Thesis (M.S.) in Ecology and Environmental Science--University of Maine, 2006. / Includes vita. Includes bibliographical references (leaves 55-60).

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-04-10T16:27:42Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2012-Dissertação-MarcoAntonioSantos.pdf: 3331059 bytes, checksum: 5771c8bf3db4a1328356c57da9a193b0 (MD5) / Made available in DSpace on 2017-04-10T16:27:42Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2012-Dissertação-MarcoAntonioSantos.pdf: 3331059 bytes, checksum: 5771c8bf3db4a1328356c57da9a193b0 (MD5) Previous issue date: 2012-08-06 / Os Arthropoda formam o grupo animal mais abundante e diverso na terra, com mais de um milhão de espécies descritas, apresentando extrema importância econômica, ambiental e médica. Devido a grande diversidade e antiguidade do grupo, inúmeras hipóteses para explicar a história evolutiva dos Arthropoda foram sugeridas ao longo dos anos. No entanto, as relações entre e dentro dos quatro principais grupos do filo (Crustacea, Hexapoda, Myriapoda e Chelicerata) permanecem como uma das grandes questões em aberto na sistemática. Neste contexto, o genoma mitocondrial representa uma importante fonte de informação para a reconstrução filogenética de um grupo taxonômico tão diverso. Assim, esse trabalho teve como objetivo elucidar as relações filogeneticas do filo Arthropoda a partir dos genomas mitocondriais, completamente sequenciados e disponíveis em bancos de dados públicos, utilizando diferentes abordagens computacionais. As análises dos genomas mitocondriais sugerem, com altos valores de suporte, o monofilétismo dos grupos Pancrustacea (Hexapoda + Crustacea) eMandibulata (Pancrustacea + Myriapoda)indicando que o grupoirmãodos demais Arthropodaé Chelicerata. Além disso, a utilização da entropia de Shannon se mostrou altamente eficiente na seleção de regiões filogeneticamente informativas, sendo mais efetivaque outros métodos utilizados tradicionalmente na análise de genomas mitocondriais. A entropia também se mostrou como ótima fonte de informações para seleção de regiões conservadas destinadas à determinação de iniciadores degenerados para a amplificação de regiões homólogas. Esse trabalho representa um importante passo para a elucidação da história filogenética do filo Arthropoda. / Arthropodaare the most abundantand diverseanimal group on earth, with overa milliondescribed species.They havevery importanteconomicand medical, environmental. Giventhe great diversityand seniorityof the group,severalhypotheses to explainthe evolutionary history ofArthropodahave been suggestedover the years. The relationships between and within these four major lineagesof the phylum(Crustacea, Hexapoda,MyriapodaandChelicerata) lineages remain one of the most contentious issues in systematics.The mitochondrial genomerepresentsanimportant sourceof information forphylogeneticreconstructionsof ataxonomic groupas diverse. Thus, thisstudy aimed toelucidate thephylogeneticsrelationshipsof the phylumArthropodaby usethecompletelysequenced andavailable mitochondrial genomesinpublic databases, using differentcomputational approaches. Analyses ofmitochondrial genomessuggestwith high values supportthemonophyly ofgroupsPancrustacea(Hexapoda+Crustacea)and Mandibulata(Pancrustacea +Myriapoda)indicating that Chelicerata is sistergroupof otherArthropoda. Furthermore, the use of Shannon's entropyprovedhighly effectivein the selection ofphylogeneticallyinformativeregions. Shannon's entropy was more effective than other methods traditionally usedin the analysis ofmitochondrial genomes. The entropy alsos howed likegreat sourceof information forselection ofconserved regionsto determination ofdegenerate primers. Thiswork represents an important step to elucidate thephylogenetics historyof the phylum Arthropoda.

