Browsing by Author "Almeida, Pedro R."
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- Influence of macrohabitat preferences on the distribution of European brook and river lampreys: Implications for conservation and managementPublication . Ferreira, Ana F.; Quintella, Bernardo R.; Maia, Carla; Alexandre, Carlos S.; Capinha, Cesar; Almeida, Pedro R.The European river lamprey, Lampetra fluviatilis (L.), and the European brook lamprey, Lampetra planeri (Bloch, 1784), are considered highly threatened in Portugal. However, the lack of information about the ecology and distribution of these species poses difficulties to the identification of concrete actions directed to their conservation. A total of 401 sampling sites, randomly distributed throughout the entire Portuguese mainland territory were selected, and Lampetra sp. ammocoetes presence or absence checked with electrofishing. These data, together with 11 macrohabitat predictors, were analyzed using Boosted Regression Trees (BRTs). The BRT models consistently identified five environmental variables as the most important for predicting the distribution of European brook and river lamprey ammocoetes: altitude, distance to coast, sand, maximum temperature of the warmest month and precipitation of the driest month. The relationships of these variables with the species probability of occurrence suggest that lampreys occur in low altitude river stretches (<170 m), relatively close to the coast (<150 km) and with a sandy substrate (>70% sand). In addition, intermediate values of temperature and precipitation were also found to have a positive correlation with the species occurrence. A map with the probability of occurrence of Lampetra sp. in Portugal was generated and stretches of rivers were delimited with different conservation priorities. Rivers classified with the highest level of conservation priority were considered to be proposed as Special Areas of Conservation, under the Natura 2000 Networking Programme.
- Seascape genomics reveals limited dispersal and suggests spatially varying selection among European populations of sea lamprey (Petromyzon marinus)Publication . Baltazar-Soares, Miguel; Britton, Robert; Pinder, Adrian; Harrison, Andrew J; Nunn, Andrew; Quintella, Bernardo R.; Mateus, Catarina; Bolland, Jonathan D.; Dodd, Jamie R.; Almeida, Pedro R.; Almela, Victoria Dominguez; Andreou, DemetraSea lamprey Petromyzon marinus is an anadromous and semelparous fish without homing behaviors. Despite being a freshwater, free-living organism for a large part of their life cycle, its adulthood is spent as a parasite of marine vertebrates. In their native European range, while it is well-established that sea lampreys comprise a single nearly-panmictic population, few studies have further explored the evolutionary history of natural populations. Here, we performed the first genome-wide characterization of sea lamprey's genetic diversity in their European natural range. The objectives were to investigate the connectivity among river basins and explore evolutionary processes mediating dispersal during the marine phase, with the sequencing of 186 individuals from 8 locations spanning the North Eastern Atlantic coast and the North Sea with double-digest RAD-sequencing, obtaining a total of 30,910 bi-allelic SNPs. Population genetic analyses reinforced the existence of a single metapopulation encompassing freshwater spawning sites within the North Eastern Atlantic and the North Sea, though the prevalence of private alleles at northern latitudes suggested some limits to the species' dispersal. Seascape genomics suggested a scenario where oxygen concentration and river runoffs impose spatially varying selection across their distribution range. Exploring associations with the abundance of potential hosts further suggested that hake and cod could also impose selective pressures, although the nature of such putative biotic interactions was unresolved. Overall, the identification of adaptive seascapes in a panmictic anadromous species could contribute to conservation practices by providing information for restoration activities to mitigate local extinctions on freshwater sites.