Persistence of British natterjack toad Bufo calamita Laurenti (Anura: Bufonidae) populations despite low genetic diversity

Like other amphibians native to Britain, the natterjack toad Bufo calamita must have colonized the islands during the relatively short period between the end of the last glaciation and the separation of Britain from mainland Europe by rising sea levels. Unlike the other native amphibians, however, B. calamita is a habitat specialist at the north-westerly edge of its biogeographical range and for most of the 8000–10000 years since its colonization has probably been restricted to open dunes, heathlands and upper saltmarshes, as isolated populations in a few discrete areas of the country. We have investigated the genetic diversity and relatedness of six widely separated British natterjack populations by allozyme analysis, and shown that all have very low diversity (Overall P _95%= 2.7%, H = 0.004) by comparison with other anurans, including natterjack populations in mainland Europe and common frogs ( Rana temporaria , L) in Britain. Eighty percent of loci were fixed for the same allele in all six British natterjack populations and genetic differentiation between colonies was extremely low. The possible significance of these findings to the persistence of small isolated populations at range edges is discussed.     

Post-glacial colonization of Western Europe brown bears from a cryptic Atlantic refugium out of the Iberian Peninsula

The European brown bear (Ursus arctos) shows a particular phylogeography that has been used to illustrate the model for contraction-expansion dynamics related to glacial refugia in Southern European peninsulas. Recent studies, however, have nuanced the once generally accepted paradigm, indicating the existence of cryptic refugia for some species further north. In this paper we collected available data on chronology and mitochondrial haplotypes from Western European brown bears, adding new sequences from present day individuals from the Cantabrian (North Iberia) area, in order to reconstruct the dynamics of the species in the region. Both genetics and chronology show that the Iberian Pleistocene lineages were not the direct ancestors of the Holocene ones, the latter entering the Peninsula belatedly (around 10,000 years BP) with respect to other areas such as the British Isles. We therefore propose the existence of a cryptic refugium in continental Atlantic Europe, from where the bears would expand as the ice receded. The delay in the recolonization of the Iberian Peninsula could be due to the orographic characteristics of the Pyrenean-Cantabrian region and to the abundant presence of humans in the natural entrance to the Peninsula.     

Phylogeography and historical demography of the Lusitanian snail <Emphasis Type="Italic">Elona quimperiana</Emphasis> reveal survival in unexpected separate glacial refugia

Background  

Present day distributions of Palearctic taxa in northern latitudes mainly result from populations having survived in local patches during the Late Pleistocene and/or from recolonizing populations from southern temperate refugia. If well-studied Mediterranean and eastern European refugia are widely accepted, some recent biogeographical assumptions still remain unclear, such as the occurrence of multiple glacial refugia in Iberia and cryptic refugia in northern Europe during the last glaciations. The Lusitanian snail Elona quimperiana has a remarkably disjunct distribution, limited to northwestern France (Brittany), northwestern Spain and the Basque Country. By describing the phylogeographical structure of this species across its entire range, the present study attempts to identify refugia and subsequent recolonization routes.     

The not‐so‐Irish spurge: Euphorbia hyberna (Euphorbiaceae) and the Littletonian plant ‘steeplechase’

The disjunct distributions of the Lusitanian flora, which are found only in south‐west Ireland and northern Iberia, and are generally absent from intervening regions, have been of great interest to biogeographers. There has been much debate as to whether Irish populations represent relicts that survived the Last Glacial Maximum (LGM; approximately 21 kya), or whether they recolonized from southern refugia subsequent to the retreat of the ice and, if so, whether this occurred directly (i.e. the result of long distance dispersal) or successively (i.e. in the manner of a ‘steeplechase’, with the English Channel and Irish Sea representing successive ‘water‐jumps’ that have to be successfully crossed). In the present study, we used a combined palaeodistribution modelling and phylogeographical approach to determine the glacial history of the Irish spurge, Euphorbia hyberna, the sole member of the Lusitanian flora that is also considered to occur naturally in south‐western England. Our findings suggest that the species persisted through the LGM in several southern refugia, and that northern populations are the result of successive recolonization of Britain and Ireland during the postglacial Littletonian warm stage, akin to the ‘steeplechase’ hypothesis. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 249–259.     

