Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Biology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 33211 - 33240 of 39343

Full-Text Articles in Entire DC Network

Chromosome Movement In Mitosis Requires Microtubule Anchorage At Spindle Poles, Michael B. Gordon, Louisa Howard, Duane A. Compton Feb 2001

Chromosome Movement In Mitosis Requires Microtubule Anchorage At Spindle Poles, Michael B. Gordon, Louisa Howard, Duane A. Compton

Dartmouth Scholarship

Anchorage of microtubule minus ends at spindle poles has been proposed to bear the load of poleward forces exerted by kinetochore-associated motors so that chromosomes move toward the poles rather than the poles toward the chromosomes. To test this hypothesis, we monitored chromosome movement during mitosis after perturbation of nuclear mitotic apparatus protein (NuMA) and the human homologue of the KIN C motor family (HSET), two noncentrosomal proteins involved in spindle pole organization in animal cells. Perturbation of NuMA alone disrupts spindle pole organization and delays anaphase onset, but does not alter the velocity of oscillatory chromosome movement in prometaphase. …


Reduced Enzyme Activity Following Hsp70 Overexpression In Drosophila Melanogaster, Robert A. Krebs, Sari H. Holbrook Feb 2001

Reduced Enzyme Activity Following Hsp70 Overexpression In Drosophila Melanogaster, Robert A. Krebs, Sari H. Holbrook

Biological, Geological, and Environmental Faculty Publications

Acclimation to environmental change can impose costs to organisms. One potential cost is the change in cell metabolism that follows a physiological response, e.g., high expression of heat shock proteins may alter specific activity of important enzymes. We examined the significance of this cost in a pair of Drosophila melanogaster lines transformed with additional copies of a gene that encodes the heat shock protein, Hsp70. Heat shock induces Hsp70 expression in all lines, but lines with extra copies produce much more Hsp70 than do excision control strains. The consequence of this supranormal Hsp70 expression is to reduce specific activity of …


Sustainable Tourism Plan For The Houtman Abrolhos Islands, Fisheries Western Australia Feb 2001

Sustainable Tourism Plan For The Houtman Abrolhos Islands, Fisheries Western Australia

Fisheries Management Papers

The Abrolhos coral reefs are the southernmost living reefs in the Indian Ocean. They have a unique assemblage of tropical species of fish, reef corals and other invertebrates, which live in close association with temperate species, particularly of algae, and species endemic to Western Australia. The Abrolhos is the centre of the fishery for the commercially valuable western rock lobster (Panulirus cygnus). Terrestrial flora and fauna of the Abrolhos are relict and provide important reference areas on ecological interactions. Virtually all the islands of the Abrolhos archipelago have sea bird nesting and breeding areas, and populations of some species of …


Post-Fledging Dispersal Of Burrowing Owls In Southwestern Idaho: Characterization Of Movements And Use Of Satellite Burrows, R. Andrew King, James R. Belthoff Feb 2001

Post-Fledging Dispersal Of Burrowing Owls In Southwestern Idaho: Characterization Of Movements And Use Of Satellite Burrows, R. Andrew King, James R. Belthoff

Biology Faculty Publications and Presentations

Using radiotelemetry, we monitored dispersing juvenile Western Burrowing Owls (Athene cunicularia hypugaea) within a migratory population in southwestern Idaho during 1994 and 1995. Owls remained within natal areas for an average (± SE) of 58 ± 3.4 days post-hatching before moving permanently beyond 300 m, which was our operational cutoff for dispersal from the natal area. On average, owls dispersed on 27 July (range: 15 July to 22 August), which was approximately 4 weeks after fledging. After initiating dispersal, juveniles continued moving farther away from their natal burrows and, by 61-65 days post-hatching, they had moved 0.6 ± …


Single Rabbit Stomach Smooth Muscle Cell Myosin Heavy Chain Smb Expression And Shortening Velocity, Thomas J. Eddinger, Daniel P. Meer Feb 2001

Single Rabbit Stomach Smooth Muscle Cell Myosin Heavy Chain Smb Expression And Shortening Velocity, Thomas J. Eddinger, Daniel P. Meer

Biological Sciences Faculty Research and Publications

Isolated single smooth muscle cells (SMCs) from different regions of the rabbit stomach were used to determine a possible correlation between unloaded shortening velocity and smooth muscle (SM) myosin heavy chain (MHC) S1 head isoform composition (SMA, no head insert; SMB, with head insert). α-Toxin-permeabilized isolated single cells were maximally activated to measure unloaded shortening velocity and subsequently used in an RT-PCR reaction to determine the SMA/SMB content of the same cell. SM MHC SMA and SMB isoforms are uniquely distributed in the stomach with cells from the fundic region expressing little SMB (38.1 ± 7.3% SMB; n = 16); …


