Biology Commons^™

Rapid Invasion Of Indo-Pacific Lionfishes (Pterois Volitans And Pterois Miles) In The Florida Keys, Usa: Evidence From Multiple Pre- And Post-Invasion Data Sets, Benjamin I. Ruttenberg, Pamela J. Schofield, J. Lad Akins, Alejandro Acosta, Michael W. Feeley, Jeremiah Blondeau, Steven G. Smith, Jerald S. Ault

Biological Sciences

Over the past decade, Indo-Pacific lionfishes, Pterois volitans (Linnaeus, 1758) and Pterois miles (Bennett, 1828), venomous members of the scorpionfish family (Scorpaenidae), have invaded and spread throughout much of the tropical and subtropical northwestern Atlantic Ocean and Caribbean Sea. These species are generalist predators of fishes and invertebrates with the potential to disrupt the ecology of the invaded range. Lionfishes have been present in low numbers along the east coast of Florida since the 1980s, but were not reported in the Florida Keys until 2009. We document the appearance and rapid spread of lionfishes in the Florida Keys using multiple …

Dynamics Of An Acute Coral Disease Outbreak Associated With The Macroalgae Dictyota Spp. In Dry Tortugas National Park, Florida, Usa, Marilyn E. Brandt, Benjamin I. Ruttenberg, Rob Waara, Jeff Miller, Brian Witcher, Andrew J. Estep, Matt Patterson

Biological Sciences

Reports of coral disease outbreaks have increased in recent decades, but often few details are known about these outbreaks, such as environmental triggers, associated biological variables, or even the precise temporal span of the outbreak. Here we document an acute outbreak of a rapid tissue loss disease on the highest live coral cover (15%–30%) reefs within Dry Tortugas National Park, Florida, USA. This disease exhibited similar signs to white plague disease with the notable exception that a white film often was observed on the recently denuded skeleton. The temporal span of the disease was short (<2 mo). Partial mortality was recorded but there was no detectable impact to overall coral cover. A significant increase and then decrease in the cover of macroalgae, primarily of the genus Dictyota, occurred simultaneously …

An Experimental Evaluation Of The Use Of C3 Δ13C Plant Tissue As A Proxy For The Paleoatmospheric Δ13Co2 Signature Of Air, B. H. Lomax, C. A. Knight, J. A. Lake

Biological Sciences

Previous work suggests that the relationship between the carbon isotope composition of air (d13Ca) and plant leaf tissue (d13Cp) can be used to track changes in the carbon isotope composition of paleo-atmospheric CO2. Here we test this assertion in a series of experiments using the model plant Arabidopsis thaliana grown under a range of atmospheric CO2 concentrations relevant to geologic time (380, 760, 1000, 1500, 2000 and 3000 ppm). Nested within these CO2 experiments water availability was controlled (giving two sets of experimental plants; low and high water treatment at each CO2 concentration) to manipulate stomatal opening, a key process …

Environmental Stress Proteomics Of Two Blue Mussel (Genus Mytilus) Congeners, Lars Tomanek

Biological Sciences

Abstract of paper presented at the 28th Congress of the New European Society of Comparative Physiology and Biochemistry Proceedings: Bilbao, Spain.

Gene Transcripts Encoding Hypoxia-Inducible Factor (Hif) Exhibit Tissue- And Muscle Fiber Type-Dependent Responses To Hypoxia And Hypercapnic Hypoxia In The Atlantic Blue Crab, Callinectes Sapidus, Kristin M. Hardy, Chandler R. Follett, Louis E. Burnett, Sean Lema

Biological Sciences

Hypoxia inducible factor (HIF) is a transcription factor that under low environmental oxygen regulates the expression of suites of genes involved in metabolism, angiogenesis, erythropoiesis, immune function, and growth. Here, we isolated and sequenced partial cDNAs encoding hif-α and arnt/hif-β from the Atlantic blue crab, Callinectes sapidus, an estuarine species that frequently encounters concurrent hypoxia (low O₂) and hypercapnia (elevated CO₂). We then examined the effects of acute exposure (1 h) to hypoxia (H) and hypercapnic hypoxia (HH) on relative transcript abundance for hif-α and arnt/hif-β in …