Histochemistry of glycoconjugates in the gallbladder epithelium of ten animal species

A battery of seven lectins and several conventional mucin histochemical techniques were used to identify the epithelial mucins of the gallbladder of ten species: man, rabbit (Oryctolagus cuniculus, mammalia), hamster (Mesocricetus auratus, mammalia), chicken (Gallus gallus, bird), sparrow (Passer domesticus, bird), moorish gecko (Tarentola mauritanica, reptilia), ladder snake (Elaphe scalaris, reptilia), lake frog (Rana perezi, amphibia), natterjack toad (Bufo calamita, amphibia) and gilthead sea bream (Sparus auratus, fish). Glycogen was found in the epithelial lining of the reptilian and amphibian gallbladders. Sulphate and carboxyl groups were frequently found in the same species, except in the ladder snake and natterjack toad gallbladders where only sulphate groups were identified. Sialic acid residues were detected in man, rabbit, bird, T. mauritanica, R. perezi and fish gallbladders. ConA binding pattern was similar in the ten species studied. In the human gallbladder only PNA failed to label the luminal surface, while the glands were only unreactive to DBA. The human gallbladder showed a large variety of saccharides. The present results suggest that no relation exists between the composition of the gallbladder mucins and the situation of the species in the phylogenetic scale.     

Microsatellite analysis of the natterjack toad (Bufo calamita) in Denmark: populations are islands in a fragmented landscape

The European natterjack toad (Bufo calamita) has declined rapidly in recent years, primarily due to loss of habitat, and in Denmark it is estimated that 50% of the isolated populations are lost each decade. To efficiently manage and conserve this species and its genetic diversity, knowledge of the genetic structure is crucial. Based on nine polymorphic microsatellite loci, the genetic diversity, genetic structure and gene flow were investigated at 12 sites representing 5–10% of the natterjack toad localities presently known in Denmark. The expected heterozygosity (H _E) within each locality was generally low (range: 0.18–0.43). Further analyses failed to significantly correlate genetic diversity with population size, degree of isolation and increasing northern latitude, indicating a more complex combination of factors in determining the present genetic profile. Genetic differentiation was high (overall θ = 0.29) and analyses based on a Bayesian clustering method revealed that the dataset constituted 11 genetic clusters, defining nearly all sampling sites as distinct populations. Contemporary gene flow among populations was undetectable in nearly all cases, and the failure to detect a pattern of isolation by distance within major regions supported this apparent lack of a gene flow continuum. Indications of a genetic bottleneck were found in three populations. The analyses suggest that the remaining Bufo calamita populations in Denmark are genetically isolated, and represent independent units in a highly fragmented gene pool. Future conservation management of this species is discussed in light of these results. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Larval fitness and immunogenetic diversity in chytrid-infected and uninfected natterjack toad (<Emphasis Type="Italic">Bufo calamita</Emphasis>) populations

Chytrid fungus Batrachochytrium dendrobatidis (Bd), an emerging disease, has been decimating amphibian populations around the world for several decades. We quantified aspects of larval fitness, adaptive (major histocompatibility complex) diversity and neutral (microsatellite) diversity in natterjack toad (Bufo calamita) populations in two regions of north-west England. Toads in region one had no evidence of chytrid infection, whereas in region two there was a substantial prevalence of Bd. Larval fitness (growth rate, time to metamorphosis and survival) of B. calamita did not differ between the regions. Genetic diversity at microsatellite loci was much higher in the infected than in the uninfected region, but the converse was true of MHC diversity indicating that genetic drift was unlikely to explain the differences in MHC between the regions. Furthermore, MHC allele frequencies varied significantly between Bd-infected and uninfected populations. Microsatellite diversity was not a robust indicator of larval fitness in these toad populations while MHC genotype frequencies varied in a way that was consistent with directional selection in response to pathogen prevalence. The acquired immune defences may therefore play an important role in determining the susceptibility of amphibian species to chytridiomycosis.     

Differences in susceptibility to Saprolegnia infections among embryonic stages of two anuran species

Many amphibians are known to suffer embryonic die-offs as a consequence of Saprolegnia infections; however, little is known about the action mechanisms of Saprolegnia and the host-pathogen relationships. In this study, we have isolated and characterized the species of Saprolegnia responsible for infections of embryos of natterjack toad (Bufo calamita) and Western spadefoot toad (Pelobates cultripes) in mountainous areas of Central Spain. We also assessed the influence of the developmental stage within the embryonic period on the susceptibility to the Saprolegnia species identified. Only one strain of Saprolegnia was isolated from B. calamita and identified as S. diclina. For P. cultripes, both S. diclina and S. ferax were identified. Healthy embryos of both amphibian species suffered increased mortality rates when exposed to the Saprolegnia strains isolated from individuals of the same population. Embryonic developmental stage was crucial in determining the sensitivity of embryos to Saprolegnia infection. The mortalities of P. cultripes and B. calamita embryos exposed at Gosner stages 15 (rotation) and 19 (heart beating) were almost total 72 h after challenge with Saprolegnia, while those exposed at stage 12 (late gastrula) showed no significant effects at that time. This is the first study to demonstrate the role of embryonic development on the sensitivity of amphibians to Saprolegnia.     

