Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 38 for “"Freshwater fishes"”.
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Various aspects of reproductive control in freshwater fishes
Male and female guppies (Poecilia reticulata) were treated with either methyl testosterone, cyproterone acetate (CA) (an antiandrogen) or a combination of the two steroids to determine effects on behavior, coloration, and gametogenesis. The antiandrogen did not fully block the effects of endogenous …
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Detection of non-native freshwater fishes using environmental DNA
… the use of eDNA methods to detect non-native freshwater fish. Sampling methods and species-specific primers were developed for pumpkinseed Lepomis gibbosus, topmouth gudgeon Pseudorasbora parva, sunbleak Leucaspius delineatus, and fathead minnow Pimephales promelas. All four species were …
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Freshwater fishes and microplastics in an era of multiple stressors
… that may cause negative impacts when consumed by freshwater fishes. However, microplastic exposure occurs in combination with other interacting multiple stressors, for example urbanisation and parasite infection, and may potentially cause a range of synergistic negative impacts. Understanding the …
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Biodiversity and systematics of parasitic Crustacea infesting southern African freshwater fishes
… to thrive in an array of habitats and hosts. Freshwater parasitic crustaceans are mostly found attached to the external surfaces of their host. These attachment structures are also adapted to the sites of infestation on their hosts. As a result of the pathological impacts of certain parasitic …
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MECHANISMS AND IMPACTS OF LAND-USE CHANGE ON FRESHWATER FISHES IN SUNDALAND
Freshwater fishes of Sundaland face threats from deforestation, yet the associated impacts and mechanisms remain inadequately understood. In this context, I sought to address the following: 1) Which are the priority regions for freshwater fish conservation in Sundaland?; 2) What are the impacts of …
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Evolutionary and Ecological Patterns of Body Size in North American Freshwater Fishes
… is known about the ecology of North American freshwater fishes, few studies have incorporated phylogenetic information into analyses of ecological and biogeographic data. Consequently, little attention has been given to the relationship between evolutionary trends, and regional and local …
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ECOLOGICAL NICHE MODELING AS A PREDICTIVE TOOL: ASIATIC FRESHWATER FISHES IN NORTH AMERICA
… the ecological requirements of 33 Asiatic freshwater fishes from native-range occurrence points, and to use these data to forecast their invasive potential in North America. The silver carp, bighead carp, grass carp, black carp, northern snakehead, Asian swamp eel and the oriental …
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Defining rarity and determining the mechanisms of rarity for North American freshwater fishes
… species as rare or common. I defined rarity for freshwater fishes based on the range extents, habitat breadths, and site abundance and examined the relationship between these dimensions of rarity and imperilment. Imperiled fishes were most often rare by all three dimensions, whereas undesignated …
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Relationships Among Swimming Ability, Habitat use, and Morphology of Freshwater Fishes from Texas and Louisiana
… selection and morphology were assessed for freshwater fishes from Gulf slope, Rio Grande, Red River, and Canadian River drainages in Texas and Louisiana to better understand the influence that flow has on structuring fish assemblages. Swimming ability, relative (body lengths per second, …
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Conservation of the native freshwater fishes of the Cape floristic region (South Africa) : management of non-native species
Freshwater fishes are among the most threatened taxa in the world. Increasing demand for freshwater, habitat degradation and the introduction of non-native species, will continue to place pressure on the remaining native freshwater fishes. A meta-analysis estimated that more than 90% of river …
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Trajectories of Change in South Africa's Freshwater Fish Fauna
In South Africa, freshwaters are the most threatened ecosystems in the country, facing pressure from water abstraction, land-use change, pollution, invasive species and climate change. These anthropogenic pressures are directly impacting the diversity, abundance, and survival of freshwater fauna …
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Towards an understanding of seasonal ecophysiology in north-temperate fish
… seasonally motivated strategies in northern freshwater fishes remains quite limited, regardless of its potential utility for predicting responses to shifting seasonal environments. In this dissertation, I investigated how fish respond to the highly seasonal energetic demands associated with …
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SCALE-DEPENDENT VARIATION IN MOLECULAR AND ECOLOGICAL PATTERNS OF INFECTION FOR ENDOHELMINTHS FROM CENTRARCHID FISHES
… variability of helminths in a widely distributed freshwater fish host. Equally rare are studies considering both large- and small-scale patterns of infection of helminth communities in a widely distributed aquatic host(s). Vanishingly few studies exist making large-scale population-level …
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Ecological consequences of indigenous and non-indigenous freshwater fish parasites.
… can have considerable consequences for their freshwater fish hosts, irrespective of whether they are intermediate or final hosts. The ecological consequences of infection arise from processes including parasite manipulation, where the parasite manipulates the host to increase their chance of …
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FATSOLUBLE VITAMINS IN BLACK SEA AND FRESHWATER FISH//МАСТНОРАЗТВОРИМИ ВИТАМИНИ В ЧЕРНОМОРСКИ И СЛАДКОВОДНИ РИБИ
… red mullet, sprat, shad and turbot) and three freshwater fish (common carp, bighead carp, grass carp) were observed. This work also present an evaluation of the effect of steaming process on fat soluble vitamin contents in one of the analyzed freshwater fishes (freshwater trout) and three …
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The impact of carbon dioxide on freshwater fish behaviors
Freshwater environments have the potential to be impacted by acidification due to increases in dissolved carbon dioxide (CO2). Recent work in the marine environment suggests that increased CO2 levels due to climate change can negatively affect a fish’s ability to detect predators, home to natal …
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Behavioral Measures and Ecological Correlates of Vision in Poeciliid Fishes
… Poeciliidae are a diverse family of Neotropical freshwater fishes and are excellent models for visual ecology research given longstanding interest in visual signaling in this group. However, despite extensive research investigating the form and function of visual signals in the poeciliids, there …
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Geomorphic Assessment and Flow Modeling of Pearl Darter (Percina aurora) Habitat in the Pascagoula River Watershed
<p>Freshwater ecosystems are complex ecosystems driven by hydrologic, geomorphic, and biological processes. Considering both abiotic and biotic factors is important to understanding resident species habitat. Geomorphology is a known, but often neglected factor in habitat assessment for freshwater …
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