Suchergebnisse

Mientras buscamos nuevas funciones para la educación superior en medio de los cambios sociales, económicos y políticos que conlleva la globalización, resulta útil reflexionar sobre las funciones que históricamente han desempeñado las universidades. Éstas han sido principalmente la creación, transmisión y conservación del conocimiento. Con el paso del tiempo, las funciones que llevaban a cabo las universidades se han visto complementadas con otras importantes actividades sociales, en diferentes sociedades y culturas y en diferentes momentos. Entre ellas se encuentran la produccióny reproducción de élites y clases profesionales; la extensión de la educación superior a otros estratos sociales mediante su democratización y masificación; la creación, destilación y difusión del conocimiento científico, y la codificación y conservación de prácticas lingüísticas y culturales. A lo largo de la historia se ha visto que las instituciones de educación superior poseen capacidad de adaptación, aunque de forma lenta y conservadora, a cambios sociales de gran alcance. Se han creado oportunidades para nuevas clases de investigación, las disciplinas han sido reorganizadas para promocionar su estudio detallado y su transmisión, y se ha abogado por los valores sociales de la investigación y las oportunidades abiertas, si bien de forma desigual. ; Peer Reviewed

Mientras buscamos nuevas funciones para la educación superior en medio de los cambios sociales, económicos y políticos que conlleva la globalización, resulta útil reflexionar sobre las funciones que históricamente han desempeñado las universidades. Éstas han sido principalmente la creación, transmisión y conservación del conocimiento. Con el paso del tiempo, las funciones que llevaban a cabo las universidades se han visto complementadas con otras importantes actividades sociales, en diferentes sociedades y culturas y en diferentes momentos. Entre ellas se encuentran la produccióny reproducción de élites y clases profesionales; la extensión de la educación superior a otros estratos sociales mediante su democratización y masificación; la creación, destilación y difusión del conocimiento científico, y la codificación y conservación de prácticas lingüísticas y culturales. A lo largo de la historia se ha visto que las instituciones de educación superior poseen capacidad de adaptación, aunque de forma lenta y conservadora, a cambios sociales de gran alcance. Se han creado oportunidades para nuevas clases de investigación, las disciplinas han sido reorganizadas para promocionar su estudio detallado y su transmisión, y se ha abogado por los valores sociales de la investigación y las oportunidades abiertas, si bien de forma desigual. ; Peer Reviewed

16 páginas, 4 figuras, 4 tablas. ; Following the introduction to a new area (preborder dispersal), post-border processes determine the success in the establishment of non-indigenous species (NIS). However, little is known on how these post-border processes shape the genetic composition of NIS at regional scales. Here, we analyse genetic variation in introduced populations along impacted coastlines to infer demographic and kinship dynamics at the post-border stage. We used as a model system the ascidian species Microcosmus squamiger that has been introduced worldwide. This species can colonize and grow fast on man-made artificial structures, impacting activities such as mariculture. However, it can also establish itself on natural substrates, thus altering natural communities and becoming an ecological problem. We genotyped 302 individuals from eight populations established on natural and artificial substrates in the north-western Mediterranean Sea, using six microsatellite loci. We then compared the resulting genotypes with those found within the native range of the species. We found high levels of genetic diversity and allelic richness in all populations, with an overall deficit of heterozygotes. Autocorrelation analyses showed that there was no withinpopulation genetic structure (at a scale of tens of metres); likewise, no significant differentiation in pairwise comparisons between populations (tens of kilometres apart) and no isolation-by-distance pattern was found. The results suggest that M. squamiger has a natural capacity for high dispersal from one patch of hard substrate to another and no differences whatsoever could be substantiated between natural and artificial substrates. Interestingly, two groups of genetically differentiated individuals were detected that were associated with the two ancestral source areas of the worldwide expansion of the species. Individual assignment tests showed the coexistence of individuals of these two clusters in all populations but with little interbreeding among them as the frequency of admixed individuals was only 15 %. The mechanism responsible for maintaining these genetic pools unmixed is unknown, but it does not appear to compromise post-border colonization of introduced populations. ; This research was funded by projects CTM2010-22218 of the Spanish Government, BIOCON08-187 of the FBBVA and PIE 200730I026 of the Spanish Research Council (CSIC). Funding to M. R. came from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no PIOF-GA-2009- 254634. V. O. was supported by a FPU PhD scholarship (AP2008/ 04209) from the Spanish Ministerio de Educacio´n. The authors are part of the research groups 2009SGR-636 and 2009SGR-484 of the Generalitat de Catalunya (Spain). ; Peer reviewed