Austro-boreal disjunctions: a remarkable biogeographical pattern illustrated by Nan Ao Island, Guangdong, China

Aim To document disjunct, insular populations of animals separated from similar conspecifics distributed to the north, inland and upland, and compare this pattern with that historically described for northern Florida and the Florida Keys islands. Location Nan Ao Island is on the Tropic of Cancer 117° E in the South China Sea, eastern Guangdong Province, China. There are archipelagos of islets extending south‐east, and several coastal islets around Nan Ao. Methods Five field surveys were made in 1999–2001. Voucher specimens were tagged, catalogued, and deposited in major museum collections. The comparable Floridian disjunct pattern was researched and described in overview. Results Five species – a toad, two lizards and two snakes – collected on Nan Ao and three satellite islands were added to the two previously documented species – a lizard and a snake – that fit the austro‐boreal disjunct pattern. One lizard and one snake are minor range extensions of a hundred or few km. One snake's Nan Ao population is disjunct by about 450 km and one lizard's by about 550 km. The small, semi‐fossorial, short‐legged toad is the most notable, separated from the main area of its range by about 800 km. This is similar to the greatest distance between north Floridian and Keys disjunct populations. Main conclusions (1) Seven Nan Ao species of terrestrial vertebrates are isolated and disjunct from conspecifics found to the north, upland and inland; this compares to five species showing a similar north Florida to Florida Keys pattern. (2) The Nan Ao species have no conspecifics known from the intervening area whereas four of the five Floridian species have conspecific, but dissimilar, populations in the gap. (3) Nan Ao and its satellite islets were high points on a large coastal plain at glacial maximum. (4) Holocene sea level rise and concomitant global warming may have isolated the Nan Ao relicts that had continuous distributions at glacial maximum. (5) The intervening mainland conspecific populations may have been replaced by tropical species that moved north along the mainland but failed to colonize the islands. (6) If so, significant adaptation to a warmer climate must have occurred to enable survival of the Nan Ao relicts to the present.     

Archive Contributions to a Molecular Phylogeography of the Toad Bufo calamita in Britain

A complete phylogeographic analysis of anyspecies requires sampling throughout its biogeographicalrange. In the case of the natterjack toad Bufocalamita in Britain, recent local extinctions haveleft substantial areas of its historical rangewithout extant populations. We therefore obtained tissuesamples of archived Bufo calamita from fourmuseums in the United Kingdom. A range of tissues(tongue, liver, skin, lung, and larval tail) was sampledfrom a total of 33 individual animals. DNA was extractedand eight polymorphic microsatellite loci were scored.One or more loci were amplified successfully from 27 individuals, and sufficient data wereobtained from regions with few or no survivingpopulations to supplement a phylogeographic analysisbased on extant populations.     

Recent changes in the distribution of a marine gastropod,Patella rustica,across the Iberian Atlantic coast did not result in diminished genetic diversity or increased connectivity

