987 resultados para Freshwater fishes -- Iberian Peninsula


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Research surrounding the transition from II to I millennium cal BC in Eastern Iberian Peninsula has a large and extensive tradition of investigation. However, the chances to do research on this historical process have been limited by the lack of a well contextualized and dated stratigraphic sequence. For this reason, recent studies in this topic have followed the periodic proposals which were developed in closer regions and areas, especially in the South East and North East of the Peninsula. The investigation perspective about the Late Bronze in Eastern Iberian has however now improved, with the development of several archaeological investigations, the increase in the number of sites being dated and more recent studies into the region helping to bring about this change. As such, it is now in the correct state to be able to propose a new periodization and delve into the changes which occurred in the transition between 1500 and 725 cal BC.

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Three questions on the study of NO Iberian Peninsula sweat lodges are posed. First, the new sauna of Monte Ornedo (Cantabria), the review of the one of Armea (Ourense), and the Cantabrian pedra formosa type are discussed. Second, the known types of sweat lodges are reconsidered underlining the differences between the Cantabrian and the Douro - Minho groups as these differences contribute to a better assessment of the saunas located out of those territories, such as those of Monte Ornedo or Ulaca. Third, a richer record demands a more specific terminology, a larger use of archaeometric analysis and the application of landscape archaeology or art history methodologies. In this way the range of interpretation of the sweat lodges is opened, as an example an essay is proposed that digs on some already known proposals and suggests that the saunas are material metaphors of wombs whose rationale derives from ideologies and ritual practices of Indo-European tradition.

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The red deer (Cervus elaphus) is currently one of the most widespread and abundant wild ungulates in the Iberian Peninsula and is extremely important both ecologically, as a key species for the functioning of the ecosystems, and economically, as a major game species. In Iberia, red deer populations are subjected to different management systems that may affect the physical condition of the individuals, with further consequences for population dynamics. Studies investigating the effects of management practices and environmental conditions on the performance of red deer are still rare regarding Mediterranean ecosystems. Much of the knowledge concerning the ecology of red deer and the impact of management on its physical condition is based on studies conducted in northern and central regions of Europe, where climatological features and management practices differ from those observed in the Mediterranean areas of Iberia. Studies on a biogeographical scale can provide important insights into the relationships between species and a particular environment and contribute to the development of more targeted and appropriate management practices. The optimisation of sampling procedures and the fine-tuning of pre-existing analytical techniques are also fundamental to a more cost-effective monitoring and, therefore, are of enormous value to wildlife managers. In this context, the main aims of this thesis were: 1) to optimise the procedures used to assess the physical condition of red deer; and 2) to identify relevant management and environmental factors affecting the nutritional condition and stress physiology of red deer in the Mediterranean ecosystems of Iberia, as well as any potential interactions between those factors. Two studies with a methodological focus, presented in the first part of the thesis, demonstrated that the physical condition of red deer can be evaluated more simply, using more cost- and time-effective procedures than those traditionally used: i) it was shown that only one kidney and its associated fat is enough to assess nutritional condition in red deer; and ii) the feasibility of using near infrared spectroscopy to predict the concentrations of stress hormone metabolites was demonstrated using faeces of red deer for the first time. Subsequently, two large-scale observational studies, conducted in representative red deer populations found in Mediterranean Iberia, highlighted the importance of considering seasonal environmental variations and variables related to hunting management practices to better understand the nutritional and physiological ecology of red deer. High population densities had adverse effects on the nutritional condition of the deer and were associated with increased stress levels in natural populations without supplementary feeding. Massive hunting events involving the use of hounds were also identified as a potential source of chronic stress in red deer. The research presented in this thesis has clear implications regarding the management and monitoring of red deer populations in Mediterranean environments and is intended to help wildlife managers to implement more effective monitoring programmes and sustainable management practices.

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This booklet describes freshwater fishes found in South Carolina waters, giving information about the fish, its range, preferred habitat, food habits, size and other miscellaneous facts. It also has information on angler ethics, catch & release programs, fishing regulations and aquatic education programs.

