Old and new records of turbellarians from the central areas of Spain

From the point of view of its biodiversity, the Iberian Peninsula is one of the most interesting areas. Its special geographical location and geological history have created a high degree of diversity within the invertebrates groups in general, and within the ecological group of the Turbellaria in particular. In the present work, old and new records of turbellarian species from the central areas of the Iberian Peninsula are presented. Data on their biology and distribution within the freshwater habitats, mainly limnic, are also provided. This study is mainly based on the project Fauna Iberica III. This revised version was published online in July 2006 with corrections to the Cover Date.     

Assessing the risk of freshwater fish introductions into the Iberian Peninsula

1. Preventing the introduction of species likely to become invaders is the best management option to deal with biological invasions. A data set consisting of native, introduced and species not currently present in Iberian Peninsula (n = 167 species) was used to identify freshwater fish species that are likely to be introduced and become successful invaders in the near future. 2. Principal component analysis (PCA) of species traits was used to determine species likely to be introduced, assuming that the traits of species introduced in the future will resemble those of previously introduced species. The likelihood of introduction was calculated as the proportion of neighbour species (in the space defined by the PCA) that have been introduced to the Iberian Peninsula and, together with metrics related to different stages of invasion, was used to construct a region‐specific risk index (Iberian risk index). 3. Introduced species had higher index values compared with native species or species currently absent from the region. The Iberian risk index was positively related to the results of an independent risk analysis for freshwater fish as well as to the geographical spread of species previously introduced to the Iberian Peninsula. 4. Iberian risk index values were used to establish a cut‐off value for estimating the probability of a successful invasion. This threshold value was used to construct a list of 20 species to be included in a ‘watch list’ to prevent freshwater fish invasions in the Iberian Peninsula.     

Historical,human, and environmental drivers of genetic diversity in the red swamp crayfish (Procambarus clarkii) invading the Iberian Peninsula

1. Patterns of genetic diversity in invasive populations can be modulated by a range of factors acting at different stages of the invasion process, including the genetic composition of the source population(s), the introduction history (e.g. propagule pressure), the environmental suitability of recipient areas, and the features of secondary introductions.
2. The North American red swamp crayfish, Procambarus clarkii, is one of the most widely introduced freshwater species worldwide. It was legally introduced into Spain twice, near the city of Badajoz in 1973 and in the Guadalquivir marshes in 1974. Thereafter the species rapidly colonised almost the entire Iberian Peninsula.
3. We used seven nuclear microsatellites to describe the genetic diversity and structure of 28 locations distributed across the Iberian Peninsula and to explain the expansion process of the red swamp crayfish. Additionally, we analysed the relationship between environmental suitability and genetic diversity of the studied locations.
4. The red swamp crayfish had a clear spatial genetic structure in the Iberian Peninsula, probably determined by the two independent introduction events in the 1970s, which produced two main clusters separated spatially, one of which was dominant in Portugal and the other in Spain.
5. The human-mediated dispersal process seemed to have involved invasion hubs, hosting highly genetically diverse areas and acting as sources for subsequent introductions. Genetic diversity also tended to be higher in more suitable environments across the Iberian Peninsula .
6. Our results showed that the complex and human-mediated expansion of the red swamp crayfish in the Iberian Peninsula has involved several long- and short-distance movements and that both ecological and anthropogenic factors have shaped the genetic diversity patterns resulting from this invasion process. Early detection of potential invasion hubs may help to halt multiple short-distance translocations and thus the rapid expansion of highly prolific invasive species over non-native areas.

     

Invasive non‐native species likely to threaten biodiversity and ecosystems in the Antarctic Peninsula region

