Orientador: Ana Maria Lima de Azeredo Espin / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-23T10:46:46Z (GMT). No. of bitstreams: 1 Lopes_AlbertoMouraMendes_M.pdf: 2739543 bytes, checksum: 13578f8ab684d7f2c1af2020305008a8 (MD5) Previous issue date: 2013 / Resumo: O Brasil possui o maior rebanho bovino comercial do mundo, sendo este um dos setores de geração de renda mais importantes para o país. As infestações por ecto e endoparasitas estão entre os principais problemas que levam à diminuição da produtividade. Dentre eles, a Cochliomyia hominivorax (Coquerel), conhecida como mosca-da-bicheira, destaca-se como uma das principais causadoras de miíases, gerando prejuízos de aproximadamente US$ 1,7 bilhões/ano ao país. Produtos sistêmicos como as lactonas macrocíclicas/macrolactonas, ativadoras, dentre outros, do canal de cloreto (GLUCL?), vêm sendo utilizados intensivamente como medida preventiva e de tratamento nas infestações por C. hominivorax e diversos parasitas, e a intensa/prolongada utilização das lactonas macrocíclicas tem levado ao surgimento da resistência a tais produtos. A identificação dos mecanismos moleculares da resistência às lactonas macrocíclicas em outras espécies indica a ocorrência de possíveis alterações no canal de cloreto associados à resistência em C. hominivorax. Utilizando-se de sequências do canal de cloreto de outras espécies, previamente depositadas no banco de dados, além de sequências obtidas na caracterização do transcriptoma de C. hominivorax, o objetivo deste projeto é amplificar e sequenciar a região codificante do gene da subunidade desse canal de cloreto dependente de L-glutamato (GluCl?) em C. hominivorax. Além disso, serão comparadas as sequências de indivíduos resistentes e suscetíveis às macrolactonas visando à identificação da(s) mutação (ões) que confere(m) resistência a tais produtos e, consequentemente, o diagnóstico molecular da resistência / Abstract: Brazil has the largest commercial cattle herd in the world, being one of the most important sectors of income generation for the country. Infestations by ecto- and endo parasites are among the major problems that lead to low productivity. Among them, the Cochliomyia hominivorax (Coquerel), known as the New World Screwworm fly, stands out as a major cause of myiasis, resulting in losses of approximately US$ 1.7 billion each year to the country. Systemic products such as macrocyclic lactones/macrolactones (MLs), mainly the MLs member ivermectin, have been extensively used as a preventive measure and treatment in infestations by C. hominivorax and various parasites, and the intense/prolonged use of macrocyclic lactones have led to the emergence of resistance to such products. The macrolactones target-sites are the cys-loop ligand-gated ion channels receptors, specially the glutamate-gated chloride channel subunit (GLUCL?). The identification of the molecular mechanisms of macrocyclic lactones resistance in other species indicates that possible alterations in chloride channels and GLYR? and nAchR?7 are associated with macrolactones resistance in C. hominivorax. Using the glutamate-gated chloride channel subunit sequences from other species, previously deposited in the database, and sequences obtained in the characterization of the transcriptome of C. hominivorax, the aim of this project was to amplify and sequence the coding region of the glutamate-gated chloride channel subunit gene (GluCl?) in C. hominivorax. In addition, sequences will be compared among putative ivermectin resistant and susceptible individuals in order to identify mutation(s) conferring resistance to such product and thereby the molecular diagnosis of resistance / Mestrado / Genetica Animal e Evolução / Mestre em Genética e Biologia Molecular

