No description available.

The prevalence of Trichostrongylus tenuis in red grouse was high and the distribution of parasites in their hosts highly aggregated. The prevalence and intensity of threadworms were greater in old birds than in young ones. There was no relationship between the body condition of individual grouse and their burden of adult worms. On the moor, T. tenuis eggs did not develop to third-stage infective larvae during the winter. In the summer, when development did occur, yields of third-stage larvae were dependent on temperature. Third-stage larvae moved laterally through the heather but were relatively short-lived and very few survived over winter. The proportion of larvae, ingested by captive grouse, which developed to adult worms varied with season and between individuals. Red grouse acquired little or no effective immunity to reinfection after challenge with infective larvae. Consequently, caecal threadworms produced a chronic infection in grouse: mature worms survived for over two years with very little mortality. Parasite fecundity decreased as the worms aged but not with intensity of infection. Third-stage larvae ingested by wild red grouse in the autumn were found to go into arrested development over the winter, resuming their development in the spring. Captive grouse with parasite burdens were later in starting to lay in spring and laid fewer eggs at a slower rate than uninfected hens. However developing larvae had greater effects than adult worms on egg production. Effects of developing larvae included inappetence and a reduced gain in body weight prior to laying. Consequently, overwintering larvae developing simultaneously in spring may reduce the breeding success of wild red grouse. This observation may also explain why outbreaks of trichostrongylosis are usually found in spring and summer. The transmission of T. tenuis is presumably influenced mainly by the density of infective larvae, which in turn was affected by weather, particularly temperature. A major regulatory constraint on this parasite is host mortality. Mortality, however, is unlikely to be linearly related to parasite intensity because developing larvae were more pathogenic than adult worms. Furthermore, there seemed to be no important intensity-dependent processes acting to regulate T. tenuis in red grouse populations. On the moor, T. tenuis eggs did not develop to third-stage infective larvae during the winter. In the summer, when development did occur, yields of third-stage larvae were dependent on temperature. Third-stage larvae moved laterally through the heather but were relatively short-lived and very few survived over winter. The proportion of larvae, ingested by captive grouse, which developed to adult worms varied with season and between individuals. Red grouse acquired little or no effective immunity to reinfection after challenge with infective larvae. Consequently, caecal threadworms produced a chronic infection in grouse: mature worms survived for over two years with very little mortality. Parasite fecundity decreased as the worms aged but not with intensity of infection. Third-stage larvae ingested by wild red grouse in the autumn were found to go into arrested development over the winter, resuming their development in the spring. Captive grouse with parasite burdens were later in starting to lay in spring and laid fewer eggs at a slower rate than uninfected hens. However developing larvae had greater effects than adult worms on egg production. Effects of developing larvae included inappetence and a reduced gain in body weight prior to laying. Consequently, overwintering larvae developing simultaneously in spring may reduce the breeding success of wild red grouse. This observation may also explain why outbreaks of trichostrongylosis are usually found in spring and summer. The transmission of T. tenuis is presumably influenced mainly by the density of infective larvae, which in turn was affected.

M.Sc. / Recent years have seen a remarkable increase in scientific research and studies conducted regarding the unique group of parasitic isopods known as gnathiids. The taxonomy of gnathiids are based solely on the morphological characteristics of the free-living adult males, which means that the female and larval life stages are often not collected and described with the males, and when collected it is seldom possible to even identify these stages when not in the company of there adult males. Numerous studies have been conducted in Australia regarding cleaning behaviour of coral reef fishes, where these gnathiid larvae are extremely abundant and are often collected. These types of studies as well as others are increasing all around the world, and because of the fact that the larvae cannot be easily identified, the results and data collected from these various studies are often misinterpreted or inconclusive and makes no sense. The fact that gnathiid larvae may serve as possible vectors for certain fish blood parasites and have various physiological and ecological effects on their fish hosts, which may lead to mortality, can have detrimental economical effects on the fisheries industry. This study was thus conducted to improve the identification methods that are currently applied to the larval life stages of gnathiid isopods through various means including increasing the number of detailed descriptions available, constructing a taxonomic key and lastly conducting a basic phylogenetic analysis of a group of known gnathiid larvae in order to aid researchers with future identifications. It was hypothesised that firstly, although there are some gnathiid descriptions from coral reefs, mostly of adult males, it is likely that there are still a great number of unknown and not yet described gnathiid species, because coral reefs are one of the most highly biodiverse marine ecosystems. Secondly, that the distribution of coral reef gnathiids is much wider than currently known or documented and lastly, that it might be possible to identify gnathiid larvae species in the absence of adult males, through the use of detailed taxonomic descriptions of these larval stages and there live colouration patterns, and to then construct a taxonomic key to aid researchers with future identifications.

