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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ocorrência de Ascocotyle sp. (Digenea: Heterophyidae) em mugilídeos (Osteichthyes: Mugilidae) comercializados no município de Iguape, São Paulo, Brasil / Occurrence of Ascocotyle sp. (Digenea: Heterophyidae) in grey mullets (Osteichthyes: Mugilidae) commercialized in Iguape, Sao Paulo, Brazil

Namba, Thales Kodi 19 August 2018 (has links)
Orientador: Marlene Tiduko Ueta / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T08:04:24Z (GMT). No. of bitstreams: 1 Namba_ThalesKodi_M.pdf: 808082 bytes, checksum: 323221cbe3d59207547b2b04abbf693b (MD5) Previous issue date: 2011 / Resumo: globalização da cultura oriental e o aumento do consumo de pescado cru evidenciaram alguns problemas, entre eles doenças causadas por parasitas. Existe grande incidência de Ascocotyle sp. em peixes mugilídeos, muito utilizados na alimentação humana em diversas partes do mundo. O estudo teve como objetivos verificar a presença de metacercárias de trematódeos Heterophyidae em peixes mugilídeos comercializados no município de Iguape/SP; estabelecer a prevalência e densidade de metacercárias em peixes capturados em praia e rio; estabelecer correlação entre metacercárias e morfometria dos peixes; constatar o hábito alimentar da população do município de Iguape/SP em relação ao consumo do pescado e a eventual ocorrência de zoonose. Foram coletados 120 peixes, 60 tainhas Mugil liza e 60 paratis Mugil curema, sendo 30 de cada espécie capturados em praia e outros 30, em rio. Foram anotados os dados biométricos dos peixes e, após a necropsia, 5g de "pool de vísceras" e de musculatura de cada espécime foram fragmentados e homogeneizados para extração e contagem de metacercárias. M. liza mediram 45,6 ± 4,8 cm, com peso de 860,6 ± 228,4g, M. curema mediram 36,2 ± 2,4 cm, com 448,5 ± 127,8g de peso. As metacercárias, identificadas como Ascocotyle sp., estavam presentes em todos os exemplares de peixes. A prevalência de metacercárias não mostrou diferenças em relação ao sexo dos peixes. A densidade de metacercárias foi maior nas vísceras do que na musculatura para as duas espécies de peixes e maior em M. liza. Em M. curema a densidade de larvas nas vísceras foi significativamente maior em exemplares capturados em rios. Os testes de correlação de Pearson mostraram valores muito baixos entre prevalência e densidade de metacercárias e dados biométricos dos peixes. Residentes no município, pesquisados para levantamento do hábito alimentar, relataram consumir peixes, frequentemente tainhas, na maioria assados ou cozidos. Um total de 3,2% das pessoas pesquisadas relataram consumir peixe cru / Abstract: The world spread of oriental culture and the common use of fish which is not cooked showed some problems related to them like diseases caused by parasites. There is a great incidence of Ascocotyle sp. parasites in mullets fishes, which are part of human culinary spread all over world. The aim of the present study is to estimate the presence of trematode Heterophyidae metacercariae among mullets fishes commercialized at Iguape city; to evaluate the prevalence and density of metacercariae among fishes from the sea and river; to stablish the inter-relation between the presence of metacercariae and the fishes morphometry; to ascertain food habits among people from Iguape city and relate food fish habits to zoonosis occurrence. 120 fishes were select, 60 Mugil liza and 60 Mugil curema, half of each species from the sea and the other half from the river. All fishes biometrical data have been score and, pos-mortem, 5g of visceral pool and muscular tissue from each sample have been fragmented and homogeneized in order to stablish the presence and amount of metacercariae. M. liza were 45,6 ± 4,8 cm length and 860,6 ± 228,4g weigth; M. curema were 36,2 ± 2,4 cm length and 448,5 ± 127,8g weigth. Metacercariae identified as Ascocotyle were present in all fishes. There were no differences for prevalence between fishes sex. The major concentration of metacercariae samples have been identified in visceral organs when compared to muscular tissue of both fish species and much greater at visceral organs from M. liza. Larval visceral concentration of M. curema was significantly high among river species. Pearson correlation tests did not show close association between metacercariae prevalence/density and biometrial fish data. People from Iguape city use to eat grilled or cooked mullet. Total of 3,2% of people consume raw fish / Mestrado / Parasitologia / Mestre em Parasitologia
2

Life History Studies of Two Digenetic Trematodes, Bolbophorus Damnificus and an Unknown Clinostomoid Species, that Infect Channel Catfish Ictalurus Punctatus

