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Full-Text Articles in Life Sciences

Consciousness Is Not Inherent In But Emergent From Life, Jon Mallatt, Todd E. Feinberg Jan 2017

Consciousness Is Not Inherent In But Emergent From Life, Jon Mallatt, Todd E. Feinberg

Animal Sentience

Reber’s theory of the cellular basis of consciousness (CBC) is right to emphasize that we should study consciousness (sentience) in its simplest form, taking its evolution into account. However, not enough evidence is presented to support CBC’s unorthodox claim that even simple, one-celled organisms are conscious. As pointed out by other commentators, the CBC seems to be based on outdated ideas about evolution and does not acknowledge that consciousness could be an evolutionary novel feature. Such emergent features are abundant in living organisms. We review our own emergentist solution, in which consciousness evolved in the elaborating nervous systems of the …


Quantification And Characterization Of Net Precipitation Bacterial Flux From A Subtropical Epiphyte-Laden Oak Forest, Preston Pound Jan 2017

Quantification And Characterization Of Net Precipitation Bacterial Flux From A Subtropical Epiphyte-Laden Oak Forest, Preston Pound

Electronic Theses and Dissertations

Transport pathways of microbes between ecosystem spheres (atmosphere, phyllosphere, and pedosphere) represent major fluxes in nutrient cycles and have the potential to significantly affect microbially-mediated biogeochemical processes. We quantified a previously unexamined microbial flux from the phyllosphere to the pedosphere during rainfall via throughfall (rainfall dripping from the canopy and through gaps) and stemflow (rainwater funneled down the stem). Bacterial concentrations were quantified using flow cytometry and validated with quantitative Polymerase Chain Reaction (qPCR) assays for samples from a Quercus virginiana (oak)- forest with heavy epiphyte cover (Tillandsia usneoides, Spanish moss) in coastal Georgia (Southeastern USA). Bacteria concentrations …


The External Microbiome Of Bats: Effects Of Season, Site, Host Species, And Body Region, Kyle G. George Jan 2017

The External Microbiome Of Bats: Effects Of Season, Site, Host Species, And Body Region, Kyle G. George

Master's Theses and Doctoral Dissertations

White-nose syndrome is a cutaneous fungal disease that has been detrimental to North American bats for over 10 years, but few investigators have examined the natural microbiota living on these mammals. I explored the influence of season, geographic site, host species, and body region on the external microbiome of four cave-hibernating and two migratory species. Automated ribosomal intergenic spacer analysis was used to profile bacterial communities from three cutaneous regions of 222 bats across winter and summer sites in Michigan, Illinois, and Kentucky. Season, site, host species, and body region all influenced the composition of external bacterial communities, but geographic …


Bacteria And The Cellular Basis Of Consciousness, Michael L. Woodruff Aug 2016

Bacteria And The Cellular Basis Of Consciousness, Michael L. Woodruff

Animal Sentience

According to Reber’s theory, the Cellular Basis of Consciousness (CBC), sentience originates as bio-sensitivity in unicellular organisms. For this reason, Reber regards sentience as evolutionarily foundational. Many bacteria show chemotaxis and, thus, according to CBC, they are sentient. Analysis of the genetic mechanisms underlying bacterial chemotaxis indicates that sentience has no explanatory power in this case. Genetic analysis also fails to show species continuity underlying bio-sensitivity in bacteria and bio-sensitivity in species with nervous systems, so it does not seem that sentience is evolutionary foundational. CBC is rejected on these grounds.


