Genetic variation in the Italian crested newt, Triturus carnifex, and the origin of a non-native population north of the Alps

Genetic variation over 40 protein loci and 46 populations representing thre e taxa of crested newts revealed moderate genetic distances between Trituru s carnifex carnifex, T. c. macedonicus and T. cristatus. Two populations fr om the Geneva Basin (presumed to be introduced) were genetically similar to T. c. carnifex and dissimilar to T. c. macedonicus and T. cristatus, showi ng that they belong to T. c. carnifex and not to native T. cristatus. A sig nificant pattern of spatial genetic variation was found within T. c. carnif ex along a north to south axis, from Croatia to Calabria. The Genevan popul ations showed highest genetic similarity with T. carnifex from Tuscany, sug gesting that the propagule originated from that area. Effects of a populati on genetic bottleneck associated with the introduction could not be documen ted. The observed high allelic variation in Genevan T. c. carnifex could no t be directly explained by introgression from T. cristatus. Comparisons acr oss the range, including zones of hybridization within the T. cristatus sup erspecies, indicated that some alleles typical for the Genevan population m ay represent the so-called 'hybrizymes'.