M.Sc. / In this research project, a variety of sites and ecosystems were studied. These ranged from tropical coral reefs (north-eastern Coast of Australia), to warm temperate intertidal pools (South Coast of South Africa, SA) and sub-tropical estuaries (East Coast of SA). The overall aims of the thesis were to examine the haematophagous gnathiid ectoparasites and blood protozoans of some host teleosts found in these systems, and to some extent to investigate the role gnathiids might play as vectors of the protozoans. Gnathiid research in Australia on the Great Barrier Reef (GBR) focuses mainly on gnathiid ecology and not taxonomy. This is not the case in SA, where gnathiid taxonomy is researched more regularly and gnathiid ecology has received little attention. In this thesis, two new gnathiid species, Gnathia aureamaculosa and Gnathia sp. B, were described from a number of teleost fishes of the GBR and several morphological features, including live colouration patterns, were highlighted as useful in future gnathiid identification and discrimination. The feeding ecology of Gnathia africana from SA was also examined and this feeding study was based on similar work done on coral reef gnathiids in Australia. Gnathiids of the GBR are mainly nocturnal due to cleaner fish predation during the day, whereas G. africana was found to have a preference for dawn/early morning/midday feeding on an intertidal teleost, Clinus superciliosus. Gnathia africana‟s behaviour/feeding patterns, especially of its different juvenile stages, are therefore determined by time of day, and likely by locality and predation by other organisms, such as fishes, though probably not by cleaner fish. Gnathiid feeding behaviours/patterns are thus, it seems, determined by environmental and biological factors, and these vary according to the type of ecosystem studied. Several gnathiids and fish blood protozoan species are known from the South Coast of SA, but the East Coast has remained largely unexplored. Sampling along the East Coast yielded the first records of haemogregarines from the blood of fishes in this region, in particular new hosts and locality records probably for both probable Haemogregarina bigemina and a Haemogregarina quadrigemina – like haemogregarine. However, both haemogregarines displayed unusual features compared with the original species descriptions, in size, development patterns, or effect on host cells. Limited data suggested that juveniles of Gnathia pilosus were possible haematophagous vectors of these haemogregarines, but further studies are required to confirm this.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / As comunidades biolÃgicas podem variar espacialmente seguindo uma relaÃÃo de diminuiÃÃo de similaridade conforme aumenta a distÃncia entre elas. Apesar de os parasitas representarem bons modelos em estudos abordando riqueza e estrutura de comunidades biolÃgicas, estudos sobre a dinÃmica ecolÃgica de populaÃÃes e comunidades de parasitas ainda sÃo bastante escassos. Nosso objetivo neste trabalho foi inventariar as comunidades de helmintos associados a diferentes populaÃÃes do lagarto Hemidactylus mabouia (Moreau de JonnÃs, 1818) no nordeste brasileiro, a fim de investigar as relaÃÃes parasita-hospedeiro quanto aos padrÃes de infecÃÃo e testar se a similaridade entre as comunidades de parasitas diminui com o aumento da distÃncia. Para isso, coletamos amostras de sete populaÃÃes de H. mabouia no litoral do nordeste brasileiro, identificamos suas comunidades componentes de parasitas e relacionamos os padrÃes de infecÃÃo com as caracterÃsticas do hospedeiro. Testamos tambÃm a relaÃÃo da similaridade com a distÃncia geogrÃfica. A riqueza de parasitas varia entre as populaÃÃes de H. mabouia, porÃm os padrÃes de infecÃÃo das espÃcies comuns a todas elas sÃo similares. O nÃmero de espÃcies de parasitas, a intensidade e prevalÃncia deles aumentam com o tamanho do hospedeiro, o que pode ser resultado do acÃmulo de eventos de infecÃÃo ao longo da vida. Machos e fÃmeas nÃo diferiram quanto à intensidade e prevalÃncia de infecÃÃo e isso deve ser reflexo da semelhanÃa intersexual na dieta. O parasitismo pode ou nÃo levar a uma diminuiÃÃo do investimento reprodutivo das fÃmeas em H. mabouia, o que pode indicar que nem todos os parasitas levam a uma diminuiÃÃo significativa de energia do hospedeiro. Diferente do esperado, nÃo encontramos uma relaÃÃo de diminuiÃÃo da similaridade com a distÃncia entre as comunidades de parasitas das populaÃÃes do hospedeiro, e isso pode ser explicada por fatores como as caracterÃsticas do contato entre suas populaÃÃes ou ainda as formas de transmissÃo da maioria das espÃcies parasitas. / Biological communities can vary spatially according to a relationship of decay of similarity with increasing distance between them. Although parasites represent good models for studies about richness and structure of biological communities, studies about ecological dynamics of parasite populations and communities are still scarce. Our objective in this work was to report the helminth communities associated to different populations of the lizard Hemidactylus mabouia (Moreau de JonnÃs, 1818) in Northeast Brazil, to investigate the host-parasite relationships regarding infection patterns and to test if the similarity among parasite communities decreased as distance increased. For this, we collected H. mabouia population samples from the Northeast coast of Brazil, identified their parasite component communities and related the infection patterns to host features. We also tested the distance decay similarity relationship. The parasite richness varies among H. mabouia populations, but the infection patterns of the common parasite species are similar. The parasite species number, intensity and prevalence increase with host size, and may be the result of infection events accumulation with time. Males and females do not differ concerning infection intensity and prevalence, and this may be the result of intersexual diet similarity. Parasitism may or may not lead to a decrease in reproductive investment in females H. mabouia, which may indicate that these parasites do not lead to a significant decrease of host energy. Unexpectedly, we find no distance decay similarity relation among parasite communities of host populations, what may be explained by factors such as characteristics of contact between host populations or the transmission mode of most parasite species.