Orientador: Arício Xavier Linhares / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T01:31:06Z (GMT). No. of bitstreams: 1 Fernandes_FernandaRodrigues_D.pdf: 1975248 bytes, checksum: d23780751c399131a44ca6f88c69adb5 (MD5) Previous issue date: 2011 / Resumo: Parasitismo é considerado uma interação interespecífica antagonística, em que uma espécie (parasito) vive dentro ou sobre outra espécie (hospedeiro), obtendo dela parte de, ou todos seus nutrientes e em geral, causa algum grau de injúria à espécie hospedeira. Por um processo coevolutivo, os artrópodes parasitos desenvolveram mecanismos para aumentar sua aptidão explorando seus hospedeiros mamíferos, por outro lado, estes se esforçam para maximizar sua própria aptidão, minimizando o efeito negativo da infestação por parasitos. Devido muitos padrões da ecologia dos parasitos estarem intimamente ligados à ecologia do hospedeiro, o presente trabalho teve como objetivo investigar a influência do sexo, tamanho corporal e local de ocorrência dos hospedeiros na abundância de ectoparasitos, bem como, a influência da filogenia e sobreposição geográfica dos hospedeiros na similaridade de fauna de ectoparasitos. Os principais resultados obtidos foram: 1. A abundância de ectoparasitos Anoplura em Oligoryzomys nigripes é influenciada pelo sexo e local de ocorrência do hospedeiro; 2. A abundância de ectoparasitos Acari (Mesostigmata) em Oligoryzomys nigripes é influenciada pela massa corporal do hospedeiro; 3. As similaridades das faunas de ectoparasitos estão correlacionadas com a filogenia dos hospedeiros / Abstract: Parasitism is considered an antagonistic interspecific interaction where one species (the parasite) lives in or on another species (the host) obtaining part of or all of its nutrients and normally causing some degree of injury to the host. Through the coevolutionary process, arthropod parasites have developed mechanisms to increase their fitness by exploiting their mammalian hosts, on the other hand, the hosts strive to maximize its own fitness by minimizing negative effects of infestation by parasites. Because many patterns of parasite ecology is intimately related to the ecology of the host, this study aimed to investigate the influence of host sex, body size and locality in ectoparasite abundance, as well as, the influence of phylogeny and geographical overlap of the hosts in ectoparasite fauna similarity. The main results are: 1. The abundance of Anoplura ectoparasites on Oligoryzomys nigripes is influenced by host sex and locality; 2. The abundance of Acari (Mesostigmata) ectoparasites on Oligoryzomys nigripes is influenced by host body mass; 3. The similarities of ectoparasite fauna is correlated with host phylogeny / Doutorado / Doutor em Ecologia

No description available.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-08T11:37:07Z No. of bitstreams: 1 2010 - Rodney kozlowiski de Azevedo.pdf: 3579688 bytes, checksum: 3baae7dd721eab10e68db71bdf0e32da (MD5) / Made available in DSpace on 2016-08-08T11:37:07Z (GMT). No. of bitstreams: 1 2010 - Rodney kozlowiski de Azevedo.pdf: 3579688 bytes, checksum: 3baae7dd721eab10e68db71bdf0e32da (MD5) Previous issue date: 2010-02-26 / Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ, FAPERJ. / The Guandu River is the most important source of water supply for the municipality of Rio de Janeiro and Baixada Fluminense. It is characterized as the river system that has the greatest diversity of fish and the largest biomass of the Basin of the Sepetiba Bay. From April 2003 to September 2009 786 fish specimens, belonging to 21 species from the Guandu River, near the dam of water treatment station (WTS) (22? 48' 32"S, 43? 37'35"W), State of Rio de Janeiro, were collected and analyzed to study the biodiversity of their metazoan parasites, considering the strategic importance of this river in the State of Rio de Janeiro. Seventy percent of the fish were parasitized by at least one metazoan parasite. Of the parasites found 55% were endoparasites and 45% were ectoparasites. A total of 81 parasite species were found, belonging to nine groups: Acanthocephala, Cestoda, Crustacea, Digenea, Hirudinea, Mollusca, Monogenea, Myxozoa and Nematoda. The monogeneans had higher species richness and the metacercariae and nematode larvae had the lowest host specificity. The results of this study indicate that the parasite communities of fishes from Guandu River were characterized by low richness and evenness, isolationist communities and higher values of taxonomic diversity in species of omnivorous fish and in species that forming schools. In this study were made 38 new host records and 25 new locality records, demonstrating the biological