13 páginas, 6 figuras, 1 tabla ; Taxonomic issues often confound the study of invasive species, which sometimes are unrecognized as introduced in newly colonized areas. Clavelina oblonga Herdman, 1880 is an abundant ascidian species along the southeastern coast of the United States and the Caribbean Sea. It was introduced into the eastern Atlantic and Brazil decades ago. In the Mediterranean Sea, a similar species had been described as C. phlegraea Salfi 1929 and reported from southern Italy and Corsica. In the last few years a species of Clavelina has proliferated in the embayments of the Ebro Delta (NW Mediterranean), a zone of active bivalve culture industry where it has smothered mussel spat, leading to economic loss. We here report the morphological and genetic identity of this species, synonymizing the Atlantic C. oblonga and the Mediterranean C. phlegraea (the latter therefore is a synonym of the former). Thus, C. oblonga has existed in the Mediterranean for over 80 years, but was known under a different name. We also found this species in natural habitats in the Iberian Atlantic coast close to the Strait of Gibraltar, raising concerns about an ongoing expansion. In order to obtain information relevant for management, we monitored growth, reproductive cycles and settlement patterns of this ascidian on bivalve cultures in the Ebro Delta. Its biological cycles were markedly seasonal, with peak abundance and reproduction during the warmest months, followed by regression during the cold season. The settlement period was short, mostly concentrated in a single month each year. Avoidance of mussel and oyster seeding during late summer and early autumn can readily reduce the damage caused by this species. ; This research was funded by the COCONET project #287844 of the 7th European Community Framework Program and by Spanish Government projects CTM2010-22218 and CTM2013-48163. ; Peer reviewed

Este artículo contiene 11 páginas, 3 tablas, 3 figuras. ; Ascidians are important both as invasive species and as a fouling group in artificial marine habitats, causing negative impacts in aquaculture settings and the surrounding environment. The Ebro Delta is one of the major centres of bivalve production in the Mediterranean and is affected by proliferation of ascidian species (mostly introduced forms). Knowledge of the patterns of settlement and growth of the fouling species is mandatory to attempt mitigation measures. Settlement PVC plates were deployed from May to September 2015 at different depths (0.2, 1 and 2 m) in the Ebro Delta oyster aquaculture facilities. The occurrences of all species and the area cover of a selected subset of 6 species were monitored on a monthly basis from June 2015 to December 2016. Fifteen species were found, of which 10 are introduced. There were some differences between the deployed plates and the oyster ropes in species abundance and composition, likely due to differences in substrate complexity. For instance, Didemnum vexillum and Clavelina oblonga occurred in few plates in contrast to their abundance on oysters. The most abundant species were Styela plicata and Clavelina lepadiformis, which together with Ecteinascidia turbinata showed a preference to grow on plates deployed in May and June. Most of the species grew more at 0.2mdepth than at deeper plates. Thus, to minimise fouling on bivalves, spat immersion during fall and below 1mdepth is recommended. The number of occurrences and cover of the species was found to be similarly informative; suggesting that a periodic monitoring of species occurrence on replicate plates is sufficient for detecting new introduced species as soon as possible and will provide information useful for management. ; This research was funded by project CHALLENGEN CTM2013-48163 from the Spanish Government. MC, VO, MP and XT are part of the research group 2014SGR-336 of the Generalitat de Catalunya. ; Peer reviewed

