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A contribution to a generic revision of Simochromis and Tropheus (Pisces : Cichlidae) - from Lake Tanganyika, with special reference to the Pharyngeal Apophysis and its taxonomic importanceAxelrod, Glen S January 1978 (has links)
The purpose of this thesis is to investigate the taxonomic status of Simochromis and Tropheue. Material for the study wae collected during three visits to Lake Tanganyika in 1976-1977. Tropheus polli G. S . Axelrod 1977, was found and described, and a new species of Simochromis was found and will be described in a forthcoming paper. Nine colour varieties of Tropheus maorii and three colour varieties of Tropheus duboisi were found and described. A diagnosis and description, with colour photographs, is given using morphometries and meristics of the five species of Simochromis and four species of Tropheus. A dissection and cleaning technique tor the pharyngeal apophysis and lower pharyngeal bone is explained, together with a method for the interpretation of relative bone composition of the pharyngeal apophysis. Photographs are included. The dentition is examined, evaluated and figured. Doubt has been cast upon the taxonomic validity of the composition of the pharyngeal apophysis as an indicator of affinity at the sub familial level. This is shown by its seeming lack of functional relationship, apparent arbitrary variation, interspecific variability in Simochromis and Tropheus, and intraspecific variability in S. diagramma and T. duboisi. Thus, the apophysis cannot be considered a reliable cichlid taxonomic characteristic at any level of classification, unless its validity is Substantiated in each instance. Furthermore, it is considered very probable that the Tropheus-Simochromis species complex is a monophyletic assemblage at the genus level, on the basis of similar dentition and mouth form, which is unique in Lake Tanganyika. It is proposed on phyletic grounds that Simochromis and Tropheus be united into the one genus Tropheus, and that Tropheus be divided into the subgenera , Tropheus (Tropheus) and Tropheus (Simochromis), along the lines of its previous division in two separate genera. Characteristics supporting this division include differences in the anal and dorsal fin meristic counts noted in the original descriptions of the genera. In addition, two modifications of the dentition were found during the course of this study which are not mentioned in any previous literature. It is considered probable, that Tropheus (Tropheus) and Tropheus (Simochromis) are monophyletic sister groups within the Tropheus complex. Pseudosimochromis Nelissen 1977 is not considered to be a taxonomically valid genus on either phyletic or gradistic grounds, and is included within Tropheus (Simochromis). The lower pharyngeal bone of T . (S.) diagramma is considered to be plesiomorphic in tooth arrangement, size and shape. A preliminary worKing hypothesis is established on the basis of the conjectures made and other available information which supports the phyletic relationship suggested by Fryer and lIes (1972). An illustration is given.
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A study of the population dynamics, production and potential yield of the sardine Limnothrissa Miodon (Boulenger) in Lake KaribaMarshall, Brian Eric January 1987 (has links)
The limnology of Lake Kariba, especially those aspects that affect sardine biology, are described. The hydrological regime of the lake is seen as a major influence and may be one of the reasons why the fish are very much smaller in Kariba than they are in Lakes Tanganyika or Kivu. Growth was reassessed and there appeared to be a correlation between rates of growth and limnological parameters. In particular, the fish appeared to grow faster, but smaller, in the man-made lakes and this may be a consequence of food shortages brought about by their hydrological characteristics. Mortality rates were also much higher in Kariba and this tended to support the view that the lake is a relatively unsuitable habitat for the sardines. However, estimates of biomass, expressed in terms of lake volume, contradicted this as they were very similar in both Kariba and Tanganyika. The life history strategy of Limnothrissa in Kariba was therefore to reduce its size and increase its productivity in order to maintain the maximum possible biomass and its very high P/B̄ ratio was probably the means by which this was achieved. In terms of lake volume the predicted yields from the pelagic communities of Kariba and Tanganyika were very similar, equivalent to about 20 000 t annually for Kariba. This is close to the yield predicted by several empirical models and the fishery now appears to be entering a phase where increases in effort will not be matched by increased yields. The mechanisms for controlling effort in the fishery appear to be inadequate and particular concern was expressed about the lack of co-ordination between the Zimbabwean and Zambian fishery authorities in planning the development of this shared resource.