Crayfish throughout North America, Europe, and Asia host assemblages of obligate ectosymbiotic annelid worms called branchiobdellidans. The work presented here is a detailed experimental and observational study of the ecological interactions between crayfish and their worms. In a comprehensive literature review, I show that branchiobdellidans have complex and context-dependent effects on their hosts, serving as both beneficial cleaners and tissue-consuming parasites. Using a field survey and laboratory experiments, I provide novel evidence for age-specific resistance as an adaptation to maximize life-long benefits of a mutualism. Specifically, I show that Cambarus crayfish display a consistent ontogenetic shift in resistance to the colonization of branchiobdellidans and this shift likely reflects underlying changes in the costs and benefits of symbiosis. I then show that this change in host resistance creates predictable patterns of symbiont diversity and composition throughout host ontogeny. Host resistance limits within-host symbiont communities to a few weakly interacting species, whereas relaxed resistance leads to more diverse symbiont communities that have strong interactions among symbiont taxa. Thus, host resistance has direct effects on within-host symbiont community structure by selectively filtering colonizing species, and indirect effects by moderating the strength of interactions among symbionts. Lastly, in a detailed study of the worm Cambarincola ingens, I depict a symbiont dispersal strategy that yields highly predictable transmission dynamics during pairwise host-host encounters and shows that variation in transmission dynamics can be explained by the fitness outcomes for dispersing symbionts. Field observations revealed that worm reproduction is contingent on host size and intraspecific competition for preferred microhabitats. Using a predictive model that assumes transmission of symbionts only when current conditions yield fitness below a minimum threshold, I was able to predict individual transmission events much more accurately than a comparable null model that assumed a fixed probability of transmission. My work provides empirical support for the emerging trend among researchers that advocates the adaptation of general ecological frameworks to understand symbiont population structure and diversity, but my work also emphasizes the value of detailed natural history studies to uncover system-specific ecological and co-evolutionary processes such as partner control mechanisms, symbiont microhabitat selections, and symbiont dispersal strategies. / Ph. D.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-20T18:25:56Z No. of bitstreams: 1 2016 - Cristina Fernandes do Amarante.pdf: 776756 bytes, checksum: 758e9e88a96110176bd0dff013f8c6ac (MD5) / Made available in DSpace on 2016-10-20T18:25:56Z (GMT). No. of bitstreams: 1 2016 - Cristina Fernandes do Amarante.pdf: 776756 bytes, checksum: 758e9e88a96110176bd0dff013f8c6ac (MD5) Previous issue date: 2016-03-03 / CNPq / This study aimed to assess the factors involved in the determination of ecological events, including parasite aggregation, abundance, and dominance, via multivariate analysis using fish as a biological model. For this purpose, we used a database consisting of 3,746 fish specimens collected on the coast of Rio de Janeiro and from the Guandu river and evaluated their characteristics, habits, and associated parasites. Parasites were grouped into seven higher taxa: Nematoda, Monogenea, Cestoda, Trematoda, Acanthocephala, Hirudinea, and Crustacea. Aggregation was calculated using the dispersion index; abundance was determined by calculating the total number of parasites; and dominance was calculated using the Berger-Parker index. Data normality was tested using the Shapiro-Wilk test; group comparisons, when necessary, were performed using the Wilcoxon test or the Kruskal-Wallis test. Adjustments were made in the linear regression models for parasite aggregation in each parasite taxon evaluated and in the mixed-effect models to evaluate abundance and dominance using Poisson and Gaussian distributions, respectively. The factors inherent to the hosts, including sex, size, habitats, formation of schools, eating habits, and aquatic environments, were tested as potential explanatory variables of these ecological events. In addition, the parasite development stage and parasite taxa were included as explanatory variables in the analysis of the determinants of aggregation and dominance, respectively. In the mixed-effects model, the ecological events were considered an outcome variable, and fish species were considered a random variable. Regression coefficients were calculated in the study of aggregation, and parasite dominance and prevalence rate were estimated in the study