Aim We test whether species of western Mediterranean aquatic Coleoptera of the 'Haenydra' lineage (Hydraenidae, Hydraena) originated through: (1) successive periods of dispersal and speciation, (2) range fragmentation by random vicariance, or (3) range fragmentation by geographic isolation owing to a general reduction of population density.Location Europe. MethodsTo discriminate between scenarios we use contrasting predictions of the relationship between phylogenetic and geographic distance. The phylogeny was based on 3 kb of four mitochondrial and two nuclear gene fragments of about half of the known species of 'Haenydra', including most western Mediterranean taxa. Divergences were estimated using a molecular clock. The relationship between phylogenetic and geographic distance was tested using bivariate plots, Mantel tests and comparison of the observed phylogeny with the one minimizing geographic distances between species, as measured using Euclidean minimum spanning trees (EMSTs). ResultsThe monophyly of 'Haenydra' was strongly supported, although its phylogenetic placement was not resolved. 'Haenydra' was estimated to be of late Miocene age, with most species originating during the Pleistocene. In two clades (Hydraena tatii and Hydraena emarginata clades) there was a significant association between geographic and phylogenetic distance, and the reconstructed phylogeny was identical to that obtained through the EMST, demonstrating a strong non-randomness of the geographic distribution of the species. In two other clades (Hydraena iberica and Hydraena bitruncata clades) there was no association between geographic and phylogenetic distance, and the observed phylogeny was not the one minimizing geographic distances. In one of the clades this seems to be due to a secondary, recent range expansion of one species (H. iberica), which erased the geographic signal of their distributions.Main conclusions We show that it is possible to obtain strong evidence of stasis of the geographic ranges of narrow-range endemic species through the study of their phylogenetic relationships and current distributions. In at least two of the studied clades, current species seem to have originated through the fragmentation of a more widely distributed species, without further range movements. A process of range expansion and fragmentation may have occurred repeatedly within the 'Haenydra' lineage, contributing to the accumulation of narrow-range endemics in Mediterranean Pleistocene refugia.
We describe Ochthebius (Enicocerus) aguilerai sp.n. from central Iberia. The species belongs to the O. exsculptus group, including O. legionensis Hebauer & Valladares, O. halbherri Reitter, O. colveranus Ferro and O. exsculptus Germar. There are few consistent differences in external morphology among species of the group, but characters of the aedeagus allow the unequivocal recognition of the new species. A molecular phylogeny of the European species of subgenus Enicocerus based on fragments of four mitochondrial and two nuclear genes recognised O. aguilerai sp.n. as sister to the remaining species of the O. exsculptus group, which according to molecular clock estimations seems to have an Iberian origin in the Late Miocene (Tortonian). There are two genetically distinct lineages within O. exsculptus, one in South Spain and a second from the Pyrenees to Ireland, but the lack of consistent morphological differences between them, and the incomplete sampling of other Iberian populations of the species, prevents the recognition of distinct taxa.
We describe Hydroporus bithynicus sp. n. (Coleoptera, Dytiscidae, Hydroporinae) from the Bolu province in north-west-ern Turkey. The species belongs to the newly defined H. ferrugineus group, and can be separated from the other two mem-bers (H. ferrugineus Stephens, 1829 and H. sanfilippoi Ghidini, 1958) by its more flattened shape, less developed eyesand shape of male genitalia. Its external morphology and the habitat in which all specimens were found (a small pool withupwelling spring water next to a stream) suggest an interstitial habitat, similar to that reported for other species of thegroup. We present a molecular phylogeny of the species of the H. memnonius and H. longulus groups, including somerepresentatives of the main lineages within the genus, based on ca. 2 kb of four mitochondrial genes. We redefine the H.memnonius group and recognise the H. ferrugineus, H. obsoletus and H. morio groups of species as separate entities. Hy-droporus neglectus Schaum, 1845 was found to be related to the species of the H. angustatus, but not the H. memnonius group.
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