Zielske s (3 risultati)

During the course of a project aiming at the reconstruction of the colonization of the South Pacific islands by tateid gastropods based on molecular data we discovered five new species on New Caledonia belonging to the genera Hemistomia and Leiorhagium, respectively. We describe these species based on morphological, anatomical and genetic data. All five species are morphologically cryptic as they closely resemble or are even indistinguishable from known species stressing the importance of a comprehensive taxonomic approach integrating several methods. As a consequence of their small and fragmented geographic ranges and the rapidly progressing anthropogenic land cover changes on New Caledonia, all five species qualify as critically endangered according to the criteria of the IUCN. New taxa: Hemistomia andreae n. sp., Leiorhagium adioincola n. sp., Leiorhagium aremuum n. sp., Leiorhagium clandestinum n. sp., Leiorhagium neteae n. sp. 15 pp., 11 figs, gr. 8.…

Morphological classification and mitochondrial phylogeny of a pair of morphologically defined species of New Caledonian freshwater gastropods, Hemistomia cockerelli and H. fabrorum, were incongruent. We asked whether these two nominal species can be unambiguously distinguished based on shell morphology or whether the taxonomic discrepancy inferred from these character types was reflected in the variation of shell morphology. Our investigations were based on phylogenetic analyses of a fragment of the mitochondrial cytochrome c oxidase subunit I, geometric morphometric analyses as well as micro computer tomography. The species presorted to morphospecies by eye overlapped in shell shape. However, statistically, all shells were correctly assigned, but not all of them significantly. Qualitatively, both nominal species can be unambiguously distinguished by the presence/absence of a prominent denticle within the shell. In the phylogenetic analyses, individuals from three populations clustered with the "wrong" morphospecies. In the absence of data from multiple loci, it was assumed for the single specimen from one of these populations that its misplacement was due to a recent hybridization event, based on its very shallow position in the tree. For the other two cases of misplacement neither introgression nor incomplete lineage sorting could be ruled out. Further investigations have to show whether the morphological overlap has a genetic basis or is due to phenotypic plasticity. In conclusion, despite their partly unresolved relationships H. cockerelli and H. fabrorum may be considered sister species, which are reliably diagnosable by the presence or absence of the denticle, but have not yet fully differentiated in all character complexes investigated. 16 pp., 7 figs, gr. 8.…

Tapa blanda. Condizione: New. 1ª edición. BADENHAUSEN, R. / H. ZIELSKE, EDS.: BÜHNENFORMEN. BÜHNENRÄUME. BÜHNENDEKORATIONEN. BEITRÄGE ZUR ENTWICKLUNG DES SPIELORTS. BERLIN, 1974, 218 p. , 375 gr. Encuadernacion original. Nuevo. (NB-4-6) 375 gr. Libro.