Rare, Threatened And Endangered Plants And Animals Of Oregon (2001), James S. Kagan, Sue Vrilakas, Eleanor P. Gaines, Cliff Alton, Ken Popper, Mark A. Stern, Eric Scheuering, John A. Christy, Mary Finnerty, Jon Hak, Anthony A. Tovar, Michael Murray, Claudine Tobalske, Oregon Natural Heritage Program Feb 2001

Rare, Threatened And Endangered Plants And Animals Of Oregon (2001), James S. Kagan, Sue Vrilakas, Eleanor P. Gaines, Cliff Alton, Ken Popper, Mark A. Stern, Eric Scheuering, John A. Christy, Mary Finnerty, Jon Hak, Anthony A. Tovar, Michael Murray, Claudine Tobalske, Oregon Natural Heritage Program

Institute for Natural Resources Publications

Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is large-scale destruction of native habitats, which has increased since European settlement began in the mid 1800's - in Oregon and throughout the New World.

Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend …


Variations In Bacterial Community Structure During A Dinoflagellate Bloom Analyzed By Dgge And 16s Rdna Sequencing, Laura B. Fandino, Lasse Riemann, Grieg F. Steward, Richard A. Long, Farooq Azam Jan 2001

Variations In Bacterial Community Structure During A Dinoflagellate Bloom Analyzed By Dgge And 16s Rdna Sequencing, Laura B. Fandino, Lasse Riemann, Grieg F. Steward, Richard A. Long, Farooq Azam

Faculty Publications

The relationship between bacterial 16S rRNA gene composition and carbon metabolism was analyzed during an intense dinoflagellate bloom off the Southern California coast during the spring of 1997. Bacterial numbers and rate processes, chlorophyll a, and the dissolved and particulate organic matter pools were measured during the bloom to provide a framework within which to assess bacterial community composition. Free bacteria were numerically dominant, generally comprising >90% of the total, and were responsible for >70% of bacterial production. Attached bacteria had higher cell-specific growth rates than free bacteria (range = 0.5 to 15.1 and 0.7 to 2.5 d-1 …


Semi-Artificial Monarch Butterfly Larval Diet, Kingston L. H. Leong Jan 2001

Semi-Artificial Monarch Butterfly Larval Diet, Kingston L. H. Leong

Biological Sciences

A semi-artificial diet of monarch butterfly larva and a process for making such a diet are provided. The diet consists of a substantial amount of dried milkweed powder and small but effective amounts of mold inhibitor and antibiotic.


The Tem1 Small Gtpase Controls Actomyosin And Septin Dynamics During Cytokinesis, John Lippincott, Katie Shannon, Wenying Shou, Raymond J. Deshaies, Rong Li Jan 2001

The Tem1 Small Gtpase Controls Actomyosin And Septin Dynamics During Cytokinesis, John Lippincott, Katie Shannon, Wenying Shou, Raymond J. Deshaies, Rong Li

Biological Sciences Faculty Research & Creative Works

Cytokinesis in budding yeast involves an actomyosin-based ring which assembles in a multistepped fashion during the cell cycle and constricts during cytokinesis. In this report, we have investigated the structural and regulatory events that occur at the onset of cytokinesis. The septins, which form an hour-glass like structure during early stages of the cell cycle, undergo dynamic rearrangements prior to cell division: the hourglass structure splits into two separate rings. The contractile ring, localized between the septin double rings, immediately undergoes contraction. Septin ring splitting is independent of actomyosin ring contraction as it still occurs in mutants where contraction fails. …


Orientation In Complex Odor Landscapes: Spatial Arrangement Of Odor Sources Influences Crayfish Food Finding Efficiency In Artificial Streams, Troy Keller Jan 2001

Orientation In Complex Odor Landscapes: Spatial Arrangement Of Odor Sources Influences Crayfish Food Finding Efficiency In Artificial Streams, Troy Keller

Faculty Bibliography

Fluid dynamics has been shown to alter ecologically important behaviors of aquatic organisms orienting to distant chemical sources. Because the fluid dynamics and chemical plumes change across hydraulic environments, it is unclear which of these factors influence orientation behavior more. This study examined how alterations in chemical signal structure, through changes in source spatial arrangement, affect chemically mediated search behavior. Microelectrochemical measurements of tracer molecules revealed that source arrangement significantly alters the downstream fine-scale structure of chemical plumes. Flume hydrodynamic characterizations (as measured with laser Doppler velocimetry) also differed among source arrangements; however, differences were minor and existed only at …


