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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Patterns of animal endemism in the Maputaland-Pondoland-Albany biodiversity hotspot.

Perera, Merennage Sandun Jayalal. 12 September 2014 (has links)
The Maputaland-Pondoland-Albany (MPA) hotspot, as is the case of all such global biodiversity hotspots, has primarily been recognised based on its high floristic endemism and delimited intuitively. Boundaries of global biodiversity hotspots have seldom been empirically tested in terms of species distribution patterns and only a few have been examined for patterns of animal endemism. This thesis presents the results of a zoogeographical study of all five major vertebrate groups and selected invertebrate groups in south-eastern Africa, refining the delimitation of the MPA hotspot and identifying areas and centres of endemism within and around it. It also provides zoogeographical regionalisation schemata for the whole of south-eastern Africa. The study employed methods of, (a) preliminary qualitative identification of “Endemic Vertebrate Distributions”, (b) phenetic clustering of operational geographical units based on species incidence matrices, using the Jaccard’s coefficient of similarity and the Unweighted Pair-Group Method using Arithmetic means (UPGMA) clustering algorithm, (c) Parsimony Analysis of Endemicity, and (d) ArcGIS-based mapping of various measures of endemism (e.g. narrow endemism and weighted endemism). The results reveal that the MPA hotspot, though defined so due to its exceptional floristic endemism, is a hotspot for the endemism of animals too, especially for the herpetofauna and invertebrate groups like the velvet worms, land snails and many others. But the current boundary of the hotspot is arbitrarily defined and not exactly matching the patterns of animal endemism (and, likely, neither those in plants). Hence, a greater Maputaland-Pondoland-Albany (GMPA) region of animal endemism is proposed as a broad priority region of conservation concern, while centres of endemism within the GMPA are identified and patterns of quantitative measures of endemism are mapped. The study also proposes a zoogeographical regionalisation placing the GMPA and Highveld regions at the province rank in the global zoogeographical hierarchy, within the south east African dominion, also describing zoogeographical districts and assemblages nested within each. Results from the vertebrate and invertebrate analyses reveals the possibility of a common zoogeographical regionalisation for south-eastern Africa. The study emphasises the importance of quantitative biogeographical methodologies in conservation biogeography, in addition to their uses in the theoretical/descriptive biogeography. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2013.
22

Effect of vegetation structure on breeding bird communities in the dry zone douglas fir forest of Southeastern British Columbia

Schwab, Francis Edward January 1979 (has links)
This thesis concerns a study into the relationship between vegetation structure and breeding birds in the dry subzone of the Interior Douglas fir BiogeocIimatic Zone. The study was conducted in the East Kootenay region of southeastern British Columbia. Studies of bird/habitat relationships often relate bird densities with successional vegetation; for management purposes it is convenient to view habitat alterations as changes from one successional stage to-another. Theoretical questions concerning the effect of succession and disturbance on species richness can be approached in this way. Also, there has been considerable interest in the effect of snags on bird density. An analysis of the effect of stumps and snags on bird density was incorporated into the study. Three questions guided the study: (1) What is the relationship between breeding birds and successional vegetation? (2) How is vegetation structure related to successional changes in bird species densities? (3) How does the number of stumps and snags affect the numbers of cavity nesting birds? There were two land management practices which altered the vegetation structure in the study area: selective logging and spring burning. This enabled me to determine the effects of these practices on breeding birds and to extend knowledge of the relationship between birds and vegetation structure. Twenty-four 300 yd by 400 yd (274 by 366 m) plots were established representing replications of each successional stage, transitions between successional stages, a selectively logged mature seral forest, a burned scrubby area, and a burned grassland/scrubby transition area. Bird data were recorded during fourteen, 20 minute visits to each plot in May and June of 1977. All birds detected by sight and sound were recorded during each visit to a plot. The vegetation data gathered on each plot included: estimates of the number of stumps and snags and estimates of crown coverage in each height zone of all species of grass, forb, shrub, and tree. The height zones recognized were 0-.5 m, .5-1 m, 1-10m, 10-24 m, and 24+ m. Multiple step-wise correlation was used to relate breeding bird densities with vegetation structure. Data from only the 25 most commonly recorded bird species were used to describe changes in the bird community with changes in vegetation succession. Results showed: (1) Bird species were non-randomly distributed with respect to successional stages. (2) Most successional stages support a unique compliment of bird species. (3) In general bird abundance was greater with greater successional age of a plot. However, dense stands of young conifer and climax Douglas fir forest had lower bird densities than the successional stages immediately preceding them. Mature serai ponderosa pine/Douglas fir forests had the highest bird densities. In some cases the bird densities on scrubby plots were comparable to the ponderosa pine/Douglas fir plots. (4) The relationship between bird species and vegetation structure is somewhat complex, but in general, visually obvious vegetation structures (i.e. height and coverage of grass, shrubs, and trees) are related to the presence of bird species. The species of trees and shrubs on a site can be used as an indicator of the bird species present. (5) The presence of cavity nesting birds was not closely linked with stumps and snags. Stumps and snags may not be a limiting resource. (6) The bird community on a grass dominated site which was burned in April 1977 was strikingly similar to that of another unburned grass dominated site. There were differences, among the bird communities on burned and unburned scrubby areas which were consistent with the recent fire history of the sites. (7) The selectively logged plot had numbers of bird species and bird species diversity similar to those of unlogged mature seral ponderosa pine/Douglas fir forest. The density of individual birds was lower on the logged plot than on the unlogged plots. Some bird species became more plentiful and others less plentiful as a result of the logging, but the bird community on the logged plot was composed of species associated with forested successional stages. A number of recommendations have been made for further study of East Kootenay bird/habitat interactions through a policy of experimental management. / Science, Faculty of / Zoology, Department of / Graduate
23