Isolation And Characterization Of Microbial Community Associated With Diadumene Lineata, The Orange-Striped Sea Anemone, Tiffany Lin, Andrew Weir Jan 2016

Isolation And Characterization Of Microbial Community Associated With Diadumene Lineata, The Orange-Striped Sea Anemone, Tiffany Lin, Andrew Weir

Student and Faculty Research Days

The orange-striped sea anemone, Diadumene lineata, is a marine invertebrate that can be found in the Northern Hemisphere. Distribution of Diadumene lineata ranges from Japan to the Gulf of Argentina. This invasive anemone originated from the Pacific Coast of Asia and serves as a host for a diverse microbial community including a photosynthetic alga. The epiphytic bacteria adhere to the outer surface as well as to the gastrovascular cavity of the host. The microbial community associated with Diadumene lineata is relatively unknown. This study attempted to isolate and identify bacteria commonly associated with this invasive marine invertebrate. Diadumene lineata was …


Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann Dec 2015

Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann

Masters Theses

Lucinid clams and their sulfur-oxidizing endosymbionts comprise two compartments of a three-stage, biogeochemical relationship among the clams, seagrasses, and microbial communities in marine sediments. A population of the lucinid clam, Stewartia floridana, was sampled from a subtidal seagrass bed at Bokeelia Island Seaport in Florida to test the hypotheses: (1) S. floridana, like other lucinids, are more abundant in seagrass beds than bare sediments; (2) S. floridana gill microbiomes are dominated by one bacterial operational taxonomic unit (OTU) at a sequence similarity threshold level of 97% (a common cutoff for species level taxonomy) from 16S rRNA genes; …


Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage May 2015

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …


Is There Specificity In A Defensive Mutualism Against Soil Versus Lab Nematodes, Dictyostelium Discoideum Farmers And Their Bacteria?, Boahemaa Adu-Oppong,, David C. Queller, Joan E. Strassmann Apr 2015

Is There Specificity In A Defensive Mutualism Against Soil Versus Lab Nematodes, Dictyostelium Discoideum Farmers And Their Bacteria?, Boahemaa Adu-Oppong,, David C. Queller, Joan E. Strassmann

Biology Faculty Publications & Presentations

Background: The social amoeba Dictyostelium discoideum is a soil-dwelling microbe, which lives most of its life cycle in the vegetative stage as a predator of bacteria and as prey for nematodes. When bacteria are sparse, amoebae aggregate into a multicellular fruiting body. Some clones of D. discoideum have agriculture (Brock et al., 2011). They carry bacteria through the social stage, eat them prudently, and use some bacteria as defence against non-farming D. discoideum competitors. Caenorhabditis elegans preys on D. discoideum in the laboratory but does not encounter it in nature because C. elegans lives on rotten fruit. The nematode …


New Tracer To Estimate Community Predation Rates Of Phagotrophic Protists, Alexander B. Bochdansky, Melissa A. Clouse Jan 2015

New Tracer To Estimate Community Predation Rates Of Phagotrophic Protists, Alexander B. Bochdansky, Melissa A. Clouse

OES Faculty Publications

Predation of eukaryotic microbes on prokaryotes is one of the most important trophic interactions on Earth, representing a major mortality term and shaping morphology and composition of prokaryotic communities. Here we introduce and validate a new tracer to determine predation rates on prokaryotes. Minicells of Escherichia coli marked with a bright green fluorescent protein (GFP) vector have many operational advantages over previously used prey analogs such as fluorescently labeled bacteria. GFP-minicells are similar in size to naturally occurring bacteria from a variety of environments including the oligotrophic open ocean and the deep sea. They are relatively stable against microbial and …


Anthropogenic Litter And Microplastic In Urban Streams: Abundance, Source, And Fate, Amanda Rae Mccormick Jan 2015

Anthropogenic Litter And Microplastic In Urban Streams: Abundance, Source, And Fate, Amanda Rae Mccormick

Master's Theses

The accumulation and ecological effects of anthropogenic litter (AL) and microplastic are well-documented in marine ecosystems, but these materials’ abundances in rivers is unknown. AL enters rivers from recreation, runoff, and illegal dumping. Microplastic fibers and pellets are abundant in wastewater treatment plant (WWTP) effluent which enters rivers. Our objectives were to: (1) quantify AL abundance and composition in urban streams, (2) measure AL flux, accumulation, and export, and (3) measure riverine microplastic concentration and analyze its bacterial communities. We collected AL from 5 urban streams and observed greater AL density in riparian habitats and greater mass in benthic habitats. …