Willa Cather And American Plant Ecology, Cheryl C. Swift, John N. Swift Jan 2001

Willa Cather And American Plant Ecology, Cheryl C. Swift, John N. Swift

Biology

The following argument began simply in our curiosity over Willa Cather's naming of flowers, particularly in her late work. Looking at these acts of naming, however, led us quickly to the beginnings of a more general historical/theoretical framework for thinking about her long relationship with natural science. Cather is of course well known as an acute botanical observer and literary user of the floral or vegetative world, as pastoral backdrop, as ornamental illustration, or as emblem. Susan Rosowski has moreover suggested a foundational "ecological dialectic" in all of her art, originating in her early university experiences with the pioneering Nebraska …


Analysis Of E. Coli Dna From Selected Source(S) Using Pulsed-Field Gel Electrophoresis, Sheema Doshi Jan 2001

Analysis Of E. Coli Dna From Selected Source(S) Using Pulsed-Field Gel Electrophoresis, Sheema Doshi

Theses, Dissertations and Capstones

The presence of fecal coliforms in surface waters is a public health issue throughout the United States and Canada. The presence of Escherichia coli (E. coli) indicates recent fecal contamination from either animal or human sources. To solve this growing problem one must identify the source(s) of such contamination by creating a database of DNA profiles of£. coli isolates. Hence, tracking the source(s) of E. coli can help link water contamination to animal source(s) of contamination. In this study, pulsed field gel electrophoresis (PFGE) was used to analyze DNA from E. coli isolates from known animals. For PFGE, the bacterial …


Factors Influencing Spatial Variability In Soil Nitrogen (N) Dynamics In N-Treated And Untreated Watersheds Of The Fernow Experimental Forest, West Virginia, Nikki Lenore Lyttle Jan 2001

Factors Influencing Spatial Variability In Soil Nitrogen (N) Dynamics In N-Treated And Untreated Watersheds Of The Fernow Experimental Forest, West Virginia, Nikki Lenore Lyttle

Theses, Dissertations and Capstones

The central Appalachian region of the United States receives some of the highest inputs of nitrogen (N) due to acidic deposition in the nation. It is believed that these high could levels contribute to a decline in forest soils within the next 50 to 70 yrs. This study examines factors that influence spatial variability in N-treated and untreated watersheds of the Fernow Experimental Forest, Parsons, West Virginia. Within each of the two watersheds [WS4 untreated control, > 100 yr.; WS3 N-treated, acidified, clear cut, ~ 31 yr.], two 0.04 ha plots, one high N and one low N, were selected for …


Characterization And Regulation Of Skn-Directed Autoimmune Skin Lesions, Pamela Jane Staton Jan 2001

Characterization And Regulation Of Skn-Directed Autoimmune Skin Lesions, Pamela Jane Staton

Theses, Dissertations and Capstones

In the Skn model of autoimmunity, pathogenic T cells sensitized to Skn epidermal antigens (Skn-immune spleen cells or SIS cells) elicited disease in the form of skin lesions when adoptively transferred into shaved immunoincompetent syngeneic adult recipients (‘lesion-forming animals’) while concomitant injection of immunoregulatory normal spleen cells at twice the concentration (2 x normal spleen cells or 2XNS cells) of SIS cells significantly lessened lesion development (‘lesion-controlling animals’) by Day 7 post cell transfer. In a time-course RT-PCR cytokine analysis of skin from lesion-forming and lesion-controlling animals, IL-7 mRNA was significantly elevated in lesion-controlling skin on Day 7 while no …


A New Species Of Extinct Oryzomyine Rodent From The Quaternary Of Curaçao, Netherlands Antilles, Donald A. Mcfarlane, Adolphe O. Debrot Jan 2001

A New Species Of Extinct Oryzomyine Rodent From The Quaternary Of Curaçao, Netherlands Antilles, Donald A. Mcfarlane, Adolphe O. Debrot

WM Keck Science Faculty Papers

An extinct new species of Oryzomyine rodent, known since 1936 from the cave of Grot van Hato on the island of Curaçao, is described from abundant new specimens collected from owl-pellet deposits at three localities on the island.