Aim The Lusitanian limpet, Patella rustica Linnaeus, 1758, is a rocky shore intertidal mollusc found throughout the Mediterranean and the north‐east Atlantic from Mauritania to southern France. A 280‐km gap in its distribution in the Iberian north‐west was first reported in the early 20th century. Between 2002 and 2005 this gap was bridged, and unusual climatic and hydrographic events that occurred in the late 1990s are hypothesized to have facilitated transport and settlement of colonizers from the southern edge of the gap. In the present work we used genetic data to investigate differentiation between the edges of the former gap, to determine the origin of colonizers and to assess patterns of connectivity across the historical and newly colonized region. Location Atlantic coast of Iberia (Portugal and north‐west Spain) and Biarritz. Methods The genetic variation of 12 sites, sampled between 2004 and 2006, was assessed through the analysis of five microsatellites (n = 412) and of a 650‐bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI; n = 163). F‐statistics were used to investigate differentiation and patterns of gene flow across the distribution of P. rustica, from southern Portugal to Biarritz. The mitochondrial DNA (mtDNA) mismatch distribution was analysed and the mutation–drift equilibrium tested to investigate putative demographic changes. Results Levels of differentiation were low and generally non‐significant. Comparisons between regions of the historical distribution were all non‐significant. For microsatellites, low yet significant genetic differentiation was observed when all three regions were included. Levels of genetic diversity of newly founded populations were similar to those observed within the historical range. Evidence of demographic changes was detected with mtDNA and microsatellites. Main conclusions The studied region is inhabited by a single population, suggesting that the gap in the distribution of P. rustica was not an effective barrier to gene flow. If it has ever prevented gene flow, it did not last enough time for genetic differentiation to occur. On the other hand, the main currents flowing along the Atlantic coast of Iberia could have been responsible for maintaining connectivity through occasional larval transport across a considerable stretch of inhospitable habitat.     

Histochemistry of glycoconjugates in the gallbladder epithelium of ten animal species

Summary A battery of seven lectins and several conventional mucin histochemical techniques were used to identify the epithelial mucins of the gallbladder of ten species: man, rabbit (Oryctolagus cuniculus, mammalia), hamster (Mesocricetus auratus, mammalia), chicken (Gallus gallus, bird), sparrow (Passer domesticus, bird), moorish gecko (Tarentola mauritanica, reptilia), ladder snake (Elaphe scalaris, reptilia), lake frog (Rana perezi, amphibia), natterjack toad (Bufo calamita, amphibia) and gilthead sea bream (Sparus auratus, fish). Glycogen was found in the epithelial lining of the reptilian and amphibian gallbladders. Sulphate and carboxyl groups were frequently found in the same species, except in the ladder snake and natterjack toad gallbladders where only sulphate groups were identified. Sialic acid residues were detected in man, rabbit, bird, T. mauritanica, R. perezi and fish gallbladders. ConA binding pattern was similar in the ten species studied. In the human gallbladder only PNA failed to label the luminal surface, while the glands were only unreactive to DBA. The human gallbladder showed a large variety of saccharides. The present results suggest that no relation exists between the composition of the gallbladder mucins and the situation of the species in the phylogenetic scale.     

Extending glacial refugia for a European tree: genetic markers show that Iberian populations of white elm are native relicts and not introductions

Conservation policies usually focus on in situ protection of native populations, a priority that requires accurate assessment of population status. Distinction between native and introduced status can be particularly difficult (and at the same time, is most important) for species whose natural habitat has become both rare and highly fragmented. Here, we address the status of the white elm (Ulmus laevis Pallas), a European riparian tree species whose populations have been fragmented by human activity and is protected wherever it is considered native. Small populations of this species are located in Iberia, where they are unprotected because they are considered introductions due to their rarity. However, Iberia and neighbouring regions in southwestern France have been shown to support discrete glacial refuge populations of many European trees, and the possibility remains that Iberian white elms are native relicts. We used chloroplast RFLPs and nuclear microsatellites to establish the relationship between populations in Iberia and the Central European core distribution. Bayesian approaches revealed significant spatial structure across populations. Those in Iberia and southwestern France shared alleles absent from Central Europe, and showed spatial population structure within Iberia common in recognized native taxa. Iberian populations show a demographic signature of ancient population bottlenecks, while those in Central European show a signature of recent population bottlenecks. These patterns are not consistent with historical introduction of white elm to Iberia, and instead strongly support native status, arguing for immediate implementation of conservation measures for white elm populations in Spain and contiguous areas of southern France.     

Gene flow and functional connectivity in the natterjack toad

Functional connectivity is a key factor for the persistence of many specialist species in fragmented landscapes. However, connectivity estimates have rarely been validated by the observation of dispersal movements. In this study, we estimated functional connectivity of a real landscape by modelling dispersal for the endangered natterjack toad (Bufo calamita) using cost distance. Cost distance allows the evaluation of 'effective distances', which are distances corrected for the costs involved in moving between habitat patches in spatially explicit landscapes. We parameterized cost-distance models using the results of our previous experimental investigation of natterjack's movement behaviour. These model predictions (connectivity estimates from the GIS study) were then confronted to genetic-based dispersal rates between natterjack populations in the same landscape using Mantel tests. Dispersal rates between the populations were inferred from variation at six microsatellite loci. Based on these results, we conclude that matrix structure has a strong effect on dispersal rates. Moreover, we found that cost distances generated by habitat preferences explained dispersal rates better than did the Euclidian distances, or the connectivity estimate based on patch-specific resistances (patch viscosity). This study is a clear example of how landscape genetics can validate operational functional connectivity estimates.     

