A comprehensive phylogeographic study of Arion vulgaris Moquin-Tandon, 1855 (Gastropoda: Pulmonata: Arionidae) in Europe

Abstract

Arion vulgaris Moquin-Tandon, 1855 is regarded as one of the 100 most invasive species in Europe. The native distribution range of this species is uncertain, but for many years, the Iberian Peninsula has been considered as the area of origin. However, recent studies indicate that A. vulgaris probably originated from France. We have investigated the genetic structure of 33 European populations (Poland, Norway, Germany, France, Denmark, Switzerland) of this slug, based on two molecular markers, mitochondrial cytochrome c oxidase subunit I (COI, mtDNA) and nuclear zinc finger (ZF, nDNA). Our investigation included published data from two previous studies, giving a total of 95 populations of A. vulgaris from 26 countries. This comprehensive dataset shows comparable haplotype diversity in Central, North and Western Europe, and significantly lower haplotype diversity in the East. All haplotypes observed in the East can be found in the other regions, and haplotype diversity is highest in the Central and Western region. Moreover, there is strong isolation by distance in Central and Western Europe, and only very little in the East. Furthermore, the number of unique haplotypes was highest in France. This pattern strongly suggests that A. vulgaris has originated from a region spanning from France to Western Germany; hence, the slug is probably alien/invasive in other parts of Europe, where it occurs. Our results indicate the necessity to cover as much of the distribution range of a species as possible before making conclusive assumptions about its origin and alien status.

Thede novogenome of the “Spanish” slugArion vulgarisMoquin-Tandon, 1855 (Gastropoda: Panpulmonata): massive expansion of transposable elements in a major pest species

“…However, the very similar external appearance with other closely related native large arionids as well as hybrid species between A. vulgaris, A. ater and A. rufus [14][15][16], might cause the misidentification of A. vulgaris, obscure the specimen records, and make it difficult to trace its origin and monitoring the spread only by morphological identification [17,18]. Controversially, recent studies based on the genetic diversity patterns of mitochondrial and nuclear loci suggested that A. vulgaris is native in central Europe rather than alien/invasive while probably invasive in other parts of Europe [19][20][21]. In either case, it is undeniable that its outstanding adaptive success, the mass occurrences and consequent pest in the last 40-50 years and the reason behind is worth exploring.…”

Annotated and Updated Checklist of Land and Freshwater Molluscs from Asturias (Northern Spain) with Emphasis on Parasite Transmitters and Exotic Species

“…The separation of both species was confirmed thanks to molecular analysis [95,98]. On the other hand, A. vulgaris, commonly named 'Spanish slug', is a wide distributed species with a high expansive and invasive character [9,104]. Although its origin is not clear, it could be native from Central Europe [104,105].…”

“…On the other hand, A. vulgaris, commonly named 'Spanish slug', is a wide distributed species with a high expansive and invasive character [9,104]. Although its origin is not clear, it could be native from Central Europe [104,105]. Thus, all the records of this species in Asturias must be reviewed [25,70,80,88,102] because only A. lusitanicus was apparently recorded.…”

“…Thus, all the records of this species in Asturias must be reviewed [25,70,80,88,102] because only A. lusitanicus was apparently recorded. Asturian records of A. lusitanicus probably must be reassigned to A. vulgaris, a slug ranked among the hundred must invasive species in Europe [104].…”

Experimental indications of gardeners’ anecdotes that snails interfere with invasive slugs

“…In Europe the only mollusc among the 100 worst invasive alien species is the Spanish slug Arion vulgaris , formerly known as A. lusitanicus ( Rabitsch, 2006 ). The exact area of origin for A. vulgaris is still not definitely determined ( Pfenninger et al, 2014 ; Zemanova, Knop & Heckel, 2014 ) and a recent study suspects it to be in France and Western Germany ( Zając et al, 2020 ). Over the last decades, however, the slug has spread over large parts of Europe ( Engelke et al, 2011 ; Kozłowski & Kozłowski, 2011 ; Hatteland et al, 2013 ; Papureanu, Reise & Varga, 2014 ; Balashov et al, 2018 ).…”