Apoptosis Of Rat Myoblasts Is Induced In Vitro By Late, But Not Early, Wound Fluids, Raymond E. Sicard, Linh Nguyen, John Menezes Jan 2001

Apoptosis Of Rat Myoblasts Is Induced In Vitro By Late, But Not Early, Wound Fluids, Raymond E. Sicard, Linh Nguyen, John Menezes

Journal of the Minnesota Academy of Science

Interstitial fluids from late wound repair environments are not "regeneration permissive" as judged by their inability to promote either proliferation or differentiation of myoblasts in vitro. This irwestigation considered whether apoptosis (induced death) was an alternative fate for myoblasts exposed to these interstitial fluids. Myoblast fate was assessed by cell counts, tritiated thymidine release, and propidium iodide staining. Fluids from early wounds increased mean cell counts and induced little thymidine release or propidium iodide labeling. In contrast, fluids from late wounds reduced cell counts and induced both thymidine release and propidium iodide labeling. These data suggest that interstitial fluids from …


Nerve Injury Induces A Rapid Efflux Of Nitric Oxide (No) Detected With A Novel No Microsensor, Shanta M. Kumar, D. M. Porterfield, Kenneth J. Muller, Peter J.S. Smith, Christie L. Sahley Jan 2001

Nerve Injury Induces A Rapid Efflux Of Nitric Oxide (No) Detected With A Novel No Microsensor, Shanta M. Kumar, D. M. Porterfield, Kenneth J. Muller, Peter J.S. Smith, Christie L. Sahley

Biological Sciences Faculty Research & Creative Works

An early step in repair of the leech CNS is the appearance of endothelial nitric oxide synthase (eNOS) immunoreactivity and NOS activity, but coincident generation of NO at the lesion after injury has not been shown. This is important because NO can regulate microglial cell motility and axon growth. Indirect measurement of NO with the standard citrulline assay demonstrated that NO was generated within 30 min after nerve cord injury. A polarographic NO-selective self-referencing microelectrode that measures NO flux noninvasively was developed to obtain higher spatial and temporal resolution. With this probe, it was possible to demonstrate that immediately after …


Ethnic Differences In Risk From Mercury Among Savannah River Fishermen, Joanna Burger, Karen F. Gaines, Michael Gochfeld Jan 2001

Ethnic Differences In Risk From Mercury Among Savannah River Fishermen, Joanna Burger, Karen F. Gaines, Michael Gochfeld

Faculty Research & Creative Activity

Fishing plays an important role in people's lives and contaminant levels in fish are a public health concern. Many states have issued consumption advisories; South Carolina and Georgia have issued them for the Savannah River based on mercury and radionuclide levels. This study examined ethnic differences in risk from mercury exposure among people consuming fish from the Savannah River, based on site-specific consumption patterns and analysis of mercury in fish. Among fish, there were significant interspecies differences in mercury levels, and there were ethnic differences in consumption patterns. Two methods of examining risk are presented: (1) Hazard Index (HI), and …


An Examination Of The First Sediment Cores From Mountain Lake, Giles County, Virginia, For Diatoms And Pollen, Jon C. Cawley, Bruce C. Parker, Terry L. Hufford Jan 2001

An Examination Of The First Sediment Cores From Mountain Lake, Giles County, Virginia, For Diatoms And Pollen, Jon C. Cawley, Bruce C. Parker, Terry L. Hufford

Virginia Journal of Science

Mountain Lake, Virginia is a small, unique, oligotrophic, subalpine ecosystem in the southern Appalachians. Its geology, origin, climate, and history have influenced its morphometry, and therefore its sedimentology and algal flora. Radiocarbon dates establish specific Mountain Lake sediment ages at 1800, 4100, and 6100 years BP. Sediment core analysis suggests at least 6 prolonged periods when Mountain Lake probably was nearly dry or very small in size. These individual low-water periods (at approximately 100, 400, 900, 1200, 1800 and 4100 years BP) are evidenced by changes in diatom and pollen content, sedimentary erosion features, and the presence of wood fragments, …


Phylogeny, Biogeography, And Revision Of The Subfamily Dallatorrellinae (Hymenoptera, Liopteridae), Zhiwei Liu Jan 2001

Phylogeny, Biogeography, And Revision Of The Subfamily Dallatorrellinae (Hymenoptera, Liopteridae), Zhiwei Liu