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The European Nature Information System (EUNIS) has been implemented for the establishment of a marine European habitats inventory. Its hierarchical classification is defined and relies on environmental variables which primarily constrain biological communities (e.g. substrate types, sea energy level, depth and light penetration). The EUNIS habitat classification scheme relies on thresholds (e.g. fraction of light and energy) which are based on expert judgment or on the empirical analysis of the above environmental data. The present paper proposes to establish and validate an appropriate threshold for energy classes (high, moderate and low) and for subtidal biological zonation (infralittoral and circalittoral) suitable for EUNIS habitat classification of the Western Iberian coast. Kineticwave-induced energy and the fraction of photosynthetically available light exerted on the marine bottom were respectively assigned to the presence of kelp (Saccorhiza polyschides, Laminaria hyperborea and Laminaria ochroleuca) and seaweed species in general. Both data were statistically described, ordered fromthe largest to the smallest and percentile analyseswere independently performed. The threshold between infralittoral and circalittoral was based on the first quartile while the ‘moderate energy’ class was established between the 12.5 and 87.5 percentiles. To avoid data dependence on sampling locations and assess the confidence interval a bootstrap technique was applied. According to this analysis,more than 75% of seaweeds are present at locations where more than 3.65% of the surface light reaches the sea bottom. The range of energy levels estimated using S. polyschides data, indicate that on the IberianWest coast the ‘moderate energy’ areas are between 0.00303 and 0.04385 N/m2 of wave-induced energy. The lack of agreement between different studies in different regions of Europe suggests the need for more standardization in the future. However, the obtained thresholds in the present study will be very useful in the near future to implement and establish the Iberian EUNIS habitats inventory.

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In this work we used the information of the Annual Hunting Reports (AHRs) to obtain a high-resolution model of the potential favourableness for wild rabbit harvesting in Andalusia (southern Spain), using environmental and land-use variables as predictors. We analysed 32,134 AHRs from the period 1993/2001 reported by 6049 game estates to estimate the average hunting yields of wild rabbit in each Andalusian municipality (n5771). We modelled the favourableness for obtaining good hunting yields using stepwise logistic regression on a set of climatic, orographical, land use, and vegetation variables. The favourability equation was used to create a downscaled image representing the favourableness of obtaining good hunting yields for the wild rabbit in 161 km squares in Andalusia, using the Idrisi Image Calculator. The variables that affected hunting yields of wild rabbit were altitude, dry wood crops (mainly olive groves, almond groves, and vineyards), temperature, pasture, slope, and annual number of frost days. The 161 km squares with high favourableness values are scattered throughout the territory, which seems to be caused mainly by the effect of vegetation. Finally, we obtained quality categories for the territory by combining the probability values given by logistic regression with those of the environmental favourability function.

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We used the results of the Spanish Otter Survey of 1994–1996, a Geographic Information System and stepwise multiple logistic regression to model otter presence/absence data in the continental Spanish UTM 10 10-km squares. Geographic situation, indicators of human activity such as highways and major urban centers, and environmental variables related with productivity, water availability, altitude, and environmental energy were included in a logistic model that correctly classified about 73% of otter presences and absences. We extrapolated the model to the adjacent territory of Portugal, and increased the model’s spatial resolution by extrapolating it to 1 1-km squares in the whole Iberian Peninsula. The model turned out to be rather flexible, predicting, for instance, the species to be very restricted to the courses of rivers in some areas, and more widespread in others. This allowed us to determine areas where otter populations may be more vulnerable to habitat changes or harmful human interventions. # 2003 Elsevier Ltd. All rights reserved.

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The Late Variscan deformation event in Iberia, is characterized by an intraplate deformation regime induced by the oblique collision between Laurentia and Gondwan. This episode in Iberia is characterized by NNE-SSW strike-slip faults, which are considered by the classic works as sinistral strike-slips. However, the absence of Mesozoic formations constraining the age of this sinistral kinematics, led some authors to consider it as the result of Alpine reworking. Structural studies in Almograve and Ponta Ruiva sectors (SW Portugal), not only shows that NNE-SSW faults presents a clear sinistral kinematics and are occasionally associated with E-W dextral shears, but also that this kinematics is related to the late deformation episodes of Variscan Orogeny. In Almograve sector, the late Variscan structures are characterized by NNE-SSW sinistral kink-bands, spatially associated with E-W dextral faults. These structures are contemporaneous and affect the previously deformed Carboniferous units. The Ponta Ruiva Sector constrains the age of deformation because the E-W dextral shears affect the Late Carboniferous (late Moscovian) units, but not the overlying Triassic series. The new exposed data shows that the NNE-SSW and the E-W faults are dynamically associated and results from the same deformation event. The NNE-SSW sinistral faults could be considered as second order dominoes structures related with first order E-W dextral shears, related with Laurasia-Gondwana collision during Late Carboniferous-Permian Times.