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Politics, politicians, and party Moshi, Tanzania ; 1968-69.Samoff, Joel. January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1972. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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Aspects of the biology of Ergasilus sarsi a gill ectoparasite of Lamprichthys tanganicanus from Lake Tanganyika11 September 2013 (has links)
M.Sc. (Zoology) / A literature survey revealed gaps in the knowledge on Ergasilus in Africa. This studied aimed to elucidate on some of these matters. Ergasilus sarsi was collected from Lamprichthys tanganicanus during an expedition to Lake Tanganyika in March 2010. The gills of the fish were removed and preserved for further studies. Preserved specimens were studied with dissection- and light microscopy. Some specimens were also studied with a scanning electron microscope (SEM). For light microscopy the specimens were sectioned and then stained with AZAN and H&E. A total of 32 Lamprichthys tanganicanus were collected and studied for ergasilids. The prevalence was 86.40%, the mean intensity 7.56 and the mean abundance 6.38. A total of 204 parasites were collected and only 27 hosts were infected. The highest intensity was 29 parasites. Pearson’s Chi-squared test was used to compare attachment preferences of Ergasilus sarsi. The parasite exhibited site selection but not host specificity. It was noticed that E. sarsi mostly attach to the tip of the gill filament of the second gill arch. The second gill arch receives the largest portion of water flow supporting distribution of newly hatch ergasilid nauplius. There was no significant preference for the dorsal, medial and ventral attachment sites (p-value = 0.000542). However, significant preference between distal, central and proximal regions (p-value = 1.19) was observed. Fryer (1965) observed that the pathology caused by ergasilids is related to their attachment position on the host. Ergasilids display variation regarding morphology of their second antennae. Some have spines and others elongated antennae that wraps around the entire gill filament. This study shows that Ergasilus sarsi (with no spines on the second antennae) wraps around the gill filament and cause considerable damage to the host. The entire gill filament structure changed due to lamellar fusion and proliferation of mucous – and epithelial cells. Comparison of an infected gill to a healthy gill revealed differences. The compression caused by the second antennae caused some blood vessels to rupture resulting in haemorrhage. The swimming legs of the parasite also cause considerable damage by scraping gill tissue off the host and pushing it towards the mouth parts of the parasite. Mucous cells, gill epithelium and blood cells were observed in the vicinity of the mouth and in the intestine of the parasite. An increase in the number of Rodlet cells and mast cells were also observed on the gills in close proximity to the parasite. Increase in the number of these cells clearly indicate an inflammatory response. This is the first record of Ergasilus sarsi on Lamprichthys tanganicanus. This study also provides the first detailed description of the pathology caused by Ergasilus sarsi as well as the attachment distribution of this parasite.