Faculty Research & Creative Activity

A recent cladistic study suggested that the parasitoid wasp subfamily Dallatorrellinae is a monophyletic clade within the cynipoid family Liopteridae. The subfamily currently includes only four known species belonging to two genera, i.e., the monotypic genus Mesocynips Cameron, 1903 and the genus Dallatorrella Kieffer, 1911 . The present study presents a revision of the subfamily, including descriptions of five new species in the genus Dallatorrella: D. maculata, D. maxima, D. pulla, D. ronquisti and D. sinica. A key to the species of the subfamily is provided. Cladistic analysis of the subfamily at species level is undertaken and the biogeographic history …


Status Of The Oak Hybrids Quercus × Leana And Q. × Runcinata In Illinois, Gordon Tucker, John Ebinger Jan 2001

Status Of The Oak Hybrids Quercus × Leana And Q. × Runcinata In Illinois, Gordon Tucker, John Ebinger

Faculty Research & Creative Activity

No abstract provided.


Genetic Heterogeneity Of White-Tailed Deer: Management Lessons From A Long-Term Study, Michael H. Smith, James M. Novak, J. D. Peles, J. R. Purdue Jan 2001

Genetic Heterogeneity Of White-Tailed Deer: Management Lessons From A Long-Term Study, Michael H. Smith, James M. Novak, J. D. Peles, J. R. Purdue

Faculty Research & Creative Activity

Genetic data from a long-term (16-year) study of white-tailed deer (Odocoileus virginianus) on the U.S. Department of Energy's Savannah River Site (SRS) were examined to evaluate spatial and temporal genetic heterogeneity in this species. Based on our analyses of the long-term data set, three major findings emerged, all of which have important implications for management of white-tailed deer: (1) There exists significant spatial genetic heterogeneity in white-tailed deer based on analyses of allozyme frequencies and mtDNA haplotypes. This heterogeneity exists on a much smaller spatial scale than would be expected for such a large and potentially mobile species as 0. …


Rna Binding Domain Of Telomerase Reverse Transcriptase, Cary Lai, James R. Mitchell, Kathleen Collins Jan 2001

Rna Binding Domain Of Telomerase Reverse Transcriptase, Cary Lai, James R. Mitchell, Kathleen Collins

Biology Faculty Publications

Telomerase is a ribonucleoprotein reverse transcriptase that extends the ends of chromosomes. The two telomerase subunits essential for catalysis in vitro are the telomerase reverse transcriptase (TERT) and the telomerase RNA. Using truncations and site-specific mutations, we identified sequence elements of TERT and telomerase RNA required for catalytic activity and protein-RNA interaction for Tetrahymena thermophila telomerase. We found that the TERT amino and carboxyl termini, although evolutionarily poorly conserved, are nonetheless important for catalytic activity. In contrast, high-affinity telomerase RNA binding requires only a small region in the amino terminus of TERT. Surprisingly, the TERT region necessary and sufficient for …


A Comparison Of Methods To Evaluate Energy Expenditure Of Incubating Wandering Albatrosses, Scott A. Shaffer, D P. Costa, H Weimerskirch Jan 2001

A Comparison Of Methods To Evaluate Energy Expenditure Of Incubating Wandering Albatrosses, Scott A. Shaffer, D P. Costa, H Weimerskirch

Faculty Publications, Biological Sciences

Measurements of incubation energetics can vary depending on the method used to measure metabolism of an incubating bird. Therefore, we evaluated the energy expenditure of six male and four female wandering albatrosses (Diomedea exulans Linnaeus) using doubly labeled water (DLW), the rate of mass loss, and estimates of metabolic water production derived from water influx rate (WIR). Incubation metabolic rates (IMR) determined with DLW ( 169 ± 21 kJ kg d SD) were significantly lower than estimates derived from mass loss ( 277 ± 46kJ kg d SD) and WIR ( males=289 ± 60 kJ kg d vs. females = …


A Fossil Blue Marlin (Makaira Nigricans Lacépède) From The Middle Facies Of The Trinidad Formation (Upper Miocene To Upper Pliocene), San José Del Cabo Basin, Baja California Sur, México, Harry L. Fierstine, Shelton P. Applegate, Gerardo González-Barba, Tobias Schwennicke, Luis Espinosa-Arrubarrena Jan 2001

A Fossil Blue Marlin (Makaira Nigricans Lacépède) From The Middle Facies Of The Trinidad Formation (Upper Miocene To Upper Pliocene), San José Del Cabo Basin, Baja California Sur, México, Harry L. Fierstine, Shelton P. Applegate, Gerardo González-Barba, Tobias Schwennicke, Luis Espinosa-Arrubarrena