diversity of Guandu River. / O Rio Guandu ? a mais importante fonte de abastecimento de ?gua para o munic?pio do Rio de Janeiro e parte da Baixada Fluminense. Caracteriza-se como o sistema fluvial que det?m a maior diversidade de peixes e a maior biomassa da bacia hidrogr?fica da Ba?a de Sepetiba. Entre o per?odo de abril de 2003 a setembro de 2009 foram coletados e analisados 786 esp?cimes de peixes, pertencentes a 21 esp?cies, provenientes do rio Guandu, pr?ximo ? barragem da Esta??o de tratamento de ?gua (ETA) (22?48?32?S, 43?37?35?W), Estado do Rio de Janeiro, com o objetivo de estudar a biodiversidade dos seus metazo?rios parasitos. Setenta por cento dos peixes estava infectado/infestado por pelo menos uma esp?cie de metazo?rio parasito. Do total de parasitos encontrados 55% foram endoparasitos e 45% foram ectoparasitos. Um total de 81 esp?cies de parasitos foi encontrado, pertencentes a nove grupos: Acanthocephala, Cestoda, Crustacea, Digenea, Hirudinea, Mollusca, Monogenea, Myxozoa e Nematoda. Os monogen?ticos apresentaram maior riqueza de esp?cies e as metacerc?rias e as larvas de nemat?ides apresentaram a mais baixa especificidade parasit?ria. Os resultados obtidos no presente trabalho indicam que as comunidades parasit?rias dos peixes do rio Guandu foram caracterizadas pela baixa riqueza e equitabilidade, por comunidades isolacionistas e pelos maiores valores de diversidade taxon?mica nas esp?cies de peixes on?voros e que formam cardumes. No presente estudo foram feitos 38 novos registros de hospedeiro e 25 novos registros de localidade, o que demonstrou a diversidade biol?gica do rio Guandu

Immune genes of the major histocompatibility complex (MHC) constitute a central component of the adaptive immune system and play an essential role in parasite resistance and associated life-history strategies. In addition to pathogen-mediated selection also sexual selection mechanisms have been identified as the main drivers of the typically-observed high levels of polymorphism in functionally important parts of the MHC. The recognition of the individual MHC constitution is presumed to be mediated through olfactory cues. Indeed, MHC genes are in physical linkage with olfactory receptor genes and alter the individual body odour. Moreover, they are expressed on sperm and trophoplast cells. Thus, MHC-mediated sexual selection processes might not only act in direct mate choice decisions, but also through cryptic processes during reproduction. Bats (Chiroptera) represent the second largest mammalian order and have been identified as important vectors of newly emerging infectious diseases affecting humans and wildlife. In addition, they are interesting study subjects in evolutionary ecology in the context of olfactory communication, mate choice and associated fitness benefits. Thus, it is surprising that Chiroptera belong to the least studied mammalian taxa in terms of their MHC evolution. In my doctoral thesis I aimed to gain insights in the evolution and diversity pattern of functional MHC genes in some of the major New World bat families by establishing species-specific primers through genome-walking into unknown flanking parts of familiar sites. Further, I took a free-ranging population of the lesser bulldog bat (Noctilio albiventris) in Panama as an example to understand the functional importance of the individual MHC constitution in parasite resistance and reproduction as well as the possible underlying selective forces shaping the observed diversity. My studies indicated that the typical MHC characteristics observed in other mammalian orders, like evidence for balancing and positive selection as well as recombination and gene conversion events, are also present in bats shaping their MHC diversity. I found a wide range of copy number variation of expressed DRB loci in the investigated species. In Saccopteryx bilineata, a species with a highly developed olfactory communication system, I found an exceptionally high number of MHC loci duplications generating high levels of variability at the individual level, which has never been described for any other mammalian species so far. My studies included for the first time phylogenetic relationships of MHC genes in bats and