01025nas a2200145   4500008004100000245007900041210006900120300001200189490000700201520053200208653005900740100001600799700002000815856004400835       1992                        eng d00aGenetic population structure of Neanthes succinea (Polychaeta: Nereididae)0 aGenetic population structure of Neanthes succinea Polychaeta Ner  a511-5170 v723 aTwo samples of Neanthes succinea from the Mediterranean Sea were investigated. Twenty-one loci were analysed; seven of them were polymorphic in both populations. The level of heterozygosity was 2.2% and 4.4% in populations from the Tyrrhenian and Adriatic coasts respectively. The value of Nei’s genetic identity index (I=0.965), together with the mean F(IT) (=0.350), shows that the samples can be considered reproductively isolated populations. F-statistics indicate that ME-1 is the discriminant locus between populations.10aCRIMP POLYCHAETES NEANTHES SUCCINEA CRIMP PHYLLODOCIDA1 aAbbiati, M.1 aMaltagliati, F.  uhttps://annelida.myspecies.info/node/5102191nas a2200181   4500008004100000245017000041210006900211300001200280490000800292520156600300100001401866700002001880700001201900700001301912700002401925700001701949856004301966       2012                        eng d00aGenetic structure of Hediste diversicolor (Polychaeta, Nereididae) from the northwestern Mediterranean as revealed by DNA inter-simple sequence repeat (ISSR) markers0 aGenetic structure of Hediste diversicolor Polychaeta Nereididae   a171-1780 v4523 aThe polychaete Hediste diversicolor is characterised by a high degree of genetic structure among populations. The genetic differentiation has been related to the presence of cryptic species, corresponding to Atlantic and Mediterranean lineages whose divergence may have been driven by vicariance and/or selection. In the present study we used DNA inter-simple sequence repeat (ISSR) markers to validate the genetic structure in 9 populations from the northwestern Mediterranean. We also analysed patterns of genetic differentiation among Mediterranean and Atlantic samples to assess the occurrence of further cryptic species in the northwestern Mediterranean. We compared our results with previous mitochondrial DNA data to assess whether nuclear and mitochondrial genetic patterns were consistent. Analysis of ISSR banding patterns showed: (1) a geographical structuring within the northwestern Mediterranean, and (2) a sharp genetic differentiation between Atlantic and Mediterranean groups of populations, confirming the findings from previous mitochondrial DNA surveys. The pattern of genetic variability found in the northwestern Mediterranean is unlikely to reflect the occurrence of cryptic species in this area. On the other hand, our results are consistent with the occurrence of 2 cryptic species in the Mediterranean and Atlantic, whose genetic differentiation may have been driven by vicariance. Finally, the present study further highlights the usefulness and effectiveness of ISSR markers for monitoring genetic diversity in aquatic invertebrates.1 aCossu, P.1 aMaltagliati, F.1 aLai, T.1 aCasu, M.1 aCurini-Galletti, M.1 aCastelli, A.  uhttps://annelida.myspecies.info/node/6