Biological Sciences

A large fossil skull and several rostra of Makaira nigricans Lacépède, 1802 (Perciformes: Istiophoridae), as well as some less diagnostic istiophorid remains, have been recovered from the middle facies of the Trinidad Formation near Rancho Algodones, San José del Cabo Basin, Baja California Sur, México. These are the only bill fish specimens known from fossiliferous deposits located between southern California and Panama. Based on published accounts of the presence of nannofossils and planktonic foraminifera, and additional field work, we conclude that the age of the study area is late Miocene to late Pliocene. Based on the habitat preferences of recent …


Adaptive Sampling In The Coastal Ocean At The Long Ecosystem Observatory, Mark A. Moline, W. Paul Bissett, Scott Glenn, Dale Haidvogel, Oscar Schofield Jan 2001

Adaptive Sampling In The Coastal Ocean At The Long Ecosystem Observatory, Mark A. Moline, W. Paul Bissett, Scott Glenn, Dale Haidvogel, Oscar Schofield

Biological Sciences

A multi-platform inter-disciplinary observation network has been operating at the Rutgers University Long-term Ecosystem Observatory (LEO) since 1996, with real-time capabilities beginning in July 1999. The network integrates numerous remote (satellites and shore- based), stationary (surface and subsurface), moveable (ships and AUVs) observation systems. The observation network provides spatially extensive updates of the physics, optics, chemistry and biology on time scales of an hour or less which are communicated in real-time to shipboard scientists and AUV operators. This rapid environmental assessment capability is already changing current paradigms for ocean adaptive sampling strategies. For example, in the well-sampled ocean, where forecast …


Modeling Atmosphere-Ocean Interactions And Primary Productivity, Joe Grzymski, Mark A. Moline, Jay T. Cullen Jan 2001

Modeling Atmosphere-Ocean Interactions And Primary Productivity, Joe Grzymski, Mark A. Moline, Jay T. Cullen

Biological Sciences

The heat budget, and hence the climate of the Earth, is sensitive to changes in the atmospheric greenhouse gas composition. Next to water vapor, carbon dioxide (CO2) is the most important atmospheric greenhouse gas affecting the Earth's radiative balance. Greenhouse gases raise the mean temperature of the Earth by absorbing and trapping long-wave radiation from the planet surface that would otherwise be lost to space.


Changes In Phytoplankton Assemblages Along The Antarctic Peninsula And Potential Implications For The Antarctic Food Web, Mark A. Moline, Herve Claustre, Thomas K. Frazer, Joe Grzymski, Maria Vernet Jan 2001

Changes In Phytoplankton Assemblages Along The Antarctic Peninsula And Potential Implications For The Antarctic Food Web, Mark A. Moline, Herve Claustre, Thomas K. Frazer, Joe Grzymski, Maria Vernet

Biological Sciences

The majority of the yearly organic carbon production int he coastal regions of the Southern ocean occurs during summer blooms. Changes in the quantity and quality of the phytoplankton standing crop during this period will likely impact organisms that occupy higher trophic levels within the ecosystem. Here we report a recurrent shift in the dominant phytoplankton taxa during the austral summer in a coastal region along the Antarctic Peninsula. The pattern was observed each year between 1991 and 1996 despite radically different biomass concentrations and meteorological and hydrographic conditions. We show that a repeated dominance of cryptophytes (Cryptophyceae) during the …


Spawning Behavior In Hemitremia Flammea (Actinopterygii: Cyprinidae), Eugene G. Maurakis, Ray Katula, William Roston Jan 2001

Spawning Behavior In Hemitremia Flammea (Actinopterygii: Cyprinidae), Eugene G. Maurakis, Ray Katula, William Roston

Virginia Journal of Science

Spawning behavior in Hemitremia flammea (Flame chub) is described from observations made in the field and laboratory. Spawning in the field occurred over clean gravel (size range=18-25 mm) at water temperatures from 12.8-14.4 C. Spawning in the laboratory occurred over clean gravel (11.3 mm) at water temperatures from 18.3-20 C. Males often pursued females and nudged their vents with their snouts. When the female settled to the substrate, a male moved forward and aligned himself alongside her body. Then the female moved slightly forward accompanied by the male and the pair vibrated their caudal peduncles and tails. The spawn ended …


Pycnothyrium Ultrastructure In Tubakia Dryina [Abstract], Josephine Taylor Jan 2001

Pycnothyrium Ultrastructure In Tubakia Dryina [Abstract], Josephine Taylor

Faculty Publications

No abstract provided.