Intraspecific Phylogeography of the Least Brook Lamprey, (Lampetra aepyptera)

Martin, Holly Renee 18 April 2006 (has links)
No description available.
24

Systematic and zoogeographical characteristics of the oribatid mite fauna (Acari: Oribatida) of Vietnam

Vu, Quang Manh, Dao, Duy Trinh, Nguyen, Hai Tien, Nguyen, Huy Tri, Lai, Thu Hien, Ha, Tra My, Do, Thi Duyen 07 January 2019 (has links)
The article is a synthesis of the studies on oribatid mites carried out in Vietnam during the period of 1980-2013, and is based on the oribatid materials obtained throughout the country. The oribatid mite fauna (Acari: Oribatida) of Vietnam is diversified, and has high specialization. It is diverse by the number of superfamilies, families, genera and species recorded. However, the number of genera per family, as well as the number of species and subspecies per genus, is not high. 43.75% and 37.50% of the total 64 families and subfamilies consist of one and of 2-3 genera, respectively. The only one family Oppiidae Grandjean, 1954 consists of 23 genera. The majority of the genera, 68.10% of the total, are represented by one species. The only two genera are represented by more than 10 species, namely Galumna Heyden, 1826 and Pergalumna Grandjean, 1936, with 13 and 11 species, respectively. The main zoogeographical characteristics of the oribatid mite fauna of Vietnam are the Oriental species, representing 60.30% of the total number. It also includes the elements of the Palaearctic – Oriental (12.2%), the Cosmopolitan (10.6%), the Afrotropical (Ethiopical) – Oriental (6.9%), the Australian – Oriental (5.0%), the Neotropical – Oriental (3.8%), the Nearctic – Oriental (0.9%), and the Pacific - Oriental (0.3%). / Để đánh giá cấu trúc phân loại và đặc điểm địa động vật của khu hệ ve giáp Việt Nam (Acari: Oribatida), trên cơ sở mẫu vật nghiên cứu thu từ toàn lãnh thổ quốc gia, công trình đã tổng hợp và phân tích các kết quả nghiên cứu về ve giáp trong giai đoạn 1980-2013. Khu hệ động vật ve giáp Việt Nam có tính chuyên biệt cao, và rất đa dạng về số lượng họ, giống và loài xác định được. Tuy nhiên số lượng giống trong 1 họ, cũng như số lượng loài trong 1 giống lại không cao. 43,75% và 37,50% của 64 họ và phân họ, tương ứng chỉ xác định được có 2 và 3 giống. Duy nhất có họ Oppiidae Grandjean, 1954 ghi nhận được 23 giống. 68,10% tổng số giống, chỉ xác định được 1 loài. Duy nhất có 2 giống ghi nhận được hơn 10 loài, là Galumna Heyden, 1826 và Pergalumna Grandjean, 1936, tương ứng có 13 và 11 loài. Đặc điểm địa động vật cơ bản của khu hệ ve giáp Việt Nam là tính chất Đông phương (Oriental), với 60,30% tổng số loài xác định được. Tính chất địa động vật của nó còn bao gồm các yếu tố sau: Cổ bắc - Đông phương (Palaearctic-Oriental, 12,2% tổng số loài xác định được), Toàn cầu (Cosmopolite, 10,6%), Nhiệt đới Phi châu - Đông phương (Afrotropical (Ethiopical)-Oriental, 6,9%), Úc châu - Đông phương (Australian-Oriental, 5,0%), Tân nhiệt đới - Đông phương (Neotropical-Oriental, 3.8%), Vùng cực - Đông phương (Nearctic-Oriental, 0.9%), và Thái Bình Dương - Đông phương (Pacific-Oriental, 0,3%).
25

