Spiders on a Hot Volcanic Roof: Colonisation Pathways and Phylogeography of the Canary Islands Endemic Trap-Door Spider Titanidiops canariensis (Araneae, Idiopidae)

Studies conducted on volcanic islands have greatly contributed to our current understanding of how organisms diversify. The Canary Islands archipelago, located northwest of the coast of northern Africa, harbours a large number of endemic taxa. Because of their low vagility, mygalomorph spiders are usually absent from oceanic islands. The spider Titanidiops canariensis, which inhabits the easternmost islands of the archipelago, constitutes an exception to this rule. Here, we use a multi-locus approach that combines three mitochondrial and four nuclear genes to investigate the origins and phylogeography of this remarkable trap-door spider. We provide a timeframe for the colonisation of the Canary Islands using two alternative approaches: concatenation and species tree inference in a Bayesian relaxed clock framework. Additionally, we investigate the existence of cryptic species on the islands by means of a Bayesian multi-locus species delimitation method. Our results indicate that T. canariensis colonised the Canary Islands once, most likely during the Miocene, although discrepancies between the timeframes from different approaches make the exact timing uncertain. A complex evolutionary history for the species in the archipelago is revealed, which involves two independent colonisations of Fuerteventura from the ancestral range of T. canariensis in northern Lanzarote and a possible back colonisation of southern Lanzarote. The data further corroborate a previously proposed volcanic refugium, highlighting the impact of the dynamic volcanic history of the island on the phylogeographic patterns of the endemic taxa. T. canariensis includes at least two different species, one inhabiting the Jandia peninsula and central Fuerteventura and one spanning from central Fuerteventura to Lanzarote. Our data suggest that the extant northern African Titanidiops lineages may have expanded to the region after the islands were colonised and, hence, are not the source of colonisation. In addition, T. maroccanus may harbour several cryptic species

Taxonomic revision and insights into the speciation mode of the spider Dysdera erythrina species-complex (Araneae : Dysderidae): sibling species with sympatric distributions

The genus Dysdera, a species-rich group of spiders that includes specialised predators of woodlice, contains several complexes of morphologically similar sibling species. Here we investigate species limits in the D. erythrina (Walckenaer, 1802) complex by integrating phenotypic, cytogenetic and molecular data, and use this information to gain further knowledge on its origin and evolution. We describe 16 new species and redescribe four poorly known species belonging to this clade. The distribution of most of the species in the complex is limited to southern France and the north-eastern Iberian Peninsula. The species studied do not show any obvious differences in habitat preference, and some of them even occur sympatrically at certain sites. They probably feed on the same type of prey as they readily capture woodlice. On the other hand, they differ in body size, mouthparts shape, sculpturing of carapace, morphology of the copulatory organs, karyotype and DNA sequences. Experimental interspecific mating showed a partial precopulatory behavioural barrier between D. erythrina and D. cechica, sp. nov. Our data suggest that karyotype evolution of the complex included chromosome fusions and fissions as well as translocations (between autosomes as well as autosomes and sex chromosomes). We hypothesise that chromosome rearrangements generating reproductive incompatibility played a primary role in speciation within Dysdera complexes. Dysdera spiders are poor dispersers, and their original distribution areas (forested areas in the Mediterranean) were repeatedly fragmented during Quarternary climatic oscillations, facilitating integration of chromosome rearrangements into karyotypes by genetic drift. Sympatric occurrence of closely related species may have been promoted by prey segregation as suggested by differentiation in body size in co-occurring species. The following new species are described: D. catalonica, sp. nov., D. cechica, D. dolanskyi, sp. nov., D. fabrorum, sp. nov., D. garrafensis, sp. nov., D. graia, sp. nov., D. kropfi, sp. nov., D. minairo, sp. nov., D. portsensis, sp. nov., D. pradesensis, sp. nov., D. pyrenaica, sp. nov., D. quindecima, sp. nov., D. septima, sp. nov., D. stahlavskyi, sp. nov., D. tredecima, sp. nov. and D. undecimal, sp. nov

Comparative analysis of tissue-specific transcriptomes in the funnel-web spider Macrothele calpeiana

