Benigno Elvira

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Freshwater ecosystems are seriously imperiled by the spread of non-native fishes thus establishing profiles of their life-history characteristics is an emerging tool for developing conservation and management strategies. We did a first approach to determine characteristics of successful and failed non-native fishes in a Mediterranean-climate area, the(More)
Factors controlling brown trout Salmo trutta recruitment in Mediterranean areas are largely unknown, despite the relevance this may have for fisheries management. The effect of hydrological variability on survival of young brown trout was studied during seven consecutive years in five resident populations from the southern range of the species distribution.(More)
Hybrids of invasive bleak Alburnus alburnus and native endemic calandino Squalius alburnoides complex and Southern Iberian chub Squalius pyrenaicus were found in the River Jarama (Tagus River basin, central Spain). Morphological analyses show that hybrids are intermediate in shape between the parent species. Molecular mitochondrial and nuclear analyses(More)
Spatial variation in growth of stream-dwelling brown trout Salmo trutta was explored in 13 populations using a long-term study (1993-2004) in the Bay of Biscay drainage, northern Spain. The high variability in fork length (L(F)) of S. trutta in the study area was similar to the body-size range found in the entire European distribution of the species. Mean(More)
Anthropogenic environmental change is causing unprecedented rates of population extirpation and altering the setting of range limits for many species. Significant population declines may occur however before any reduction in range is observed. Determining and modelling the factors driving population size and trends is consequently critical to predict(More)
Common name: Skadarsko skobalj (Serbian). Njilë e Shkodrës (Albanian), Skadar nase (English). Conservation status: Extinct (EX; Crivelli 2005). Described from nine specimens caught 125 years ago, in spite of intensive investigations (P.G. Bianco in 1999 and J. Freyhof in 2003, pers.comm.), no specimens have since been recorded, so assumed Extinct (Reynolds(More)
Structure and composition of benthic macroinvertebrate assemblages were investigated during three consecutive years in six headwater streams that exhibit a high variation in environmental conditions, habitat structure and predatory pressure. We examined whether the abundance of functional feeding groups could be best predicted by the abundance of predators(More)
Common name: Loina (Spanish). Júcar Nase (English). Conservation status: Endangered (EN A1ae B1+2bcde, Spanish Red Data book, Doadrio 2002). Critically Endangered (CR A2ace; B2ab (i, ii, iii, iv, v), Crivelli 2005, Smith and Darwall 2006). Identification: D III + (7)8, A III + 8–10, V II + 8, P I + 14–15, pharyngeal teeth 6–5 or 5–5, LL 44–53, gill rakers(More)
Greg T. O. LeBreton, F. William H. Beamish & R. Scott McKinley (editors) 2004. Sturgeons and Paddlefish of North America. Kluwer, Dordrecht, 323 pp, US $86.00 (hardcover) Sturgeons and paddlefishes belong to an ancient group of vertebrates, the order Acipenseriformes, and are among the most valuable commercial fishes. They are anadromous or restricted to(More)
We used two different approaches involving two organizational levels and spatial scales to explore altitudinal and latitudinal variation in life histories of non-anadromous brown trout Salmo trutta. First, we studied the factors influencing the maturation of individuals from populations in northern Spain. Second, we explored the effects of altitude (range(More)