Tardigrada (Water Bears)

Bertolani, R., Altiero, T., Nelson, D. R. 01 January 2009 (has links)
The Tardigrada are hydrophilous, segmented, molting micrometazoans that occupy a diversity of niches in freshwater, marine, and terrestrial habitats. A sister group of the arthropods, this phylum of bilaterally symmetrical lobopods, most less than 1 mm in length, have a hemocoel, a complete digestive tract, a dorsal gonad with one or two gonoducts, and a dorsal lobed brain with a ventral nerve cord and five ganglia. About 1000 species have been described based on the morphology of sclerified structures, especially the claws and buccal-pharyngeal apparatus. Reproduction occurs through fertilized or unfertilized eggs, with individuals being either gonochoric, unisexual, or hermaphroditic, and eggs are deposited either freely or within the shed exuvium. Parthenogenesis, very frequent in limnic and terrestrial tardigrades, allows them to colonize new territories by passive dispersal of a single individual. Quiescence (cryptobiosis: anhydrobiosis, anoxybiosis, cryobiosis, and osmobiosis) and diapause (encystment and resting eggs) occur during the tardigrade life history. Ecological parameters and global distribution patterns are poorly known or understood. Methods for collection, microscopy, and culturing have been developed.
26

Révision taxonomique de la famille des Harrimaniidae (Hemichordata: Enteropneusta) incluant les descriptions de sept espèces de la côte Est du Pacifique