Acute Effects Of Tio2 Nanomaterials On The Viability And Taxonomic Composition Of Aquatic Bacterial Communities Assessed Via High-Throughput Screening And Next Generation Sequencing, Binh Chu, Tiezheng Tong, Jean-François Gaillard, Kimberley A. Gray, John J. Kelly Aug 2014

Acute Effects Of Tio2 Nanomaterials On The Viability And Taxonomic Composition Of Aquatic Bacterial Communities Assessed Via High-Throughput Screening And Next Generation Sequencing, Binh Chu, Tiezheng Tong, Jean-François Gaillard, Kimberley A. Gray, John J. Kelly

Biology: Faculty Publications and Other Works

The nanotechnology industry is growing rapidly, leading to concerns about the potential ecological consequences of the release of engineered nanomaterials (ENMs) to the environment. One challenge of assessing the ecological risks of ENMs is the incredible diversity of ENMs currently available and the rapid pace at which new ENMs are being developed. High-throughput screening (HTS) is a popular approach to assessing ENM cytotoxicity that offers the opportunity to rapidly test in parallel a wide range of ENMs at multiple concentrations. However, current HTS approaches generally test one cell type at a time, which limits their ability to predict responses of …


The Effects Of Insects, Nutrients, And Plant Invasion On Community Structure And Function Above- And Belowground, Phoebe Wright, Melissa A. Cregger, Lara Souza, Nathan J. Sanders, Aimee T. Classen Feb 2014

The Effects Of Insects, Nutrients, And Plant Invasion On Community Structure And Function Above- And Belowground, Phoebe Wright, Melissa A. Cregger, Lara Souza, Nathan J. Sanders, Aimee T. Classen

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Soil nutrient availability, invasive plants, and insect presence can directly alter ecosystem structure and function, but less is known about how these factors may interact. In this 6-year study in an old-field ecosystem, we manipulated insect abundance (reduced and control), the propagule pressure of an invasive nitrogen-fixing plant (propagules added and control), and soil nutrient availability (nitrogen added, nitrogen reduced and control) in a fully crossed, completely randomized plot design. We found that nutrient amendment and, occasionally, insect abundance interacted with the propagule pressure of an invasive plant to alter above- and belowground structure and function at our site. Not …


Plant-Mediated Effects On Microbial Diversity In Mesocosms Of An Oligotrophic Bog, Karl J. Romanowicz Iv Jan 2013

Plant-Mediated Effects On Microbial Diversity In Mesocosms Of An Oligotrophic Bog, Karl J. Romanowicz Iv

Dissertations, Master's Theses and Master's Reports - Open

Globally, peatlands occupy a small portion of terrestrial land area but contain up to one-third of all soil organic carbon. This carbon pool is vulnerable to increased decomposition under projected climate change scenarios but little is known about how plant functional groups will influence microbial communities responsible for regulating carbon cycling processes. Here we examined initial shifts in microbial community structure within two sampling depths under plant functional group manipulations in mesocosms of an oligotrophic bog. Microbial community composition for bacteria and archaea was characterized using targeted 16S rRNA Illumina gene sequencing. We found statistically distinct spatial patterns between the …


Effects Of Dissolved Nutrient Ratios And Concentrations On Litter-Associated Microbial Activity In Streamside Channels, Timothy Burns Jan 2013

Effects Of Dissolved Nutrient Ratios And Concentrations On Litter-Associated Microbial Activity In Streamside Channels, Timothy Burns