The funnel-web spider Macrothele calpeiana is a charismatic Mygalomorph with a great interest in basic, applied and translational research. Nevertheless, current scarcity of genomic and transcriptomic data of this species clearly limits the research in this non-model organism. To overcome this limitation, we launched the first tissue-specific enriched RNA-seq analysis in this species using a subtractive hybridization approach, with two main objectives, to characterize the specific transcriptome of the putative chemosensory appendages (palps and first pair of legs), and to provide a new set of DNA markers for further phylogenetic studies. We have characterized the set of transcripts specifically expressed in putative chemosensory tissues of this species, much of them showing features shared by chemosensory system genes. Among specific candidates, we have identified some members of the iGluR and NPC2 families. Moreover, we have demonstrated the utility of these newly generated data as molecular markers by inferring the phylogenetic position M. calpeina in the phylogenetic tree of Mygalomorphs. Our results provide novel resources for researchers interested in spider molecular biology and systematics, which can help to expand our knowledge on the evolutionary processes underlying fundamental biological questions, as species invasion or biodiversity origin and maintenance

A DNA barcode-assisted annotated checklist of the spider (Arachnida, Araneae) communities associated to white oak woodlands in Spanish National Parks

Background: A large scale semi-quantitative biodiversity assessment was conducted in white oak woodlands in areas included in the Spanish Network of National Parks, as part of a project aimed at revealing biogeographic patterns and identify biodiversity drivers. The semiquantitative COBRA sampling protocol was conducted in sixteen 1-ha plots across six national parks using a nested design. All adult specimens were identified to species level based on morphology. Uncertain delimitations and identifications due to either limited information of diagnostic characters or conflicting taxonomy were further investigated using DNA barcode information. New information: We identified 376 species belonging to 190 genera in 39 families, from the 8,521 adults found amongst the 20,539 collected specimens. Faunistic results include the discovery of 7 new species to the Iberian Peninsula, 3 new species to Spain and 11 putative new species to science. As largely expected by environmental features, the southern parks showed a higher proportion of Iberian and Mediterranean species than the northern parks, where the Palearctic elements were largely dominant. The analysis of approximately 3,200 DNA barcodes generated in the present study, corroborated and provided finer resolution to the morphologically based delimitation and identification of specimens in some taxonomically challenging families. Specifically, molecular data confirmed putative new species with diagnosable morphology, identified overlooked lineages that may constitute new species, confirmed assignment of specimens of unknown sexes to species and identified cases of misidentifications and phenotypic polymorphisms

Diversity and evolutionary history of mygalomorph spiders in the Western Mediterranean and the Canary Islands = La diversidad e historia evolutiva de las arañas migalomorfas en el Mediterráneo Occidental y las Islas Canarias