Aquatic arthropods communities were examined with respect to factors determining species distributions and community structure in a series of eight lakes on the Chilcotin Plateau of British Columbia. Climate, altitude, physical location, water temperature and basin shape were similar for all lakes, and although size differed, no evidence was found for the influence of basin morphology on community structure. Salinity and vegetation characteristics differed widely among lakes, so three major processes were investigated: the association of (1) salinity with faunal communities, (2) salinity with floral communities, and (3) faunal with floral communities. These relationships were examined in light of diversity-stability hypotheses. The severity component of environmental stability was represented by salinity, and mean surface water conductivity ranged from 56 to 13115 μS cm-¹ at 25 °C. Salinity variations among lakes were determined primarily by the ions Na, HCO₃, CO₃, C1 and K. Two classification schemes (taxonomic and ecological) and several analytical techniques (community parameters and cluster analysis) indicated that the distribution and structure of faunal and floral communities were related to salinity. In total, 84 arthropod taxa and 26 macrophyte species were found and divided into three groups: those characteristic of high salinities (>5000 μS), of moderate or low salinities (<5000 μS), or tolerant of all salinities. Faunal assemblages in all lakes were dominated by filter feeders, and predators were more abundant in saline lakes. Shredders, collectors and predators were found in all the lakes, but saline lakes had fewer size groups. Floating leaved macrophytes occurred only in freshwater lakes, submerged forms were rare in highly saline lakes, and emergent forms were found in all lakes, although they were less abundant at high salinities. Generally, this study supports the hypothesis that saline habitats have less diverse communities than freshwater ones. In all floral and faunal sample sets, increased salinity was accompanied by a decrease in species richness. Virtually all measures of macrophyte community diversity and productivity were inversely correlated with salinity. Faunal subgroups must be examined separately when measures of community structure incorporate relative abundances. Patterns of association observed in the entire faunal community were dictated by the numerically dominant entomostracan subcommunity, and patterns in other subgroups were masked. Zooplankton trophic level diversity increased with decreasing salinity and changes in community composition were analogous to those of eutrophication. In both coleopteran and hemipteran communities, diversity decreased and density increased with increasing salinity. Possible causal mechanisms structuring each community are hypothesized. Faunal distributions corresponded to their known habitat preferences in terms of macrophyte communities. It was difficult to distinguish between the influence of salinity or macrophyte communities on animal communities as animal communities were often associated with both. / Science, Faculty of / Zoology, Department of / Graduate

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No description available.

Se estudió la ostracofauna recuperada en diversos sitios del estuario de Bahía Blanca con el objetivo de utilizar sus resultados a modo de análogos modernos y asi poder interpretar con mayor precisión los muestreos realizados en ambientes de edad Holoceno. Con este fin se analizaron sedimentos actuales provenientes de las planicies intermareales ubicadas en varios sectores del estuario de Bahía Blanca caracterizados por el tipo de vegetación dominante. Se muestrearon planicies vecinas al Club Almirante Brown y desembocadura del Canal Maldonado en la porción interior, desembocadura del Canal Tres Brazas y Villa del Mar en la porción intermedia, y en la planicie intermareal vecina a Puerto Rosales en el sector más externo del estuario. En las cubetas salinas o salt pan se registró la asociación de Cyprideis salebrosa hartmanni y Callistocythere litoralensis; los canales de marea se caracterizaron por presentar a C. salebrosa hartmanni como única especie; en las marismas la asociación de Neocytherideis ruidis y Loxocythere variasculpta, la asociación de Cyprideis salebrosa y Callistocytere litoralensis con poblaciones poco abundantes y la asociación de Callistocythere litoralensis; en las planicies de marea se reconoció la asociación de C. s. hartmanni y C. litoralensis. En los sedimentos actuales del intermareal bajo y medio de Puerto Rosales se encuentran los ostrácodos mixohalinos C. s. hartmani, Cyprideis multidentata y Leptocythere darwini; mixo-euhalinos Neocytherideis ruidis, Loxocythere variasculpta y Callistocythere litoralensis; y