Deland, Carine 04 1900 (has links)
Cette étude comparative est une révision de la famille des Harrimaniidae basée sur les caractères morphologiques d'espèces connues et nouvelles provenant des collections de William E. Ritter, Theodore H. Bullock et Kandula P. Rao rassemblées au cours du 20e siècle. Les descriptions présentées ici portent le total des genres de cinq à neuf par l'ajout de Horstia n. gen., Mesoglossus n. gen., Ritteria n. gen et Saxipendium, un genre auparavant attribué à la famille monospécifique des Saxipendidae. Le nombre d'espèces est porté à 34 par la description de cinq nouvelles espèces du Pacifique oriental: Horstia kincaidi, Mesoglossus intermedius, Mesoglossus macginitiei, Protoglossus mackiei et Ritteria ambigua. La description d'une sixième espèce, Stereobalanus willeyi Ritter et Davis, 1904 (nomen nudum) est présentée ici pour la première fois, ainsi qu'une description abrégée de Saxipendium coronatum. Quatre espèces précédemment attribuées au genre Saccoglossus sont transférées au genre Mesoglossus: M. bournei, M. caraibicus, M. gurneyi, et M. pygmaeus et Saccoglossus borealis est transféré au genre Harrimania. Une hypothèse phylogénétique sur la famille des Harrimaniidae est émise, présentant l'évolution possible des caractères morphologiques au sein du groupe. Finalement, des notes sur la distribution géographique étendue mais discontinue de plusieurs espèces suggère que les entéropneustes auraient pu avoir une distribution ancienne continue et plus grande qui aurait été fragmentée par la suite. / This comparative study is a revision of the family Harrimaniidae based on morphological characters of described and undescribed species from the collections of William E. Ritter, Theodore H. Bullock and Kandula P. Rao, gathered in the 20th century. The new descriptions bring the total number of genera to nine by the addition of Horstia n. gen., Mesoglossus n. gen., Ritteria n. gen and Saxipendium, a genus previously assigned to the monospecific family Saxipendidae The number of species is increased to 34, resulting from the description of five new species from the eastern Pacific: Horstia kincaidi, Mesoglossus intermedius, Mesoglossus macginitiei, Protoglossus mackiei and Ritteria ambigua. The description of a sixth species, Stereobalanus willeyi Ritter et Davis, 1904 (nomen nudum) is presented here for the first time and a brief description of Saxipendium coronatum is also presented. Four species previously assigned to the genus Saccoglossus are transfered to the genus Mesoglossus: M. bournei, M. caraibicus, M. gurneyi, and M. pygmaeus, while Saccoglossus borealis is transfered to the genus Harrimania. A phylogenetic hypothesis on the Harrimaniidae is postulated presenting the possible evolution of morphological characters within the group. Finally, notes on the wide but spotty distribution of several species suggest that the Enteropneusta may have once had a wider distribution that has since become fragmented.
27

Révision taxonomique de la famille des Harrimaniidae (Hemichordata: Enteropneusta) incluant les descriptions de sept espèces de la côte Est du Pacifique

Deland, Carine 04 1900 (has links)
Cette étude comparative est une révision de la famille des Harrimaniidae basée sur les caractères morphologiques d'espèces connues et nouvelles provenant des collections de William E. Ritter, Theodore H. Bullock et Kandula P. Rao rassemblées au cours du 20e siècle. Les descriptions présentées ici portent le total des genres de cinq à neuf par l'ajout de Horstia n. gen., Mesoglossus n. gen., Ritteria n. gen et Saxipendium, un genre auparavant attribué à la famille monospécifique des Saxipendidae. Le nombre d'espèces est porté à 34 par la description de cinq nouvelles espèces du Pacifique oriental: Horstia kincaidi, Mesoglossus intermedius, Mesoglossus macginitiei, Protoglossus mackiei et Ritteria ambigua. La description d'une sixième espèce, Stereobalanus willeyi Ritter et Davis, 1904 (nomen nudum) est présentée ici pour la première fois, ainsi qu'une description abrégée de Saxipendium coronatum. Quatre espèces précédemment attribuées au genre Saccoglossus sont transférées au genre Mesoglossus: M. bournei, M. caraibicus, M. gurneyi, et M. pygmaeus et Saccoglossus borealis est transféré au genre Harrimania. Une hypothèse phylogénétique sur la famille des Harrimaniidae est émise, présentant l'évolution possible des caractères morphologiques au sein du groupe. Finalement, des notes sur la distribution géographique étendue mais discontinue de plusieurs espèces suggère que les entéropneustes auraient pu avoir une distribution ancienne continue et plus grande qui aurait été fragmentée par la suite. / This comparative study is a revision of the family Harrimaniidae based on morphological characters of described and undescribed species from the collections of William E. Ritter, Theodore H. Bullock and Kandula P. Rao, gathered in the 20th century. The new descriptions bring the total number of genera to nine by the addition of Horstia n. gen., Mesoglossus n. gen., Ritteria n. gen and Saxipendium, a genus previously assigned to the monospecific family Saxipendidae The number of species is increased to 34, resulting from the description of five new species from the eastern Pacific: Horstia kincaidi, Mesoglossus intermedius, Mesoglossus macginitiei, Protoglossus mackiei and Ritteria ambigua. The description of a sixth species, Stereobalanus willeyi Ritter et Davis, 1904 (nomen nudum) is presented here for the first time and a brief description of Saxipendium coronatum is also presented. Four species previously assigned to the genus Saccoglossus are transfered to the genus Mesoglossus: M. bournei, M. caraibicus, M. gurneyi, and M. pygmaeus, while Saccoglossus borealis is transfered to the genus Harrimania. A phylogenetic hypothesis on the Harrimaniidae is postulated presenting the possible evolution of morphological characters within the group. Finally, notes on the wide but spotty distribution of several species suggest that the Enteropneusta may have once had a wider distribution that has since become fragmented.
28

