855 resultados para Carolus Linnaeus


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Sandy beaches of the Anapa Bay Bar are a unique natural resource, but they are gradually being degrade under both natural and anthropogenic factors. Emissions of sand and shelly ground from the adjacent sea bottom partly compensate for this process. Concentration of carbonates may reach up to 50% in beach sands, and most of these carbonates are of mollusk origin. The major deposit formation role belongs to the key bivalve species: Chamelea gallina (Linnaeus, 1758). Average biomass of this mollusk species reaches up to 450 g/m**2 at depths 5-10 m. The other two subdominating mollusk species, bivalve Donax trunculus (Linnaeus, 1758) and gastropod Rapana venosa (Valenciennes, 1846), may impact as 16 g/m**2 and 6 g/m**2, respectively. Annually, 350 kg of shelly ground per running meter are newly deposited on the Anapa beach.

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Cryploendolithic microbial communities in the Ross Desert (McMurdo Dry Valleys) are characterized on the basis of photosymlictic microorganisms and fungi. Two eukaryotic communities (the lichen-dominated and Hemichloris communities) and three cyanobacterial communities (the red Gloeocapsa, Hormathonema-Gloeocapsa and Chroococcidiopsis communities) are described. Eleven coccoid. ohne pleurocapsoid, and five filamentous cyanobacteria occurring in these communities are characterized and illustrated. The moisture grade of the rock substrate seems to affect pH. Formation of primary iron stain, and the distribution of microbial communities.

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Diversity of endolithic Dry Valley rock microorganisms was studied by evaluating the presence of morphotypes in enrichments. Storage of rock samples for 16 h over dry ice affected the diversity of endolithic organisms, especially that of algae and fungi. Diversity in various samples depended on rock location and exposure, on the rock type, and to some extent on the pH of the pulverized rock samples. In most cases sandstone contained more morphotypes than dolerite or granite. Presence of many different phototrophs resulted in greater diversity of the heterotrophs in the enrichments. Samples from Linnaeus Terrace and Battleship Promontory had higher morphotype (MT) numbers than those from more exposed sites such as New Mountain, University Valley, Dais, or Mt. Fleming. Beacon sandstone (13 samples) from Linnaeus Terrace varied greatly with respect to MT numbers, although the pH values ranged only from 4.2-5.3. The highest MT number of 24 per sample was obtained from the upper surface of a flat boulder tilted to the North. Only two MT's were found in a hard sandstone sample from the wind-exposed and more shaded east side of the Terrace. 15 sandstone samples from Battleship Promontory contained more diverse populations: there occurred a total of 131 different MT's in these samples as compared to only 68 in Linnaeus Terrace samples. Cysts of colorless flagellates were found in some Battleship Promontory samples; rnost samples were populated with a wealth of different cyanobacteria. Studies on the distribution of actinomycete morphotypes in Linnaeus Terrace sandstone revealed great differences between individual boulders. Identification tests and lipid analyses made with representative strains of the isolated 1500 pure cultures led to genus names such as Caulobacter, Blastobacter, Hyphomicrobium, Micrococcus, Arthrobacter, Brevibacterium, Corynebacterium, Bifidobacterium, Mycobacterium, Nocardia (Amycolata), Micromonospora, Streptomyces, Blastococcus, and Deinococcus. Our data demonstrate the great diversity of Antarctic endolithic microbial populations.

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Analogous to West- and North Africa, East Africa experienced more humid conditions between approximately 12 to 5 kyr BP, relative to today. While timing and extension of wet phases in the North and West are well constrained, this is not the case for the East African Humid Period. Here we present a record of benthic foraminiferal assemblages and sediment elemental compositions of a sediment core from the East African continental slope, in order to provide insight into the regional shallow Indian Ocean paleoceanography and East African climate history of the last 40 kyr. During glacial times, the dominance of a benthic foraminiferal assemblage characterized by Bulimina aculeata, suggests enhanced surface productivity and sustained flux of organic carbon to the sea floor. During Heinrich Stadial 1 (H1), the Nuttallides rugosus Assemblage indicates oligotrophic bottom water conditions and therefore implies a stronger flow of southern-sourced AAIW to the study site. During the East African Humid Period, the Saidovina karreriana Assemblage in combination with sedimentary C/N and Fe/Ca ratios suggest higher river runoff to the Indian Ocean, and hence more humid conditions in East Africa. Between 8.5 and 8.1 kyr, contemporaneous to the globally documented 8.2 kyr Event, a severe reduction in river deposits implies more arid conditions on the continent. Comparison of our marine data with terrestrial studies suggests that additional moisture from the Atlantic Ocean, delivered by an eastward migration of the Congo Air Boundary during that time period, could have contributed to East African rainfall. Since approximately 9 kyr, the gaining influence of the Millettiana millettii Assemblage indicates a redevelopment of the East African fringe reefs.