Electronic Theses and Dissertations

Heterotrophic consumers, such as microorganisms and invertebrates, play a fundamental role in the flow of carbon and energy in streams. The effects of dissolved nutrient concentrations, and especially ratios, on litter—associated microorganisms and decomposition rates of detritus are poorly understood. This study addressed the responses of heterotrophic microbes to a wide range of concentrations and ratios of dissolved inorganic nitrogen (N) and phosphorus (P) in streamside channels simulating headwater streams. Two main questions were: (1) do microbial parameters and litter decomposition rates peak at a dissolved N:P ratio that approaches the nutrient ratio of microbial biomass, and (2) does microbial …


Coastal Bacterioplankton Community Dynamics In Response To A Natural Disturbance, Sara K. Yeo, Megan J. Huggett, Alexander Eiler, Michael Rappe Jan 2013

Coastal Bacterioplankton Community Dynamics In Response To A Natural Disturbance, Sara K. Yeo, Megan J. Huggett, Alexander Eiler, Michael Rappe

Research outputs 2013

In order to characterize how disturbances to microbial communities are propagated over temporal and spatial scales in aquatic environments, the dynamics of bacterial assemblages throughout a subtropical coastal embayment were investigated via SSU rRNA gene analyses over an 8-month period, which encompassed a large storm event. During non-perturbed conditions, sampling sites clustered into three groups based on their microbial community composition: an offshore oceanic group, a freshwater group, and a distinct and persistent coastal group. Significant differences in measured environmental parameters or in the bacterial community due to the storm event were found only within the coastal cluster of sampling …


Soil Nematodes And Their Prokaryotic Prey Along An Elevation Gradient In The Mojave Desert (Death Valley National Park, California, Usa), Amy M. Treonis, Kelsey Sutton, Brendan Kavanaugh, Archana Narla, Timothy Mcllarky, Jasmine Felder, Cecilia O'Leary, Megan Riley, Alyxandr Pikus, Sarah Thomas Oct 2012

Soil Nematodes And Their Prokaryotic Prey Along An Elevation Gradient In The Mojave Desert (Death Valley National Park, California, Usa), Amy M. Treonis, Kelsey Sutton, Brendan Kavanaugh, Archana Narla, Timothy Mcllarky, Jasmine Felder, Cecilia O'Leary, Megan Riley, Alyxandr Pikus, Sarah Thomas

Biology Faculty Publications

We characterized soil communities in the Mojave Desert across an elevation gradient. Our goal was to test the hypothesis that as soil quality improved with increasing elevation (due to increased productivity), the diversity of soil prokaryotes and nematodes would also increase. Soil organic matter and soil moisture content increased with elevation as predicted. Soil salinity did not correlate to elevation, but was highest at a mid-gradient, alluvial site. Soil nematode density, community trophic structure, and diversity did not show patterns related to elevation. Similar results were obtained for diversity of bacteria and archaea. Relationships between soil properties, nematode communities, and …


Microbial Community Structure And Ecosystem Function In A Changing World, Melissa Ann Cregger Aug 2012

Microbial Community Structure And Ecosystem Function In A Changing World, Melissa Ann Cregger

Doctoral Dissertations

Understanding the effects climate change will have on the structure and function of global ecosystems is a pressing ecological and social issue. Global change driven changes in atmospheric warming and precipitation régimes have begun to alter the distribution of plants and animals in, as well as the function of, ecosystems. Using two large-scale climate change manipulations, I assessed the effect of changing precipitation and temperature regimes on soil microbial community structure and function. Soil microbial communities regulate decomposition and nutrient cycling rates in ecosystems, thus understanding their response to climatic changes will enable scientists to better predict carbon feedbacks to …


Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan Jan 2012

Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan

School of Biological Sciences: Faculty Publications

Soil microbial diversity is vast, and we lack even basic understanding of how this diversity is distributed ecologically. Using pyrosequencing and microarray methods, we quantified the structure of bacterial communities in two contrasting soils underlying Bornean rain forest (clay and sandy loam) that differ markedly in soil properties, aboveground tree flora, and leaf litter decomposition rates. We found significant soil-related taxonomic and phylogenetic differences between communities that, due to their proximity, are independent of climate. Bacterial communities showed distinct compositional and taxon-abundance distributions that were significantly correlated with the structure of the overlying tree community. Richness of bacteria was greater …


