02434nas a2200217   4500008004100000245016400041210006900205260009100274300001000365490000700375520156000382653002701942653001901969653000801988653001501996653001802011653000902029100001802038700002302056856013702079       2008                        eng d00aMorphological and molecular characterisation of two putative Xiphinema americanum-group species, X-parasimile and X-simile (Nematoda : Dorylaimida) from Serbia0 aMorphological and molecular characterisation of two putative Xip  aPLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDSbBRILL ACADEMIC PUBLISHERS  a15-250 v103 aProblems associated with the taxonomic status of Xiphinema porasimile and X. simile are reviewed. Their accurate identification is difficult due to their high morphological and morphometrical similarity. A comparative morphological and molecular study of these species was done to define their specific status and differences. Lip region morphology showed less variability in comparison with tail shape in both species, which was more variable in X. simile. Differences in lip region were constant between these species, but specimens with similar tail shape rarely occurred. Both species showed considerable overlap in all morphometrical data and a polytomous key is inadequate for their practical identification. In practice, the most reliable approach for accurate determination of X. parasimile and X. simile is the use of a combination of morphometrics with morphology of lip and vulval regions and tail shape. Total DNA was isolated from individual nematodes of both species and the ITS region of the 18S and 26S rDNA and D1-D2 expansion segments of the 26S rDNA were amplified and cloned. The ITS-RFLP patterns clearly revealed X. simile and X. parasimile to be distinct species. The restriction profiles of the D1-D2 amplicons also discriminated these species. D1-D2 sequences revealed no intrapopulation variability and their comparison showed 89% of similarity to each other. These data show that both ribosomal regions are useful to differentiate X. parasimile and X. simile as two distinct species despite similar morphology and morphometrics.10aD1-D2 expansion domain10aDNA sequencing10aITS10amorphology10amorphometrics10aRFLP1 aBarsi, Laszlo1 aDe Luca, Francesca  uhttps://nematoda.myspecies.info/content/morphological-and-molecular-characterisation-two-putative-xiphinema-americanum-group-species02492nas a2200289   4500008004100000245014900041210006900190260007600259300000900335490000800344520150100352653000801853653000901861653001701870653001801887653001301905653000801918653002301926653001901949100001601968700001601984700001902000700002002019700001302039700001302052856013702065       2008                        eng d00aDisentangling taxonomy within the Rhabditis (Pellioditis) marina (Nematoda, Rhabditidae) species complex using molecular and morphological tools0 aDisentangling taxonomy within the Rhabditis Pellioditis marina N  a9600 GARSINGTON RD, OXFORD OX4 2ZG, OXON, ENGLANDbBLACKWELL PUBLISHING  a1-150 v1523 aCorrect taxonomy is a prerequisite for biological research, but currently it is undergoing a serious crisis, resulting in the neglect of many highly diverse groups of organisms. In nematodes, species delimitation remains problematic due to their high morphological plasticity. Evolutionary approaches using DNA sequences can potentially overcome the problems caused by morphology, but they are also affected by theoretical flaws. A holistic approach with a combination of morphological and molecular methods can therefore produce a straightforward delimitation of species. The present study investigates the taxonomic status of some highly divergent mitochondrial haplotypes in the Rhabditis (Pellioditis) marina species complex by using a combination of molecular and morphological tools. We used three molecular markers (COI, ITS, D2D3) and performed phylogenetic analyses. Subsequently, morphometric data from nearly all lineages were analysed with multivariate techniques. We included R. (P.) mediterranea and R. (R.) nidrosiensis to infer species status of the observed lineages. The results showed that highly divergent genotypic clusters were accompanied by morphological differences, and we created a graphical polytomous key for identifications. This study indisputably demonstrates that R. (P.) marina and R. (P.) mediterranea belong to a huge species complex and that biodiversity in free-living marine nematodes may be seriously underestimated. (C) 2008 The Linnean Society of London.10aCOI10aD2D310adelimitation10aDNA-barcoding10aholistic10aITS10aPellioditis marina10apolytomous key1 aDerycke, S.1 aFonseca, G.1 aVierstraete, A1 aVanfleteren, J.1 aVincx, M1 aMoens, T  uhttps://nematoda.myspecies.info/content/disentangling-taxonomy-within-rhabditis-pellioditis-marina-nematoda-rhabditidae-species-comp