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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

Metazoan parasites and health of selected cyprinids at Nwanedi-Luphephe dams

Mbokane, Esau Mathews January 2011 (has links)
Thesis (M.SC. (Aquaculture)) --University of Limpopo, 2011 / The present MSc dissertation emanates from seasonal surveys conducted by the fish parasitological group of the Department of Biodiversity and Aquaculture Research Unit of the University of Limpopo, Turfloop Campus. The first part of the present study was aimed at investigating the metazoan parasites of three cyprinids occurring in the Nwanedi-Luphephe Dams. The main purpose of it was to determine temporal changes in the intensity of infestation in terms of prevalence, mean intensity and abundance of parasite species parasitizing the cyprinids studied over a two year period. Ecological parameters including species host-specificity, seasonality, and gender preference and host size versus species intensity are discussed for each parasite. Altogether 152 specimens were examined for parasites and a total of 2 432 metazoan parasites of ten species were recorded. At the sampling site, all three hosts co-occurred, however, a substantial proportion of Barbus radiatus was collected from the perennial stream feeding one of the twindams. Fish were sampled by means of gill nets and electrofishing or seine netting in accordance with the habitat conditions. Hosts were killed and organs investigated for metazoan parasites. After collection of parasites, standard methods for processing individual parasites were followed. The results obtained revealed the following groups of parasites; monogeneans (ectoparasites) included Dactylogyrus spinicirrus, D. afrolongicornis afrolongicornis, D. afrolongicornis alberti, Afrodiplozoon polycotyleus, Gyrodactylus sp., and Dogielius sp. (all recorded from the gills); Crustacea, Dolops ranarum was found from the mouth cavity, gills and skin of Labeobarbus marequensis. Of these, only two specialists, both monogeneans, were found on Barbus trimaculatus namely, D. afrolongicornis afrolongicornis and D. afrolongicornis alberti. Based on morphology of the haptoral hard parts, these two species were almost similar to each other than to D. spinicirrus. The appreciable difference between D. afrolongicornis afrolongicornis and D. afrolongicornis alberti was mainly in the shape of the marginal bar. Both D. spinicirrus and A. polycotyleus were widely distributed and recorded on the gills of all hosts during all seasons. Both species were recorded for the first time on B. radiatus. Also, D. spinicirrus was recorded for the first time on the gills of B. trimaculatus. Based on comparison with the original material, the species could be identified to species level. These analyses provided sufficient evidence for restoration of Afrodiplozoon polycotyleus as a valid taxon. The existence of two species, Gyrodactylus sp. and Dogielius sp. were recorded for the first time on B. radiatus in South Africa, and this possibly represents new species. The endoparasites included the following groups: digeneans- Diplostomulum metacercariae from the eyes of Lb. marequensis, Ornithodiplostomum sp. and black spot (grubs) were recorded from B. trimaculatus. The latter was also recorded in the muscle of B. radiatus. Unidentified digenean cysts were recovered from the gills and in the body cavity of both Lb. marequensis and B. trimaculatus; nematodes were represented by Contracaecum larvae in the body cavity of both Lb. marequensis and B. trimaculatus; cestodes were represented by gryporynchid larvae from the intestine of B. radiatus. The general high prevalence and intensities of ectoparasites recorded is an indication that the Nwanedi-Luphephe Dams has a biotic mechanism which might have enabled it to sustain the growth rate of ectoparasite intra-population. There was no correlation between either fish length or condition factor and the number of parasites. The study indicated that the abundance of monogeneans is partly influenced by season and that of endoparasites was principally governed by the presence of intermediate hosts and definitive hosts. The second part of this dissertation dealt with the health status of Lb. marequensis. Fish health was assessed using condition-related indices including condition factor and a modified Health Assessment Index (HAI) and the associated Parasite Index (PI). The HAI was performed to determine and examine any macroscopic abnormalities regarding external features and internal organs. The purpose of combining the two indices was to use the infestation of the metazoan parasites found on and/or in Lb. marequensis to determine whether or not the environment they live in was healthy. Both indices together with the condition factor provided relatively simple and rapid indications of how well fish were coping in their environment. The HAI score varied amongst the four sampling seasons. The highest individual mean value was 63 in winter, followed by a score of 50 in autumn, while the lowest were 42 and 33 in summer and spring respectively. To authenticate the HAI and PI data, certain water quality variables were measured and are discussed in detail in this dissertation. The Nwanedi-Luphephe Dams are generally believed to have good water quality. This was supported in this study; conditions assessed in fish using the aforementioned indices did not differ greatly between seasons, nor did the conditions deviate appreciably from normality. The HAI values were low overall which signifies a healthy fish profile for the system. The present investigation showed the existence of differences in the occurrence of individual parasite to be linked to water temperature changes. Thus, seasonal changes do influence parasite developmental stages to a certain degree. Tested heavy and trace metals were within the permissible limits as provided by the Department of Water Affairs and Tourism (DWAF, 1996).
2

Metazo?rios parasitos de Pimelodus spp. e estrutura da comunidade parasit?ria de Pimelodus maculatus (Siluriformes: Pimelodidae) coletados em duas bacias hidrogr?ficas do Brasil / Metazoan parasites of Pimelodus spp. and structure of the parasite community of Pimelodus maculatus (Siluriformes: Pimelodidae) collected in two river basins of Brazil

Vieira, Vivian Suane de Freitas 20 January 2016 (has links)
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.

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