11 páginas, 4 figuras ; Non-indigenous ascidians are of particular concern to aquaculture industry and, paradoxically, the activities associated with it represent an important way to translocate these species worldwide. In 2012 a non-indigenous ascidian was found covering the oyster crops in the Ebro Delta (Western Mediterranean). We have identified the ascidian genetically and morphologically as Didemnum vexillum Kott, 2002. This finding indicates that the species is currently expanding its distribution in the Mediterranean Sea, as it has recently been found in the eastern basin (Venice, Adriatic Sea). Introduced populations of D. vexillum are found in temperate and cold waters worldwide, and a successful establishment in the Mediterranean implies a remarkable capacity of adaptability to warm, subtropical conditions. We assessed the life cycle (growth and reproduction) of the ascidian at the studied site. The species has a marked seasonal cycle, with regression in the warmest months and reappearance during winter. In spring D. vexillum reaches its maximum abundance, followed by a peak in reproduction just before regression. This cycle is reversed with respect to the one observed in colder waters, highlighting a plastic biological cycle of this invader and an hitherto unknown ability to establish itself in warm waters. We also analysed the genetic structure of the population of the Ebro Delta and the one established in the Lagoon of Venice using COI sequence data. The low genetic diversity in our samples (three haplotypes) was consistent with what is observed in the introduced populations worldwide. It is likely that the ascidian was introduced with oyster stock from bivalve cultures in the Atlantic French coasts, where the same three haplotypes have been reported. The high boating activity in the Ebro Delta makes further human-mediated transport of the species highly likely, and nearby fishing grounds can be severely affected if invaded. It is urgent to implement measures to prevent the continuous expansion of this ascidian pest in the Mediterranean. ; This research was funded by Projects CTM2010-22218 and CTM2013-48163 of the Spanish Government and by the COCONET Project (EU #287844, 7th Framework Program) ; Peer reviewed

15 páginas, 7 figuras, 5 tablas. ; Recurrent introductions of non-indigenous species generate novel interactions that vary with local conditions and the composition of the receiving community. Most studies examine relationships of newcomers with native species, but interactions among introduced species could also affect community shifts. As early ontogenetic stages are particularly vulnerable to biotic interactions, we explored direct and indirect interactions across early life-history stages in space-dominating marine invertebrates. We used introduced ascidians and both native and introduced mussels. To increase generality, we ran our experiments in 2 distant locations, one in the northern and one in the southern hemisphere (Mediterranean and South Africa). We found no sperm interference between the ascidians, nor were there interspecific effects on settlement or metamorphosis success. However, larvae of the ascidian species reacted to each other by shifting from aggregated to random settlement. Juvenile mussels consumed large numbers of ascidian larvae, though larvae that avoided mussel predation showed higher settlement success. Mussel species in the southern hemisphere locality (native Perna perna and introduced Mytilus galloprovincialis) consumed more ascidian larvae than mussels in the northern locality (native M. galloprovincialis), with a tendency for ascidian larvae to avoid settling close to mussels in the northern locality. We conclude that larval consumption by mussels affects the establishment of ascidians, but that the magnitude of this effect is context dependant. These results emphasize the importance of the composition of the receiving community in determining its susceptibility to invasion. Whether the species comprising this community are native or introduced is, however, less important than what manner of species they are. ; This research was funded by project CTM2010-22218 of the Spanish Government and by the South African Research Chairs Initiative of the Department of Science and Technology and the National Research Foundation. V.O. was supported by a FPU PhD scholarship (AP2008/04209) from the Spanish Ministerio de Educación. The authors are part of the research groups 2009SGR-636 and 2009SGR-484 of the Generalitat de Catalunya (Spain). The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. PIOF-GA-2009- 254634 to M.R. ; Peer reviewed

11 páginas, 4 tablas, 4 figuras. ; All ontogenetic stages of a life cycle are exposed to environmental conditions so that population persistence depends on the performance of both adults and offspring. Most studies analysing the influence of abiotic conditions on species performance have focussed on adults, while studies covering early life-history stages remain rare. We investigated the responses of early stages of two widely introduced ascidians, Styela plicata and Microcosmus squamiger, to different abiotic conditions. Stressors mimicked conditions in the habitats where both species can be found in their distributional ranges and responses were related to the selection potential of their populations by analysing their genetic diversity. Four developmental stages (egg fertilisation, larval development, settlement, metamorphosis) were studied after exposure to high temperature (30uC), low salinities (26 and 22%) and high copper concentrations (25, 50 and 100 mg/L). Although most stressors effectively led to failure of complete development (fertilisation through metamorphosis), fertilisation and larval development were the most sensitive stages. All the studied stressors affected the development of both species, though responses differed with stage and stressor. S. plicata was overall more resistant to copper, and some stages of M. squamiger to low salinities. No relationship was found between parental genetic composition and responses to stressors. We conclude that successful development can be prevented at several life-history stages, and therefore, it is essential to consider multiple stages when assessing species' abilities to tolerate stress. Moreover, we found that early development of these species cannot be completed under conditions prevailing where adults live. These populations must therefore recruit from elsewhere or reproduce during temporal windows of more benign conditions. Alternatively, novel strategies or behaviours that increase overall reproductive success might be responsible for ensuring population survival. ; The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013), through the Marie Curie International Reintegration Grant (EU-FP7-PEOPLE-2010-RG 277038) to S.L.-L. and a Marie Curie International Outgoing fellowship (EU-FP7-PEOPLE- 2009-IOF-254634) to M.R. Funding was also provided by the Spanish Government projects CTM2010- 22218 and CTM2010-17755, and by the South African Research Chairs Initiative of the Department of Science and Technology and the National Research Foundation. MCP was awarded with an APIF fellowship from the University of Barcelona travel to South Africa ; Peer reviewed