Investigation Of The Importance Of Rock Chemistry For Saxicolous Lichen Communities Of The New Idria Serpentinite Mass, San Benito County, California, Usa, Nishanta Rajakaruna, Kerry Knudsen, Alan M. Fryday, Ryan E. O'Dell, Nathaniel S. Pope, Fred C. Olday, Suzie Woolhouse

Biological Sciences

Although several lichen inventories exist for European ultramafic sites, only four surveys of serpentine lichens for North America have been published to date. Of those, only one has been conducted in California. We conducted a survey of saxicolous lichens from ultramafic rocks (including nephrite, partially serpentinized peridotite, and serpentinite) and non-ultramafic rocks (including silica-carbonate, shale, and sandstone) at the New Idria serpentinite mass, San Benito County, California. X-ray Fluorescence Analysis of the rocks from which the lichens were collected revealed significant elemental differences between the ultramafic and non-ultramafic rocks for 26 of the 32 major and trace elements analyzed. We …

How Do Host Sex And Reproductive State Affect Host Preference And Feeding Duration Of Ticks?, Nicholas B. Pollock, Larisa K. Vredevoe, Emily N. Taylor

Biological Sciences

Parasitism is one of the most notable forms of symbiosis in the biological world, with nearly all organisms hosting parasites. In many vertebrates, males have higher ectoparasite burdens than females, especially when testosterone concentrations are elevated. Furthermore, reproductive females may have higher ectoparasite burdens than non-reproductive females. It is possible that testosterone-stimulated behaviors in males and offspring investment by females incur energetic costs that inhibit immune function. If questing ticks can sense host sex or reproductive condition prior to attachment, they could potentially choose hosts with the poorest immune function, thereby leading to improved feeding success and decreased feeding duration. …

Characterization Of A Vibrio Fischeri Aminopeptidase And Evidence For Its Influence On An Early Stage Of Squid Colonization, Pat M. Fidopiastis, Bethany A. Rader, David G. Gerling, Nestor A. Gutierrez, Katherine H. Watkins, Michelle West Frey, Spencer V. Nyholm, Cheryl A. Whistler

Biological Sciences

Vibrio fischeri cells are the sole colonists of a specialized light organ in the mantle cavity of the sepiolid squid Euprymna scolopes. The process begins when the bacteria aggregate in mucus secretions outside the light organ. The cells eventually leave the aggregate, enter the light organ, and encounter a rich supply of peptides. The need to dissociate from mucus and presumably utilize peptides led us to hypothesize that protease activity is integral to the colonization process. Protease activity associated with whole cells of Vibrio fischeri strain ES114 was identified as the product of a putative cell membrane-associated aminopeptidase (PepN). To …

Hypoxia-Sensitive Gene Expression In The Gastrocnemius Muscle Following Chronic Hind Limb Ischemia, Andrew Tilton

Biological Sciences

Chronic ischemia, caused by the formation atherosclerotic plaque occlusions in major conduit arteries, is the leading cause of morbidity and mortality in western societies. Vascular remodeling can help compensate for the adverse effects of atherosclerotic plaque formation. Vascular remodeling relies heavily on vascular endothelial growth factor (VEGF), a critical protein that contributes to all forms of vascular formation and remodeling including angiogenesis, arteriogenesisand vasculogenesis. VEGF itself is up-regulated by the transcription factor, hypoxia inducible factor 1 alpha (HIF-1α), which becomes activated in low oxygen environments.