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A climate study of the incidence of downward surface global solar radiation (SSRD) in the Iberian Peninsula (IP) based primarily on ERA-40 reanalysis is presented. NCEP/NCAR reanalysis and ground-based records from several Portuguese and Spanish stations have been also considered. The results showthat reanalysis can capture a similar inter-annual variability as compared to ground-based observations, especially on a monthly basis, even though annual ERA-40 (NCEP/NCAR) values tend to underestimate (overestimate) the observations with a mean relative difference of around 20Wm–2 (40Wm–2). On the other hand, ground-based measurements in Portuguese stations during the period 1964–1989 show a tendency to decrease until the mid-1970s followed by an increase up to the end of the study period, in line with the dimming/brightening phenomenon reported in the literature. Nevertheless, there are different temporal behaviours as a greater increase since the 1970s is observed in the south and less industrialized regions. Similarly, the ERA-40 reanalysis shows a noticeable decrease until the early 1970s followed by a slight increase up to the end of the 1990s, suggesting a dimming/brightening transition around the early 1970s, earlier in the south and centre and later in the north of the IP. Although there are slight differences in the magnitude of the trends as well as the turning year of the dimming/brightening periods, the decadal changes of ERA-40 fairly agree with the ground-based observations in Portugal and Spain, in contrast to most of the literature for other regions of the world, and is used in the climatology of the SSRD in the study area. NCEP/NCAR reanalysis does not capture the decadal variations of SSRD in the IP. The results show that part of the decadal variability of the global radiation in the IP is related to changes in cloud cover (represented in ERA-40).

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Describing the genetic patterns and the demographic history of expanding species is essential for providing insights into the processes linked with range dynamics. We analysed the mitochondrial diversity of the Egyptian mongoose (Herpestes ichneumon) across the Iberian Peninsula, where the species is currently expanding northwest. A total of 242 individuals were analysed, together with nine representatives from the North African dispersal source. Haplotype segregation and strong differentiation between Iberian and North African populations confirmed the longterm presence of the species in the Iberian Peninsula. The distribution of mitochondrial diversity fitted the pattern of a historically diversified population in southern Iberia, from which the recent dispersals into northern areas may have occurred. Higher levels of haplotype and nucleotide diversities in the northern areas, together with the heterogeneous distribution of pairwise population differentiations and the weak signal for isolationbydistance suggest the existence of longdispersal migrants across the Iberian Peninsula. Sudden and spatial expansion scenarios of H. ichneumon in the Iberian Peninsula were supported by mismatch analysis and marginally supported by neutrality tests. However, the precise time of occurrence of the detected expansion remains unclear. Future studies should incorporate additional markers in order to further clarify the population dynamics of the Egyptian mongoose in its Iberian range.

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In the last three decades, the range of the Egyptian mongoose (Herpestes ichneumon) has increased in the Iberian Peninsula. A panel of microsatellites was used to confront the patterns of genetic diversity of the species with the scenario of its recent northward expansion in its Iberian range. Evidence of substructure and significant genetic differentiation within the studied population were recorded, with a central-northern subpopulation (CNorth) and a southern subpopulation (S). Northward range expansion was supported by the observed allelic frequencies, diversity parameters, and observed heterozygosity of the studied loci, with S showing a higher allelic diversity and a higher number of private alleles than CNorth. Patterns of isolation-by-distance and isolation-by-barrier as a result of the Tagus River were demonstrated, suggesting that the river acted as a semi-permeable barrier, possibly leading to genetic differentiation of the studied population. The observed individuals from CNorth in southern locations and individuals from S in central/northern areas might comprise evidence for long range dispersals across the studied range. A bottleneck event after population expansion was supported by a significant heterozygosity deficiency in CNorth, which is in agreement with a scenario of founder events occurring in recently colonized areas after the crossing of the Tagus River.