las especies euhalinas Cornucoquimba lutziana y Oculocyteroptheron escobasensis, éstas últimas sólo están presentes en el intermareal inferior. En el intermareal superior sólo se registra la especie eurihalina C. s. hartmanni debido a la prolongada exposición aérea. Por otro lado, se estudiaron tres testigos de edad holocena a los que se le realizaron dataciones radiocarbónicas sobre fango orgánico, las cuales fueron calibradas a edades calendario. En el testigo PD24, con una edad radiocarbónica cal. 8.045-8.319 años A.P. en la base, se determinó un ambiente de planicie de marea; mientras que hacia el techo, con una edad cal. de 7.623-7.836 años A.P., se observa una progradación del área con sedimentos que, si bien son intermareales, presentan frecuente exposición aérea. En el testigo KP60Bis el estudio sedimentológico y micropaleontológico permitió reconocer antiguas planicies de marea en su porción inferior y media, datadas en cal. 6.672-6.952 años A.P. y cal. 2.019-2.332 años A.P., respectivamente. En sedimentos de la base del testigo TB datados en cal. 5.662-5.907 años A.P. se pudo determinar un ambiente costero mareal con marismas, mientras que hacia niveles superiores, a partir de los cal. 4.647- 4.234 años A.P., se registra un aumento notable en la energía ambiental que indicaría una profundización del ambiente, posiblemente como consecuencia de un ascenso en el nivel medio del mar (NMM). En el sector superior de este testigo se evidenció una mayor influencia de aguas continentales que indicarían un mejoramiento climático. Mediante el estudio de estos testigos se aporta nueva información que sustenta la hipótesis que indica que durante el Holoceno habrían ocurrido al menos tres oscilaciones del NMM, originados por una ciclicidad de la actividad solar con un período de aproximadamente 2.400 años. / The ostracofauna present in different sites around the Bahía Blanca estuary was studied to use these results as a modern analogous to interpret more accurately the environments of the samplings from Holocene age. For this purpose, sediments were analyzed from the intertidal flats located in various sites of the Bahía Blanca estuary characterized by dominant vegetation type: plains near the Club Almirante Brown and mouth of the Canal Maldonado in the inner portion, mouth of the Canal Tres Brazas and Villa del Mar in the intermediate portion, and the adjacent tidal flat to Puerto Rosales on the external sector of the estuary. In the salt pan the association of Cyprideis salebrosa hartmanni and Callistocythere litoralensis was found; tidal channels were characterized by C. salebrosa hartmanni as a single species; in marshes the association of Neocytherideis ruidis and Loxocythere variasculpta, the association of Callistocytere litoralensis and Cyprideis salebrosa hartmanni with low population, and the association of Callistocythere litoralensis; on the tidal flats the association of C. salebrosa hartmanni and C. litoralensis was found. In the current low and half intertidal sediments of Puerto Rosales are the mixohalinos ostracods C. s. hartmani, Cyprideis multidentata and Leptocythere Darwini are found; mixo-euhalinos Neocytherideis ruidis, Loxocythere variasculpta and Callistocythere litoralensis; and the euhaline species Cornucoquimba lutziana and Oculocyteroptheron escobasensis, the latter are only present in the lower intertidal. In the upper intertidal only the eurihaline species C. s. hartmanni is recorded due to prolonged air exposure. Tree cores from Holocene age were studied, radiocarbon dates were performed on organic mud, which were calibrated to calendar ages. In PD24 core with a radiocarbon age of cal. 8.045-8.319 years B.P. on based a tidal flat environment was determined; towards the top with an age of cal. 7.623-7.836 years B.P., one progradation area is observed with sediments that although intertidal, have frequent air exposure. In the core KP60Bis sedimentological and micropaleontological studies permitted to recognize an old tidal flats in the lower and middle levels of the core, dated to cal. 6.672-6.952 years B.P. and 2.019-2.332 years B.P., respectively. In sediments from the base of the core TB dated to cal. 5.662-5.907 years BP could be determined a tidal coastal environment with marsh. In top levels from the cal. 4.647- 4.234 years B.P., a marked increase in environment energy could indicate a deepening of the environment following a rise in middle sea level MSL recorded. In the upper area, a greater influence of fresh waters was evident, indicating an environment improvement. Through the study of these cores new information is provided that supports the hypothesis that during the Holocene, at least three swings in MSL and the origin of a cycle with a period of about 2.400 years of solar activity have ocurred.

