The chemosensory system has experienced relevant changes in subterranean animals, facilitating the perception of specific chemical signals critical to survival in their particular environment. However, the genomic basis of chemoreception in cave‐dwelling fauna has been largely unexplored. We generated de novo transcriptomes for antennae and body samples of the troglobitic beetle Speonomus longicornis (whose characters suggest...

Specialization to extreme environments is often considered an evolutionary dead‐end, leading to irreversible adaptations and reduced evolvability. There is, however, mixed evidence for this macroevolutionary pattern, and limited data from speciose lineages. Here, we tested the effect of habitat specialization to hypersaline waters in the diversification rates of aquatic beetles of the genus Ochthebius (Coleoptera, Hydraenidae)...

The complex geological history of the western Mediterranean region conceals the interpretation of the evolutionary history of its current fauna, as similar distribution patterns may have very different temporal and geographic origins. Particularly intriguing are some subterranean species in islands, which origin is usually difficult to interpret as their strongly modified morphologies obscure their relationships. We studied su...

Some species of the diving beetle tribe Hygrotini (subfamily Hydroporinae) are among the few insects able to tolerate saline concentrations more than twice that of seawater. However, the phylogenetic relationships of the species of Hygrotini, and the origin and evolution of tolerance to salinity in this lineage, are unknown. In this work, we aim to reconstruct how many times salinity tolerance did evolve in Hygrotini, whether...

Dispersal is a critical factor determining the spatial scale of speciation, which is constrained by the ecological characteristics and distribution of a species’ habitat and the intrinsic traits of species. Endogean taxa are strongly affected by the unique qualities of the below‐ground environment and its effect on dispersal, and contrasting reports indicate either high dispersal capabilities favoured by small body size and me...

Aim The deep subterranean environment is an ideal system to test the effect of physical constraints on the ecology and evolution of species, as it is very homogeneous and with simple communities. We studied the effect of substratum karstificability in the dispersal of the strictly subterranean Troglocharinus ferreri (Reitter) (Coleoptera, Leiodidae) by comparing the genetic diversity and structure of populations in limestone (...

Transitions from fresh to saline habitats are restricted to a handful of insect lineages, as the colonization of saline waters requires specialized mechanisms to deal with osmotic stress. Previous studies have suggested that tolerance to salinity and desiccation could be mechanistically and evolutionarily linked, but the temporal sequence of these adaptations is not well established for individual lineages. We combined molecul...

Aim Current geographical distributions in conjunction with species‐level phylogenies have been viewed as offering an enormous potential for investigating the causes of speciation. However, many authors have concluded that species ranges are too dynamic to retain the historical signal of the speciation processes. We develop an approach to explore the extent to which range changes have erased the geographical signal of speciatio...

Species of the genus Meladema (Dytiscidae, Colymbetinae) are some of the largest macroinvertebrates in the western Palearctic region, being top predators in fishless streams. Two of the three described species, Meladema imbricata (Wollaston, 1871) and Meladema lanio (Fabricius, 1775) are Macaronesian endemics from the Canary Islands and Madeira, respectively, while the third, Meladema coriacea Laporte, 1835, is widely distribu...

Aim To reconstruct the evolutionary history of a genus of freshwater beetle with a pan‐Mediterranean distribution, to test classic hypotheses which proposed a Miocene origin for groups with high biodiversity in the Iberian and Anatolian peninsulas. Location Mediterranean basin. Methods We sequenced four mitochondrial and one nuclear gene from 51 specimens of 30 of the c . 60 extant species of Deronectes (Dytiscidae), all typic...

Aim To test different biogeographical scenarios for the evolution of the ground beetles of the Trechus fulvus group, a lineage with many narrowly distributed flightless subterranean species, highly suitable for tracing their biogeographical history. Location The Western Palaearctic, focusing on the Betic–Rifean area between south‐east Iberia and north Morocco. Methods We sequenced 3.3 kb of four mitochondrial and two nuclear g...

Salinity is one of the most important drivers of the distribution, abundance and diversity of organisms. Previous studies on the evolution of saline tolerance have been mainly centred on marine and terrestrial organisms, while lineages inhabiting inland waters remain largely unexplored. This is despite the fact that these systems include a much broader range of salinities, going from freshwater to more than six times the salin...

Aim To investigate the possibility of range expansion and diversification within the subterranean environment in a genus of troglobiont beetles of the family Leiodidae ( Troglocharinus ), which have a disjunct distribution between the Pyrenees and the Catalonian coast. Location North‐eastern Iberian Peninsula. Methods We sequenced 4 kb of five mitochondrial and two nuclear genes of 50 specimens of 12 of the 18 species of Trogl...

Aim The contrasting habitat permanence over geological time‐scales of lotic and lentic habitats may impose different constraints on the dispersal ability of their macroinvertebrate populations, and ultimately on the degree of equilibrium with current climate. We aim to test for differences between species typical of either habitat type in their potential versus realized distributions as a surrogate measure of degree of climate...

Aim In aquatic ecosystems, standing (lentic) and running (lotic) waters differ fundamentally in their stability and persistence, shaping the comparative population genetic structure, geographical range size and speciation rates of lentic versus lotic lineages. While the drivers of this pattern remain incompletely understood, the suite of traits making up the ability of a species to establish new populations is instrumental in...

Faille, A., Casale, A. & Ribera, I. (2010). Phylogenetic relationships of Western Mediterranean subterranean Trechini groundbeetles (Coleoptera: Carabidae). — Zoologica Scripta , 40 , 282–295. Carabid beetles of tribe Trechini (Coleoptera) are one of the main groups of insects that colonized the subterranean environment. Many species of this group have developed similar morphological modifications related to the subterranean l...

Aim To undertake a quantitative review of the Quaternary fossil record of European water beetles to evaluate their geographical and temporal coverage, and to characterize the extent and typology of the shifts in their geographical ranges. Location Europe. Methods We compiled Quaternary water beetle records from public databases and published references. We included in the analyses species of 10 families of aquatic Coleoptera,...

The family Meruidae has been established recently for the newly discovered species Meru phyllisae Spangler & Steiner, 2005 from Southern Venezuela. These beetles are morphologically highly distinct and at a body length of 0.8 mm represent the perhaps smallest individuals of Adephaga. Here, we use DNA sequence data to place this enigmatic taxon relative to other aquatic groups in this suborder. Meruidae was most closely associa...

Aim To establish the phylogeny and geographical origin of the genera of the diving beetle tribe Hyphydrini in order to investigate the origin of differences in geographical range size, intrageneric species‐richness and morphological disparity. In particular, we tested the hypothesis that the geographically restricted, species‐poor and morphologically deviating genera found in the Cape Region of South Africa are a paraphyletic...