Effects of predator interactions, prey palatability and habitat structure on survival of natterjack toad Bufo calamita larvae in replicated semi-natural ponds

The significance of predation and aquatic habitat structures to the survivorship of natterjack toad Bufo calamita larvae was investigated by manipulating predator numbers and pond characteristics in a series of replicated semi-natural pools over three consecutive years Two species of fish (common carp Cyprinus carpio and perch Perca fluviatilis) increased the survival of small tadpoles severalfold by selectively consuming predatory invertebrates, but a third species of fish (rudd Scardinius erythrophthalmus) devoured tadpoles and invertebrates indiscriminately Survival of larger tadpoles later in larval development was less affected by the reduction of invertebrate predation pressure from carp and perch, probably because abiotic factors (pond desiccation and anoxia) were stronger agents of tadpole mortality In ponds of low pH (ca 4 5) there was greatly increased spawn mortality and reduced tadpole growth rates but no significant change in tadpole predation compared with circumneutral controls Neutralisation of acid ponds to pH 7 by addition of Ca(OH)₂ restored spawn viability and tadpole growth rates to control levels without affecting predation level Addition of organic nutrients stimulated tadpole growth rates significantly m ohgotrophic ponds but not sufficiently to improve survival of small larvae in the face of predation Extensive growths of macrophytes increased predator numbers up to more than twofold but effects on tadpole mortality rates differed between experiments Replacement of natural substrates by concrete basins substantially increased tadpole survival throughout development, probably because both predation by invertebrates and abiotic mortality factors were ameliorated Predation was a strong force early in natterjack tadpole development irrespective of chemical and biological conditions within ponds, but became much less important compared with abiotic factors as an agent of mortality at later tunes     

Microsatellite analysis of natterjack toad Bufo calamita Laurenti populations: consequences of dispersal from a Pleistocene refugium

Populations of the amphibian Bufo calamita were sampled for genetic analysis in eleven areas distributed across its biogeographical range in Europe. Genetic diversity estimates across eight microsatellite loci showed a decline in polymorphism, numbers of alleles and heterozygosity as a function of distance from the presumed ice-age refugium in Iberia. Trials with a selection of tree-building algorithms indicated mat UPGMA of Cavalli-Sforza chord distances (D_c) generated the tree topology most easily reconciled with other biogeographical information. Genetic distance measures were also calibrated against a postglacial event from which the separation of extant populations could be estimated in real time. D_c again outperformed two other measures (Nei's standard distance, D_s , and δμ²) in producing realistic correlations with minimal variance. The genetic analysis was consistent wim die hypodiesis that B. calamita survived in a single refugium (Iberia) during the Pleistocene glaciation and indicated that it spread north and east from there during the last interstadial which commenced about 14 000 years before present (BP). Microsatellites should provide useful tools for biogeographical investigations of other species, especially with respect to patterns of population dispersal.     

Evolutionary history of Lissotriton helveticus: multilocus assessment of ancestral vs. recent colonization of the Iberian Peninsula

The Pleistocene was characterized by climatic changes that greatly altered the distribution of organisms. Population extinctions, bottlenecks, isolation, range expansions and contractions were often associated with glaciations, leaving signatures in the spatial patterns of genetic diversity across species. Lissotriton helveticus belongs to a Pan-European lineage of newts that were strongly affected by glaciations and represent an excellent model to analyse the effect of generalized climatic changes in phylogeographic patterns. We studied the genetic diversity of the species using data from two mitochondrial and three nuclear genes analyzed in a Bayesian phylogenetic framework to investigate the historical processes shaping spatial patterns of genetic diversity. Mitochondrial haplotypes cluster in four different groups present in the Iberian Peninsula and of Pleistocene origin, probably by allopatric fragmentation. Nuclear genes present no obvious geographic structure patterns, suggesting gene flow and generalized incomplete lineage sorting. Populations north of the Pyrenees are closely related to those from northeastern Iberia, suggesting recent range expansion from this region. Historical demographic analyses indicate a demographic expansion starting about 100,000years ago and more recent population declines. Compared to other Lissotriton species, L. helveticus includes only relatively young genetic lineages, suggesting a Central European pre-Pleistocene distribution followed by complete extirpation of the species during glaciations in that area. Historical demographic trends in the Iberian Peninsula are reversed with respect to the more Mediterranean species Lissotriton boscai, indicating different responses of both species to climate changes. Diversity patterns among Lissotriton species seem to be defined by four main factors: ancestral distributions, colonization capabilities, interactions with other species and effective population sizes. Differences in these factors define two types of species, referred to as "R" (refugia) and "S" (sanctuaries) that explain part of the diversity in patterns of genetic diversity created by glaciations in Western Europe.     