Dissertation (PhD)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Within arthropods, inter-individual and inter-population variation is generally poorly explored for physiological parameters. Such physiological variability is important, as it can provide insight into the capacity for evolutionary adaptation and how animals may cope with anthropogenic climate change. Insect vectors of human and animal diseases, such as tsetse flies (Diptera, Glossinidae) which carry trypanosomes, are of particular interest. Predictions of tsetse fly (Glossina spp.) range expansion, possibly paralleled by increased disease occurrence, have been made under future climate scenarios. Moreover, since there are generally strong relationships between abiotic variables (e.g. temperature and moisture availability), population dynamics, distribution and abundance, determining the physiological mechanisms influencing such relationships has utility for predictive modelling of spatial and temporal changes in tsetse fly distributions. I investigated physiological variation among individuals and populations, focusing mainly on Glossina spp. but using other arthropods to address certain issues. Specifically, I show the following: i) metabolic rate is repeatable (intra-class correlation coefficient) within individuals, and may be influenced by several factors such as age, gender, body mass and pregnancy; ii) while metabolic rate is repeatable within individuals, it remains unaltered with acclimation to laboratory conditions from field collection; iii) within a population, metabolic rate-temperature relationships are surprisingly invariant among physiological states such as age, gender, feeding status, pregnancy and temperature acclimation; iv) the magnitude of the effect of temperature acclimation differs among traits, in that upper thermal tolerances respond less than lower thermal tolerances, while metabolic rate responds to heat but not to cold. Water loss rate is relatively unresponsive to either treatment; v) plasticity can account for most inter-population variation in physiological traits related to climatic stress resistance (e.g. thermotolerances and desiccation rates) in the natural environment; vi) adult physiological performance responds differently to developmental and adult acclimation, such that marked traitspecific variation occurs, and combinations of both developmental and adult plasticity can result in further alteration of adult performance. These results have implications for the evolution of stress resistance to abiotic factors in these and other arthropods. I conclude by discussing the potential physiological patterns linking population dynamics and abiotic factors, with particular reference to tsetse flies. / AFRIKAANSE OPSOMMING: Binne arthropoda, is tussen-individu en tussen-bevolking variasie in die algemeen sleg bestudeer vir fisiologiese parameters. Hierdie fisiologiese variasie is belangrik want dit kan insig gee in die mate van evolusionêre aanpassing en hoe diere antropogenies klimaatsverandering kan hanteer. Dit is veral belangrik in die geval van insekte wat mens- en diersiektes kan dra, soos tsetse vlieë (Diptera, Glossinidae) wat trypanosome oordra. In die geval van tsetse vlieë (Glossina spp.) is voorspellings vir verhoogde verspreiding, en gevolglik verhoogde siekte voorkoms, gemaak onder toekomstige voorkoms klimaat senario’s. Verder, aangesien daar in die algemeen sterk verwantskappe tussen abiotiese parameters (bv. temperatuur en water beskikbaarheid), bevolkingsdynamika, verspreiding en voorkoms is, is die bepaling van die fisiologiese meganisme, wat ‘n invloed het op hierdie verwantskappe, nuttig vir die voorspelling van tsetse oor spasie en tyd. Hier, met hoofsaaklik die gebruik van Glossina spp., maar ook ander arthropoda wanneer dit nodig is, word navorsing wat fisiologiese variasie tussen individue en bevolkings aanspreel voorgelê. Spesifiek, word dit gewys dat i) metaboliese tempo is herhaalbaar (intra-klas korrelasie koeffisient) binne individue, alhowel metaboliese tempo kan beinvloed word deur faktore soos ouderdom, geslag, liggaamsmassa en swangerskap, ii) terwyl metaboliese tempo binne individue herhaalbaar is, verander dit nie met akklimasie na laboratorium toestande vanaf versameling in die veld, iii) binne ‘n bevolking metaboliese tempo-temperatuur verwantskappe is verbasend eenders tussen fisiologiese toestande soos ouderdom, geslag, voeding staat, swangerskap en temperatuur akklimasie, iv) die grootte van die effek van temperatuur akklimasie verskil tussen eienskappe, en die boonste termiese limiete reageer minder as laer termiese limiete, terwyl metaboliese tempo reageer op hitte maar nie koue nie, en waterverlies tempo is relatief terughoudend tot enige temperatuur toestand, v) buigbaarheid kan die meeste van inter-bevolkingsvariasie in fisiologiese eienskappe van klimaatstres weerstandsvermoë (termiese toleransie en uitdrogingstempo) in die natuurlike omgewing verklaar, vi) volwasse fisiologiese prestasie reageer verskillend op ontwikkelende en volwasse akklimasie, soveel dat eienskap-spesifieke variasie kan voorkom, en ‘n kombinasie van beide ontwikkelende en volwasse buigbaarheid ‘n verskillende volwasse prestasie tot gevolg kan hê. Hierdie resultate het implikasies vir die evolusie van weerstandsvermoë tot abiotiese faktore in hierdie en ander arthropoda. Hierdie tesis word afgesluit met ‘n bespreeking van die moontlikke fisiologiese patrone wat bevolkingsdinamika en abiotiese faktore kan verbind, met ‘n fokus op tsetse vlieë.