The Antarctic is considered to be a pristine environment relative to other regions of the Earth, but it is increasingly vulnerable to invasions by marine, freshwater and terrestrial non‐native species. The Antarctic Peninsula region (APR), which encompasses the Antarctic Peninsula, South Shetland Islands and South Orkney Islands, is by far the most invaded part of the Antarctica continent. The risk of introduction of invasive non‐native species to the APR is likely to increase with predicted increases in the intensity, diversity and distribution of human activities. Parties that are signatories to the Antarctic Treaty have called for regional assessments of non‐native species risk. In response, taxonomic and Antarctic experts undertook a horizon scanning exercise using expert opinion and consensus approaches to identify the species that are likely to present the highest risk to biodiversity and ecosystems within the APR over the next 10 years. One hundred and three species, currently absent in the APR, were identified as relevant for review, with 13 species identified as presenting a high risk of invading the APR. Marine invertebrates dominated the list of highest risk species, with flowering plants and terrestrial invertebrates also represented; however, vertebrate species were thought unlikely to establish in the APR within the 10 year timeframe. We recommend (a) the further development and application of biosecurity measures by all stakeholders active in the APR, including surveillance for species such as those identified during this horizon scanning exercise, and (b) use of this methodology across the other regions of Antarctica. Without the application of appropriate biosecurity measures, rates of introductions and invasions within the APR are likely to increase, resulting in negative consequences for the biodiversity of the whole continent, as introduced species establish and spread further due to climate change and increasing human activity.     

Using historical accounts to set conservation baselines: the case of Lynx species in Spain

The knowledge of the historical range of organisms is necessary to understand distribution dynamics and their drivers as well as to set reference conditions and conservation goals. We reviewed written sources documenting the presence of lynxes in Spain between the sixteenth and nineteenth centuries, trying to infer whether Lynx records referred to the Iberian (Lynx pardinus) or the Eurasian (Lynx lynx) species. We compiled 151 spatially specific, non-redundant Lynx records, dating between 1572 and 1897. Records appeared split in two neatly separated areas, North and South. Arguably, all historical records from the South area correspond to Iberian lynx, since almost all of them fall within the estimated range of the species in the 1950s. This suggests that the core distribution area of the species remained relatively stable for centuries, until the second half of the twentieth century. The reported range in the 1950s is thus an appropriate scenario to set conservation goals for this critically endangered species. The North area extended from Galicia and northern Portugal to the Mediterranean, mainly occupying the Atlantic-climate area of northern Iberia. Reported direct measurements and the accumulation of indirect evidences suggest that most, if not all, northern Lynx records refer to the Eurasian lynx, which had been previously detected in archaeological sites of the area. This species was apparently present in the Iberian Peninsula until the early-nineteenth century. Our results provide an objective, baseline distribution of Lynx species in Spain useful to guide conservation efforts both at the Iberian and European levels.     

Non-indigenous species (NIS) of polychaetes (Annelida: Polychaeta) from the Atlantic and Mediterranean coasts of the Iberian Peninsula: an annotated checklist

This study provides an updated catalogue of non-indigenous species (NIS) of polychaetes reported from the continental coasts of the Iberian Peninsula based on the available literature. A list of 23 introduced species were regarded as established and other 11 were reported as casual, with 11 established and nine casual NIS in the Atlantic coast of the studied area and 14 established species and seven casual ones in the Mediterranean side. The most frequent way of transport was shipping (ballast water or hull fouling), which according to literature likely accounted for the introductions of 14 established species and for the presence of another casual one. To a much lesser extent aquaculture (three established and two casual species) and bait importation (one established species) were also recorded, but for a large number of species the translocation pathway was unknown. About 25% of the reported NIS originated in the Warm Western Atlantic region, followed by the Tropical Indo West-Pacific region (18%) and the Warm Eastern Atlantic (12%). In the Mediterranean coast of the Iberian Peninsula, nearly all the reported NIS originated from warm or tropical regions, but less than half of the species recorded from the Atlantic side were native of these areas. The effects of these introductions in native marine fauna are largely unknown, except for one species (Ficopomatus enigmaticus) which was reported to cause serious environmental impacts. In other cases, the displacement of native species or economic damages are suspected.     

An invaded invader: high prevalence of entocytherid ostracods on the red swamp crayfish <Emphasis Type="Italic">Procambarus clarkii</Emphasis> (Girard, 1852) in the Eastern Iberian Peninsula