Through the use of animal chronic hindlimb ischemia models, these genes can be evaluated as …

Stressors And Threats To The Flora Of Acadia National Park, Maine: Current Knowledge, Information Gaps, And Future Directions, Tanner B. Harris, Nishanta Rajakaruna, Sarah J. Nelson, Peter D. Vaux

Biological Sciences

Acadia National Park is a center of plant diversity in northeastern North America. The Park's varied habitats and flora are sensitive to a number of natural and anthropogenic perturbations. Stressors such as invasive plants, pest and pathogens, ozone, acidic fog and sulfur deposition, nitrogen deposition, heavy metals, fire and fire suppression, over-browsing, visitor use, hurricanes, and climate change have all had effects on the Park's habitats and plant species at some point and it is unclear how many of these stressors are currently affecting the flora of Acadia National Park. We discuss the botanical diversity of Acadia, assess the natural …

The Spatial Games: Investigating The Spatial Distribution Of Anax And Select Prey As A Function Of Predator-Prey Interactions, Shane Elizabeth Johnson, Nene Kumashe Ugbah

Biological Sciences

Our study investigated the spatial distribution and movement behavior of predatory dragonfly larvae (Anax) and of two prey types: mosquito larvae and amphipods. Predator-prey interactions have important consequences for the population dynamics of both predator and prey groups and these interactions can shape community structure. We measured behavior of each prey type in the presence of the Anax predator and the behavior of the predator in the presence of these alternative prey types. Observations were made in five-gallon aquaria where a grid pattern allowed us to track the number of moves made by individuals. We compiled data from …

Probing The T-Box Riboswitch: A Novel, High-Throughput Transcription Reporter Assay Using A Fluorophore-Binding Aptamer, Nishtha Modi

Biological Sciences

In most Gram-positive bacteria, including important pathogens, expression of many aminoacyl tRNA synthetase (aaRS) genes is controlled by the tRNA substrate specific to each of these enzymes. This riboswitch regulatory mechanism is unique to Gram-positive bacteria and because correct and efficient aminoacylation of tRNAs is essential to an organism’s viability, it is an ideal target for the development of new antibiotics. The 5’-untranslated region (5’UTR) of the aaRS mRNA adopts a conformation that determines whether readthrough or termination of transcription occurs by interacting with unacylated or acylated tRNA, respectively. Our goal is to uncover a new class of small molecules …

The Senescence-Associated Secretory Phenotype (Sasp) And Redox-Dependent Invasion Of Metastatic Cancer Cells, Brooke A. Pati

Biological Sciences

Throughout your lifetime renewable tissues and those which are exposed to prolonged inflammation experience an accumulation of senescent cells. These cells have previously been shown to acquire the senescence-associated secretory phenotype (SASP) that promotes proliferation and tumorigenesis of epithelial cells, thus increasing the invasive ability of tumor cells (1). SASP is characterized by an upregulation in mRNA levels of a number of secretory factors, such as growth factors, cytokines, and chemokines. It has been shown that lifetime exposure to oxidative stress can influence cell cytoskeleton reorganization and influence aging processes (2). In addition matrix metalloproteinases are key SASP factors that …

The Distribution Of 4-Nonylphenol In Marine Organisms Of North American Pacific Coast Estuaries, Jennifer Diehl, Sarah E. Johnson, Kang Xia, Amy West, Lars Tomanek

Biological Sciences

One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ¹⁵N and δ¹³C) to quantify trophic position. 4-NP concentrations in organisms from Morro Bay included 25000 ± 8600 ng g⁻¹ lw in liver of California sea lion, 14000 ± 5600 ng g⁻¹ lw in liver of harbor porpoise, 138000 …

Do Thick Leaves Avoid Thermal Damage In Critically Low Wind Speeds?, A. Leigh, S. Sevanto, M. C. Ball, J. D. Close, D. S. Ellsworth, Charles A. Knight, A. B. Nicotra, S. Vogel

Biological Sciences

• Transient lulls in air movement are rarely measured, but can cause leaf temperature to rise rapidly to critical levels. The high heat capacity of thick leaves can damp this rapid change in temperature. However, little is known about the extent to which increased leaf thickness can reduce thermal damage, or how thick leaves would need to be to have biological significance. We evaluated quantitatively the contribution of small increases in leaf thickness to the reduction in thermal damage during critically low wind speeds under desert conditions.

