BMAR - Artigos em revistas internacionais
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Browsing BMAR - Artigos em revistas internacionais by Author "Almada, Vítor Carvalho"
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- Ex situ reproduction of Portuguese endangered cyprinids in the context of their conservationPublication . Santos, Carla Sousa; Gil, Fátima; Almada, Vítor CarvalhoInexistente
- Icelandic lampreys (Petromyzon marinus): Where do they come from?Publication . Pereira, Ana Martins; Jonsson, Benony; Johannsson, Magnus; Robalo, Joana Isabel; Almada, Vítor CarvalhoThe recent discovery of sea lamprey wounds on salmonids in Icelandic rivers prompted an investigation on the origin of sea lampreys in Icelandic waters. Using a mitochondrial DNA fragment, the origin of the lampreys examined was assigned to the European stock and not to the North American one.
- Phylogeography and demographic history of Atherina presbyter (Pisces: Atherinidae) in the North-eastern Atlantic based on mitochondrial DNAPublication . Francisco, Sara Martins; Castilho, Rita; Soares, Miguel; Congiu, Leonardo; Brito, Alberto; Vieira, Maria Natividade; Almada, Vítor CarvalhoA fragment of the mitochondrial control region was used to assess phylogeographic patterns and historical demography of the sand-smelt Atherina presbyter in the North-eastern Atlantic, covering its geographical range. A striking result is the highly marked diVerentiation between the Canary Islands population and western European ones. A genetic structure among European populations of A. presbyter was revealed, with a pattern of isolation-by-distance or a gradient eVect at a scale of hundreds kilometres, an uncommon pattern likely related to the biological and life-history traits of the sand-smelt. The northern European populations present a much lower genetic diversity when compared to southern populations, which is consistent with a recent colonization from southern populations. The results showed signs of Pleistocene signatures, with the population age estimates for the European populations being clearly older than the Last Glacial Maximum (18,000 years bp). Nevertheless, paleotemperature reconstructions show that the sand-smelt could not have inhabited the western European shores during the last glacial phase.
- Phylogeography of the shanny Lipophrys pholis (Pisces: Blenniidae) in the NE Atlantic records signs of major expansion event older than the last glaciationPublication . Francisco, Sara Martins; Faria, Cláudia Barreiros Macedo de; Lengkeek, W.; Vieira, Maria Natividade; Velasco, Eva Maria; Almada, Vítor CarvalhoThe study of the phylogeography of inshore fish from West Europe is revealing diverse geographical and demographical patterns. Some species conform to the phylogeographic patterns typical of terrestrial organisms, with marked signatures of the last glaciation and a decline of genetic diversity to the north of the species range. Other species, however, reveal no decline in diversity with latitude and signatures of expansions older than the last glaciation. The shanny Lipophrys pholis is a common intertidal resident fish in west European rocky shores. It is unable to leave the rocky stretch where it settled as a juvenile, so that dispersal depends entirely on the planktonic larval stage. These life-history and behavioural traits make the shanny an interesting species for phylogeographical analysis, as long-range movements by adults, which could blur historical signals, are absent. In this paper the phylogeography of L. pholis was studied using a fragment of the mitochondrial control region and one from the first intron of the S7 ribosomal protein gene. The European samples (ranging from SW Spain to the Netherlands) did not display population differentiation, isolation-by-distance or latitudinal declines in genetic diversity. Iberia was proposed as having operated as the main glacial refugium for the shanny. The genealogy of the European population showed that the largest expansion detected was older than the last glaciation, with lineages persisting from the early Pleistocene, which does not conform to colonisation by a few founders in the current interglacial. It is argued that if fishes have very large population sizes and high dispersal rates, populations can efficiently track climatic shifts so that little or no genetic structure remains after each range expansion and latitudinal gradients of genetic diversity tend to be weak or non-existent.
- A rapid and inexpensive molecular technique to discriminate the north-eastern Atlantic and Mediterranean Atherina species and its potential applications in ecology and larval identificationPublication . Almada, Vítor Carvalho; Francisco, Sara Martins; Rosa, Inês; Domingues, Vera dos Santos; Cabral, Henrique; Almada, Frederico José Oliveira de; Henriques, Miguel; Robalo, Joana IsabelThis note describes a rapid and inexpensive Restriction Fragment Length Polymorphism technique to discriminate all species of Atherina (Pisces: Atherinidae) of the north-eastern Atlantic and the Mediterranean. This technique is based on digestion of a fragment of the 12S ribosomal RNA (12SrRNA) gene region of mitochondrial DNA with restriction enzymes that recognize species-specific nucleotide sites. The three currently recognized species in the area, as well as two additional forms awaiting formal description, can be discriminated using a set of four endonucleases. We argue that this simple and fast technique may be of great help in the identification of young stages and in ecological surveys.
- Unexpected high genetic diversity at the extreme northern geographic limit of Taurulus bubalis (Euphrasen, 1786)Publication . Almada, Vítor Carvalho; Almada, Frederico José Oliveira de; Francisco, Sara Martins; Castilho, Rita; Robalo, Joana IsabelThe longspined bullhead (Taurulus bubalis, Euphrasen 1786) belongs to the family Cottidae and is a rocky shore species that inhabits the intertidal zones of the Eastern Atlantic since Iceland, southward to Portugal and also the North Sea and Baltic, northward to the Gulf of Finland, with some occurrences in the northern Mediterranean coasts eastward to the Gulf of Genoa. We analysed the phylogeographic patterns of this species using mitochondrial and nuclear markers in populations throughout most of its distributional range in west Europe. We found that T. bubalis has a relatively shallow genealogy with some differentiation between Atlantic and North Sea. Genetic diversity was homogeneous across all populations studied. The possibility of a glacial refugium near the North Sea is discussed. In many, but not all, marine temperate organisms, patterns of diversity are similar across the species range. If this phenomenon proves to be most common in cold adapted species, it may reflect the availability of glacial refugia not far from their present-day northern limits.