of abundance. Significance was determined using confidence intervals (CI) and the Wald test. All calculations were performed using R software with a confidence interval of 95%. Statistically significant associations between levels of parasite aggregation and explanatory variables (factors inherent to the host and the percentage of larvae) varied according to the parasite taxon. The coefficient of determination was lower than 60% in all of the adjusted models, indicating that factors other than those analyzed may be associated with the level of parasite aggregation. Parasite abundance was significantly associated with sex, formation of schools, habitats, and host length, which were considered risk factors. The numerical dominance of parasites was significantly associated with host length and the taxa Nematoda, Trematoda, Monogenea, Hirudinea, and Crustacea. In addition, our results indicate that the mixed-effects model was more parsimonious compared with the classical model, underscoring the importance of choosing a statistical model that takes into consideration the nature of the data to avoid spurious results, especially when autocorrelations data were not considered. In general, our results point to the need for developing studies with more comprehensive databases and larger samples of parasite species, in which data on the life cycles of fish species and parasite taxa can be analyzed more thoroughly. / Este trabalho teve como objetivo avaliar fatores envolvidos na determina??o dos eventos ecol?gicos: agrega??o, a abund?ncia e a domin?ncia parasit?ria por meio de an?lises multivariadas, utilizando peixes como modelo biol?gico. Para tanto, foi utilizado um banco de dados composto por 3.746 esp?cimes de peixes, suas caracter?sticas e h?bitos e seus parasitos, provenientes do litoral do Rio de Janeiro e do Rio Guandu. Os parasitos foram agrupados em sete t?xons superiores: Nematoda, Monogenea, Cestoda, Trematoda, Acanthocephala, Hirud?nea e Crust?cea. A agrega??o foi calculada atrav?s do ?ndice de dispers?o; a abund?ncia pela quantidade total de parasitas computados; e a domin?ncia atrav?s do ?ndice de Berger Parker. A normalidade dos dados foi testada pelo teste de Shapiro Wilk e a compara??o de grupos, quando necess?ria, foi realizada pelo teste de Wilcoxon ou Kruskal-Wallis. Foram ajustados modelos de regress?o linear para a agrega??o parasit?ria para cada t?xon parasit?rio estudado e modelos de efeitos mistos para an?lise dos determinantes da abund?ncia e da domin?ncia, com distribui??o de Poisson e gaussiana, respectivamente. Os fatores inerentes aos hospedeiros tais como: sexo, tamanho, habitat, forma??o de cardumes, h?bitos alimentares e ambiente aqu?tico foram testados como poss?veis vari?veis explicativas desses eventos ecol?gicos. Al?m desses, na an?lise dos determinantes da agrega??o e domin?ncia foram inclu?dos os fatores est?dio de desenvolvimento do parasita e os t?xons parasit?rios como vari?veis explicativas, respectivamente. Os eventos ecol?gicos foram considerados vari?veis desfecho e nos modelos mistos a esp?cie de peixe como vari?vel aleat?ria. Foram calculados os coeficientes de regress?o nos estudos de agrega??o e domin?ncia parasit?ria e estimada a raz?o de preval?ncia no estudo de abund?ncia. A signific?ncia foi verificada por meio o intervalo de confian?a (IC) e do teste de Wald. Todos os c?lculos foram realizados utilizando o software R, com um IC de 95%. As associa??es estatisticamente significativas entre o n?vel de agrega??o parasit?ria e as vari?veis explicativas (fatores inerentes ao hospedeiro e propor??o de larvas) variaram conforme o t?xon parasit?rio. O coeficiente de determina??o foi inferior a 60%, em todos os modelos ajustados, indicando que outros, fatores al?m dos analisados, devam estar relacionados ao grau de agrega??o parasit?ria. A abund?ncia parasit?ria mostrou-se associada significativamente ?s vari?veis: sexo, forma??o de cardumes, habitat e comprimento do hospedeiro, que se comportaram como poss?veis fatores de risco. A domin?ncia num?rica de parasitos esteve associada significativamente ao comprimento do hospedeiro e aos t?xons Nematoda, Trematoda, Monogenea, Hirud?nea e Crust?cea. Os resultados mostraram que os modelos mistos foram mais parcimoniosos em rela??o aos modelos cl?ssicos, refor?ando a import?ncia da escolha de um modelo estat?stico mais adequado ? natureza dos dados, evitando-se resultados esp?rios, principalmente quando n?o se leva em conta a autocorrela??o dos dados..De um modo geral, os resultados deste estudo sinalizam para a necessidade de pesquisas com bancos de dados mais abrangentes e com amostras maiores de esp?cies de parasitos, nos quais as caracter?sticas do ciclo biol?gico das esp?cies de peixes e dos t?xons parasit?rios possam ser mais detalhados nas an?lises.