Doffitt, Cynthia Michelle 09 December 2011 (has links)
The commercial production of channel catfish (Ictalurus punctatus) is major industry in Mississippi. Infections of channel catfish with the digenetic trematode Bolbophorus damnificus have often been associated with heavy economic losses in the industry. To efficiently control transmission of this trematode, the avian hosts need to be identified. In the first study, two American white pelicans, two double-crested cormorants, two great blue herons, and two great egrets were fed channel catfish infected with B. damnificus metacercariae. The presence of Bolbophorus damnificus ova in pelican feces at three days post infection (dpi) indicated the pelicans had patent infections. Mature B. damnificus were recovered from the intestines of both pelicans at 21 dpi. No B. damnificus infections were observed in the other bird species. In a second study, 33 American white pelicans, 34 double-crested cormorants, 35 great blue herons, and 32 great egrets were collected in the Mississippi Delta. The prevalence of B. damnificus in the American white pelican was 93.9%, with an average of 158 B. damnificus found per bird (range 0-681). Bolbophorus damnificus was not found in any of the other bird species. The results of these two studies confirm that the AWPE is the only proven natural host for B. damnificus. In a third study, two previously undescribed cercariae were found infecting rams-horn snails in commercial catfish ponds. In challenge studies, channel catfish were exposed to both cercariae types. Only one type of cercariae (type I) was infective to channel catfish. The first evidence of type I metacercariae was seen histologically at 14 dpi and grossly at 21 dpi. Development continued until 120 dpi, when both gross examination and histology suggested that the metacercariae were mature. The type I metacercariae appeared to cause little host damage. Molecular analysis of the 18S rRNA gene region indicated that the type I cercariae and metacercariae may be a species of Clinostomum. The data generated in these three studies provides additional information that can be used in the development of efficacious management schemes to control digenetic trematodes infecting commercial catfish.
3

Inventory, dynamics and impact of the trematodes parasites in bivalves with high economic importance / nventaire, dynamique et impact des parasites trématodes sur des bivalves à forte importance économique / Inventário, dinâmica e impacto dos parasitas trematodes em bivalves de elevada importância económica