I found signs for a family-specific independent mode of evolution of duplicated genes, regardless whether the highly variable exon 2 (coding for the antigen binding region of the molecule) or more conserved exons (3, 4; encoding protein stabilizing parts) were considered indicating a monophyletic origin of duplicated loci within families. This result questions the general assumed pattern of MHC evolution in mammals where duplicated genes of different families usually cluster together suggesting that duplication occurred before speciation took place, which implies a trans-species mode of evolution. However, I found a trans-species mode of evolution within genera (Noctilio, Myotis) based on exon 2 signified by an intermingled clustering of DRB alleles. The gained knowledge on MHC sequence evolution in major New World bat families will facilitate future MHC investigations in this order. In the N. albiventris study population, the single expressed MHC class II DRB gene showed high sequence polymorphism, moderate allelic variability and high levels of population-wide heterozygosity. Whereas demographic processes had minor relevance in shaping the diversity pattern, I found clear evidence for parasite-mediated selection. This was evident by historical positive Darwinian selection maintaining diversity in the functionally important antigen binding sites, and by specific MHC alleles which were associated with low and high ectoparasite burden according to predictions of the ‘frequency dependent selection hypothesis’. Parasite resistance has been suggested to play an important role in mediating costly life history trade-offs leading to e.g. MHC- mediated benefits in sexual selection. The ‘good genes model’ predicts that males with a genetically well-adapted immune system in defending harmful parasites have the ability to allocate more resources to reproductive effort. I found support for this prediction since non-reproductive adult N. albiventris males carried more often an allele associated with high parasite loads, which differentiated them genetically from reproductively active males as well as from subadults, indicating a reduced transmission of this allele in subsequent generations. In addition, they suffered from increased ectoparasite burden which presumably reduced resources to invest in reproduction. Another sign for sexual selection was the observation of gender-specific difference in heterozygosity, with females showing lower levels of heterozygosity than males. This signifies that the sexes differ in their selection pressures, presumably through MHC-mediated molecular processes during reproduction resulting in a male specific heterozygosity advantage. My data make clear that parasite-mediated selection and sexual selection are interactive and operate together to form diversity at the MHC. Furthermore, my thesis is one of the rare studies contributing to fill the gap between MHC-mediated effects on co-evolutionary processes in parasite-host-interactions and on aspects of life-history evolution. / Innerhalb des adaptiven Immunsystems spielen die Gene des MHC (Major Histocompatibility Complex) eine zentrale Rolle. Neben ihrer Funktion für die körpereigene Parasitenabwehr haben sie auch einen entscheidenden Einfluss auf damit verbundene ‚life-history’ Strategien. Typischerweise sind die funktional für die Pathogenerkennung wichtigen Genabschnitte hoch variabel, was evolutiv nicht nur durch die Vielfalt der Pathogene bedingt ist, sondern im Zuge der sexuellen Selektion durch entsprechende Partnerwahl gefördert wird. Dabei wird die individuelle MHC-Konstitution sehr wahrscheinlich über körpereigene Duftstoffe vermittelt, denn MHC Gene bestimmen nicht nur den individuellen Körpergeruch, sondern liegen in chromosomaler Kopplung mit olfaktorischen Rezeptorgenen. Außerdem werden sie auch auf Sperma- und Trophoplastenzellen exprimiert, so dass MHC-bedingte sexuelle Selektionsmechanismen nicht nur über die direkte Partnerwahl, sondern auch durch kryptische Mechanismen während der Fortpflanzung wirken können. Fledermäuse und Flughunde (Chiroptera) bilden die zweitgrößte Säugetiergruppe und gelten als wichtiges Reservoir und Überträger für den Menschen und andere Wildtiere hoch