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 13 of 13 for “"benthic fish"”.
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Multiple-scale habitat models of benthic fish abundance in riffles
… underwater observation as a method of estimating benthic fish densities is also assessed. Distributions of perpendicular sighting distances indicate models assuming equal sighting probability are not appropriate for benthic species but distance sampling models assuming decreased sighting …
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Ecological impacts of shrimp trawling on juveniles of selected benthic fish species in the southwestern Gulf of Maine
… of shrimp trawling on juveniles of selected benthic fish were studied in the southwestern Gulf of Maine. The fish community and selected environmental variables were sampled at two sites in summer and winter during 1998 and 1999. The community was composed of 24 species in 12 families. Site 1 …
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Crayfish: Scavenger or deadly predator? Examining a potential predator-prey relationship between crayfish and benthic fish in aquatic food webs
Benthic food webs are complex and often poorly understood. Crayfish in particular play a key role in the transfer of energy to higher trophic levels, and can constitute the highest proportion of benthic invertebrate biomass in an aquatic system. Commonly referred to as a keystone species, crayfish …
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Characterizing Patterns Of Round Goby (Neogobius Melanostomus) Distribution Using Morphometrics, Occupancy Modeling, And Population Genetics
… goby invasion and the native pumpkinseed sunfish Lepomis gibbosus population along the lake shoreline as reflected by morphological differences, (2) estimated the co-occupancy of round goby and native benthic fish (i.e. darters) in the tributary system and (3) analyzed the impact on …
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Association of Lead and Zinc on Fish Diversity in the Spring River Basin, Missouri
… of this thesis project was to determine if fish diversity and community integrity were associated with zinc and lead contamination in the Spring River Basin, southwest Missouri. Sampling sites were located in the Tri-State mining district where zinc and lead were once heavily mined, and from …
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Friends in Low Places: Responses of a Benthic Stream Fish to Intra-Guild Alarm Cues
… Rainbow Darters (Etheostoma caeruleum) are benthic fish that co-occur with native Ozark Minnows (Notropis nubilus), recently-introduced Western Mosquitofish (Gambusia affinis), and native Oklahoma Salamanders (Eurycea tyrnerensis), all of whom are vulnerable to the same predators. We tested …
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Variation in Behavior of Different Populations and Sex Classes of Paedomorphic Oklahoma Salamanders
… exposing salamanders to chemical stimuli from a benthic fish predator (Ozark sculpin, Cottus hypselurus). Salamanders from both populations were more likely to swim to the surface and altered their latencies to move following exposure to predatory threat from sculpin. Latency differences were …
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Resident Benthic Fishes of Artificial Reefs in the Mississippi Sound: Effects of Habitat Relief and Subregion
… artificial reefs increase the production of fish biomass, or simply aggregate existing fish biomass. Most previous research has focused on production of transient fish biomass, because of the high recreational and commercial value of these species. Establishing a link between transient fish …
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The biology, ecology and population trends of jacopever Helicolenus dactylopterus in South Africa
Helicolenus dactylopterus is a deep-water benthic fish in the subfamily Sebastinae. Sebastinae species are slow-growing, long-lived and potentially vulnerable to overexploitation. Helicolenus dactylopterus is exploited throughout its Atlantic distribution. In South Africa, it is the eighth-most …
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The individual and collective behavior of social organisms across environments
… use of two organisms; three-spined stickleback fish (Gasterosteus aculeatus) and odorous house ants (Tapinoma sessile). Both of these species are group-living, exhibit considerable variation in behavior at both the individual and collective level, and have significant population level divergence …
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The Ecological Niche of Darters (Pisces:Percidae) Across Multiple Scales in the Ohio River Basin
… in North Carolina and Tennessee, where benthic fish species are currently being reintroduced. I found that strongly benthic-associated species, such as <i>Etheostoma</i> darters and <i>Cottus carolinae</i>, were associated with different substrate classes, while weakly pelagic species, …
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Trophic relevance of gelatinous zooplankton for commercial fisheries in the Irish Sea
Jellyfish can compete with fish for food resources, or feed on fish eggs and larvae. They also provide habitat and space for developing larval and juvenile fish which use their hosts as means of protection from predators and feeding opportunities. However, the broader ecological relevance of …
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Effects of habitat characteristics on cryptic fish assemblages
… structure is known to influence the abundance of fishes on temperate reefs. Biotic interactions play a major role in determining the distribution and abundance of species. The significance of these forces in affecting the abundance of fishes may hinge on the presence of organisms that either …