Invasion of Arion subfuscus/fuscus complex

Érik L’Heureux

Department of Biological Sciences

Arion fuscus, Johnville Bog & Forest Park, Johnville, Quebec, Canada,  2017

Université de Montréal, Québec, Canada

Constance Boone Award at the American Malacological Society

I had the opportunity to participate and present my research at the 83rd meeting of the American Malacological Society. During this conference, I learned a lot about several new topics and met a lot of passionate people. This congress was rich in exchanges of knowledge. I greatly appreciated my experience and hope to have the chance to come back year after year.

I study a group of terrestrial slug species called the Arion subfuscus/fuscus complex. These European slugs are now very common in northeastern North America. During my master's degree, I collected specimens throughout southern Québec (Canada). Of course, I was fortunate to have help from many people who also collected specimens for my project. I have identified molecularly more than 750 individuals [1]. Comparing the present distribution of this complex in Québec with the distribution as determined in the 1960s by Chichester and Getz [2], I found that it has had an incredible expansion of distribution over the last 50 years. Thanks to the molecular identification of the haplotypes, it was possible to determine that the slugs of the complex dispersed mainly passively on a large scale. Although A. fuscus and A. subfuscus were detected, A. fuscus is by far the most common species in Québec, which is surprising, as previous studies did not report this species in the northeast of the United States [3]. My hypothesis is that the border could restrict the passive dispersion of slugs via human activities, which I would like to investigate in the coming years by sampling in the northern United States.

For my Ph.D. project, preliminary results indicate that A. fuscus is extremely generalist in its choice of habitats. The next step of the project will be to assess the determinants of the invasion success of A. fuscus in North America. I will try to elucidate the strategies used by this species to occupy several types of habitats. To achieve this objective, I plan to use genetic and transcriptomic techniques to estimate genetic diversity and to assess the environment-dependent gene expression. Finally, I will measure environment-dependent morphological variations. Thanks to these multiple approaches, I will try to determine the role of plasticity or tolerance in this invasive exotic species and, of course, I would like to present my results next year at the meeting! This project will allow to understand how exotic species with very limited genetic diversity can manage to invade many habitats.

References

 

[1]     L’Heureux, É., and Angers, B. in press. A discreet invasion: distribution, origins, and expansion of the European slug complex Arion subfuscus s. l. in Québec. Canadian Journal of Zoology.

[2]     Chichester, L.F., and Getz, L.L. 1969. The zoogeography and ecology of arionid and limacid slugs introduced into northeastern North America. Malacologia. 7: 313-346.

[3]     Pinceel, J., Jordaens, K., Van Houtte, N., Bernon, G., and Backeljau, T. 2005. Population genetics and identity of an introduced terrestrial slug: Arion subfuscus s.l. in the north-east USA (Gastropoda, Pulmonata, Arionidae). Genetica. 125: 155-171.