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LATE QUATERNARY PALEOLIMNOLOGY IN THE SOUTHERN HEMISPHERE TROPICSMcGlue, Michael Matthew January 2011 (has links)
Lake deposits are widespread throughout the Phanerozoic rock record and have long intrigued geologists and paleobiologists in search of natural resources or fossil biota. Low-energy lacustrine depositional environments, characterized by relatively rapid sediment influx rates and shallow zones of bioturbation, likewise produce highly-resolved archives of climate and ecosystems evolution. This dissertation describes four studies that use lake sediments for Quaternary environmental analysis. In East Africa, many decades of prior study provided the critical framework necessary for in-depth paleoenvironmental research at Lake Tanganyika (3° - 9°S). Seismic stratigraphic analysis integrated with radiocarbon-dated sediment cores from the Kalya horst and platform document a dramatic lake level lowstand prior to ~106 ka and a minor, short-lived regression during the Last Glacial Maximum (32 - 14 ka). Paleobathymetric maps reveal that Lake Tanganyika remains a large, connected water body even during episodes of extreme drought, which has implications for local and regional fauna. Over shorter timescales, geochronological, taphonomic and sedimentological analyses of shell beds around Kigoma (central Lake Tanganyika) document three distinct facies-types that are time-averaged over the latest Holocene. Lake level fluctuations associated with the termination of the Little Ice Age (~ 16th century CE) and subsequent encrustation played a key role in shell bed formation and persistence along high-energy littoral platforms, which has implications for structuring specialized communities of benthic fauna. In central South America (18° - 22°S), we studied the limnogeology of small lakes in the Puna and the Pantanal. Analyses of these sites were undertaken to: 1) ascertain how the lakes act as depositional basins; 2) assess sedimentation rates; and 3) construct limnogeological databases to guide future interpretations of ancient sediment cores. At Laguna de los Pozuelos (Argentine Puna), linear sedimentation rates approach 0.14 cm*y⁻¹ in the playa-lake center, and litho- and organo-facies development are dominantly controlled by basin hydrology, climate and biological feedbacks (both nutrient cycling and bioturbation) from waterbirds. At Lagoas Gaíva, Mandioré and Vermelha (Brazilian Pantanal), short-lived radioisotopes indicate uninterrupted depositional rates of 0.11 - 0.24 cm*y⁻¹, and hydrochemical and depositional patterns respond sensitively to changes in the seasonal flooding cycle of the Upper Paraguay River.
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We are one: the emergence and development of national consciousness in TanzaniaDemulling, Katrina 08 April 2016 (has links)
This thesis examines the emergence and development of national consciousness and identity in the East African nation Tanzania. A work in the science of humanity, it connects traditional social sciences through the approach of mentalism. To date, research on African nationalism centers on the nation-state and national party, and on the teleological assumption that nation building implies cultural unification within the boundaries of the state's territory. National sovereignty is seen as a natural desire; nationalism in Africa is conflated with anti-colonialism and treated as the inevitable transition from the colonial to post-colonial order. Yet this approach to the study of African nationalism cannot account for many important processes, such as why many African states have failed, why corruption is rampant, and why authoritarian regimes predominate.
I argue many aspects of modern African history are impossible to understand without recognizing that nationalism ushers in modernity and transforms and affects the major cultural institutions. I show how the process of national identity formation within Tanzania was the same process that occurs elsewhere. Nationalism did not exist in Tanzania among the native inhabitants prior to independence. Moreover, the creation of a shared sense of national identity began only after independence: the independent state was not a nation. In examining the national image created by several integral Tanzanian intellectuals, I reflect both on the significance they placed on their narratives and how it shaped the wider social world and the identities of those they influenced.
My argument regarding Tanzania may apply to Africa more generally. The processes I described appear true of social and political developments across the continent. Many in Africa do now see themselves as equal members of sovereign societies and believe that the people are the ultimate source of political legitimacy. This work provides a methodology and argument that can be applied to address additional questions of how specifically nationalism has transformed African societies.
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Supply response and market imperfections : the implications for welfare analysisMartuscelli, Antonio January 2013 (has links)
In this thesis we investigate the supply side of farm households in the Tanzanian region of Kagera and incorporate the results into a welfare analysis of price shocks and trade policy options. The first chapter discusses the relevance of agriculture as an engine of growth and poverty reduction and introduces the context and the data used for the empirical analysis. The second chapter tests for separability of the households demand and supply sides and then estimates supply functions for the main crops. We find that separability cannot be rejected for this sample and that farmers are only partially responsive to price incentives. The third chapter analyses the role of market participation decisions and transaction costs for food supply. We find that transaction costs play an important role in households supply decisions. Moreover, we show that there is a positive although small supply response to prices once controlling for the unresponsiveness of self-sufficient households. The fourth chapter extends the standard welfare impact analysis of price shocks to incorporate supply and demand responses as well as the role of market participation and transaction costs. We find that the results are sensitive to the introduction of households' output, wage and consumption responses.