Diversity Of The Ohio River Bacterial Communities Using Next-Generation Sequencing Techniques, Emily Michele Anneken Jan 2012

Diversity Of The Ohio River Bacterial Communities Using Next-Generation Sequencing Techniques, Emily Michele Anneken

Theses, Dissertations and Capstones

The ability to sequence bacterial genetic material directly from environmental samples has unlocked the field of metagenomics. Next-generation sequencing techniques, such as pyrosequencing, have been instrumental in providing knowledge about bacterial communities. This study focused on identifying the bacterial diversity of the Ohio River via pyrosequencing and compared the diversity of cultivable bacteria versus the entire river community. To ensure the maximum number of cultivable bacteria was obtained, cultures were grown on nonselective media and incubated at river temperature. Bacterial DNA was extracted, sequenced, and classified. The dominant phyla for the Ohio River included Cyanobacteria (38-66% of the total), Actinobacteria …


Effects Of Sugar-Amendment On Bacterial & Fungal Abundance In Native Vs. Nonnative-Dominated Soils Of A Puget Lowland Prairie, Jessica Wong Jan 2012

Effects Of Sugar-Amendment On Bacterial & Fungal Abundance In Native Vs. Nonnative-Dominated Soils Of A Puget Lowland Prairie, Jessica Wong

Summer Research

Scotch broom is a nonnative plant that has invaded the plant communities of the Pacific Northwest in the United States. It associates with bacteria in the soil to fix nitrogen from the atmosphere, thereby elevating soil nitrogen levels and encouraging the invasion of the community by other nonnative plants like itself. Researchers have used sugar-amendment to decrease soil nitrogen and restore native plant growth. Our study took place in Glacial Heritage Preserve, a Puget lowland prairie that has been invaded by broom in several areas. We aimed to investigate whether sugar-amendment increased or decreased bacterial and fungal abundance in native …


Reduction Of Iron (Iii) And Humic Substances Plays A Major Role In Anaerobic Respiration In An Arctic Peat Soil, David A. Lipson, Mony Jha, Ted K. Raab, Walter C. Oechel Dec 2010

Reduction Of Iron (Iii) And Humic Substances Plays A Major Role In Anaerobic Respiration In An Arctic Peat Soil, David A. Lipson, Mony Jha, Ted K. Raab, Walter C. Oechel

Ted K. Raab

Arctic peat soils contain vast reserves of organic C and are largely anaerobic. However, anaerobic respiration, particularly the role of Fe(III) and humic substances as electron acceptors, is not well understood in such ecosystems. We investigated these processes in a drained thaw lake basin on the Arctic coastal plain near Barrow, Alaska. We measured concentrations of soluble Fe and other potential electron acceptors, described the microbial community, and performed experiments in the laboratory and field to measure net rates of Fe(III) reduction and the relationship of this process to C cycling. In most areas within the basin, aerobic conditions existed …


Microbial Ecology Of Keane Wonder Spring, Death Valley National Park, Alexander B. Michaud, Duane P. Moser Aug 2008

Microbial Ecology Of Keane Wonder Spring, Death Valley National Park, Alexander B. Michaud, Duane P. Moser

Undergraduate Research Opportunities Program (UROP)

This research is focused on developing a better understanding of he physiological and phylogenetic diversity as well as environmental abundance of bacteria of the genus: Shewanella in selected desert ecosystems. Prior research from this laboratory has revealed that these bacteria are very abundant in sulfurand organic-rich aquatics habitats. We have selected a number of habitats for detailed investigation (cultivation, molecular ecology and relevant environmental chemistry) including the Tropicana Wash, spring in Death Valley, the lower Virgin River and possibly Big Soda Lame, Nevada.


