SUMMARY1. Various groundwater habitats have exceptionally high levels of endemism caused by strong hydrographical isolation and low dispersal abilities of their inhabitants. More than 10% of macro-stygobiotic species nevertheless occupy relatively large ranges, measuring from some hundred to over 2000 km in length. These species represent a challenge because their distributions disregard hydrographical boundaries, and their means to disperse and maintain long-term gene flow are unknown. 2. Based on mitochondrial and nuclear gene sequences, we examined the phylogeographic structure of six formally recognised stygobiotic species (Niphargus virei, N. rhenorhodanensis, Troglocaris anophthalmus, T. hercegovinensis, Spelaeocaris pretneri, Proteus anguinus) and searched for cryptic lineage diversity in a genus-wide phylogeny of Niphargus. Using treebased criteria as well as comparative divergence measures, we identified cryptic lineages, which may tentatively be equated with cryptic species. 3. Fourteen analysed nominal stygobiotic species with large ranges emerged as highly diversified, splitting into 51 tentative cryptic lineages. The degree of divergence was within the range or larger than the divergence of other related pairs of sister species. A substantial part (94%) of the cryptic lineages had ranges <200 km in length. One half of them were recorded at single sites only. The largest range recorded was that of a cryptic N. virei lineage (700 km), while none of the very large traditional ranges (e.g. Niphargus aquilex -2300 km, N. tauri -1900 km) could be corroborated. 4. These data suggest that small ranges of macro-stygobionts are the rule, and ranges over 200 km are extremely rare. 5. The implications of this result for groundwater biodiversity assessment and conservation include a considerable increase in overall diversity at the regional and continental scale and a strong decrease in faunal similarities among regions, coupled with greater endemism.

Current theory predicts that a shift to a new habitat would increase the rate of diversification, while as lineages evolve into multiple species, intensified competition would decrease the rate of diversification. We used Holarctic amphipods of the genus Gammarus to test this hypothesis. We sequenced four genes (5,088 bp) for 289 samples representing 115 Gammarus species. A phylogenetic analysis showed that Gammarus originated from the Tethyan region with a saline ancestry in the Paleocene, and later colonized the freshwater habitat in the Middle Eocene. Ancestral range reconstruction and diversification mode analysis combined with paleogeological and paleoclimatic evidence suggested that the habitat shift from saline to freshwater led to an increased diversification rate. The saline lineage of Gammarus dispersed to both sides of the Atlantic at 55 million years ago (Ma), because of the few barriers between the Tethys and the Atlantic, and diversified throughout its evolutionary history with a constant diversification rate [0.04 species per million years (sp/My)]. The freshwater Gammarus, however, underwent a rapid diversification phase (0.11 sp/My) until the Middle Miocene, and lineages successively diversified across Eurasia via vicariance process likely driven by changes of the Tethys and landmass. In particular, the freshwater Gammarus lacustris and Gammarus balcanicus lineages had a relatively high diversification shift, corresponding to the regression of the Paratethys Sea and the continentalization of Eurasian lands during the Miocene period. Subsequently (14 Ma), the diversification rate of the freshwater Gammarus decreased to 0.05 and again to 0.01 sp/My. The genus Gammarus provides an excellent aquatic case supporting the hypothesis that ecological opportunities promote diversification.evolution | molecular dating | range expansion

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The world's obligate cave‐dwelling fauna holds considerable promise for biogeographic analysis because it represents a large number of independent evolutionary experiments in isolation in caves and adaptation to subterranean life. We focus on seven north temperate regions of at least 2000 km2, utilizing more than 4300 records of obligate cave‐dwelling terrestrial invertebrates. In North America, highest diversity was found in northeast Alabama while in Europe highest diversity was found in Ariège, France, and in southeast Slovenia. Based on these regions as well as more qualitative data from 16 other regions, we hypothesize that a ridge (ca 42°–46° in Europe and 34° in North America) of high biodiversity occurs in temperate areas of high productivity and cave density. This may reflect a strong dependence of cave communities on long term surface productivity (as reflected in actual evapotranspiration), because the subterranean fauna relies almost entirely on resources produced outside caves. This dependence may explain the unique biodiversity pattern of terrestrial cave invertebrates.

