Origin and history of Phoxinus (Cyprinidae) introductions in the Douro basin (Iberian Peninsula): an update inferred from genetic data

The number of non-native freshwater fishes in the Iberian Peninsula has been greatly increasing. In this study, individuals of the genus Phoxinus were detected in 18 out of 138 stream sites sampled across the Douro Basin in 2017 and 2018. A total of 26 individuals were barcoded using partial cytochrome c oxidase subunit I (COI) and cytochrome b (cytb) genes for species identification and determination of geographical origin. Molecular data provided the first record of a second Phoxinus species in western Douro (Portugal, Iberian Peninsula), with haplotypes closely matching those found in the Charente River (southern France). This species is suspected to be a recent introduction associated with the use of minnows as live bait by freshwater anglers, which was facilitated by human movements between France and Portugal. Individuals from watercourses in eastern Douro (Spain) were genetically assigned to Phoxinus bigerri, an introduced species previously known for that region, which confirms reports of introduction events from Ebro to Douro Basin probably also related to freshwater angling and facilitated by geographic proximity. The potential ecological impacts of this genus in the region are unknown and need further investigation.We acknowledge Fernando Teixeira, Fernando Miranda, Mario Ferreira, Sara Carona, Jose Pedro RamiAo and Francisco Carvalho for the valuable assistance during fieldwork. We specially thank Maria Filomena MagalhAes for previous fruitful discussions and logistic support. We are grateful to Matthias F. Geiger and Andrea Corral Lou for facilitating genetic data and coordinates of sampling sites. Finally, we appreciate the comments of the three anonymous reviewers that improved the quality of the manuscript. AFF and AGR were supported by the project FRESHING founded by the Portuguese Foundation for Science and Technology (FCT) and COMPETE (PTDC/AAGMAA/2261/2014 - POCI-01-0145-FEDER-356016824). FMSM was supported by the FCT PhD grant SFRH/BD/104703/2014. This study was conducted as part of the projects FRESHING and FRESHCO. The latter is also supported by FCT and COMPETE (PTDC/AGR-FOR/1627/2014 - 04/SAICT/2015) and UID/AGR/04033/2019. Logistic support was also facilitated by the ENVMETAGEN - Capacity Building at InBIO for Research and Innovation Using Environmental Metagenomics project at CIBIO laboratories (668981; EUH2020-WIDESPREAD-2014-2)

South-North Labour Migration Within the Crisis-Affected European Union: New Patterns, New Contexts and New Challenges

peer reviewedDrawing on previous chapters and on available statistical data we identify the main features of the South-North migration. Firstly, we indicate that the intensity of the current South-North is relatively low if we take into account, on the one hand, the scale of the crisis-driven deterioration of the labour markets in southern countries and, on the other, the volume of the previous South-North migration in the post-war period. Secondly we show that new Southern European migrants are predominantly young and highly educated, particularly when compared with their counterparts, who migrated during the 1950s, 1960s and 1970s. We argue that, while the asymmetric impact of the economic crisis throughout the European Union and the unique features of the deeply fragmented labour markets of its Southern member countries may be considered primordial factors that triggered a renewed South-North intra-European mobility, its volume and composition are determined by the previous long term structural, demographic, social and economic transformations experienced by both Southern and Northern EU countries