For many decades the taxonomy of the genus Dinlostomum von Nordmann, 1832 has remained in a state of confusion in the literature. The present study aimed at determining where the problems lie and what-can be done to resolve them. A brief survey of the farmed and wild populations of fish in Scotland indicated that there were four highly prevalent forms of Diolostomum metacercariae in the eyes of the fish. Type 1 were located in the lens of rainbow trout (Salmo gairdneri Richardson), Type 2 in the humour of rainbow trout, Type 3-in the retina of rainbow trout and Type 4, in the retina of perch (Perca fluviatilis Mitchell). The four types were examined morphmetrically using-Principal Components Analysis (PCA) and this revealed that the four types grouped separately. Type 1 metacercariae could be distinguished by the closeness of their lappets, Type 3 by their small size, Type 4 by their large size and high breadth to length ratio and Type 2 lacked any of these distinguishing features. The culture of the metacercariae to adults revealed biological differences between the four types. Type 1 grew in both domestic chickens and herring gull chicks (Larus argentus Pontoppidan), but best in the latter. Type 2 also grew in both of these hosts, but best growth was achieved in the chicken. Chickens were refractive to Types 3 and 4, but both established and developed in herring gulls. The adults obtained from the bird host were also examined morphometrically using PCA, and again the four forms grouped separately, indicating that they were morphologically distinct. In experimental infections it was found that the hind-body did not fully develop until day 16-18 p. 1. and, therefore, morphological analysis was only carried out on worms which had been cultured in the bird host for more than 16 days. This was particularly significant in Type 1 adults where the relative position of the ovary was affected. Type 1 adults were distinguished from the others by the posterior position of the ovary in the hind-body, Type 2 by the small dimensions of the ovary and its position at the intersegmental region, Type 4 by the anterior extent of the vitellarlum and Type 3 adults lacked any of the distinguishing features. Completion of the life-cycle of the diplostomes also revealed differences in the cercarial stage both morphologically and in the sensory papillar patterns determined by the use of chaetotaxy. The life-cycle was completed for all the diplostomes apart from Type 2. It was found that Type 2 miracidia would not establish in Lvmnaea Dereger, although the other three types established. Infection of fingerling rainbow trout with Types 1,3 and 4 cercariae revealed that the trout were refractive to Type 4 cercariae, but Types 1 and 3 established in the lens and retina, respectively. When perch were exposed to Type 4 cercariae it was found that metacercariae established in the retina. This indicated that the metacercariae are very site specific and also may show some host specificity. Biochemical analysis of the metacercarlae of Types 1-4 by analysing isoenzyme profiles with the use of Isoelectric Focusing (IEF) also revealed that there may also be some differences biochemically between the four types. Identification of the four diplostomes was attempted using the keys (Dubois, 1970; Shigin, 1986) and information available in the literature. However, a confident identification could only be made for Type 1 which keyed down to D. soathaceum sensu Niewiadomska. The other three types could not, however, be identified with such confidence, but tentative identifications were made. The fact that the metacercarial, cercarial and adult stages were obtained and described for three out of the four diplostomes and still a positive identification could not be made perhaps reflects the inadequecies of the keys available in the literature. The present study has successfully determined the problematic areas surrounding the taxonomy of the genus and has, therefore, cleared the way for future study.