Made available in DSpace on 2016-04-28T20:16:19Z (GMT). No. of bitstreams: 1 2006-Aline Rodrigues Paraguassu.pdf: 983519 bytes, checksum: 0c74cca0a30825c36292d89b35424d4e (MD5) Previous issue date: 2006-02-21 / Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / From April 2002 to July 2003, 296 freshwater fishes from Lajes Reservoirs in the State of Rio de Janeiro, Brazil (22?42 - 22?50 S, 43?53 - 44?05 W) were necropsied to study their community metazoan parasites: 39 Astyanax bimaculatus (Linnaeus, 1758), 79 A. fasciatus (Cuvier, 1819), 65 Geophagus brasiliensis (Quoy & Gaimard, 1824), 23 Hypostomus affinis (Steindachner, 1877), 26 Hoplias malabaricus (Bloch, 1794), 30 Loricariichthys castaneus (Castelnau, 1855) and 34 Trachelyopterus striatulus (Steindachner, 1877). The majority specimens of G. brasiliensis (81.5%), H. affinis (95.6%) and H. malabaricus (84.6%) was parasitized by one or more metazoan species. In A. bimaculatus, A. fasciatus, L. castaneus and T. striatulus 41%, 39.2%, 56.7 and 14.7% of specimens were parasitized, respectively.Ten different metazoan parasites species were collected: 2 in A. bimaculatus, 3 in A. fasciatus, 6 in G. brasiliensis, 3 in H. affinis, 4 in H. malabaricus, 4 in L. castaneus and 1 in T. striatulus. Six species were common in at least two communities. The glossiophonid was collected in 6 communities. The larval stage of digeneans were the majority of the parasite specimens collected in H. malabaricus and L. castaneus with 45.9% and 80.4%, respectively. In A. bimaculatus and A. fasciatus the nematodes were the majority of the parasite specimens collected, while in G. brasiliensis and H. affinis the hirudine glossiophonid was the majority of the parasite specimens collected. Only one spcecies of monogenean was collected in T. striatulus. The parasite of 7 host species showed the typical aggregate pattern of distribution. Two cases of negative correlation between host s total length and prevalence and parasite abundance were found. The parasite community of L. castaneus showed the higher values of mean intensity, index of dispersion and higher values of diversity. While the parasite community of H. affinis showed the higher values of mean abundance and the mean parasite species richness. Only in A. fasciatus and L. castaneus the abundance and parasite species richness showed positive correlations with the host s total length. Geophagus brasiliensis was the species with higher number of species: ectoparasites (3), adult endoparasites (1) and larval stage of endoparasites (2). The parasite communities of the studied fishes showed scarcity of significant correlation of parasitic abundance, scpecies richness and diversity and the size of the host. The low scpecies richness and diversity of parasite communities could be attribute by oligotrophic characteristics of the Lajes Reservoirs. / Entre abril de 2002 e julho de 2003, foram necropsiados 296 esp?cimes de peixes: 39 Astyanax bimaculatus (Linnaeus, 1758), 79 A. fasciatus (Cuvier, 1819), 65 Geophagus brasiliensis (Quoy & Gaimard, 1824), 23 Hypostomus affinis (Steindachner, 1877), 26 Hoplias malabaricus (Bloch, 1794), 30 Loricariichthys castaneus (Castelnau, 1855) e 34 Trachelyopterus striatulus (Steindachner, 1877) provenientes do Reservat?rio de Lajes (22?42 - 22?50 S, 43?53 - 44?05 O), Estado do Rio de Janeiro, Brasil, para estudo das suas comunidades parasit?rias. A maioria dos esp?cimes de G. brasiliensis (81,5%), H. affinis (95,6%) e H. malabaricus (84,6%) estavam parasitados por pelo menos uma esp?cie de metazo?rio. Em A. bimaculatus, A. fasciatus, L. castaneus e T. striatulus 41%, 39,2%, 56,7% e 14,7% dos esp?cimes estavam parasitados, respectivamente. Foram coletadas 10 diferentes esp?cies de metazo?rios parasitos: 3 digen?ticos, 1 monogen?tico, 2 nemat?ides, 1 cop?pode, 1 hirud?neo, 1 bivalve e 1 is?pode. Seis esp?cies de metazo?rios parasitos foram comuns a pelo menos duas comunidades. O glossiphon?deo foi encontrado em seis das sete comunidades estudadas. Os est?gios larvais de digen?ticos corresponderam ? maioria dos esp?cimes coletados em H. malabaricus e L. castaneus com 45,9% e 