Lipases hidrolisam triacilgliceróis a glicerol e ácidos graxos. Neste trabalho foram estudadas as lipases digestivas no mosquito Aedes aegypti (larva e adulto) e no carrapato Amblyomma cajennense, vetores de Dengue e da Febre Maculosa. As lipases estudadas pertencem a família das lipases neutras, são estáveis em ampla faixa de pH e em altas temperaturas. Estas enzimas apresentam maior eficiência hidrolítica sobre substratos de cadeias carbônicas curtas (butirato e heptanoato). As lipases digestivas nas duas fases de desenvolvimento do mosquito são distintas cinéticamente. O estudo combinado do genoma de Ae. aegypti e PCR comprovaram a expressão diferencial destas enzimas constituintes de uma família multigênica envolvida na expressão de lipases digestivas provavelmente reguladas pela dieta. / Lipases hidrolyse triacylglycerol to glycerol and fat acids. In the present work we studied the digestive lipases from Aedes aegypti (larvae and adults) and Amblyomma cajennense. Studied lipases belong to the neutral lipase family, stable in a large range of pH and to high temperatures. These enzymes have a higher catalytic efficiency upon short substrates like butyrate and heptanoate. The digestive lipases from both larval and adult mosquitoes are kinetically distinct. Combined study of Ae.aegypti genome and PCR showed the differential expression of lipases which belong to a multigenic family of enzymes probably regulated by diet.

Lipases hidrolisam triacilgliceróis a glicerol e ácidos graxos. Neste trabalho foram estudadas as lipases digestivas no mosquito Aedes aegypti (larva e adulto) e no carrapato Amblyomma cajennense, vetores de Dengue e da Febre Maculosa. As lipases estudadas pertencem a família das lipases neutras, são estáveis em ampla faixa de pH e em altas temperaturas. Estas enzimas apresentam maior eficiência hidrolítica sobre substratos de cadeias carbônicas curtas (butirato e heptanoato). As lipases digestivas nas duas fases de desenvolvimento do mosquito são distintas cinéticamente. O estudo combinado do genoma de Ae. aegypti e PCR comprovaram a expressão diferencial destas enzimas constituintes de uma família multigênica envolvida na expressão de lipases digestivas provavelmente reguladas pela dieta. / Lipases hidrolyse triacylglycerol to glycerol and fat acids. In the present work we studied the digestive lipases from Aedes aegypti (larvae and adults) and Amblyomma cajennense. Studied lipases belong to the neutral lipase family, stable in a large range of pH and to high temperatures. These enzymes have a higher catalytic efficiency upon short substrates like butyrate and heptanoate. The digestive lipases from both larval and adult mosquitoes are kinetically distinct. Combined study of Ae.aegypti genome and PCR showed the differential expression of lipases which belong to a multigenic family of enzymes probably regulated by diet.

Arthropods typically show two types of segmentation: the embryonic parasegments and the adult segments that lie out of register with each other. Such a dual nature of body segmentation has not been described from Onychophora, one of the closest arthropod relatives. Hence, it is unclear whether onychophorans have segments, parasegments, or both, and which of these features was present in the last common ancestor of Onychophora and Arthropoda. To address this issue, we analysed the expression patterns of the "segment polarity genes" engrailed, cubitus interruptus, wingless and hedgehog in embryos of the onychophoran Euperipatoides rowelli. Our data revealed that these genes are expressed in repeated sets with a specific anterior-to-posterior order along the body in embryos of E. rowelli. In contrast to arthropods, the expression occurs after the segmental boundaries have formed. Moreover, the initial segmental furrow retains its position within the engrailed domain throughout development, whereas no new furrow is formed posterior to this domain. This suggests that no re-segmentation of the embryo occurs in E. rowelli. Irrespective of whether or not there is a morphological or genetic manifestation of parasegments in Onychophora, our data clearly show that parasegments, even if present, cannot be regarded as the initial metameric units of the onychophoran embryo, because the expression of key genes that define the parasegmental boundaries in arthropods occurs after the segmental boundaries have formed. This is in contrast to arthropods, in which parasegments rather than segments are the initial metameric units of the embryo. Our data further revealed that the expression patterns of "segment polarity genes" correspond to organogenesis rather than segment formation. This is in line with the concept of segmentation as a result of concerted evolution of individual periodic structures rather than with the interpretation of \"segments\" as holistic units.