9 research outputs found
Spatial analysis of shell parameters suggests low species number of Mastus (Gastropoda: Pulmonata: Enidae) in central and eastern Crete
Contrasting views in recent literature set the species number of the land snail Mastus in Crete
(Greece) between 3 and over 17. In order to contribute to a better understanding of the spatial complexity of the genus, a biogeographical approach was employed in central and eastern Crete (6,000 km2) where distribution patterns of shell parameters of 1,600 samples totalling 5,500 specimens were analysed and evaluated at a 2 km scale. The results support grouping of the central and eastern Cretan populations in five obviously independent and genetically separated systematic entities, which are referred toas species. M. cretensis (Pfeiffer) and M. sitiensis Maassen are widely distributed in Crete. M. abundans Maassen, M. gittenbergeri Maassen and M. violacea Maassen occupy smaller ranges which largely conform with those of endemic species of the clausiliid Albinaria. The conclusions are only partly in agreement with the previous results of anatomical studies, but are consistent with predictions based on species-area relation data
Phylogeography of the land snail Albinaria hippolyti (Pulmonata: Clausiliidae) from Crete, inferred from ITS-1 sequences
The polytypic Cretan land snail Albinaria hippolyti has a range that is partly fragmented and partly subdivided by hybrid zones. For this reason, it has served as a model species for investigating speciation and radiation in Mediterranean Clausiliidae. The first internal transcribed spacer (ITS-1) of the nuclear ribosomal DNA was sequenced in 20 populations of A. hippolyti and phylogenetically analysed using maximum parsimony. We employed a novel method involving logarithmic weighting of gaps and topological constraints based on bootstrap values. The resulting phylogeography suggests that the species has undergone a recent cycle of range expansion and range reduction. Speciation cannot be linked to major geological vicariance events in the Miocene and Pliocene, as has been suggested previously. The subspecies A. h. arthuriana appears unrelated to other A. hippolyti subspecies, which supports recent suggestions, based on morphology, to regard it as a separate species. (C) 2004 The Linnean Society of London