• We employed a numerical model to investigate the effect of thickness relative …

Ecosystem Service Tradeoff Analysis Reveals The Value Of Marine Spatial Planning For Multiple Ocean Uses, Crow White, Benjamin S. Halpern, Carrie V. Kappel

Biological Sciences

Marine spatial planning (MSP) is an emerging responsibility of resource managers around the United States and elsewhere. A key proposed advantage of MSP is that it makes tradeoffs in resource use and sector (stakeholder group) values explicit, but doing so requires tools to assess tradeoffs. We extended tradeoff analyses from economics to simultaneously assess multiple ecosystem services and the values they provide to sectors using a robust, quantitative, and transparent framework. We used the framework to assess potential conflicts among offshore wind energy, commercial fishing, and whale-watching sectors in Massachusetts and identify and quantify the value from choosing optimal wind …

Ear Length As A Diagnostic Character For Identifying Species Of Kangaroo Rats, Daniel W. Ziebron

Biological Sciences

The following study examines the use of ear length as a diagnostic field character for differentiating between species of Kangaroo rats in San Luis Obispo County. Data was taken from a study of Kangaroo rats in the Guadalupe-Nipomo Dunes National Wildlife Refuge, as well as various collections under the supervision of Francis X. Villablanca, Ph. D. and California Polytechnic State University, San Luis Obispo. An ANOVA was used to compare subspecies within Dipodomys heermanni and t-tests were used to compare ear lengths between Dipodomys heermanni and Dipodomys venustus. The analysis shows a statistically significant difference and supports the hypothesis …

Potential For Barn Owl As Rodent Biological Control In Central California Vineyards, Hannah Tillmann

Biological Sciences

The pocket gopher (Thomomys bottae) and voles (Microtus spp.) cause significant economic damage to vineyards. In response, many growers have taken steps to attract Barn Owls (Tyto alba) to their properties to help keep these rodent populations in check. This research project investigated Barn Owl consumption of pocket gophers and voles in Central California vineyards in order to assess the efficiency of this integrated pest management strategy. I collected a total of 715 owl pellets from five vineyard locations in Templeton and Paso Robles, California over an eight-month period during nesting and post-fledging seasons. I …

Science & The Senses: Perceptions & Deceptions, William D. Stansfield

Biological Sciences

Science requires the acquisition and analysis of empirical (sense-derived) data. Given the same physical objects or phenomena, the sense organs of all people do not respond equally to these stimuli, nor do their minds interpret sensory signals identically. Therefore, teachers should develop lectures on human sensory systems that include some common examples of sensory limitations, variations, deficiencies, malfunctions, and diseases (as discussed herein) because they have important implications for conducting scientific investigations, science education, and introspection that are seldom included in biology textbooks. Students need to be made aware of the human tendency to self deception in order to avoid …

Fishing Top Predators Indirectly Affects Condition And Reproduction In A Reef-Fish Community, S.M. Walsh, S.L. Hamilton, Bi. Ruttenberg, M.K. Donovan, S.A. Sandin

Biological Sciences

To examine the indirect effects of fishing on energy allocation in non-target prey species, condition and reproductive potential were measured for five representative species (two-spot red snapper Lutjanus bohar, arc-eye hawkfish Paracirrhites arcatus, blackbar devil Plectroglyphidodon dickii, bicolour chromis Chromis margaritifer and whitecheek surgeonfish Acanthurus nigricans) from three reef-fish communities with different levels of fishing and predator abundance in the northern Line Islands, central Pacific Ocean. Predator abundance differed by five to seven-fold among islands, and despite no clear differences in prey abundance, differences in prey condition and reproductive potential among islands were found. Body condition …

Dobzhansky's Dictum: An Object Lesson For Critical Thinking, William D. Stansfield

Biological Sciences

A creationist has called Dobzhansky's dictum a myth. Discussion of this debate could be used as an object lesson for critical thinking.