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In the Mediterranean Sea, infralittoral and circalittoral rocky bottoms (from 15 to 120 m) are characterized by a biogenic habitat, named "coralligenous", formed by the concretion of calcareous organisms, mainly algal thalli, and- to a lesser extent- by animal skeletons. This complex habitat is inhabited by a rich fauna that belongs to different taxonomic groups. Sponges, bryozoans, cnidarians and ascidians are the most common sessile organisms that inhabit the area while crustacean and molluscs are the common mobile organisms. Little information on the diversity of the molluscs that thrive in the coralligenous habitat is known while this information is highly important for biodiversity management purposes. After thoroughly studying the available and accessible published literature, a database for the molluscs of the coralligenous habitat has been designed and implemented for the collection and management of this information. From its index compilation more than 511 species of molluscs have been recorded so far from the coralligenous formations, the majority of which belongs to the class Gastropoda (357 sp.) followed by the Bivalvia (137 sp.), Polyplacophora (14 sp.), Cephalopoda (2 sp.) and Scaphopoda (1 sp.). Among these, the gastropod Luria lurida (Linnaeus, 1758) and Charonia lampas (Linnaeus, 1758), the endemic bivalve Pinna nobilis Linnaeus, 1758 and the endolithic bivalve Lithophaga lithophaga (Linnaeus, 1758), are protected by international conventions.

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Sign.: A4

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This paper provides data on diet and feeding habits of five benthic fish species (Torpedo torpedo (Linnaeus,1758), Mullus surmuletus (Linnaeus, 1758), Uranoscopus scaber (Linnaeus,1758), Scorpaena scrofa (Linnaeus,1758) and Synaptura lusitanica (Capello,1868)) common in the artisanal fisheries in the Cullera coast (Mediterranean sea – Spain) and T.torpedo, U.scaber y S. lusitánica feeding habits are almost unknown. T. torpedo preferred small preys like fishes, polychaetes and molluscs, these preys were feed in small portions. M. surmuletus showed the highest feeding dynamic, consuming small prey in large numbers like crustaceans (brachyura and amphypoda). U. scaber had similar feeding habits, but the numbers of preys in the stomach were lower. The principal preys were fishes, crustaceans, molluscs and polychaetes. S.scrofa ate larger prey items such as fish, followed by crustaceans and molluscs. Finally S. lusitánica had a high vacuity index, feeding polychaetes as the most important prey in their diet. Feeding strategy indicates a specialization of T.torpedo, S.scrofa and S. lusitanica; conversely M. surmuletus and U. scaber were generalized species.

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The aim of the present study is to identify and evaluate the relationship between Woodpigeon (Columba palumbus, Linnaeus, 1758) density and different environmental gradients (thermotype, ombrotype, continentality and latitudinal), land use and landscape structure, using geographic information systems and multivariate modelling. Transects (n = 396) were developed to estimate the density of Woodpigeon in the Marina Baja (Alicante, Spain) from 2006 to 2008. The highestdensity for Woodpigeon was in September-October (1.28birds/10ha) and the lowest inFebruary-March (0.34birds/10ha). Moreover, there were more Woodpigeons in areas with a mesomediterranean thermotypethan in thermomediterranean or supramediterranean ones. There was greater densityinthe intermediate zones compared to thecoast and interior. The natural or cultural landscape had the highest Woodpigeon density (1.53birds/10ha), with both denseand clear pine forest values standing out. Therefore, it is very important to conserve these traditional landscapes with adequate management strategies in order to maintain, resident and transient Woodpigeon populations. These natural areas are open places where the Woodpigeons find food and detect the presence ofpredators. Thus, this study will enable more precise knowledge of the ecological factors (habitat variables) that intervene in the distribution of Woodpigeon populations and their density.

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Este trabajo de investigación es pionero y original ya que nunca antes se ha realizado un estudio del tejón (Melesmeles) dentro del ámbito valenciano y más concretamente sobre la relación de su distribución con los factores geográficos que la condicionan en el Parque Natural Sierra de Mariola. Un mejor conocimiento de su ocupación en el espacio será de interés para la definición de medidas de gestión de fauna del Parque. En 2009, utilizando técnicas de fototrampeo se recopilaron 29.941 imágenes con algún contacto animal. De estas imágenes, el 0,16% de las fotografías registradas son de tejón y se ha detectado su presencia en 6 de las 63 cuadrículas (4 Km2) del Parque Natural Sierra de Mariola (9,38%). Este estudio ha permitido integrar la información recopilada en campo con las bases de datos existentes para concluir que la situación del tejón en Sierra de Mariola no es preocupante.