Made available in DSpace on 2016-01-26T18:55:31Z (GMT). No. of bitstreams: 1 dissertacao.pdf: 491677 bytes, checksum: 83f265cf94c6d8c1fbbc0b78a34e8a36 (MD5) Previous issue date: 2011-02-24 / Austrodiplostomum compactum (Digenea, Diplostomidae) Lutz,1928 is a trematode that causes ophtalmic and tissue lesions in a variety of fish species. The aim of this study was to evaluate the parasitism index of A. compactum in fishes captured in Paraná river, Presidente Epitácio, São Paulo, Brazil, and the relation of these index with weather and water quality. Monthly, specimen of Plagioscion squamosissimus, Geophagus surinamensis, Hoplias malabaricus and Cichla sp. were captured. All individuals captures were individually examined. Muscle, organs, cavities and ocular globe were macroscopically evaluated. Recovered parasites were stained and identified under optic microscopy. Influence of climate (temperature and rainfall) and water quality (temperature, oxigen level, pH e alcalinity) on the prevalence was investigated. All the recovered parasites were restricted to ocular globe fishes. A. compactum was observed in 93.3%, 66.6%, 52.1%, 46.1%, respectively, of P. squamosissimus, H. malabaricus, Cichla sp. and G. surinamensis. Prevalence of H. malabaricus and Cichla sp. was higher in autumn, whereas G. surinamensis was higher in winter than in the other seasons. Regarding P. squamosissimus, it was observed a prevalence of 100% and recovery of the parasite in the whole year. Parasite recovery was directly proportional to the high temperature and rainfall regimen. Based on the results it is possible to admit that the river Paraná fish of commercial value are susceptible to infection by A. compactum. / Austrodiplostomum compactum Lutz,1928 (Digenea, Diplostomidae) é um trematódeo responsável por lesões oculares e teciduais em diversas espécies de peixes. Este estudo avaliou os índices parasitológicos de A. compactum em peixes do rio Paraná, Presidente Epitácio, São Paulo, Brasil, e sua relação com o clima e qualidade da água. Foram coletados, mensalmente, exemplares de corvina (Plagioscion squamosissimus), de cará (Geophagus surinamensis), de traíra (Hoplias malabaricus) e de tucunaré (Cichla sp.). Os peixes foram avaliados individualmente. A musculatura, órgãos, cavidades e globo ocular foram examinados macroscopicamente. Os parasitos recuperados foram corados e identificados sob microscopia ótica. Foi avaliada relação entre prevalência e clima (temperatura e pluviosidade) e qualidade da água (temperatura, oxigênio dissolvido, pH e alcalinidade). Todos os parasitos recuperados estavam restritos no globo ocular. Das 57 corvinas capturadas, 56 (93,3%) estavam infestadas. Em relação à traíra, tucunaré e cará, a prevalência foi, respectivamente, de 66,6% (17/28), 52,1% (12/23) e 46,1% (18/40). As maiores prevalências foram observadas no outono, no caso de traíra e tucunaré, e no inverno, em cará. Houve 100% de corvinas parasitadas em todas as estações, com exceção de um animal capturado no outono. A recuperação de parasitos foi diretamente proporcional à elevação da temperatura e da pluviosidade. Os dados mostram que os peixes de valor comercial do rio Paraná são suscetíveis à infecção por A. compactum.

Made available in DSpace on 2016-07-18T17:53:07Z (GMT). No. of bitstreams: 1 dissertacao.pdf: 491677 bytes, checksum: 83f265cf94c6d8c1fbbc0b78a34e8a36 (MD5) Previous issue date: 2011-02-24 / Austrodiplostomum compactum (Digenea, Diplostomidae) Lutz,1928 is a trematode that causes ophtalmic and tissue lesions in a variety of fish species. The aim of this study was to evaluate the parasitism index of A. compactum in fishes captured in Paraná river, Presidente Epitácio, São Paulo, Brazil, and the relation of these index with weather and water quality. Monthly, specimen of Plagioscion squamosissimus, Geophagus surinamensis, Hoplias malabaricus and Cichla sp. were captured. All individuals captures were individually examined. Muscle, organs, cavities and ocular globe were macroscopically evaluated. Recovered parasites were stained and identified under optic microscopy. Influence of climate (temperature and rainfall) and water quality (temperature, oxigen level, pH e alcalinity) on the prevalence was investigated. All the recovered parasites were restricted to ocular globe fishes. A. compactum was observed in 93.3%, 66.6%, 52.1%, 46.1%, respectively, of P. squamosissimus, H. malabaricus, Cichla sp. and G. surinamensis. Prevalence of H. malabaricus and Cichla sp. was higher in autumn, whereas G. surinamensis was higher in winter than in the other seasons. Regarding P. squamosissimus, it was observed a prevalence of 100% and recovery of the parasite in the whole year. Parasite recovery was directly proportional to the high temperature and rainfall regimen. Based on the results it is possible to admit that the river Paraná fish of