80,4%, respectivamente. Em A. bimaculatus e A. fasciatus os nemat?ides corresponderam a maioria dos esp?cimes coletados, enquanto em G. brasiliensis e H. affinis o glossiphonideo correspondeu a maioria dos esp?cimes coletados. Apenas uma esp?cie de monogen?tico foi coletada em T. striatulus. As comunidades de metazo?rios parasitos dos sete peixes estudados apresentaram t?pico padr?o de distribui??o agregada. Apenas o glossiphonideo apresentou correla??o negativa entre a abund?ncia e a preval?ncia parasit?rias e o comprimento total em H. malabaricus e L. castaneus, respectivamente. A comunidade parasit?ria de L. castaneus apresentou os maiores valores de intensidade m?dia, ?ndice de dispers?o e diversidade. Enquanto a comunidade parasit?ria de H. affinis apresentou os maiores valores de abund?ncia m?dia e riqueza parasit?ria. Apenas em A. fasciatus e L. castaneus a abund?ncia e a riqueza parasit?ria apresentaram correla??o positiva com o comprimento total do hospedeiro. Geophagus brasiliensis foi o hospedeiro com o maior n?mero de esp?cies de parasitos: ectoparasitos (3), endoparasitos adultos (1) e est?gios larvais de endoparasitos (2). As comunidades parasit?rias dos peixes estudados apresentaram escassez de correla??o entre a abund?ncia, riqueza parasit?ria e diversidade com o comprimento total dos hospedeiros. Os baixos valores de riqueza e diversidade das comunidades parasit?rias podem ser atribu?dos as caracter?sticas oligotr?ficas do Reservat?rio de Lajes.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-09-14T11:46:46Z No. of bitstreams: 1 2011 - Vivian Suane de Freitas Vieira.pdf: 2001045 bytes, checksum: 2cce4947186746927e3f6cc35826b411 (MD5) / Made available in DSpace on 2016-09-14T11:46:46Z (GMT). No. of bitstreams: 1 2011 - Vivian Suane de Freitas Vieira.pdf: 2001045 bytes, checksum: 2cce4947186746927e3f6cc35826b411 (MD5) Previous issue date: 2016-01-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / A list of metazoan species associated to Pimelodus Lac?p?de, 1803 genus has been prepared in this work. The total of 516 records in 10 host species of genus was compiled. Were included in the list of new geographic records monogeneans parasites of Pimelodus maculatus Lac?p?de, 1803 collected from Midwest, Southeast and South of Brazil. New morphological data of Cucullanus pinnai pinnai Travassos, Artigas & Pereira, 1928, parasite of P. maculatus collected in the Guandu river, in the State of Rio de Janeiro have been reported. This work noted that the position of the excretory pore and deirids of the specimens are at the level or posterior to the oesophagus- intestine junction in the most specimens and gubernaculums size is greater than in other previously studied of C. pinnai pinnai. Nematodes were studied using light and scanning electron microscopy (SEM) and differential interference contrast (DIC) and analyzes confirmed morphological details of the cephalic region and the caudal papillae that species. Comparative study of parasitic communities of P. maculatus was also performed. 50 specimens of the P. maculatus were collected from Guandu river, in the State of Rio de Janeiro and others 50 from Mogi-Gua?? river, State of S?o Paulo. In the samples from Guandu river were identified the following species: Ameloblastella paranaensis Fran?a, Isaac, Pavanelli & Takemoto, 2003 (P= 8%; MI= 1,0?0,0); A. satoi Monteiro, Kritsky, Brasil-Sato, 2010 (P= 8%; MI= 1,0?0,0); Demidospermus bidiverticulatum Suriano & Incorvaia, 1995 (P= 8%; MI= 1,0?0,0); D. paravalenciennesi Guti?rrez & Suriano, 1992 (P=90%; MI=14,77?5,04), D. uncusvalidus Guti?rrez & Suriano, 1992 (P=90%; MI=12,37?4,86), D. valenciennesi Guti?rrez & Suriano, 1992 (P=56%; MI=6,06?3,95) e Cucullanus pinnai pinnai Travassos, Artigas & Pereira, 1928 (P=64%; MI=3,28?4,87). In the rio Mogi-Gua?? the parasites identified were: Ameloblastella paranaensis (P= 8%; MI= 1,0?0,0), Ameloblastella satoi (P= 8%; MI= 1,0?0,0), Demidospermus paravalenciennesi (P=86%; MI=18,58?10,79), D. uncusvalidus (P=84%; MI=16,73?7,74), D. valenciennesi (P=52%; IM=6,84?4,55) e Cucullanus pinnai pinnai (P= 44%; MI= 3,88?4,87). The females of P. maculatus had