infektiöser Krankheiten. Innerhalb der evolutionären Ökologie sind sie außerdem auf Grund ihrer z.T. komplexen olfaktorischen Kommunikation während der Partner-wahl und den damit verbundenen fitness relevanten Vorteilen interessante Forschungsobjekte. In Anbetracht dessen ist es erstaunlich, dass bisher so gut wie nichts über den MHC in dieser Säugergruppe bekannt ist. Das Ziel meiner Dissertation war es, zum einen Einblicke in die Evolution und Diversität funktional wichtiger MHC Gene (MHC Klasse II DRB) bei Fledermäusen zu erhalten, und zum anderen zu untersuchen, inwieweit die individuelle MHC-Konstitution am Beispiel der kleinen Hasenmaulfledermaus (Noctilio albiventris) einen Einfluss auf Parasitenresistenz und Fortpflanzung hat und welche Selektionsmechanismen dabei für das entstandene genetische Diversitätsmuster verantwortlich sind. Meine Arbeit zeigt, dass Prozesse, die bei anderen Vertebratenordnungen das Diversitätsmuster am MHC hervorrufen, wie balancierende und positive Selektion, Rekombination und Genkonversion ebenfalls für Fledermäuse zutreffen. In der Anzahl exprimierter DRB loci unterscheiden sich die untersuchten Fledermausarten allerdings beträchtlich. Bemerkenswert ist die extrem hohe Anzahl DRB loci bei Saccopteryx bilineata, die in dieser Ausprägung noch bei keiner anderen Säugetierart beschrieben wurde, einer Fledermaus mit einem hoch entwickelten olfaktorischen Kommunikations-system. Die hier erstmals durchgeführten phylogenetischen Untersuchungen zeigen, dass sich anders als für die meisten anderen Säugetiergruppen beschrieben, die duplizierten DRB Loci unabhängig voneinander entwickelt haben. Dieser mono-phyletische Ursprung duplizierter Loci innerhalb von Fledermausfamilien bestätigte sich für alle Bereiche des Genes: dem hochvariablen Exon 2, das für den funktional entscheidenden Pathogen-bindenden Bereich des Proteins kodiert, sowie für Exon 3 und 4, die für die Molekülstruktur erhaltende Bereiche des Proteins kodieren. Innerhalb der Gattungen (Noctilio, Myotis), basierend auf Exon 2, fand ich das für andere Säugergruppen typische Bild eines ‚trans-species polymorphism’, bei dem MHC-Allele von verschiedenen Arten sich untereinander ähnlicher sein können als Allele der gleichen Art. Meine Ergebnisse sind ein wichtiger Beitrag zum Verständnis der MHC Evolution in der Gruppe der Fledermäuse und liefern hilfreiche Kenntnisse für zukünftige Studien zum MHC in dieser Säugetierordnung. Meine Studien an einer frei lebenden Population der kleinen Hasenmaulfledermaus zeigten dass der exprimierte DRB Locus typische Anzeichen pathogenbedingter aber auch sexueller Selektionsmechanismen zeigt. Ich fand eine ausgeprägte populations-weite Heterozygotie, positive darwinsche Selektion, die den Polymorphismus in Codons die direkt an der Pathogenerkennung beteiligt sind erhält, sowie spezifische Allele die entweder mit einer erhöhten oder einer geringen Parasitenbelastung einhergehen, entsprechend den Annahmen der ‚Frequenz-abhängigen Selektions-Hypothese’. Die individuelle Parasitenresistenz gilt als ein wichtiger Faktor um ressourceabhängige ‚life-history’ Strategien auszuloten. Vor allem Männchen mit einem effektiven Immunsystem, sollten mehr Energien für die Fortpflanzung zur Verfügung haben (‚good-genes model’). Meine Daten bestätigen diese Annahme, Männchen die stärker parasitisiert waren, waren weniger häufig reproduktiv aktiv und trugen häufiger ein DRB-Allele das mit erhöhter Parasitenbelastung einherging. Genetisch unterschieden sie sich darin nicht nur von den reproduktiv aktiven Männchen der Population sondern auch von den Jungtieren. Die Jungtiere trugen zudem häufiger ein für die Parasitenabwehr vorteilhaftes Allel. Die Ergebnisse zeigen dass die individuelle MHC-Konstitution einen nicht zu unterschätzenden Einfluss auch auf den Reproduktionserfolg eines Männchens haben kann und vorteilhafte Allele sich bereits in nachfolgenden Generationen durchsetzen. Meine Doktorarbeit gehört damit zu einer der seltenen Studien, die nicht nur zeigen konnte inwieweit der MHC an co-evolutionären Prozessen der Parasit-Wirt-Interaktion beteiligt ist, sondern dass er darüber hinaus auch direkt für die individuelle ‚life-history’ Entwicklung von Bedeutung ist.