commercial value are susceptible to infection by A. compactum. / Austrodiplostomum compactum Lutz,1928 (Digenea, Diplostomidae) é um trematódeo responsável por lesões oculares e teciduais em diversas espécies de peixes. Este estudo avaliou os índices parasitológicos de A. compactum em peixes do rio Paraná, Presidente Epitácio, São Paulo, Brasil, e sua relação com o clima e qualidade da água. Foram coletados, mensalmente, exemplares de corvina (Plagioscion squamosissimus), de cará (Geophagus surinamensis), de traíra (Hoplias malabaricus) e de tucunaré (Cichla sp.). Os peixes foram avaliados individualmente. A musculatura, órgãos, cavidades e globo ocular foram examinados macroscopicamente. Os parasitos recuperados foram corados e identificados sob microscopia ótica. Foi avaliada relação entre prevalência e clima (temperatura e pluviosidade) e qualidade da água (temperatura, oxigênio dissolvido, pH e alcalinidade). Todos os parasitos recuperados estavam restritos no globo ocular. Das 57 corvinas capturadas, 56 (93,3%) estavam infestadas. Em relação à traíra, tucunaré e cará, a prevalência foi, respectivamente, de 66,6% (17/28), 52,1% (12/23) e 46,1% (18/40). As maiores prevalências foram observadas no outono, no caso de traíra e tucunaré, e no inverno, em cará. Houve 100% de corvinas parasitadas em todas as estações, com exceção de um animal capturado no outono. A recuperação de parasitos foi diretamente proporcional à elevação da temperatura e da pluviosidade. Os dados mostram que os peixes de valor comercial do rio Paraná são suscetíveis à infecção por A. compactum.

This study is focused on cercarial cysteine peptidases of the trematode Diplostomum pseudospathaceum. It follows previous research which confirmed the presence of a 24kDa cysteine peptidase in cercariae biochemically and by mass spectrometry. It was postulated, that the function of this peptidase is histolytic, when cercariae penetrate the tissues. During an attempt to purify this peptidase and characterize its peptidolytic activity, it was found out that the cercarial homogenate containsmore different peptidases varying in their pI. Tests of peptidolytic activity and inhibition have shown that these peptidases are cathepsin L-like. They are active over a broad spectrum of pH with optima of activities in weakly acidicor neutral pH. Using degenerate primers based on conserved motifs of cysteine pepridases, partial sequences of three genes for cathepsin L of D. pseudospataceum (DpCL1, 2 a 3) were obtained. Then the complete sequences of DpCL2 and 3 genes and partial sequence (without 5'end) of DpCL1 were obtained by RACE PCR. To confirm function of these peptidases we tried to immunolocalize them. We assumed that they are localized in penetration glands. Preliminary results suggested that some of the cathepsins could be also localized in the gut of cercariae. For more detailed biochemical...

In this thesis, the efficiency of orally applied praziquantel (PQ) in two concentrations (Pramik 1 and Pramik 2) and mebendazole (MB) were tested on metacercaria of eye flukes (Diplostomum spathaceum, Rudolphi, 1819) in the grass carp (Ctenopharyngodon idella, Valenciennes, 1844). Naturally infected fish (average fish weight was 1.6 g and standard deviation was 0.1) were divided into four groups, for each tested group (Pramik 1, Pramik 2 and MB) belonged two aquariums of 100 liters each with 25 fish and for a control group belonged three aquariums of 100 liters each with 25 fish. The fish in the individual groups were fed with medicated feed containing praziquantel (Pramik 1 - 2.5 g PQ. kg-1 of feed, Pramik 2 - 1.25 g PQ. kg-1 of feed) and medicated feed mixture KP1 enriched with mebendazole (2.5 g MB. kg-1 of feed). The control group was fed with KP1 without drug addition. During the test the parasitological examinations of the ophthalmic lens were performed. The prevalence and intensity of infection were recorded. In the group of fish fed with medicated mixture containing MB, no statistically significant differences of the intensity of the infection indicating the MB potential in the fight against this fish infection were reported during the test. In the case of tested groups of fish fed with medicated feed mixture containing PQ (Pramik 1, Pramik 2), a statistically significant difference in the intensity of the infection was proved compared with the control group already after the first examination (estimated dose of consumed PQ. kg-1 of weight of fish = 500 and 250 mg). Near complete elimination of the eye flukes occurred in the group fed with feed mixture Pramik 1 after the expected consumption of 900 mg PQ. kg-1 of weight of fish. Statistically significant differences in the intensity of the infection in PQ treated fish groups compared to control groups indicate the usability of medicated feed containing PQ in the fight against fish diplostomosis.