higher weight and length of males in both samples. The sex and o length of the hosts did not influence the level of parasitism. Positive correlation was observed between weight of host and abundance of D. uncusvalidus only in the sample of the Guandu river. Aggregate distribution was observed in all the prevalent species of metazoan parasites of P. maculatus in the two localities. D. paravalenciennesi showed a higher frequency of dominance and relative dominance in the samples of Guandu river and D. uncusvalidus in the samples of Mogi-Gua?? river. The results of the qualitative similarity index Jaccard (CJ) and quantitative Sorensen (CS) within the collected samples were homogenea. The Jaccard index indicated heterogeneity while Sorensen index indicated homogeneity between samples. The results demonstrated that the relationship between parasites and their hosts are constant even in different river basins. / Uma lista de esp?cies de metazo?rios associados ao g?nero Pimelodus Lac?p?de, 1803 foi elaborada neste trabalho. O total de 516 registros em 10 esp?cies de hospedeiros do g?nero foi compilado. Foram inclu?dos na lista novos registros de geogr?ficos de parasitos monogen?ticos de Pimelodus maculatus Lac?p?de, 1803 coletados nas regi?es Centro-oeste, Sudeste e Sul do Brasil. Novos dados morfol?gicos de Cucullanus pinnai pinnai Travassos, Artigas & Pereira, 1928, parasito de P. maculatus coletado no rio Guandu, no Estado do Rio de Janeiro foram relatados. Foi observado que a posi??o do poro excretor e deir?deos nos esp?cimes estudados s?o posteriores ao final do es?fago na maioria dos esp?cimes e o tamanho do gubern?culo ? maior do que em outros de C. pinnai pinnai estudados anteriormente. Os nematoides foram estudados utilizando microscopia eletr?nica de varredura (MEV) e contraste interferencial de fase (DIC) e as an?lises confirmaram detalhes morfol?gicos da regi?o cef?lica e as papilas caudais dessa esp?cie. Estudo comparativo das comunidades parasit?rias de P. maculatus tamb?m foi realizado. Foram coletados 50 esp?cimes de P. maculatus no rio Guandu, no Estado do Rio de Janeiro e outros 50 exemplares no rio Mogi-Gua??, no Estado de S?o Paulo, foram examinados para o estudo de sua parasitofauna, no per?odo de maio ? dezembro de 2012. No rio Guandu foram coletadas as seguintes esp?cies: Ameloblastella paranaensis Fran?a, Isaac, Pavanelli & Takemoto, 2003 (P= 8%; IM= 1,0?0,0); A. satoi Monteiro, Kritsky, Brasil-Sato, 2010 (P= 8%; IM= 1,0?0,0); Demidospermus bidiverticulatum Suriano & Incorvaia, 1995 (P= 8%; IM= 1,0?0,0); D. paravalenciennesi Guti?rrez & Suriano, 1992 (P=90%; IM=14,77?5,04), D. uncusvalidus Guti?rrez & Suriano, 1992 (P=90%; IM=12,37?4,86), D. valenciennesi Guti?rrez & Suriano, 1992 (P=56%; IM=6,06?3,95) e Cucullanus pinnai pinnai Travassos, Artigas & Pereira, 1928 (P=64%; IM=3,28?4,87). No rio Mogi-Gua?? os parasitos identificados foram: Ameloblastella paranaensis (P= 8%; IM= 1,0?0,0), Ameloblastella satoi (P= 8%; IM= 1,0?0,0), Demidospermus paravalenciennesi (P=86%; IM=18,58?10,79), D. uncusvalidus (P=84%; IM=16,73?7,74), D. valenciennesi (P=52%; IM=6,84?4,55) e Cucullanus pinnai pinnai (P= 44; IM= 3,88?4,87). As f?meas de P. maculatus apresentaram peso e comprimento maiores que dos machos nas duas amostras. O sexo e o comprimento dos hospedeiros n?o influenciaram o n?vel de parasitismo. Correla??o positiva foi observada entre o peso e a abund?ncia de D. uncusvalidus somente na amostra do rio Guandu. Foi observada distribui??o agregada de todas as esp?cies mais prevalentes de metazo?rios parasitos de P. maculatus nas duas bacias de coleta. D. paravalenciennesi apresentou maior freq??ncia de domin?ncia e domin?ncia relativa no rio Guandu e D. uncusvalidus no rio Mogi-Gua??. Os resultados dos ?ndices de similaridade qualitativa de Jaccard (CJ) e quantitativa de Sorensen (CS) dentro das amostras coletadas demonstraram homogeneidade. O ?ndice Jaccard indicou heterogeneidade e o ?ndice de Sorensen indicou homogeneidade entre as amostras. Os resultados demonstram que o relacionamento entre parasitos e seus hospedeiros s?o constantes, mesmo em diferentes bacias hidrogr?ficas.