The American red swamp crayfish Procambarus clarkii (Girard, 1852) was introduced in 1973 into the Iberian Peninsula for commercial purposes. As a result of both the expansion from the Iberian Peninsula and, probably, further introductions in other European countries, now it is widely distributed throughout much of Europe. The ecological impacts of this invading crayfish have received increasing attention, but nothing is known about its symbiotic entocytherid ostracods outside the American continent. The present survey has examined more than 200 crayfishes from 12 localities distributed over a wide area of Eastern Spain. Entocytherid ostracods were extracted from individual crayfishes and they were identified, counted, assigned to developmental instars and sexed. In all the study locations but one, we found at least one crayfish individual infected by entocytherid ostracods and the species determined was the same in all cases: Ankylocythere sinuosa (Rioja, 1942). The number of ostracods on individual P. clarkii varied notably in relation to crayfish size and also differed significantly among sampling sites. The crayfish size effects on ostracod densities might be related to the amount of resources and to the crayfish age and moulting frequency affecting ostracod distribution and population structure. In addition, the spatial variation in ostracod densities could also be related to site-specific habitat traits and the variability of crayfish population dynamics. Our study represents the first citation of an alien entocytherid species in Europe and demonstrates its wide distribution in the Iberian Peninsula. Further research is needed to know the potential effects of this ostracod species on the ecology of P. clarkii and of native species, with implications on the management of this aquatic invader.     

Reservoirs promote the taxonomic homogenization of fish communities within river basins

Most studies analyzing patterns in biotic homogenization of fish communities have used large-scale approaches, while the community-level effects of species introductions and local extinctions within river basins have been sparsely analyzed. In this article, we examine patterns in freshwater fish α- and β-diversity in relation to the presence of reservoirs in a Mediterranean river (Guadiana river; Iberian Peninsula). We used fish samples from 182 river localities and 59 reservoir ones to address two main questions: (i) do reservoirs favor the establishment of invasive fish species?; and (ii) do reservoirs bear taxonomically homogenized fish communities? Although total species richness was not different between rivers and reservoirs, the latter had more invasive species and less native ones. Fish species found in reservoirs tended to be larger ones, but invasive species of any size showed higher preferences for reservoirs. Native species that were rare or absent in reservoirs were those that showed higher sensitivity to invasive species in rivers. Reservoir fish communities were taxonomically homogenized in relation to river ones, both when considering all fish species and using only natives or only invasive ones. Our results suggest that invasive species occupying reservoirs constitute an ecological filter excluding most native species from such systems. Invasive species in the study area are often widely introduced elsewhere, while native species found in reservoirs are congeneric and ecologically similar to those found in other Iberian studies. Thus, we conclude that reservoirs promote taxonomic homogenization at multiple spatial scales, while could also be promoting the functional homogenization of Iberian fish communities.     

Freshwater fish introductions in mediterranean‐climate regions: are there commonalities in the conservation problem?

Aim To compare patterns and drivers of freshwater fish introductions across five climatically similar regions and evaluate similarities and differences in the non‐native species introduced. Location Five mediterranean‐climate regions: California (USA), central Chile, south‐western Australia, the Iberian peninsula (Spain and Portugal) and the south‐western Cape (South Africa). Methods Species presence–absence for native and non‐native fishes were collated across the regions, and patterns of faunal change were examined using univariate and multivariate statistical approaches. Taxonomic patterns in freshwater fish introductions were evaluated by comparing the number of species introduced by order to the numbers expected from binomial probabilities. Factors influencing multiple introductions of freshwater fish species in mediterranean regions were determined using generalized linear modelling. Results High levels of endemism (70–90%) were revealed for south‐western Cape, south‐western Australia and Chile. Despite their high rates of endemism, all regions currently have more non‐native species than endemic species. Taxonomic selection was found for five orders, although this was only significant for Salmoniformes across regions. The average increase in regional compositional similarity of fish faunas resulting from non‐native fish introductions was 8.0%. Important factors predicting multiple introductions of a species include previous introduction success and mean latitude of its distribution Main conclusions The mediterranean‐climate regions of the world, separated by vast distances, originally had a few fish species in common but are now more similar, owing to species introductions, illustrating the extent and importance of taxonomic homogenization. Introductions are largely driven by taxonomically biased human interests in recreational fisheries, aquaculture and ornamental pet species.     

