Systematics and phylogenetic species delimitation within Polinices s. l. (Caenogastropoda: Naticidae) based on molecular data and shell morphology Hollmann, Thomas Huelsken Daniel Tapken Tim Dahlmann Heike Wägele Cynthia Riginos Michael Organisms Diversity & Evolution 2012 New York, N. Y. 2012-10-19 12 4 349 375 7PD2F Montfort, 1810 Montfort 1810 [212,479,1421,1444] Gastropoda Naticidae Polinices Animalia Littorinimorpha 22 371 Mollusca genus  The patterns of genetic variation in the monophyletic  P. mammilla(0 P.sp.1) between Egypt(clade 1), Indonesia, New Caledonia(clade 2) and the Great Barrier Reef (clades 2/3) correspond to the phylogeographic category II of Avise (2000)in which it is assumed that the different mitochondrial haplotypes originated either from hitherto unidentified sympatric species or from previously isolated lineages with restricted genetic connectivity (see Thomaz et al. 1996; Avise 2000). Thus, the mtDNAs appear to have diverged in allopatry, with a secondary admixture of populations in the northern Great Barrier Reef. This is supported by the fact that two genetically distinct lineages have been found on Lizard Island (clades 2/3). However, the specimens from Vanuatuand Lizard Island in clade 2 are also clearly separated from clade 3 by the slower evolving protein-coding histone H3gene fragment (see Supplementary Fig. S2). Thus, the apparent genetic divergences between the three  P. mammillalineages support a separation at species level. However, as all specimens are conchologically identical and grouped together in a single monophyletic taxon, more data will be needed to test whether these clades may indeed represent different species. The phylogenetic separation of the morphologically virtually identical  P. constantiand  P. jukesii( Figs. 2, 3and 4) could either indicate the existence of non-monophyletic species with two mitochondrial lineages caused by incomplete lineage sorting or hybridisation, or indicate the existence of two independent species ( Davison 2000; Funk and Omland 2003; Meyer and Paulay 2005; Huelsken et al. 2011b). The genetic divergence between  P. jukesiiand  P. constantiis identical to, or even higher than, values calculated for conchologically well-separated  Polinicesspeciesin this group, such as  P. mellosus,  P.cf. tawhitirahiaand  P. cumingianus( Table 4). Additionally, virtually identical mitochondrial and nuclear sequences for  P. jukesiiwere obtained from two independent and not directly connected localities in the Philippinesand the Great Barrier Reef indicating strong genetic connectivity. The two taxa are furthermore strictly separated by the slower evolving protein-coding histone H3gene fragment, with  P. jukesiisharing the same genetic information with  P. cumingianus,  P. mediopacificusand  P. peselephantiin this gene fragment (see Supplementary Fig. S2). The molecular data in combination with slight differences in protoconch morphology therefore rather reject the hypotheses of hybridisation or incomplete lineage sorting in  P. jukesiiand  P. constantibut support the idea that the two taxa are separated at the species level.