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Recent continental-scale phylogeographic studies have demonstrated that not all freshwater fauna colonized Europe from the classic Mediterranean peninsular refugia, and that northern or central parts of the continent were occupied before, and remained inhabited throughout the Pleistocene. The colonization history of the ubiquitous aquatic isopod crustacean Asellus aquaticus was assessed using mitochondrial COI and a variable part of nuclear 28S rDNA sequences. Phylogeographic analysis of the former suggested that dispersion proceeded possibly during late Miocene from the western part of the Pannonian basin. Several areas colonized from here have served as secondary refugia and/or origins of dispersion, well before the beginning of the Pleistocene. Postglacial large-scale range expansion was coupled with numerous separate local dispersions from different refugial areas. Connectivity of the freshwater habitat has played an important role in shaping the current distribution of genetic diversity, which was highest in large rivers. The importance of hydrographic connections for the maintenance of genetic contact was underscored by a discordant pattern of mtDNA and nuclear rDNA differentiation. Individuals from all over Europe, differing in their mtDNA to a level normally found between species or even genera (maximal within population nucleotide divergence reached 0.16 +/- 0.018), shared the same 28S rRNA gene sequence. Only populations from hydrographically isolated karst water systems in the northwestern Dinaric Karst had distinct 28S sequences. Here isolation seemed to be strong enough to prevent homogenization of the rRNA gene family, whereas across the rest of Europe genetic contact was sufficient for concerted evolution to act.

It is known that electron donating groups have quite a different effect on the π-delocalization of a conjugate system when bonded at ortho and para as compared to meta positions in the phenyl ring. In the present work, the BF2 complex of 1-phenyl-3-(3,5-dimethoxyphenyl)-propane-1,3-dione (1), a molecule with two methoxy groups in one of the phenyl rings at meta positions, was prepared. Compound 1 exists as two polymorphs having different mutual orientations of the two methoxy groups: in polymorph A away from each other (termed anti), while in polymorph B one methoxy group is oriented toward the other (syn-anti). In both crystals, the molecules which are antiparallel (the subPh rings as well as dioxaborine are on opposite sides) form stacks through face-to-face π-π interactions, while in polymorph A the crystal packing is further stabilized by intermolecular C(phenyl)-H···F and C(methoxy)-H···F hydrogen bonds. Solid A possesses numerous chromic effects, including mechano-, thermo-, and chronochromism, though the latter to a lesser extent, as well as the effect of rearrangement of the amorphous phase into a more stable crystalline phase A, associated with crystallization-induced emission enhancement (CIEE). The solid-state emission can be repeatedly switched regarding its color and efficiency with excellent reversibility by external stimuli. On the other hand, crystalline solid B undergoes thermal interconversion of syn-anti to the anti conformer. Compound 1 shows a solvatochromic effect (SE), is aggregation-induced emission (AIE) active, and through the sublimation process displays self-assembling crystalline platelike microstructures or microfibers that reveal an obvious optical waveguide effect.

Amphipods are brooding peracaridan crustaceans whose young undergo direct development, with no independent larval dispersal stage. Most species are epibenthic, benthic, or subterranean. There are some 1,870 amphipod species and subspecies recognized from fresh or inland waters worldwide at the end of 2005. This accounts for 20% of the total known amphipod diversity. The actual diversity may still be several-fold. Amphipods are most abundant in cool and temperate environments; they are particularly diversified in subterranean environments and in running waters (fragmented habitats), and in temperate ancient lakes, but are notably rare in the tropics. Of the described freshwater taxa 70% are Palearctic, 13% Nearctic, 7% Neotropical, 6% Australasian and 3% Afrotropical.