| Abstract |
The aim of this study was to evaluate the taxonomic characters used in the genus Mastus Beck, 1837 (Gastropoda, Pulmonata: Enidae) and propose those that will ensure a solid classification within it. In order to achieve this goal, besides the genetic distances based on three loci, the morphology of the shell, the terminal genitalia and the spermatophore of the populations under study, was approached. For the evaluation of the spermatophore as a species-specific character within the genus, a very good knowledge of its use and behavior during copulation is a prerequisite. For this reason, several couples were studied, while the possibility of temporal isolation between different species, was examined in two sympatric populations. From the multivariate analysis of the morphometric data based on the shell and on the terminal genitalia, it was concluded that the shell characters are better discriminants of the different populations. All the spermatophores examined point out to the conclusion that there are a few basic patterns of spermatophore's morphology. According to those basic patterns a few groups of populations were formed. Those groups comprised populations that were very distinct in the shell morphology and in some cases, in the genitalia morphology as well. Beyond this grouping of the populations the minor differences between the spermatophores of the populations did not allow us to further divide the groups into distinct and unique populations as it would be the case if the spermatophore was a power ful discriminant character. Therefore it became obvious that the spermatophore is not a species-specific character within the genus Mastus. The electrophoretic data were of limited value due to the small amount of phylogenetically important information obtained. The reason for this was mainly the small number of loci scored in each population. The approach of the genus with a more elaborate technique such as the mtDNA analysis, is considered necessary at this point. On the basis of the molecular phylogeny, an evaluation of the morphological characters used in the taxonomy of the genus, will be achieved.
|
Διαφοροποίηση του γένους Mastus(Beck,1837) (Gastropoda, Pulmonata: Enidae) στην Κρήτη
