<i>Deroceras juranum</i>—a Mendelian colour morph of <i>D. rodnae</i> (Gastropoda: Agriolimacidae)

Abstract

The terrestrial slug Deroceras juranum Wüthrich, 1993 (Gastropoda: Agriolimacidae) has been described as an endemic species of the Swiss Jura Mountains (Switzerland) where it occurs at high altitudes. The species description was mainly based on its characteristic blackish‐violet body colour. Breeding experiments and comparative studies of the genital anatomy and mating behaviour indicate that D. juranum is nothing but a colour morph of the usually cream‐coloured D. rodnae Grossu &amp; Lupu, 1965. The body colour seems to be coded by a single locus with two alleles, of which violet is dominant over cream. Topographical colour variation has also been observed in arionid slugs. Its possible biological (i.e. selective?) meaning is discussed. The slugs are able to reproduce uniparentally with their offspring showing recombination.