Made available in DSpace on 2014-12-17T14:10:16Z (GMT). No. of bitstreams: 1 GustavoSA.pdf: 4369904 bytes, checksum: 083c60d4ddf64c0281449771173dade6 (MD5) Previous issue date: 2008-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / ?Oligoplites palometa (Cuvier) and Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) are coastal pelagic fish species. The objective of this study was to investigate the effect of parasitism by isopods and the reproductive biology of the leather jack, Oligoplites spp. A total of 113 individuals of Oligoplites spp (35 of O. saurus and 78 of O. palometa) were captured during the period between January, 2005 and July, 2007 from the coastal waters of Natal, RN. The morphometric and meristic characters were registered; macroscopic analyses were done to collect the isopod parasites and the gonads were observed to verify the reproductive aspects. The crustacean isopod parasite, Cymothoa spinipalpa (Isopoda: Cymothidae) was encountered on the tongue in the oral cavity in both fish hosts. The parasitic indices of C. spinipalpa showed high values of prevalance of 51,4% for O. saurus and 64,1% for O. palometa. The host presented significant correlations between body mass and body length of O. palometa and the number of parasites. Body lengths of female C. spinipalpa were small due to the limited space available in the oral cavity of the host. There was a significant difference in the sex ratio of O. palometa, males outnumbered the females. The isopod parasites showed specificity to the oral cavity of hosts. Macroscopic analyses of gonads showed four stages of gonadal development for both sex of O. palometa: immature, maturing, mature and spent / ?As esp?cies Oligoplites palometa (Cuvier) e Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) s?o peixes costeiros pel?gicos. O objetivo do presente trabalho foi estudar o parasitismo por is?podos e a biologia reprodutiva em tibiro, Oligoplites spp. Foram capturados cento e treze exemplares de Oligoplites spp durante o per?odo de janeiro de 2005 a julho de 2007 nas ?guas costeiras de Natal, RN. Foram realizadas as medidas morfom?tricas e mer?sticas, a an?lise macrosc?pica para coleta dos parasitos is?podos e a retirada das g?nadas para o estudo dos aspectos reprodutivos. Foi encontrada uma nova esp?cie de ectoparasito, Cymothoa spinipalpa (Isopoda: Cymothidae), sobre a l?ngua na cavidade oral em ambas as esp?cies de Oligoplites. Os ?ndices parasit?rios de C. spinipalpa indicaram uma alta preval?ncia sendo de 51,4% para O. saurus e de 64,1% para O. palometa. Em O. palometa existe uma correla??o significativa entre peso do hospedeiro e o n?mero de parasito como tamb?m entre o comprimento total do hospedeiro e o n?mero de parasito. As f?meas de C. spinipalpa tiveram seu comprimento limitado pelo ambiente f?sico dispon?vel na cavidade bucal do hospedeiro. Foi encontrada uma diferen?a significativa na propor??o sexual de O. palometa, com um maior n?mero de machos em rela??o ao n?mero de f?meas. Os is?podos t?m especificidade pela cavidade oral dos hospedeiros. A an?lise macrosc?pica das g?nadas permitiu a identifica??o de quatro est?dios distintos de matura??o em ambos os sexos de O. palometa: imaturo, em matura??o, maduro e esvaziado

Orientador: Reinaldo José da Silva / Resumo: Peixes da família Loricariidae (Siluriformes) apresentam grande plasticidade fenotípicaintraespecífica durante toda sua ontogenia. O conhecimento limitado sobre os aspectosbiológicos, padrões biogeográficos e elevada variabilidade morfológica destes peixesdificultam estudos sobre a biodiversidade acerca deste grupo, incluindo estudos sobre afauna parasitária. Assim, o objetivo deste estudo foi realizar levantamento dabiodiversidade de parasitas de peixes da família Loricariidae em áreas sob a influência daconstrução de Pequenas Centrais Hidrelétricas (PCHs) no rio Sapucaí-Mirim, Estado deSão Paulo, Brasil. Ademais, avaliar a estrutura das comunidades parasitárias doshospedeiros analisados (ao nível de infracomunidade e comunidade componente) epossíveis mudanças na abundância das infracomunidades baseadas em variáveisexplanatórias (espaciais, temporais e fatores intrínsecos ao hospedeiro). Para tanto, duranteos anos de 2012 e 2013 foram realizadas duas amostragens anuais (período seco/chuvoso),em oito áreas amostrais situadas nos reservatórios de três PCHs: Palmeiras, Anhanguera eRetiro. Foram necropsiados 334 loricarídeos pertencentes a 10 espécies: Loricaria prolixa,Hypostomus margaritifer, Hypostomus heraldoi, Hypostomus strigaticeps, Hypostomusregani, Hypostomus ancistroides, Hypostomus cf. margaritifer, Hypostomus topavae,Hypostomus aff. topavae, além de uma espécie não identificada pertencente ao gêneroHypostomus. Foram encontrados 29 ta... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Loricariid fishes (Siluriformes) presents great intraspecific phenotypic plasticity throughouttheir ontogeny. The limited knowledge about the biological aspects, biogeographic patternsof distribution and high morphological variability of these fishes make the studies onbiodiversity of this group difficult, including that about parasites. Therefore, the aim of thisstudy was to survey the biodiversity of parasites of Loricariidae fishes from an area underthe influence of the construction of Small Hydro Power Plants (SHPPs) in the Sapucaí-Mirim River, São Paulo State, Brazil. Moreover, the study evaluated the structure ofparasitic communities of these hosts (at both the component community andinfracommunity levels), assessing the possible variation in infracommunity abundanceamong sites and fish species based on explanatory variables (spatial, temporal, and hosttraits). During 2012 and 2013, two annual samples (dry/rainy seasons) were carried out, ineight sampling sites situated in the reservoirs of three SHPPs: Palmeiras, Anhanguera, andRetiro. Specimens of Loricaria prolixa, Hypostomus regani, Hypostomus ancistroides,Hypostomus strigaticeps, Hypostomus heraldoi, Hypostomus margaritifer, Hypostomus cf.margaritifer; Hypostomus topavae; Hypostomus aff. topavae and Hypostomus sp., wereanalyzed, totaling 334 fishes. Twenty-nine taxa were found, totaling 15,957 parasitespecimens, and Monogena was the dominant group, which showed the greatest richness ... (Complete abstract click electronic access below) / Doutor

L’évolution divergente est un processus clef générant de la biodiversité. Elle peut avoir lieu entre localités, via la réduction des flux de gènes, et au sein des localités via la spécialisation écologique. Dans le cas des systèmes parasitaires multi-hôtes, l’adaptation dépend des taux relatifs de flux de gènes des hôtes et des parasites entre différentes localités, ainsi que des échanges locaux de parasites entre différents types d’hôtes. En combinant génétique des populations et expérimentations sur le système composé de la puce Ceratophyllus gallinae et deux de ses hôtes, la mésange charbonnière Parus major et le gobe-mouche à collier Ficedula albicollis dans un habitat fragmenté, nous avons examiné comment l’adaptation et l’isolation génétique façonnent l’évolution des parasites. Nous avons aussi testé comment les choix d’habitat des hôtes pouvaient influencer la rencontre avec des populations de parasites spécialisées. Les analyses de microsatellites révèlent que les populations de puce sont différenciées à une échelle spatiale fine, et fréquemment entre espèces hôtes. De plus, des populations de parasites semblent adaptées à chaque type d’hôte. Cependant, aucune variation dans les choix d’habitats par rapport aux parasites n’a été observée chez les hôtes. Enfin, la réponse des hôtes aux parasites variait entre nos deux zones réplica ; l’histoire des populations d’hôtes pourrait donc influer sur la coevolution avec leurs parasites. Ce système semble donc localement façonné à la fois par une isolation génétique et une sélection par différents hôtes. L’étude de nouveaux sites permettraient d’évaluer si cette évolution divergente peut être génératrice de biodiversité / Divergent evolution is a key process generating biodiversity. This can occur between localities, through reduced gene flow followed by local adaptation or genetic drift, and within localities through ecological specialization. In the case of multi-host parasite systems, adaptation can be driven by the relative rate of host-parasite gene flow among spatially isolated populations, and the amount of parasite exchange among local host types. Combining population genetics and field experiments, we examined how adaptation and genetic isolation shape parasite evolution. Focusing on the hen flea Ceratophyllus gallinae, a presumed host generalist, and two of its hosts, the great tit Parus major and the collared flycatcher Ficedula albicollis, we investigated parasite population structure and adaptation within a fragmented landscape. Additionally, we tested how hosts can influence encounter rates with specialized flea populations through their habitat choice. Neutral markers analyses show that flea populations are genetically differentiated at fine spatial scales, and frequently between the two host species. Evidence for parasite adaptation to each host type were also observed. Host specialization may therefore be ongoing in hen fleas. However, birds did not show specific habitat choice strategies regarding flea-infested nests. Host responses differed between two replicate sites, indicating that local population history may impact parasite evolution. Both isolation and host-based selection are therefore acting on hen flea populations at a local scale. Investigations in new localities will help to assess to what extend this divergent evolution may generate biodiversity

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