Browsing by Author "Perea, Silvia"
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- Conservation challenges imposed by evolutionary history and habitat suitability shifts of endangered freshwater mussels under a global climate change scenarioPublication . Reis, Joaquim; Perea, Silvia; Gama, Mafalda; Mendes, Sofia L.; Sousa, Vitor C.; Lima, Cristina S.; Banha, Filipe; Gil, Maria; Alvarez, Maria Garcia; Anastácio, P.M.; Santos, Carla Sousa; Araujo, RafaelClimate change and associated shifts in temperature and precipitation patterns have become an increasing concern as drivers of ongoing biodiversity loss. The Mediterranean region is particularly vulnerable, being both a biodiversity hotspot and a region very prone to desertification. Freshwater mussels are amongst the most threatened invertebrate taxa worldwide. Unio tumidiformis is an endemic and endangered species restricted to the southern Iberian Peninsula, living in temporary Mediterranean-type streams. Freshwater mussels need a fish host for successful larval transformation, meaning U. tumidiformis must belong to the genus Squalius. The main objective of this study was to evaluate the vulnerability of U. tumidiformis to climate change, by studying its population genetics and evolutionary history, its current and future habitat suitability, and that of its hosts. Genetic population structure and diversity were assessed using Single-Nucleotide Polymorphisms through Genotyping by Sequencing and used to infer species evolutionary history. The species potential distribution was modeled using an ensemble forecasting approach, and future shifts in habitat suitability were assessed with the projected climate data layers from Worldclim. Most populations showed extreme genetic differentiation (Fst up to 0.745), even from close neighboring ones. Upper Guadiana populations were more diverse and less differentiated. We hypothesize that U. tumidiformis originated in Upper Guadiana and followed the same colonization routes as their hosts with numerous founder effects and bottlenecks. Our results also predicted a reduction of 99% of climatically suitable areas for U. tumidiformis in the Iberian Peninsula until 2040. For the fish hosts, a maximum 42% reduction in suitable areas was estimated throughout the century, with remaining adequate habitats in the north. Our results suggest that difficult conservation options are necessary, prioritizing the preservation of populations, translocations to the northern area of its historical range and stream engineering to increase resilience to droughts.
- Descripción de dos especies nuevas del género Squalius Bonaparte, 1837 (Actinopterygii, Leuciscidae) en la Península IbéricaPublication . Doadrio, Ignacio; Sousa-Santos, Carla; Perea, SilviaTwo new species, Squalius gaditanus sp. nov. and Squalius tartessicus sp. nov. are described on the basis of morphological and genetic traits. Squalius gaditanus is restricted to the Barbate, Jara and Miel drainages in the province of Cádiz (Southern Spain). Squalius gaditanus sp. nov. can be distinguished from other Squalius species from the Iberian Peninsula through a combination of morphometric, meristic and genetic characters: 36-40 (χ = 38) pored scales on the lateral line; 6-7 (χ = 6.7) scales above the lateral line; 2-3 (χ = 2.8) scales below the lateral line; vertebrae 37-39 (χ = 38); second infraorbital bone narrower than the third in adults; maxilla with reduced pointed anterior process; posterior process of the maxilla long and thin; lower branch of the pharyngeal bone short and robust; pharyngeal plate of basioccipital rounded and two autapomorphies in the mitochondrial cytochrome b gene. Squalius tartessicus sp. nov. inhabits the Almargem, Gilão, Odiel, Guadiana, Guadalquivir, Guadalete, Guadalhorce, Velez, Guadalfeo and Segura drainages in the southern part of the Iberian Peninsula. Squalius tartessicus sp. nov. can be differentiated from other Squalius species from the Iberian Peninsula through a set of morphometric, meristic and genetic traits: 37-41(χ = 38.8) pored scales on the lateral line; 6-7 (χ = 7) scales above the lateral line; 2-3 (χ = 2.9) scales below the lateral line; 37-39 (χ = 38) number of vertebrae; infraorbital bones unusually wide in adults; maxilla with discernable pointed anterior process; posterior process of the maxilla long and thin; lower branch of the pharyngeal bone short and robust; pharyngeal plate of basioccipital triangular in shape; posterior lamina of cleithrum expanding posteriorly.
- Historical biogeography of the Iberian Peninsula: multilocus phylogeny and ancestral area reconstruction for the freshwater fish genus Squalius (Actinopterygii, Leuciscidae)Publication . Perea, Silvia; Sousa‐Santos, Carla; Robalo, Joana; Doadrio, IgnacioThe Iberian Peninsula is one of the most ancient geological areas in Europe. Its complex orography is a consequence of several geological episodes related with two orogenic episodes that occurred from Late Devonian (Variscan orogeny) to the Cenozoic (Alpine orogeny). Unraveling the evolutionary history of strict freshwater fauna, such as leuciscid fishes, may contribute to our understanding of the paleogeographic history of a region and its configuration along time. Within the Iberian freshwater fish fauna, the genus Squalius is one of the oldest and most diversified leuciscids. Here, we used phylogenetic, phylogeographic, and ancestral area reconstruction approaches to infer relationships among Iberian drainages and the biogeographic history of these Squalius species, particularly of two of the most widely distributed species, S. carolitertii and S. pyrenaicus. Our results confirmed, in agreement with previous studies, an underestimation of the real diversity of Squalius in the Iberian Peninsula and identified divergent evolutionary lineages, highlighting the reticulate evolutionary history of the Iberian Squalius species. The ancestral reconstruction analyses indicated that several vicariance and dispersal processes occurred among different Squalius lineages, linked to the paleogeographic configuration of the Iberian Peninsula during the Cenozoic period.