Light Dependence Of Selenium Uptake By Phytoplankton And Implications For Predicting Selenium Incorporation Into Food Webs, Stephen B. Baines, Nicholas S. Fisher, Martina A. Doblin, Gregory A. Cutter, Lynda S. Cutter, Brian Cole Jan 2004

Light Dependence Of Selenium Uptake By Phytoplankton And Implications For Predicting Selenium Incorporation Into Food Webs, Stephen B. Baines, Nicholas S. Fisher, Martina A. Doblin, Gregory A. Cutter, Lynda S. Cutter, Brian Cole

OES Faculty Publications

The potentially toxic element selenium is first concentrated from solution to a large but highly variable degree by algae and bacteria before being passed on to consumers. The large loads of abiotic and detrital suspended particles often present in rivers and estuaries may obscure spatial and temporal patterns in Se concentrations at the base of the food web. We used radiotracers to estimate uptake of both selenite (Se(IV)) and C by intact plankton communities at two sites in the Sacramento/San Joaquin River Delta. Our goals were to determine (1) whether C and Se(IV) uptake were coupled, (2) the role of …


Size Doesn't Matter: Microbial Selection Experiments Address Ecological Phenomena, Michael Feldgarden, Daniel M. Stoebel, Dustin Brisson, Daniel E. Dykhuizen Jan 2003

Size Doesn't Matter: Microbial Selection Experiments Address Ecological Phenomena, Michael Feldgarden, Daniel M. Stoebel, Dustin Brisson, Daniel E. Dykhuizen

All HMC Faculty Publications and Research

Experimental evolution is relevant to ecology because it can connect physiology, and in particular metabolism, to questions in ecology. The investigation of the linkage between the environment and the evolution of metabolism is tractable because these experiments manipulate a very simple environment to produce predictable evolutionary outcomes. In doing so, microbial selection experiments can examine the causal elements of natural selection: how specific traits in varying environments will yield different fitnesses. Here, we review the methodology of microbial evolution experiments and address three issues that are relevant to ecologists: genotype-by-environment interactions, ecological diversification due to specialization, and negative frequency-dependent selection. …


Microbial Ecology Of Ballast Water During A Transoceanic Voyage And The Effects Of Open-Ocean Exchange, Lisa A. Drake, Gregory M. Ruiz, Bella S. Galil, Timothy L. Mullady, Daniela O. Friedmann, Fred C. Dobbs Jan 2002

Microbial Ecology Of Ballast Water During A Transoceanic Voyage And The Effects Of Open-Ocean Exchange, Lisa A. Drake, Gregory M. Ruiz, Bella S. Galil, Timothy L. Mullady, Daniela O. Friedmann, Fred C. Dobbs

OES Faculty Publications

The only procedure used frequently to reduce the risk of invasion by ballast-mediated biota is open-ocean exchange of ballast water, a procedure in which vessels release coastal water and replace it with oceanic water. Limited information exists concerning the effects of transport upon the aquatic microbial community throughout transit and following open-ocean exchange, A transoceanic voyage aboard a commercial bulk carrier afforded us the opportunity to sample the microbial community in exchanged and unexchanged ballast-water holds during the journey from Hadera, Israel to Baltimore, USA. Five days following the exchange process, all microbial metrics tested (i.e. bacteria concentration, virus-like particle …


Trophic Cascades, Nutrients, And Lake Productivity: Whole-Lake Experiments, Stephen R. Carpenter, Jonathan J. Cole, James R. Hodgson, James F. Kitchell, Michael L. Pace, Darren Bade, Kathryn L. Cottingham May 2001

Trophic Cascades, Nutrients, And Lake Productivity: Whole-Lake Experiments, Stephen R. Carpenter, Jonathan J. Cole, James R. Hodgson, James F. Kitchell, Michael L. Pace, Darren Bade, Kathryn L. Cottingham