Profiling invasive fish species: the importance of phylogeny and human use

Understanding the ecological differences between native and invasive species is of considerable scientific and practical interest. We examined such differences between native and invasive inland fish species from the Iberian Peninsula in order to analyse the importance of phylogenetic correction and variability (in addition to central tendency). We collected 26 quantitative and qualitative variables on the ecology, life‐history traits and human use of the 69 inland fish species of the Iberian Peninsula, including native, invasive and migratory species. The taxonomic distribution of invasive fish species deviated significantly from world freshwater richness and in contrast to native species, invasive fish belongs to only five taxonomic orders but to a wide spectrum of families not native to the Iberian Peninsula. Because the life‐history traits were highly dependent on taxonomy, the results, with or without applying phylogenetic methods, differed and after accounting for phylogeny, invasive species displayed higher and wider latitude in general and a different reproductive season mainly among salmonids and cyprinids. Human use was also significantly different between native and invasive fish species and produced more variability in life‐history traits of invasive species and uneven taxonomic distribution because of the high diversity of species introduced. We show that accounting for taxonomy and studying variability in addition to central tendency is important in the comparison of life‐history traits between native and invasive species.     

On the Iberian endemism <Emphasis Type="Italic">Eurylophella iberica</Emphasis> Keffermuller and Da Terra 1978 (Ephemeroptera,Ephemerellidae): current and future potential distributions,and assessment of the effectiveness of the Natura 2000 network on its protection

Eurylophella iberica Keffermüller and Da Terra, 1978 is an endemic insect species of the Iberian Peninsula whose distribution has been poorly studied to date with rather old and scattered records. Here we compiled all existing distribution records and add new records from recent sampling activities. We also used this updated distributional information and environmental data (climate and geology) to estimate both current and future potential distributions in different climate change scenarios. We found that currently ca. 50% of the total Iberian region could present suitable environmental conditions for E. iberica (all the Iberian Peninsula, save the most eastern and Mediterranean areas). However, the potential distributions estimated when considering future climate change scenarios showed a marked reduction in the areas with suitable environmental conditions for the species, especially in the south. The northwest part of the Iberian Peninsula is a crucial zone for the future survival of this endemic species. We also found that most populations that occur in areas with suitable (both current and future) environmental conditions fall outside the Natura 2000 network of protected areas. Our results represent the first attempt to estimate the potential distribution of this endemic species providing important insights for its conservation.     

Predicting the distribution of cryptic species: the case of the spur-thighed tortoise in Andalusia (southern Iberian Peninsula)

Some species are very difficult to observe in the wild, and some of these present an apparently incongruent distribution, as is the case of the spur-thighed tortoise Testudo graeca in the southern Iberian Peninsula. This species has a discontinuous distribution with two main reproductive areas: one in the contiguous provinces of Almeria and Murcia, and the other in Huelva province. Both populations are thought to maintain reproductive isolation. However, we present new records obtained from two areas (the provinces of Malaga and Cadiz) which are outside their previously known range. Malaga province and Cadiz province are located between the two traditional reproductive areas. The new records were based on 16 interviews with shepherds as well as information provided by three naturalists. The aim of this work was to analyze the spatial distribution of areas favourable to the spur-thighed tortoise in the southern Iberian Peninsula, using different models with the same group of variables but with a different number of records: known records, new records and a combination of them. We obtained a distribution model for the species in Andalusia consistent with all observations, which was related to climatic stability, climatic disturbances, and spatial situation. This model presented three main favourable areas: two are coincident with the two known nuclei, and the other is situated in the southern part of the region, in the contiguous provinces of Cadiz and Malaga. We conclude that it is important to consider all the observations in the distribution models because records outside the traditional reproductive areas can include other environmental characteristics appropriate for the species.     

Review of Iberian Cladocera with remarks on ecology and biogeography

A checklist of 88 freshwater Cladocera from the Iberian Peninsula is given, based on the examination of approximately 1500 samples collected from all parts of the peninsula from 1976 to 1989. Ecology and species assemblages are considered. Distribution of the species versus regional limnology of the Iberian Peninsula is discussed.     