Este artículo contiene 14 páginas, 7 figuras, 2 tablas. ; Global environmental changes may have a profound impact on ecosystems. In this context, it is crucial to gather biological and ecological information of the main species in marine communities to predict and mitigate potential effects of shifts in their distribution, abundance, and interactions. Using genotyping by sequencing (GBS), we assessed the genetic structure of a keystone species in the Mediterranean shallow littoral ecosystems, the black sea urchin Arbacia lixula. This bioengineer species can shape their communities due to its grazing activity and it is experiencing an ongoing expansion with increasing temperatures. The population genomic analyses on 5,241 loci sequenced in 240 individuals from 11 Mediterranean sampled populations revealed that all populations were diverse and showed significant departure from equilibrium. Albeit genetic differentiation was in general shallow, a significant break separated the western and eastern Mediterranean populations, a break not detected in previous studies with less resolutive markers. Notably, no clear effect of the Almería-Oran front, an important break in the Atlanto-Mediterranean transition, could be detected among the western basin populations, where only a slight differentiation of the two northernmost populations was found. Despite the generally low levels of genetic differentiation found, we identified candidate regions for local adaptation by combining different genomic analysis with environmental data. Salinity, rather than temperature, seemed to be an important driver of genetic structure in A. lixula. Overall, from a population genomics standpoint, there is ample scope for A. lixula to continue thriving and adapting in the warming Mediterranean. ; This research was funded by projects PopCOmics (CTM2017- 88080, funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe" of the European Union) and MarGeCh (PID2020-118550RB, funded by MCIN/AEI/10.13039/501100011033) from the Spanish Government. This is a contribution from the Consolidated Research Group "Benthic Biology and Ecology" SGR2017-1120 (Catalan Government). Some localities were sampled under the European FP7 CoCoNet project (Ocean 2011-4, Grant Agreement #287844). ; Peer reviewed

Este artículo contiene 17 páginas, 6 figuras, 2 tablas. ; Aim: The Atlanto-Mediterranean edible purple sea urchin, Paracentrotus lividus, is a commercially exploited keystone species in benthic communities. Its browsing activity can deeply modify the littoral landscape, and changes in its abundance are of major conservation concern. This species is facing nowadays contrasting anthropogenic pressures linked to predator release, exploitation and sea warming. Management of this key species requires knowledge of its genetic structure, connectivity and local adaptation. Our goal was to assess the current global status of the species under a genomic perspective. Location: Atlanto-Mediterranean shores from Morocco and France to Turkey. Methods: We used genotyping by sequencing (GBS) of 241 individuals belonging to 11 populations spanning the known range of distribution of the species. We obtained 3,348 loci for population genomics and outlier analyses. Results: We identified significant genetic structure and a gradient matching the longitudinal position of the localities. A hierarchical analysis revealed two main clusters (Atlantic and Mediterranean) and subtler patterns of differentiation within them. Candidate markers for selection identified between and within these two main clusters were mostly different, likely indicating different selective pressures. Adaptation to maximum salinity and maximum temperature appeared as an important driver of the transition between Atlantic and Mediterranean basins. Other stressors, such as minimum temperature or range of temperature, seem to define the structuring within the Mediterranean. Main conclusions: Our study shows the potential of hierarchical analyses on population genomics to detect fine-scale genetic structure and adaptation signatures in marine species with long dispersal capabilities. Although genetic interchange occurs widely in Paracentrotus lividus, the species is sensitive to dispersal barriers, displays isolation by distance and faces local selective pressures associated to environmental conditions, all of which can render it more vulnerable than previously thought. ; This work was supported by the Spanish Government projects ChallenGen CTM2013-48163 and PopCOmics CTM2017-88080 (MCIU, AEI/FEDER, UE). This is a contribution from the Consolidated Research Group "Benthic Biology and Ecology" SGR2017-1120 (Catalan Government). ; Peer reviewed