01802nas a2200109   4500008004100000245015100041210006900192520134800261100002101609700001601630856004601646       2013                        eng d00aSipunculus nudus Linnaeus, 1766 (Sipuncula): cosmopolitan or a group of pseudo-cryptic species? An integrated molecular and morphological approach0 aSipunculus nudus Linnaeus 1766 Sipuncula cosmopolitan or a group3 aSipunculan taxonomy relies on a limited set of external morphological and internal anatomical characters. In addition, this marine group is characterized by an unusual large number of putatively cosmopolitan species. However, this ‘cosmopolitan’ status could be an artifact of their conserved morphology and the small number of unambiguous taxonomic characters available for delimiting species. Species delimitation can therefore be aided by molecular techniques. We investigated the case of the widespread and common species Sipunculus nudus Linnaeus, 1766 to determine its systematic validity. We analysed the morphology of multiple specimens of S. nudus collected from 11 localities around the world and undertook phylogenetic analyses using molecular sequence data from four genes (28S rRNA, 16S rRNA, histone H3 and cytochrome c oxidase subunit I). High levels of genetic differentiation are present between distantly related populations of the putative species S. nudus. Five distinct lineages were identified by phylogenetic analyses, three of which – the best-represented populations – can be distinguished morphologically. Our phylogenetic and morphological analyses thus do not favor the cosmopolitan status of S. nudus, suggesting instead that it constitutes a complex of morphologically similar but distinguishable species.1 aKawauchi, G., Y.1 aGiribet, G.  uhttps://sipuncula.myspecies.info/node/30201941nas a2200277   4500008004100000020001400041245013700055210006900192260000800261300001400269490000800283520109800291653002201389653001901411653002201430653002101452653003101473653001901504653002501523653000801548653002001556653001601576100002101592700001601613856003401629       2010                        eng d  a0025-316200aAre there true cosmopolitan sipunculan worms? A genetic variation study within Phascolosoma perlucens (Sipuncula, Phascolosomatidae)0 aAre there true cosmopolitan sipunculan worms A genetic variation  cJul  a1417-14310 v1573 aPhascolosoma perlucens is one of the most common intertidal sipunculan species and has been considered a circumtropical cosmopolitan taxon due to the presence of a long-lived larva. To verify whether P. perlucens is a true cosmopolitan species or a complex of cryptic forms, we examined the population structure and demographics of 56 putative P. perlucens individuals from 13 localities throughout the tropics. Analysis of two mitochondrial markers, cytochrome c oxidase subunit I and 16S rRNA, suggests high levels of genetic differentiation between distantly located populations of P. perlucens. At least four different lineages identified morphologically as P. perlucens were distinguished. These lineages are likewise supported by phylogenetic analysis of the two mitochondrial markers and by the haplotype network analysis. Our results suggest that P. perlucens is a case of overconservative taxonomy, rejecting the alleged cosmopolitanism of P. perlucens. However, cryptic speciation also exists in some areas, including a possible case of geminate species across the Isthmus of Panama.10aDNA-SEQUENCE DATA10aLIFE HISTORIES10aMITOCHONDRIAL-DNA10aNEUTRALITY TESTS10aPHYLOGENETIC-RELATIONSHIPS10aPHYLOGEOGRAPHY10aPOPULATION-STRUCTURE10aSEA10aSPECIES-COMPLEX10aSYSTEMATICS1 aKawauchi, G., Y.1 aGiribet, G.  u<Go to ISI>://00027883760000101260nas a2200169   4500008004100000020001400041245009100055210006900146260001100215300000900226490000800235520076200243653001301005100002101018700001701039856003401056       2009                        eng d  a0006-324X00aTwo new species of Nephasoma (Sipuncula: Golfingiidae) from the western Atlantic Ocean0 aTwo new species of Nephasoma Sipuncula Golfingiidae from the wes  cMar 20  a1-130 v1223 aTwo new species of the genus Nephasoma, phylum Sipuncula, are described from subtropical waters of the western Atlantic. Nephasoma (Nephasoma) columbaris is described from the central east coast of Florida where it is found along the edge of the continental shelf at depths of 61 to 104 m associated with the rubble from the reefs of the deep water coral Oculina varicosa. A second species, Nephasoma (Nephasoma) ditadii, is described from Brazilian waters in sand habitats at 150 m on the continental shelf off the coast of the state of Sao Paulo. Morphology of the two species is compared with allied species in the genus and the phylum. Usage in the taxonomic literature of the diagnostic characters "shield" and "pseudoshield" is reviewed and evaluated.10arevision1 aKawauchi, G., Y.1 aRice, M., E.  u<Go to ISI>://000264469400001