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Ujamaa na dini : a study of some aspects of society and religion in Tanzania 1961-1977 /Westerlund, David. January 1980 (has links)
Akademisk avhandling--Religionshistoria--Stockholm, 1980. / Bibliogr. p. 187-198.
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Eco-ethology of shell-dwelling cichlids in Lake TanganyikaBills, Ian Roger January 1997 (has links)
Observations of habitats are reported. A series of underwater experiments were conducted in natural habitats to answer questions concerning a) why Lamprologus ocellatus and Lamprologus ornatipinnis bury gastropod shells refuges into the substrate, and b) to examine interspecies differences in shell-using behaviours. Some behaviour patterns were analysed using phylogenetic methods. Lamprologus ocellatus and L. ornatipinnis responded to new shells in a variety of ways, shells were moved, buried (and used) or hidden (buried and not used). How shells are utilised seems to be dependant on a complex of factors such as the size and quality of new the shell and the number already in the territory. Shell use may also be affected by neighbour species, sex, size and predation levels. There are interspecific differences in the size of shells used and the methods of shell use. The latter results in species-characteristic shell orientations, vertical burial in L. ocellatus and horizontal burial in L. ornatipinnis. Shell orientation does affect other species/use of shells. Shell movement and vertical orientation appear to be apomorphic while shell hiding and burial are pleisiomorphic within the genus Lamprologus. Numerous cues are involved in stimulating shell burial. Most of these cues are actively sought by the fish by external and internal inspections. Shell burial therefore appears to be a method of reducing the information gathering ability of potential shell-dwelling competitors. Shell burial can therefore be regarded as an investment process which enhances the residents ability to defend its territory. Males can also control the distribution of open shells within teritories and thus control mate access to shells. This behaviour could be a significant factor in the evolution of marked sexual dichromatism exhibited within the genus.
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Three essays on agriculture and economic development in TanzaniaSilwal, Ani Rudra January 2016 (has links)
One cannot study poverty in Tanzania without understanding the agricultural sector, which employs more than two-thirds of the population and accounts for nearly a quarter of national GDP. This thesis examines three themes that focus on the difficulties that rural Tanzanians face in achieving a reasonable livelihood: the adverse legacy of a failed historical policy, a difficult climate, and market failures. The first empirical chapter examines the legacy of the villagization program that attempted to transform the predominantly agricultural and rural Tanzania. Between 1971 and 1973, the majority of rural residents were moved to villages planned by the government. This essay examines if the programs e↵ects are persistent and have had a long-run legacy. It analyzes the impact of exposure to the program on various outcome measures from recent household surveys. The primary finding of this study is that households living in districts heavily exposed to the program have worse measures of various current outcomes. The second empirical chapter examines the role of reliability of rainfall, which is important in Tanzania as agriculture is predominantly rain-fed and a small fraction of plots are irrigated. This chapter investigates if households cope with this major risk to income by re-allocating their labor supply between agriculture, wage labor, and self-employment activities. This chapter combines data on labor allocation of households within and outside of agriculture from the National Panel Survey with high-resolution satellite-based rainfall data not previously used in this literature. The primary finding of this study is that households allocate more family labor to agriculture in years of good rainfall and more labor to self-employment activities in years of poor rainfall. Market failures are often cited as a rationale for policy recommendations and government interventions. The third chapter implements four tests of market failures suggested in the literature, all of which rely on the agricultural household model but di↵er in how market failures are manifested. The common finding of these tests is that market failures exist in agricultural factor markets in Tanzania, although significant heterogeneity exists. Markets are more likely to fail in rural areas, remote locations, and are more likely to affect female-headed households. Households are also more likely to face market failure when they try to supply labor to the market than when they try to hire labor from the market.
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