High levels of population subdivision in a morphologically conserved Mediterranean toad (Alytes cisternasii) result from recent,multiple refugia: evidence from mtDNA,microsatellites and nuclear genealogies

Pleistocene glaciations often resulted in differentiation of taxa in southern European peninsulas, producing the high levels of endemism characteristic of these regions (e.g. the Iberian Peninsula). Despite their small ranges, endemic species often exhibit high levels of intraspecific differentiation as a result of a complex evolutionary history dominated by successive cycles of fragmentation, expansion and subsequent admixture of populations. Most evidence so far has come from the study of species with an Atlantic distribution in northwestern Iberia, and taxa restricted to Mediterranean‐type habitats remain poorly studied. The Iberian Midwife toad (Alytes cisternasii) is a morphologically conserved species endemic to southwestern and central Iberia and a typical inhabitant of Mediterranean habitats. Applying highly variable genetic markers from both mitochondrial and nuclear genomes to samples collected across the species’ range, we found evidence of high population subdivision within A. cisternasii. Mitochondrial haplotypes and microsatellites show geographically concordant patterns of genetic diversity, suggesting population fragmentation into several refugia during Pleistocene glaciations followed by subsequent events of geographical and demographic expansions with secondary contact. In addition, the absence of variation at the nuclear β‐fibint7 and Ppp3caint4 gene fragments suggests that populations of A. cisternasii have been recurrently affected by episodes of extinction and recolonization, and that documented patterns of population subdivision are the outcome of recent and multiple refugia. We discuss the evolutionary history of the species with particular interest in the increasing relevance of Mediterranean refugia for the survival of genetically differentiated populations during the Pleistocene glaciations as revealed by studies in co‐distributed taxa.     

Do distributional shifts of northern and southern species of algae match the warming pattern?

Well-documented changes in species abundances and distributions coinciding with global warming have been increasing during recent years. A trend of raising sea-surface temperature has also been observed along the Portuguese coast which could affect intertidal species' ranges. The present study aimed at evaluating the direction and intensity of distribution changes of macroalgae in the area. The last 50-year trend of coastal air and sea temperature was reassessed, providing an accurate estimate of the warming process. Information on species' range shifts was obtained by comparing data from recent resurveys with historical records of algal distributions collected during the 1950s and 1960s. Although a prevalence of northward migrations was anticipated, this work showed a marked difference in the average direction of changes between cold- and warm-water species. Cold-water species, when considered together, showed no particular shifting trend, because the number of species that shifted north or south was the same. Contrarily, all shifting warm-water species expanded their range northwards. Therefore, generalizations about poleward range shifts due to increasing temperature should be made with caution.     

Genetic study reveals close link between Irish and Northern Spanish specimens of the protected Lusitanian slug Geomalacus maculosus

The slug Geomalacus maculosus is a prominent member of the Lusitanian fauna. As its global distribution is restricted to western Ireland and northern Iberia, it is protected under EU legislation. Nothing is known about the genetic variability and population structure of this species, so, with a special view to shedding light on the origin of the Irish G. maculosus, tissue samples from 78 specimens were collected from 13 locations within Ireland and ten locations within Iberia and partial sequences of the mitochondrial 16S rRNA and cytochrome oxidase subunit 1 (COI) and from the nuclear internal transcribed spacer 1 region (ITS‐1) were compared. The genetic diversity of the Irish G. maculosus was found to be greatly reduced compared with the Iberian populations, with only one (16S rRNA) and two (COI) mitochondrial haplotypes identified respectively. No private Irish ITS‐1 haplotype was found. Based on the COI sequences, the Irish specimens clustered closest to Spanish specimens from Northern Asturias and Cantabria, and the bGMYC analysis identified five further Iberian clades that were highly genetically differentiated suggesting long‐term allopatric divergence.