Les interactions hôte – parasites sont des systèmes qui affectent probablement la totalité des êtres vivants et constituent un facteur clé dans la compréhension de la dynamique des maladies infectieuses. On a abordé cette problématique en utilisant le système Fasciola hepatica/Lymnaeidae dans sur l'île de Cuba. Cette thèse utilise une approche basée sur différentes disciplines de la biologie comme l’écologie des populations (distribution et abondances de mollusques hôtes intermédiaires), l'écologie parasitaire (données de prévalences naturelles de parasites chez les hôtes), la génétique des populations en utilisant des marqueurs microsatellites (tant pour le parasite que pour les mollusques hôtes), et des études de susceptibilité et compatibilité douve/limnée.En ce qui concerne la diversité génétique du parasite, une très haute diversité et une forte probabilité d’allofécondation ont été observées. En revanche, on n’a pas trouvé de différentiation significatives entre souches. Les taux d’infection chez le bétail sont très élevés.Pour ce qui est de la biologie des populations des limnées hôtes, on a cartographié la distribution des deux espèces présentes à Cuba : Galba cubensis qui est très répandue et Pseudosuccinea columella qui n'est présente que dans la partie centre-occidentale. Nous avons mis en évidence des différences concernant les types d’habitats préférés pour chaque espèce : G. cubensis est plus plastique écologiquement et se retrouve beaucoup plus dans les sites anthropisés.L'étude des compatibilités douve/mollusque a révélé l’existence de populations avec une résistance naturelle à l’infection par F. hepatica chez la limnée P. columella. Ces populations sont génétiquement différenciées des populations sensibles. La plupart des populations sensibles sont monomorphes avec le même haplotype très répandu. Par contre, on a observé une diversité génétique plus importante chez G. cubensis qui suggère un temps évolutif plus ancien à Cuba. L’échantillonnage fait dans une aire de où la fasciolose sévit fortement chez le bétail a révélé un très faible taux d’infection naturel chez les limnées, mais avec de fortes variations d'intensités. Différentes combinaisons douve/limnée sympatriques et allopatriques testées expérimentalement ont montré une compatibilité supérieure de G. cubensis qui suggère une meilleure adaptation aux souches de F. hepatica cubaines.Les résultats obtenus montrent que la compréhension de la dynamique des maladies infectieuses ainsi que leur contrôle doivent s’appuyer sur des connaissances très solides de la biologie, écologie, génétique et évolution des systèmes hôtes – parasites. / Host – parasite interactions are biological systems that probably affect every living being. It also constitute a key factor in the understanding of infectious diseases. This subject has been studied using the Fasciola hepatica/Lymnaeidae system in the insular environment of Cuba. This thesis makes a biological multidisciplinary approach through population ecology (distribution and abundance of intermediary hosts snails), infection rates estimations of parasites in their hosts, population genetics using microsatellites markers (for both parasite and snails hosts), and studies of susceptibility and compatibility fluke/snail.The genetic diversity of the parasite is characterized by high values of diversity as well as probability of cross fertilization. However, we failed to detect significant differences between the strains but a highly infection rate is shared in cattle.Regarding the lymnaeid snails, the distribution of the two occurring species is mapped showing that Galba cubensis is widely distributed while Pseudosuccinea columella only exists in central-western Cuba. Both snail species differ in preferred habitat types and G. cubensis displays a higher ecological plasticity commonly observed in heavily human-transformed sites.Differences in host-parasite compatibilities have been revealed. It has been noted the existence of some populations of P. columella with a natural resistance to F. hepatica infection which display a marked differentiation of their population genetic structure compared to susceptible populations. Most susceptible populations are monomorphic with a very common haplotype in Cuba. Conversely, we observed a higher diversity in G. cubensis indicating a larger evolutionary time in Cuba. The sampling conducted in a fasciolosis endemic area revealed very low prevalences in the snail populations. However, strong variation in parasite mean intensity within individuals supports the high infection rates observed in cattle. Different sympatric and allopatric fluke/snail combinations were experimentally tested in which G. cubensis proved to be more compatible and suggest a better adaptation to the circulating F. hepatica in Cuba.Our results show that the understanding of infectious diseases’ dynamics and their effective control must strictly rely in a full knowledge of the biology, ecology, genetics and evolution of host – parasite systems.