Dartmouth Scholarship

Responses of zooplankton, pelagic primary producers, planktonic bacteria, and CO2 exchange with the atmosphere were measured in four lakes with contrasting food webs under a range of nutrient enrichments during a seven-year period. Prior to enrichment, food webs were manipulated to create contrasts between piscivore dominance and planktivore dominance. Nutrient enrichments of inorganic nitrogen and phosphorus exhibited ratios of N:P > 17:1, by atoms, to maintain P limitation. An unmanipulated reference lake, Paul Lake, revealed baseline variability but showed no trends that could confound the interpretation of changes in the nearby manipulated lakes. Herbivorous zooplankton of West Long Lake (piscivorous fishes) …


Development And Lipid Composition Of The Harpacticoid Copepod Nitocra Spinipes Reared On Different Diets, Gregory M. Weiss, George B. Mcmanus, H. Rodger Harvey Jan 1996

Development And Lipid Composition Of The Harpacticoid Copepod Nitocra Spinipes Reared On Different Diets, Gregory M. Weiss, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

We reared the harpacticoid copepod Nitocra spinipes on diets of bacteria, a diatom, or a macroalga, evaluating survivorship and growth in short-term (≤ 1 generation) experiments. Lipid content of the copepods and their diets was measured and used as an index of nutrition. Although growth, survivorship and lipid content of N. spinipes were significantly greater when fed the diatom, which had the highest lipid content of the 3 diets, the copepod was able to develop from egg to adult when fed a lipid- poor bacterial diet. Furthermore, this species was able to go through developmental molts without the addition of …


Nutrient Limitation In A Southwestern Desert Reservoir: Eutrophication Of Las Vegas Bay, Lake Mead, Nevada, Davine M. Lieberman Sep 1995

Nutrient Limitation In A Southwestern Desert Reservoir: Eutrophication Of Las Vegas Bay, Lake Mead, Nevada, Davine M. Lieberman

Publications (WR)

Algal bioassay tests were conducted with Selenastrum capricornutum and natural algae on inner Las Vegas Bay, Lake Mead, Nevada, from December 1992 through September 1993, to identify any nutrient limitation in an area of the reservoir that has experienced problems associated with severe nutrient enrichment. Three areas were sampled based on a gradient of water quality conditions that existed in Las Vegas Bay (LVB). Disodium ethylenedinitrilotetraacetate (EDTA) significantly stimulated algal growth compared to non-EDTA treatment. Algal bioassays indicated that phosphorus (P) was the primary limiting nutrient at all stations for most of the test dates. Chl a response with EDTA …


Trophic Transfer Of Fatty Acids, Sterols, And A Triterpenoid Alcohol Between Bacteria, A Ciliate, And The Copepod Acartia Tonsa, Melissa C. Ederington, George B. Mcmanus, H. Rodger Harvey Jul 1995

Trophic Transfer Of Fatty Acids, Sterols, And A Triterpenoid Alcohol Between Bacteria, A Ciliate, And The Copepod Acartia Tonsa, Melissa C. Ederington, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

The incorporation of lipids into the copepod Acartia tonsa and its eggs was measured when it was fed either a bacterivorous ciliate (Pleuronema sp.) or a diatom (Thalassiosira weissflogii). Egg production was 10-fold higher on the diatom diet, whereas hatch success of eggs was the same for algal and ciliate diets. Adult copepods fed diatoms contained more total fatty acid and sterols than copepods fed the ciliate diet, and individual lipids reflected the dietary source. Eggs from diatom-fed copepods had fewer fatty acids but more sterols than eggs from copepods on a ciliate diet. Ciliate-fed copepods and …


Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection May 1987

Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Rationale of review and for proposed changes to the Nevada Pollution Control Regulations (NAC 445.1354, 445.1355, 445.1356, 455.1367, 445.1352, 445.1353, 445.1350, 445.1351) before the State Environmental Commission on June 23 and 24, 1987.