@article {274, title = {Evolutionary history of the Tricladida and the Platyhelminthes: an up-to-date phylogenetic and systematic account}, journal = {International Journal of Developmental Biology}, volume = {56}, year = {2012}, pages = {5-17}, chapter = {5}, abstract = {

Within the free-living platyhelminths, the triclads, or planarians, are the best-known group, largely as a result of long-standing and intensive research on regeneration, pattern formation and Hox gene expression. However, the group\’s evolutionary history has been long debated, with controversies ranging from their phyletic structure and position within the Metazoa to the relationships among species within the Tricladida. Over the the last decade, with the advent of molecular phylogenies, some of these issues have begun to be resolved. Here, we present an up-to-date summary of the main phylogenetic changes and novelties with some comments on their evolutionary implications. The phylum has been split into two groups, and the position of the main group (the Rhabdithophora and the Catenulida), close to the Annelida and the Mollusca within the Lophotrochozoa, is now clear. Their internal relationships, although not totally resolved, have been clarified. Tricladida systematics has also experienced a revolution since the implementation of molecular data. The terrestrial planarians have been demonstrated to have emerged from one of the freshwater families, giving a different view of their evolution and greatly altering their classification. The use of molecular data is also facilitating the identification of Tricladida species by DNA barcoding, allowing better knowledge of their distribution and genetic diversity. Finally, molecular phylogenetic and phylogeographical analyses, taking advantage of recent data, are beginning to give a clear picture of the recent history of the Dugesia and Schmidtea species in the Mediterranean.

}, doi = {10.1387/ijdb.113441mr}, url = {http://www.ijdb.ehu.es/web/paper.php?doi=113441mr}, author = {Marta Riutort and Marta {\'A}lvarez-Presas and Eva M. L{\'a}zaro and Eduard Sol{\`a} and Jordi Paps} } @article {483, title = {Integrative delineation of species of Mediterranean freshwater planarians (Platyhelminthes: Tricladida: Dugesiidae)}, journal = {Zoological Journal of the Linnean Society}, volume = {169}, number = {3}, year = {2013}, month = {11/2013}, pages = {523{\textendash}547}, chapter = {523}, abstract = {

The paper presents an integrative taxonomic study on dugesiid freshwater flatworms from the north-eastern Mediterranean region by applying both morphological and molecular criteria in the formulation of stable species hypotheses. The morphological information obtained for the specimens was used in a traditional way by comparing the organismal traits of the various populations and candidate species with those of known species, as documented in the taxonomic literature and as revealed by examination of histological sections of museum specimens. In the molecular species delimitation the General Mixed Yule-Coalescent method (GMYC) was used. Results of this study (1) supported the presence of 13 Dugesia species in the Hellenic area (including D. sicula Lepori, 1948, a pan-Mediterranean species), (2) culminated in the description of four new Dugesia species, (3) suggested the presence of two Confirmed Candidate Species, (4) pointed to 12 GMYC-delimited units in Greece and two in Slovakia as Unconfirmed Candidate Species and (5) revealed the presence of an entirely new genus, represented by two newly described species and a third Unconfirmed Candidate Species. Our results revealed a high diversity of dugesiid species in this relatively small region. It is concluded that the morphological features used by taxonomists in comparative studies of dugesiid flatworms generally result in reliable identifications and delineations of species taxa, except in the case of cryptic species.

}, doi = {10.1111/zoj.12077}, url = {http://onlinelibrary.wiley.com/doi/10.1111/zoj.12077/abstract}, author = {Ronald Sluys and Eduard Sol{\`a} and Gritzalis, Konstantinos and Miquel Vila-Farr{\'e} and Mateos, Eduardo and Marta Riutort} } @article {312, title = {Fluvial basin history in the northeastern Mediterranean region underlies dispersal and speciation patterns in the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae)}, journal = {Molecular Phylogenetics and Evolution}, volume = {66}, year = {2013}, month = {2013/3//}, pages = {877 - 888}, abstract = {

In this study we analyzed the phylogenetic relationships of eastern Mediterranean freshwater planarians of the genus Dugesia, estimated divergence times for the various clades, and correlated their phylogeographic patterns with geological and paleoclimatic events, in order to discover which evolutionary processes have shaped the present-day distribution of these animals. Specimens were collected from freshwater courses and lakes in continental and insular Greece. Genetic divergences and phylogenetic relationships were inferred by using the mitochondrial gene subunit I of cytochrome oxidase (COI) and the nuclear ribosomal internal transcribed spacer-1 (ITS-1) from 74 newly collected individuals from Greece. Divergence time estimates were obtained under a Bayesian framework, using the COI sequences. Two alternative geological dates for the isolation of Crete from the mainland were tested as calibration points. A clear phylogeographic pattern was present for Dugesia lineages in the Eastern Mediterranean. Morphological data, combined with information on genetic divergences, revealed that eight out of the nine known species were represented in the samples, while additional new, and still undescribed species were detected. Divergence time analyses suggested that Dugesia species became isolated in Crete after the first geological isolation of the island, and that their present distribution in the Eastern Mediterranean has been shaped mainly by vicariant events but also by dispersal. During the Messinian salinity crisis these freshwater planarians apparently were not able to cross the sea barrier between Crete and the mainland, while they probably did disperse between islands in the Aegean Sea. Their dependence on freshwater to survive suggests the presence of contiguous freshwater bodies in those regions. Our results also suggest a major extinction of freshwater planarians on the Peloponnese at the end of the Pliocene, while about 2 Mya ago, when the current Mediterranean climate was established, these Peloponnese populations probably began to disperse again. At the end of the Pliocene or during the Pleistocene, mainland populations of Dugesia colonized the western coast, including the Ionian Islands, which were then part of the continent.

}, keywords = {Aegean, Biogeography, COI, Divergence times, Freshwater planarians, ITS-1, Molecular clock, Phylogeography}, isbn = {1055-7903}, doi = {10.1016/j.ympev.2012.11.010}, url = {http://www.sciencedirect.com/science/article/pii/S1055790312004423}, author = {Eduard Sol{\`a} and Ronald Sluys and Gritzalis, Konstantinos and Marta Riutort} }