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The thesis examines the technical aspects of unglazed molded ceramics from Mértola, in the context of Islamic archaeology of the Iberian Peninsula (Almohad period, end of 12th and the beginning of 13th century). Ceramics of the time period under discussion (12th – 13th century) are understudied, including in what concern to shaping and firing of ceramic vessels, the origin of raw materials used in ceramics and glazes, and decoration methods such as slip painting and/or colored glazes. Moreover, the use of archaeometry tools is rare. Along with providing a general picture of molded ceramic production in Mértola, this work provides a new dimension to the discipline of Islamic ceramic studies by the analytical tool used and demonstrating the importance of archaeological ceramics of the western peripheries to the understanding the production of ceramics and the transmission of knowledge and cultural traditions within the Islamic caliphate. The chemical and mineralogical characterization of 12th/13th century Almohad unglazed molded ware from Mértola was accomplished through multi – analytical approach combining SEM, Powder/uXRD and LA-ICP-MS methods. In this paper unglazed and glazed samples were analyzed but the attention was given to unglazed specimens, while the glazed samples were used for the comparison with the previous group in order to determine possible similarities or dissimilarities, thus providing enough data to discuss about technical aspects and potential provenance; Resumo: A tese debruça-se sobre os aspetos técnicos de cerâmica de molde não-vidrada de Mértola, no contexto da arqueologia islâmica da Península Ibérica (período Almóada, final de XII e início do século XIII). A cerâmica do período em discussão (séculos XII-XIII) é pouco estudada inclusive no que concerne ao fabrico e à cozedura, à de fonte de matérias-primas, na pasta ou nos esmaltes e aos métodos de decoração, como pintura, presença de engobes ou esmaltes. Além disso, o uso de ferramentas de Arqueometria é raro. Para fornecer uma visão geral da produção de cerâmica moldada em Mértola, este trabalho oferece uma nova dimensão para a disciplina de cerâmica islâmicas pelas ferramentas analíticas utilizadas. Demonstrando a importância da cerâmica arqueológica da periferia ocidental para a compreensão da produção cerâmica e a transmissão de conhecimentos e tradições culturais no califado islâmico. A caracterização mineralógica e química das cerâmicas de molde e não-vidrada, Almóada, dos séculos XII-XIII de Mértola foi realizada através de uma abordagem multi-analítica que combina métodos de SEM-EDS, uXRD e LA-ICP-MS. Neste trabalho, as cerâmicas vidradas e não-vidradas foram analisadas conjuntamente, dando mais atenção aos espécimes não vidrados. As amostras de cerâmicas vidradas foram utilizados para a comparação com o grupo anterior, a fim de determinar as possíveis semelhanças ou diferenças, proporcionando, assim, dados suficientes para discutir os aspetos técnicos e o potencial de proveniência das cerâmicas não vidradas

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Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives’ decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions

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Lake Banyoles is the second largest lake in the Iberian Peninsula and due to this relative uniqueness, its peculiar geological origin, and its considerable age attracted the early attention of the late Professor Ramon Margalef. One of the first papers by Margalef was on the biota of Lake Banyoles and two of the first four Ph.D. theses that he supervised were about the limnology of this lake. Unfortunately, the uniqueness of this lake also implied that it was the first place of introduction into the Iberian Peninsula of several exotic fish species, early in the XXth Century and nowadays the lake fish assemblage is dominated by invasive species, and some native ones have been extirpated. Although the limnological studies in Lake Banyoles were pioneering within the Iberian Peninsula, studies on fish ecology of the lake did not start until 1989. Thereafter, four Ph.D. theses have been completed on different aspects of the fish assemblages of Lake Banyoles. The aim of this paper is to provide a short overview of this research, largely brought about by the considerable limnological information previously available for this lake, thanks to the insightful, pioneering work of Professor Margalef

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After an ichthyofaunistic survey in several epigean (surface) water bodies of the Serra do Ramalho, southern Bahia, conducted in May 2007, 44 species were recorded; in addition, three non-troglomorphic (normally eyed and pigmented) and two troglomorphic species were recorded only in caves, totaling 49 species of fishes for the area, which represents a little more than one fourth of the total registered in the literature for the entire Rio São Francisco basin. In these caves, which have been studied since 2005, eight non-troglomorphic species were sampled and their presence in both epigean and subterranean habitats, associated to the lack of morphological differences, indicate that they may be either troglophiles (species encompassing individuals able to live and complete their life cycle either in the surface or in the subterranean environment), trogloxenes (individuals regularly found in subterranean habitats, but which must return periodically to the surface in order to complete their life cycle) or even accidental in caves. In addition, two troglomorphic species (with reduced eyes and melanic pigmentation when compared to close epigean relatives), belonging respectively to the genera Rhamdia and Trichomycterus, were recorded exclusively in caves, thus classified as troglobites. Interestingly, no epigean representative of the genus Trichomycterus was collected. The new data are integrated into updated lists of Brazilian troglobitic and troglophilic fishes, based on published data and new records recently confirmed.