Distribution patterns of freshwater molluscs along environmental gradients in the southern Guadiana River basin (SW Iberian Peninsula)

The taxonomic status of the freshwater mollusc fauna of the Iberian Peninsula it is reasonably well known, but, unlike other benthic macroinvertebrate, its distribution and ecology has been poorly studied. In this article, I study the relationships between environmental characteristics and distribution and community structure of freshwater molluscs along climatic, hydrological, physicochemical, and heterogeneity gradients in the southwestern Iberian Peninsula. Ninety-four sampling points were analysed, in which, in addition to habitat features, the presence/absence and abundance of species were evaluated. The environmental gradients were measured by use of principal-components analysis (PAC), which orders the variables along two gradients: headwaters-mouth gradient (PC1) and water availability (PC2). According to canonical correspondence analysis (CCA), the main environmental factors related to species distribution and community structure were conductivity, permanency, channel width, turbidity, slope, and distance to the main river axis. The relationship between biodiversity (measured as species richness and the Shannon–Weiner diversity index), the ratio of the number of introduced species to the total number of species (zoogeographic integrity coefficient), and environmental variables was best explained by a regression model incorporating, basically, the permanence of water in streams as the variable that accounted for most of the variance. This study demonstrates that the distribution of freshwater molluscs along a Mediterranean gradient highly stressed by drought depends, mainly, on the hydrological stability and environmental conditions of the headwaters and estuarine sites.     

A new species of Cytisus Desf. (Fabaceae) from islands off the west coast of Galicia (north-west Iberian Peninsula)

A new species of the section Spartopsis Dumort. of the genus Cytisus Desf. (Fabaceae) is described. The new species, Cytisus insularis , is restricted to the western islands of Galicia (north-west Iberian Peninsula), where it principally colonizes cliffs. A possible recent hybrid origin for these populations is considered but rejected in view of the results of experimental tests of pollen viability and seed germination. Characters permitting discrimination from the most similar taxa are detailed, and possible relationships with the other species of the section are discussed.     

Paleobiogeography of an Iberian endemic species,Luciobarbus sclateri (Günther, 1868) (Actinopterygii,Cyprinidae), inferred from mitochondrial and nuclear markers

Since the Cenozoic Era, the southern Iberian Peninsula has undergone a series of complex geological and climatic changes that have shaped the hydrographic configuration of the freshwater network, influencing the present‐day distribution of primary freshwater species and favoring a high level of local endemicity. The cyprinid species Luciobarbus sclateri (Günther, 1968) is an endemic species confined to the southern Iberian Peninsula and characterized by a complex evolutionary history. Previous studies linked the structure of L. sclateri populations to the effects of climate change during glaciations and were not able to explain the genetic discordance found between nuclear and mitochondrial markers. The results of this study show that the structure of L. sclateri populations is a reflection of diversification processes linked to the geological history of the region. Thus, we found three main mitochondrial phylogroups: the first one corresponding to small basins in southern Iberian Peninsula, a second one in eastern Iberian Peninsula, corresponding to Segura population, and a third one including the rest of the basins where the species is distributed. The southern group began diverging in the Pliocene as result of tectonic dynamics characterized by the emersion of the basins around the Strait of Gibraltar. The other two groups began diverging with the formation of the current Iberian hydrographic system during Pleistocene. So, the isolation of the hydrographic basins was the main factor driving intraspecific differentiation, followed by recent secondary contacts, admixture, and re‐isolation of the populations.     

Crepis novoana (Asteraceae), a new species restricted to coastal cliffs in northern Galicia (northwest Iberian Peninsula)

A new species of the section Lepidoseris (Rchb.) Benth. of the genus Crepis L. (Asteraceae) is described. The new species is restricted to a single known locality on near-vertical coastal cliffs of the Ria de Cedeira in northern Galicia (northwest Iberian Peninsula). Morphometric characters permitting discrimination from the most similar taxa are detailed, and possible phylogenetic relationships with other species of the section Lepidoseris (particularly those of the C. vesicaria complex) are discussed.     

Biogeographical regions of the Iberian peninsula based on freshwater fish and amphibian distributions

