 32 species sharedBINs, distinguishable by very shallow sequence divergence(<2%). Another 43 species showed deep (>2%) intraspecificdivergence (i.e. BIN splits). The sequence diversity in wolfspider genera shows a clear barcode gap in most cases with amean intraspecific divergence of 3.4% vs. a minimum nearest-neighbour (NN) distance averaging 17.3% (Table 1).

Results and Discussion

Fig. 2. A. Histogram of BIN distribution by number of ecoregions covered;B. Accumulation curves of all valid species names with BINs.

B.A.

Although all BIN splits and interim species need furtherstudy to clarify the taxonomic status of the entitiesinvolved, DNA barcodes discriminated 85% of all species.70 of the 75 Nearctic World Wildlife Fund ecoregions wererepresented by 1-42 BINs (and eleven represented by >20BINs), which will permit a thorough exploration of distributionalpatterns (Fig. 2A).

Table 1. Statistical analysis of North American wolf spiders generawith intraspecific divergence and BIN information, discriminated byNJ analysis.

Genus n Taxa BINsBIN

sharingBIN

splitsMin

Dist(%)Mean

Dist(%)Max

Dist(%)Acantholycosa 2 1 1 - - 0 0 0Allocosa 18 10 11 - 1 5.8 8.4 10.9Alopecosa 615 8 11 2 1 0.7 6.8 10.1Arctosa 292 10 17 4 5 0 13.6 50Camptocosa 30 2 2 - - 9 9.7 10.3Geolycosa 227 9 16 - 3 4.1 10.8 17.3Gladicosa 62 3 3 - - 4.3 5.9 7.6Hogna 304 15 29 - 7 2.7 11.2 17.1Melocosa 23 1 2 - 1 0 0 0Pardosa 3800 52 67 22 16 0 5.8 9.9Pirata 400 15 15 2 - 3 10.4 13.5Piratula 452 4 6 2 1 0.3 7.3 10.9Rabidosa 126 4 6 - 1 5.5 8 9.8Schizocosa 333 17 29 - 4 3.3 6.7 11.3Sosippus 11 5 5 - - 5.7 9.6 12.7Tigrosa 153 5 10 - 1 5.1 9.8 12.9Trabeops 23 1 1 - - 0 0 0Trebacosa 7 1 1 - - 0 0 0Trochosa 373 4 6 - 2 0.2 6.6 12.8Varacosa 143 3 3 - - 1.9 3.4 4.5

Total 7394 170 241 32 43

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10+

No

. BIN

s

No. Ecoregions Recorded

BIN Ecoregion Coverage