Magalhães, Luísa Virgínia de Sousa 29 October 2018 (has links)
Parmi les agents qui modulent la dynamique des populations, le parasitisme est important mais souvent négligé. Il est urgent non seulement d’inventorier les différentes espèces de parasites, mais aussi de comprendre la sensibilité des hôtes à l’infection (notamment des bivalves) et étudier les interactions entre les parasites et les autres facteurs environnementaux. Par conséquent, cette thèse avait comme objectif principal de caractériser et de quantifier les communautés de trématodes (les plus abondants et répandus des macroparasites de bivalves dans les eaux côtières) qui infectent Cerastoderma edule (coque) et Donax trunculus (telline), deux des bivalves les plus importants au Portugal et en France d’un point de vue écologique et économique.Dans un premier temps, la dynamique des populations de bivalves a été étudiée en tenant compte de la relation entre la température et la période de recrutement et des effets en retour du recrutement sur la biomasse adulte. Pour cela, une base de données a été analysée couvrant 17 ans d’observations mensuelles d’une population de coques dans une réserve nationale (Banc d’Arguin, Arcachon, France). Ces observations à long terme ont montré que la durabilité d’une population de coques dépend du succès du recrutement. Pour les coques, le succès du recrutement a été montré comme étant en partie, mais pas totalement, dépendant de la température. Ainsi, la durée de vie d’une cohorte pourrait être estimée plus tôt, grâce à des indices se produisant en amont du recrutement. Suite à ces résultats, le rôle du parasitisme dans la dynamique des populations de bivalves a été étudié.Premièrement, en raison de leur forte pathogénicité pour les bivalves, une attention particulière a été accordée aux parasites Bucephalus minimus et Bacciger bacciger qui utilisent C. edule et D. trunculus, respectivement, comme premier hôte intermédiaire (où se développe le stade parasitaire sporocyste). [...]Deuxièmement, cette étude s’est concentrée sur l’infection des bivalves par les métacercaires, c’est-à-dire lorsqu’ils servent de second hôte intermédiaire dans le cycle de vie du parasite. […]Enfin, la sensibilité des bivalves à l’infection parasitaire a été évaluée expérimentalement lorsqu’ils sont confrontés à des facteurs liés au changement climatique (salinité, température et pH) et à la contamination (arsenic). Les résultats ont montré que l’exposition de l’hôte à des conditions de stress liées à des scénarios de changement global peut modifier le succès de l’infection parasitaire et altérer les réponse biochimiques de l’hôte.Les résultats présentés dans cette thèse ont amélioré la connaissance des effets de différentes variables sur les bivalves, soulignant le rôle crucial du parasitisme. S’ils sont appliqués, ces nouveaux concepts peuvent promouvoir la gestion durable des bivalves, une ressource marine importante, en augmentant son potentiel de production et donc son potentiel économique. / Among population dynamics drivers, parasitism is significant but often neglected. Beyond inventory of the various parasites, it is urgent to understand the susceptibility of hosts, namely bivalves, to infection, and to investigate the interaction among parasites and other environmental conditions.In this way, the present study aimed to characterize and quantify the trematode macroparasites, the most abundant and prevalent in coastal waters, infecting Cerastoderma edule and Donax trunculus, which are among the most ecologically important and economically explored bivalve species in Portugal and France.The first step was to study bivalve population dynamics, evaluating the relationship between temperature and recruitment timing and the reciprocal effects of recruitment on adult biomass. For this, a large database spanning 17 years of monthly observations of a cockle population inhabiting a national protected area (Banc d’Arguin, Arcachon, France) was analysed. Long-term observations showed that the sustainability of a cockle population is recruitment-success dependent. In cockles, recruitment success showed to be partly, but not only, dependent on temperature. Hence, the sustainability of a cohort could be set earlier, i.e. by processes happening before recruitment. Following this clue, the role of parasitism on the bivalve host population dynamics was explored.Firstly, due to high pathogenicity for bivalves, special attention was given to the parasites Bucephalus minimus and Bacciger bacciger which use C. edule and D. trunculus, respectively, as first intermediate hosts (where their sporocysts parasitic stage develops). […]Then, the study focused on metacercariae infection in its bivalve second intermediate host, a relationship that is usually reported as less deleterious. […]Lastly, the susceptibility of bivalves to parasites infection when challenged by climate change related factors (salinity, temperature and pH) and contamination (Arsenic) was experimentally assessed. Main results showed that hosts exposure to stressful conditions related to global change scenarios can modify the parasite infection success and induced host biochemical response alterations.The findings presented in this thesis improved the knowledge on the effects of different constraints on bivalves, highlighting the crucial role of parasitism. If applied, these new insights can promote the sustainable management of bivalves, such an important marine resource, with greater production and economic potential. / Entre os agentes que modulam a dinâmica populacional, o parasitismo é significativo masmuitas vezes negligenciado. É urgente não só inventariar as várias espécies de parasitas, bem comocompreender a suscetibilidade dos hospedeiros à infeção (nomeadamente os bivalves) e investigar ainteração entre os parasitas e outras condições ambientais. Pelo que, esta tese teve como objetivoprincipal caracterizar e quantificar os macroparasitas trematodes (os mais abundantes e prevalentesem águas costeiras) que infetam Cerastoderma edule (berbigão) e Donax trunculus (conquilha), doisdos bivalves mais importantes em Portugal e França tanto do ponto de vista ecológico comoeconómico.Primeiramente, a dinâmica populacional dos bivalves foi estudada, tendo em conta a relaçãoentre a temperatura e o período de recrutamento e os efeitos recíprocos do recrutamento nabiomassa de adultos. Para isso, foi analisada uma base de dados abrangendo 17 anos deobservações mensais de uma população de berbigões que habitam uma área nacional protegida(Banc d’Arguin, Arcachon, França). Estas observações de longa duração mostraram que asustentabilidade de uma população de berbigão é dependente do sucesso do recrutamento. Emberbigões, o sucesso do recrutamento mostrou ser em parte, mas não totalmente, dependente datemperatura. Por esta razão, a sustentabilidade de uma coorte pode estar a ser estabelecida maiscedo, isto é, por processos que acontecem antes do recrutamento. Seguindo esta pista, o verdadeiropapel do parasitismo na dinâmica populacional dos bivalves foi mais explorado.De seguida e devido à elevada patogenicidade para os bivalves, foi dada especial atençãoaos parasitas Bucephalus minimus e Bacciger bacciger que usam C. edule e D. trunculus,respetivamente, como primeiros hospedeiros intermediários (onde o estádio parasítico esporocisto sedesenvolve). […].Depois, este estudo focou-se na infeção dos bivalves por metacercariae, ou seja, quandoservem de segundos hospedeiros intermediários no ciclo de vida do parasita. […]Por fim, foi experimentalmente avaliada a suscetibilidade dos bivalves à infeção por parasitasquando desafiados por fatores relacionados com as alterações climáticas (salinidade, temperatura epH) e contaminação (Arsénio). Os resultados mostraram que a exposição dos hospedeiros acondições de stress relacionadas com cenários de alterações globais podem modificar o sucesso dainfeção parasitária e induzir alterações na resposta bioquímica do hospedeiro.As descobertas apresentadas nesta tese melhoraram o conhecimento dos efeitos dediferentes variáveis nos bivalves, salientando o papel crucial do parasitismo. Se aplicados, estesnovos pontos de vista podem promover a gestão sustentável dos bivalves, um recurso marinho tãoimportante, aumentando o seu potencial de produção e económico.

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