We classified the main Iberian river basins based on the presence and absence of freshwater fishes and amphibians. For both taxonomic groups we analysed three data sets; 1) endemic species only, to search for biotic boundaries related to historical events, 2) indigenous species, which include endemic ones, to search for biotic boundaries related to ecological factors, 3) indigenous and well-established introduced species, to assess the influence of man in the current biogeographical patterns of fishes and amphibians. We used both phenetic and cladistic methods, followed by a consensus analysis to provide an overall biogeographical pattern. Based on all fish distributions, the Iberian Peninsula is divided into three biogeographical regions: Cantabrian, Atlantic and Mediterranean, No boundary existed between the Cantabrian and Atlantic regions when only indigenous fish species were considered. This suggests that this boundary has been induced by man, probably through the differential introduction of fish species into reservoirs at one or other side of the boundary. Run-off and the size of the river basins are the environmental factors that distinguished the Atlantic and Mediterranean regions. However, regionalization based only on endemic freshwater fishes showed a latitudinal pattern that agrees with the paleogeographic events of the Upper Oligocene-Lower Miocene period. By contrast, one northern and one southern region were distinguished based on all amphibian distributions and on indigenous amphibians only, which suggests that human activity has not significantly affected the overall biogeographical pattern of amphibians in the Iberian Peninsula. Interannual predictability of precipitation best accounts for this regionalization. Based on endemic amphibians, the Iberian Peninsula is divided into three regions that closely resemble the three separate land areas of the Upper Eocene-Lower Oligocene period. The consensus between the biogeographical regions based on fishes and amphibians yields five pairs of basins. Geological origin of the basins seems to better explain the consensus between the biogeographical patterns of fishes and amphibians, whereas ecological factors probably contribute to the differences between them.     

Past tree range dynamics in the Iberian Peninsula inferred through phylogeography and palaeodistribution modelling: A review

The forests in the Iberian Peninsula have been strongly influenced by past climatic changes, but reconstructing their historical distributions and dynamics is very difficult due to the complex climatic characteristics and relief of the region. Research disciplines such as phylogeography and species distribution modelling can describe the past range dynamics of individual tree species in relatively great detail and help elucidate how these species have reacted to climatic changes. Here we review phylogeographical and modelling studies from species representative of the major Iberian forest types and attempt to extract general trends from the diversity of individual species histories in the Peninsula. To date most studies focus on geographical range dynamics during the Pleistocene, but an increasing body of evidence shows that some species have also retained the genetic imprints of much more ancient processes. Many widespread Iberian species show a deep and often remarkably clear-cut divide between populations from the Mediterranean and from the Atlantic regions of the Iberian Peninsula, suggesting that both areas have independently sustained viable populations over extended periods. In fact, phylogeographical studies commonly find that species had several glacial refugia across the Iberian Peninsula. On the other hand, distribution models help identifying further suitable areas that could have sustained so far undetected refugia. Such studies are of interest for species conservation, because refugium populations are high-priority targets due to their long-term persistence and unique evolutionary trajectory. Overall, we conclude that palaeoecology, phylogeography and species distribution modelling have a great potential to inform each other because of their complementary perspectives and results. A true integration of these approaches is therefore fundamental for further progress in our understanding of past Iberian environments and the organisms they harboured.     

DYS19 and DYS390 Y-STR polymorphism in the Iberian Peninsula: a multivariate analysis

Genetic polymorphism of two Y-specific short tandem repeats (DYS19 and DYS390) was investigated in six populations from the Iberian Peninsula (Andalusia, Castilla-La Mancha, Castilla-Leon, Extremadura, Galicia and South East Spain) comprising a total of 895 unrelated and native individuals, and a complete database of DYS19 and DYS390 allele frequency distributions in 34 world-wide populations collected from literature was analysed. DYS19 and DYS390 polymorphism was screened by automated fluorescence analysis of PCR-amplified labelled sample fragments performed with and ABI PRISM 377 Genetic Analyser. The degree of population differentiation was analysed using the STP Test to calculate G Statistic values. Correspondence Analysis based on the allelic frequencies of each locus and combining both was performed using the NTSYS-PC version 1.70 computer package. The diversity of the genetic profiles of gene frequencies suggests an important population heterogeneity in the Iberian Peninsula as a whole (DYS390 being particularly evident), which is corroborated after statistical analyses (G = 139.8457, p = 1.7822 x 10(-14) for DYS19, G = 116.0293, p = 4.6845 x 10(-12) for DYS390). However, multivariate analysis indicates a well defined cluster of the populations of the Central region, and sets them apart from the positions within which peripheral Iberian Peninsula populations are distributed. The Galician population shows trends which bring it closer to the positions throughout which European Atlantic populations are distributed. The results shown by the Central Iberian Peninsula seem to lend support to a model of settlement population stocks which came from the region of Castilla-Leon after the Islam invasions, whereas in the South-East populations the genetic record of Middle Eastern populations is still present, a consequence of the expansion of Islam in Southern Europe in the Middle Ages.