- Multilocus phylogeny and systematics of Iberian endemic Squalius (Actinopterygii, Leuciscidae)Publication . Perea, Silvia; Santos, Carla Sousa; Robalo, Joana; Doadrio, IgnacioInferring the evolutionary history of a group of species can be challenging given the many factors involved. In recent years, the increased availability of sequences of multiple genes per species has spurred the development of new methodologies to analyse multilocus data sets. Two approaches that analyse such data are concatenated supermatrix and coalescent-based species-tree analyses. In this study, we used both of these methods to infer the phylogenetic relationships of Iberian species of the genus Squalius from one mitochondrial and six nuclear genes. We found mitonuclear discordance in the phylogenetic relationships of the group. According to the mitochondrial gene analysis, all species were recovered as monophyletic except S. pyrenaicus; besides, in the concatenated supermatrix analysis of the nuclear markers, this species resolved as polyphyletic with three divergent evolutionary lineages. The coalescent-based nuclear species-tree analysis rendered a well-resolved phylogeny compared with the supermatrix analysis, which was unable to discern between S. carolitertii, S. castellanus and one of the evolutionary lineages of S. pyrenaicus. This result is likely due to the better integration of population uncertainty in the coalescent approach. Furthermore, Bayesian multilocus species delimitation analyses based on a BPP approach strongly supported the distinct nuclear lineages as different species. Nevertheless, the supermatrix analysis was able to obtain well-supported relationships in the divergent lineages with low numbers of individuals. Our study highlights the usefulness of different analytical methodologies to obtain a more complete picture of the evolutionary history of taxa, especially when discordant patterns among genes are found.
- New distribution data on spanish autochthonous species of freshwater fishPublication . Perea, Silvia; Garzón, Paloma; González, José Luis; Almada, Vítor Carvalho; Pereira, Ana Martins; Doadrio, IgnacioOver the last two years (2008-2010) we performed a monitoring project to update the Spanish freshwater fish fauna. We have collected in 785 sampling localities homogeneously distributed throughout Spain each year. We find as the most important result of this study the occurrence of several species that constitute new records for some rivers or basins in Spain: Lampetra planeri, Petromyzon marinus, Barbus haasi, Iberochondrostoma lemmingii, Squalius alburnoides, Squalius carolitertii, Squalius malacitanus, Cobitis calderoni, Cobitis paludica, and Salaria fluviatilis. Finally we corroborate the existence of Barbatula barbatula in the Duero basin and the assignation of the northeastern populations of this genus to B. quignardi.
- Spatial heterogeneity in the Mediterranean Biodiversity Hotspot affects barcoding accuracy of its freshwater fishesPublication . Geiger, Matthias F.; Herder, Fabian; Monaghan, Michael T.; Almada, Vítor Carvalho; Barbieri, Roberta; Bariche, Michel; Berrebi, Patrick; Bohlen, Jörg; Casal-Lopez, Miriam; Delmastro, Giovanni B.; Denys, Gäel P. J.; Dettai, Agnès; Doadrio, Ignacio; Kalogianni, Elena; Kärst, Heiko; Kottelat, Maurice; Kovacic, Marcelo; Laporte, Martin; Lorenzoni, Massimo; Marcic, Zoran; Özulug, Müfit; Perdices, Anabel; Perea, Silvia; Persat, Henri; Porcellotti, Stefano; Puzzi, Cesare; Robalo, Joana Isabel; Sanda, Radek; Schneider, Michael; Slechtova, Vendula; Stumboudi, Maria; Walter, Simon; Freyhof, JörgIncomplete knowledge of biodiversity remains a stumbling block for conservation planning and even occurs within globally important Biodiversity Hotspots (BH). Although technical advances have boosted the power of molecular biodiversity assessments, the link between DNA sequences and species and the analytics to discriminate entities remain crucial. Here, we present an analysis of the first DNA barcode library for the freshwater fish fauna of the Mediterranean BH (526 spp.), with virtually complete species coverage (498 spp., 98% extant species). In order to build an identification system supporting conservation, we compared species determination by taxonomists to multiple clustering analyses of DNA barcodes for 3165 specimens. The congruence of barcode clusters with morphological determination was strongly dependent on the method of cluster delineation, but was highest with the general mixed Yule-coalescent (GMYC) model-based approach (83% of all species recovered as GMYC entity). Overall, genetic morphological discontinuities suggest the existence of up to 64 previously unrecognized candidate species. We found reduced identification accuracy when using the entire DNA-barcode database, compared with analyses on databases for individual river catchments. This scale effect has important implications for barcoding assessments and suggests that fairly simple identification pipelines provide sufficient resolution in local applications. We calculated Evolutionarily Distinct and Globally Endangered scores in order to identify candidate species for conservation priority and argue that the evolutionary content of barcode data can be used to detect priority species for future IUCN assessments. We show that large-scale barcoding inventories of complex biotas are feasible and contribute directly to the evaluation of conservation priorities.