[spa] El infraorden Mygalomorphae es uno de los tres linajes evolutivos principales reconocidos dentro de las arañas, pero su diversidad en el Mediterráneo ha sido en general poco estudiada. Los factores que contribuyen al escaso conocimiento taxonómico del grupo tienen que ver con sus hábitos crípticos y su uniformidad fenotípica. Dicha uniformidad, convierte al grupo en un sistema para testar métodos de delimitación de especies. Por otro lado, el grupo se caracteriza por un baja capacidad de dispersión y elevado sedentarismo, constituyendo un modelo excelente para estudios de biogeografía, ya que sus distribuciones pueden reflejar procesos geológicos tales como la deriva continental. En esta tesis se ha utilizado una metodología integrativa que combina secuencias de DNA de múltiples genes, genotipado mediante AFLPs y modelación de distribución de especies, para abordar una serie de cuestiones relacionadas con la diversidad de este grupo. Mediante el uso de los métodos de análisis filogenéticos, inferencia del marco temporal de la diversificación del grupo y la aplicación de los métodos bayesianos coalescentes para la delimitación de especies se identifican los principales factores que promovieron la diversificación de los migalomorfos en la cuenca mediterránea, se contrastan diferentes escenarios biogeográficos sobre su origen y se investiga su estatus taxonómico. Los resultados de esta tesis mejoran notablemente el conocimiento actual sobre la diversidad críptica, la biogeografía y la filogenia de las familias Ctenizidae, Hexathelidae e Idiopidae que habitan el Mediterráneo e Islas Canarias. En todos los grupos estudiados se han detectado linajes evolutivos independientes que pueden corresponder a especies nuevas. Nuestros resultados ponen en evidencia que los eventos geológicos pasados tales como la desintegración de Gondwana, Laurasia y el Cinturón Herciniano modelaron la distribución actual de los migalomorfos Mediterráneos y que las Islas Canarias fueron colonizadas desde el continente una sola vez. Los resultados de esta tesis también confirman la polifilia de las familias Ctenizidae y Hexathelidae y ponen de manifiesto la necesidad de reevaluar los caracteres morfológicos utilizados en la taxonomía actual.[eng] The spider infraorder Mygalomorphae, comprising tarantulas, funnel-web spiders and the trap-door spiders, is one of the three main evolutionary lineages recognized within spiders. Its family level phylogenetic relationships are with a few exceptions relatively well solved, but its actual diversity in the Mediterranean region is probably underestimated. Because of the extremely low dispersal capacity, mygalomorph spiders usually show high levels of local endemism and deep population genetic structure, however, closely related species tend to be morphologically conservative. The low vagility and high habitat fidelity of mygalomorphs makes them a perfect model system for biogeographic studies as their distribution ranges are more likely to reflect geological processes such as continental break ups or tectonic plates rearrangements, while their conservative morphology makes them a good system to test species delimiting methods. The present Ph.D. thesis provides insights into the cryptic diversity, distribution patterns and phylogenetic relationships of the species of the families Ctenizidae, Hexathelidae and Idiopidae that inhabit the Western Mediterranean and the Canary Islands. By using a multi-locus approach and state of the art phylogenetic inference methods, the pattern and time frame of the diversification of these groups is inferred. The phylogenetic and temporal information sheds light on the biogeographic scenario and the diversification drivers of the selected families. Molecular based species delimitation approaches are further used to identify species boundaries in morphologically conservative groups. The results of the present study have greatly contributed to improve our current understanding of the diversity, biogeography and phylogeny of the mygalomorph spiders inhabiting the Mediterranean region and the Canary Islands. The existence of the independent evolutionary lineages that may correspond to undescribed species was detected in all studied groups, so far neglected by taxonomists due to their secluded habits and uniform morphology. The study also reveals that the past geological events had a great impact on the present day distribution of Mediterranean mygalomorphs. In the family Ctenizidae, the amphi-Atlantic distribution of Ummidia, traces back to a former Laurasian distribution and the rearrangement of the microplates following the Hercynian Belt break up, drove the diversification of both Cteniza and Ummidia in the Western Mediterranean. Our findings support that the genus Macrothele colonised the Mediterranean region during the Eocene in two independent waves, presumably from Asia, which in turn may have been colonised from Africa by rifting on the Indian subcontinent, following the Gondwana break up. On the other hand, the Canary Islands were colonised once by the genus Titanidiops presumably by passive rafting from the nearby mainland. Finally, the study sheds additional light on the high level phylogeny of mygalomorph spiders. The first ever-molecular phylogeny of the family Ctenizidae that includes representatives of all genera was conducted, revealing that their current higher taxonomic groupings are polyphyletic and failing to retrieve the monophyly of the family as whole, mostly due to the position of Cteniza and Cyrtocarenum. Unfortunately, topology tests could not reject the single origin of the family. Similarly, the results further confirmed the polyphyly of the family Hexathelidae, mostly due to the inclusion of the Atracinae subfamily. Our findings emphasize the need for redefining the limits of the families Ctenizidae and Hexathelidae and re-evaluating the morphological characters used in the current taxonomy of both groups

Diversity and evolutionary history of mygalomorph spiders in the Western Mediterranean and the Canary Islands = La diversidad e historia evolutiva de las arañas migalomorfas en el Mediterráneo Occidental y las Islas Canarias