The Genus Milnesium (Tardigrada: Eutardigrada: Milnesiidae) in the Great Smoky Mountains National Park (North Carolina and Tennessee, USA), With the Description of Milnesium Bohleberi sp. Nov.

Bartels, Paul J., Nelson, Diane R., Kaczmarek, Łukasz, Michalczyk, Łukasz 30 June 2014 (has links)
For many decades the genus Milnesium was thought to consist of a single, cosmopolitan species: Milnesium tardigradum Doyere, 1840. However, recently the genus has been re-evaluated, and numerous new species have been described. Cur-rently, over twenty extant species and one fossil are recognised, and most appear to have very narrow geographic ranges. It is doubtful that M. tardigradum sensu stricto is truly cosmopolitan, but to evaluate this hypothesis, specimens previously identified as M. tardigradum must be re-examined using newly proposed taxonomic characters. As part of the All Taxa Biodiversity Inventory (ATBI) we collected Milnesium specimens from various locations in the Great Smoky Mountains National Park (GSMNP). Two Milnesium species have been evaluated, and one of them, Milnesium bohleberi sp. nov., is new to science. The new species is most similar to M. eurystomum but differs by shorter claws and a shorter, narrower, and more cylindrical buccal tube. The other Milnesium species, very rare in our collection, is morphologically indistin-guishable from Milnesium granulatum Ramazzotti 1962, which was previously known only from Chile, Italy and Roma-nia. Based on the recently revised description of M. tardigradum sensu stricto, this nominal species for the genus has not been found in the GSMNP samples.
29

Exploring Levels of Genetic Variation in the Freshwater Mussel Genus Villosa (Bivalvia Unionidae) at Different Spatial and Systematic Scales: Implications for Biogeography, Taxonomy, and Conservation

Kuehnl, Kody F. 29 September 2009 (has links)
No description available.
30

Invent?rio das esp?cies de peixes da costa do Estado do Rio Grande do Norte e aspectos zoogeogr?ficos da ictiofauna recifal do Oceano Atl?ntico

Garcia J?nior, Jos? 04 May 2006 (has links)
Made available in DSpace on 2014-12-17T14:02:05Z (GMT). No. of bitstreams: 1 JoseGJ.pdf: 808378 bytes, checksum: 5bcac6baa0f225c071f882f6f3c2b442 (MD5) Previous issue date: 2006-05-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / We present a checklist of the shores fishes of the coast of the Rio Grande do Norte state. Species were registered through the specimens collection, underwater records, samples in landings of artisanal fleet and by compilation of data from literature and ichthyologic collections, between January 2004 to 2006. A total of 440 species form 2 classes, 25 orders, 106 families and 253 genus were registered. It is believed that due the great increase of the number of species registered, the ichthyofauna of the coast of this state is reasonably known / Considerando a reconhecida import?ncia envolvendo o conhecimento acerca da biodiversidade, o objetivo do presente trabalho foi realizar um invent?rio detalhado das esp?cies de peixes presentes na costa do Estado do Rio Grande do Norte. As esp?cies foram assinaladas atrav?s da coleta de exemplares, registros fotogr?ficos, acompanhamentos dos desembarques da frota pesqueira artesanal, consulta ?s bases de dados de cole??es cient?ficas e registros de literatura, durante o per?odo de janeiro de 2004 a janeiro de 2006. Foi registrada a ocorr?ncia de 2 classes, 25 ordens, 106 fam?lias, 253 g?neros e 440 esp?cies de peixes. Acredita-se que devido o grande aumento no n?mero de esp?cies registradas na costa do Estado do Rio Grande do Norte, sua ictiofauna encontra-se razoavelmente conhecida

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