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This scarce antiquarian book is a selection from Kessinger Publishing's Legacy Reprint Series. Due to its age, it may contain imperfections such as marks, notations, marginalia and flawed pages. Because we believe this work is culturally important, we have made it available as part of our commitment to protecting, preserving, and promoting the world's literature. Kessinger Publishing is the place to find hundreds of thousands of rare and hard-to-find books with something of interest for everyone! ... Read more

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Kapitel: Marrella, Isoxys, Aaveqaspis Inesoni, Acanthomeridion Serratum, Guangweicaris, Arthropleura, Megalothorax Sanctistephani, Misszhouia, Euarthropoda, Podura Aquatica, Collembola, Diplura, Tracheata, Isotoma Saltans, Hexapoda, Protura, Isotoma Nivalis, Trilobita. Aus Wikipedia. Nicht dargestellt. Auszug: An arthropod is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages. Arthropods are members of the Phylum Arthropoda (from Greek ἄρθρον arthron, "joint", and ποδός podos "foot", which together mean "jointed feet"), and include the insects, arachnids, crustaceans, and others. Arthropods are characterized by their jointed limbs and cuticles, which are mainly made of α-chitin; the cuticles of crustaceans are also biomineralized with calcium carbonate. The rigid cuticle inhibits growth, so arthropods replace it periodically by molting. The arthropod body plan consists of repeated segments, each with a pair of appendages. It is so versatile that they have been compared to Swiss Army knives, and it has enabled them to become the most species-rich members of all ecological guilds in most environments. They have over a million described species, making up more than 80% of all described living species, and are one of only two animal groups that are really successful in dry environments - the other being the amniotes. They range in size from microscopic plankton up to forms a few meters long. Arthropods' primary internal cavity is a hemocoel, which accommodates their internal organs and through which their blood circulates; they have open circulatory systems. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. Their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, and their brain...http://booksllc.net/?l=de ... Read more

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This digital document is a journal article from European Journal of Soil Biology, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

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The Pampa region is the most important agricultural area in Argentina. Although intensive agricultural activity is leading to important levels of soil degradation, studies on the impact on soil fauna are scarce. Despite the environmental importance of collembolans, symphylans and pauropods in soil, information on the influence of land management on their population densities is poor, particularly in Neotropical agroecosystems. The aim of this study was to investigate the effects of different management systems on the density of collembolans, symphylans and pauropods. Population abundance of these arthropods was examined in a natural site and a cattle raising, a mixed and an agricultural management system on a Typic Hapludoll soil in La Colacha, Cordoba, Argentina. All the sites studied had the same land use history until approximately 50 years before sampling and have the same soil type. Total abundance of the studied groups varied in the different management systems. Our results suggest that conventional agricultural management tends to reduce the density of collembolans and pauropods. Our data do not support our hypothesis that the cattle raising management system constitutes an intermediate situation between the natural site and the high-input management systems. We conclude that the reduction of collembolan and pauropod densities in high-input management systems is largely explained by the mechanical and chemical perturbations produced by conventional agricultural management practices and by particular abiotic soil conditions present in the intensively managed sites that are unfavourable for these organisms. Surprisingly, symphylans were more abundant in the mixed management site. The implications of our findings on soil ecosystem functioning are discussed. ... Read more

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This digital document is an article from Macmillan Reference USA Science Library: Animal Sciences, brought to you by Gale®, a part of Cengage Learning, a world leader in e-research and educational publishing for libraries, schools and businesses.The length of the article is 2714 words.The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase.You can view it with any web browser.This interdisciplinary resource explores the wide-ranging diversity that exists within the animal kingdom. Entries examine how animals develop, animal ecology and behavior, and the connection between animals and humans. Also includes biographies of key scientists who have contributed to the study of animal life, as well as career opportunities within the field. ... Read more