The spider infraorder Mygalomorphae, comprising tarantulas, funnel-web spiders and the trap-door spiders, is one of the three main evolutionary lineages recognized within spiders. Its family level phylogenetic relationships are with a few exceptions relatively well solved, but its actual diversity in the Mediterranean region is probably underestimated. Because of the extremely low dispersal capacity, mygalomorph spiders usually show high levels of local endemism and deep population genetic structure, however, closely related species tend to be morphologically conservative. The low vagility and high habitat fidelity of mygalomorphs makes them a perfect model system for biogeographic studies as their distribution ranges are more likely to reflect geological processes such as continental break ups or tectonic plates rearrangements, while their conservative morphology makes them a good system to test species delimiting methods. The present Ph.D. thesis provides insights into the cryptic diversity, distribution patterns and phylogenetic relationships of the species of the families Ctenizidae, Hexathelidae and Idiopidae that inhabit the Western Mediterranean and the Canary Islands. By using a multi-locus approach and state of the art phylogenetic inference methods, the pattern and time frame of the diversification of these groups is inferred. The phylogenetic and temporal information sheds light on the biogeographic scenario and the diversification drivers of the selected families. Molecular based species delimitation approaches are further used to identify species boundaries in morphologically conservative groups. The results of the present study have greatly contributed to improve our current understanding of the diversity, biogeography and phylogeny of the mygalomorph spiders inhabiting the Mediterranean region and the Canary Islands. The existence of the independent evolutionary lineages that may correspond to undescribed species was detected in all studied groups, so far neglected by taxonomists due to their secluded habits and uniform morphology. The study also reveals that the past geological events had a great impact on the present day distribution of Mediterranean mygalomorphs. In the family Ctenizidae, the amphi-Atlantic distribution of Ummidia, traces back to a former Laurasian distribution and the rearrangement of the microplates following the Hercynian Belt break up, drove the diversification of both Cteniza and Ummidia in the Western Mediterranean. Our findings support that the genus Macrothele colonised the Mediterranean region during the Eocene in two independent waves, presumably from Asia, which in turn may have been colonised from Africa by rifting on the Indian subcontinent, following the Gondwana break up. On the other hand, the Canary Islands were colonised once by the genus Titanidiops presumably by passive rafting from the nearby mainland. Finally, the study sheds additional light on the high level phylogeny of mygalomorph spiders. The first ever-molecular phylogeny of the family Ctenizidae that includes representatives of all genera was conducted, revealing that their current higher taxonomic groupings are polyphyletic and failing to retrieve the monophyly of the family as whole, mostly due to the position of Cteniza and Cyrtocarenum. Unfortunately, topology tests could not reject the single origin of the family. Similarly, the results further confirmed the polyphyly of the family Hexathelidae, mostly due to the inclusion of the Atracinae subfamily. Our findings emphasize the need for redefining the limits of the families Ctenizidae and Hexathelidae and re-evaluating the morphological characters used in the current taxonomy of both groups.El infraorden Mygalomorphae es uno de los tres linajes evolutivos principales reconocidos dentro de las arañas, pero su diversidad en el Mediterráneo ha sido en general poco estudiada. Los factores que contribuyen al escaso conocimiento taxonómico del grupo tienen que ver con sus hábitos crípticos y su uniformidad fenotípica. Dicha uniformidad, convierte al grupo en un sistema para testar métodos de delimitación de especies. Por otro lado, el grupo se caracteriza por un baja capacidad de dispersión y elevado sedentarismo, constituyendo un modelo excelente para estudios de biogeografía, ya que sus distribuciones pueden reflejar procesos geológicos tales como la deriva continental. En esta tesis se ha utilizado una metodología integrativa que combina secuencias de DNA de múltiples genes, genotipado mediante AFLPs y modelación de distribución de especies, para abordar una serie de cuestiones relacionadas con la diversidad de este grupo. Mediante el uso de los métodos de análisis filogenéticos, inferencia del marco temporal de la diversificación del grupo y la aplicación de los métodos bayesianos coalescentes para la delimitación de especies se identifican los principales factores que promovieron la diversificación de los migalomorfos en la cuenca mediterránea, se contrastan diferentes escenarios biogeográficos sobre su origen y se investiga su estatus taxonómico. Los resultados de esta tesis mejoran notablemente el conocimiento actual sobre la diversidad críptica, la biogeografía y la filogenia de las familias Ctenizidae, Hexathelidae e Idiopidae que habitan el Mediterráneo e Islas Canarias. En todos los grupos estudiados se han detectado linajes evolutivos independientes que pueden corresponder a especies nuevas. Nuestros resultados ponen en evidencia que los eventos geológicos pasados tales como la desintegración de Gondwana, Laurasia y el Cinturón Herciniano modelaron la distribución actual de los migalomorfos Mediterráneos y que las Islas Canarias fueron colonizadas desde el continente una sola vez. Los resultados de esta tesis también confirman la polifilia de las familias Ctenizidae y Hexathelidae y ponen de manifiesto la necesidad de reevaluar los caracteres morfológicos utilizados en la taxonomía actual

Systematics and phylogeography of the Dysdera erythrina species complex (Araneae, Dysderidae) in Sardinia

Volume: 16Start Page: 319End Page: 34