Genital and allozyme similarity between Arion urbiae and A. anguloi (Mollusca: Pulmonata)

Abstract

A comparison of the genital features of Arion urbiae and A. anguloi suggests that the species are extremely similar, if not identical. This hypothesis is supported by an electrophoretic analysis of 13 putative enzynme loci, which shows that the two species are also genetically yery similar (I = 0.947), while the related A. subfuscus consists of two distinct genetic types (I = 0.421). These results are further confirmed by a study of esterase profiles obtained with isoelectric focusing. It is therefore concluded that A. urbiae and A. anguloi are most probably conspecifie, whereas the genetic types of A. subfuscus may represent two different species.

Molecular and morphological data reveal cryptic taxonomic diversity in the terrestrial slug complex Arion subfuscus/fuscus (Mollusca, Pulmonata, Arionidae) in continental north-west Europe

“…This is consistent with the idea that some A. subfuscus populations are not purely the product of outcrossing. McCracken & Selander (1980), Foltz et al (1982) and Backeljau et al (1994) have already suggested that mixed breeding systems occur in A. subfuscus s.l., similar to many other slugs, including arionids (McCracken & Selander, 1980;Foltz et al, 1982Foltz et al, , 1984Backeljau et al, 1997;Jordaens et al, 2000).…”

“…data) noticed the existence of two very different gonad (ovotestis) morphologies among populations of what he then considered to be a single species, A. subfuscus, and suggested the existence of a species complex (De Winter, 1986). Backeljau et al (1994Backeljau et al ( , 1996 observed two greatly differing genetic forms among specimens from Belgium, the Netherlands, Italy and Austria, labelled 'F' and 'S' because they consistently differed by a fast and a slow electromorph at phosphoglucomutase (Pgm). The F-slugs all had a small and dark-coloured gonad, whereas the S-slugs possessed a large and much paler gonad, corresponding to De Winter's two gonad types (T. Backeljau & A. J.…”

DNA barcodes and phylogenetic affinities of the terrestrial slugs Arion gilvus and A. ponsi (Gastropoda, Pulmonata, Arionidae)

“…north of, and facing, the Balearic Islands. Conversely, the sister taxon of Arion gilvus is the “tandem” of Arion urbiae and Arion anguloi , two species that have been synonymized by Backeljau et al (1994) and that jointly should be referred to as Arion urbiae . Our DNA sequence data on COI, 16S and ITS1 (e.g.…”

“…Uncorrected p-distances (hereafter simply referred to as p-distance) were calculated in MEGA v5 (Tamura et al 2011). For these calculations we considered the following Molecular Operational Taxonomic Units (MOTUs): 1) the five 16S rDNA clades of Arion subfuscus (S1 to S5) defined by Pinceel et al (2005a), 2) Arion anguloi and Arion urbiae jointly as a single MOTU (Backeljau et al 1994, Quinteiro et al 2005), 3) Arion wiktori and Arion paularensis jointly as a single MOTU (Backeljau et al 1996, Quinteiro et al (2005), and 4) Arion lusitanicus from Portugal vs. Arion lusitanicus from elsewhere as two different MOTUs (Davies 1987, Castillejo 1998, Quinteiro et al 2005). Standard errors of mean p-distances among taxa and MOTUs were calculated on 1000 bootstrap replicates.…”

“…Arion subfuscus (Draparnaud, 1805) (type locality: Montagne Noire, France) is probably the most problematic “species” within Mesarion as it shows an overwhelming amount of variation in body pigmentation, genital anatomy, and reproductive behavior [see Garrido et al (1995) and the references listed in their table 1]. This variation often has been interpreted as indicating reproductive isolation between geographically isolated populations, and Arion subfuscus thus is considered a species complex (Wiktor 1973, Waldén 1976, De Winter 1986, Backeljau 1989, Altonaga et al 1994, Backeljau et al 1994, Garrido et al 1995). Especially in the Pyrenees and the coastal regions of Spain there are local, morphologically diverged populations (e.g.…”