Spontaneous Multiscale Phase Separation Within Fluorinated Xerogel Coatings For Fouling-Release Surfaces, Anastasiya Sokolova, Joseph J. Bailey, Grant T. Waltz, Lenora H. Brewer, John A. Finlay, Jill Fornalik, Dean Wendt, Maureen E. Callow, James A. Callow, Frank V. Bright, Michael R. Detty

Biological Sciences

Four-component xerogel films consisting of 1 mole-% n-octadecyltrimethoxysilane (C18) and 50 mole-% tetraethoxysilane (TEOS) in combination with 1–24 mole-% tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (TDF) and 25–48 mole-% n-octyltriethoxysilane (C8) and a 1:49:50 mole-% C18/TDF/TEOS were prepared. Settlement of barnacle cyprids and removal of juvenile barnacles, settlement of zoospores of the alga Ulva linza, and strength of attachment of 7-day sporelings (young plants) of Ulva were compared amongst the xerogel formulations. Several of the xerogel formulations were comparable to poly(dimethylsiloxane) elastomer with respect to removal of juvenile barnacles and removal of sporeling biomass. The 1:4:45:50 and 1:14:35:50 C18/TDF/C8/TEOS xerogels displayed some phase …

Evaluation Of Bio-Optical Inversion Of Spectral Irradiance Measured From An Autonomous Underwater Vehicle, Mark A. Moline, Ian Robbins, Brian Zelenke, W. Scott Pegau, Hemantha Wijesekera

Biological Sciences

Autonomous underwater vehicles (AUVs) can map water conditions at high spatial (horizontal and vertical) and temporal resolution, including under cloudy conditions when satellite and airborne remote sensing are not feasible. As part of the RADYO program, we deployed a passive radiometer on an AUV in the Santa Barbara Channel and off the coast of Hawaii to apply existing bio-optical algorithms for characterizing the optical constituents of coastal seawater (i.e., dissolved organic material, algal biomass, and other particles). The spectral differences between attenuation coefficients were computed from ratios of downwelling irradiance measured at depth and used to provide estimates of the …

Can Vertical Migrations Of Dinoflagellates Explain Observed Bioluminescence Patterns During An Upwelling Event In Monterey Bay, California?, Igor Shulman, Bradley Penta, Mark A. Moline, Steven H.D. Haddock, Stephanie Anderson, Matthew J. Oliver, Peter Sakalaukus

Biological Sciences

Extensive AUVs surveys showed that during the development of upwelling, bioluminescent dinoflagellates from the northern part of the Monterey Bay, California (called the upwelling shadow area), were able to avoid advection by southward flowing currents along the entrance to the Bay, while non-bioluminescent phytoplankton were advected by currents. It is known that vertical swimming of dinoflagellates to deeper layers helps them avoid losses due to advection. In the present paper, we investigate if modeling dinoflagellates’ vertical swimming can explain the observed dinoflagellates’ ability to avoid advection during the upwelling development. The dynamics of a dinoflagellate population is modeled with the …

Experimentally Altered Navigational Demands Induce Changes In The Cortical Forebrain Of Free-Ranging Northern Pacific Rattlesnakes (Crotalus O. Oreganus), Matthew L. Holding, Julius A. Frazier, Emily N. Taylor, Christine R. Strand

Biological Sciences

The hippocampus of birds and mammals plays a crucial role in spatial memory and navigation. The hippocampus exhibits plasticity in adulthood in response to diverse environmental factors associated with spatial demands placed on an animal. The medial and dorsal cortices of the telencephalon of squamate reptiles have been implicated as functional homologues to the hippocampus. This study sought to experimentally manipulate the navigational demands placed on free-ranging northern Pacific rattlesnakes (Crotalus o. oreganus) to provide direct evidence of the relationship between spatial demands and neuroplasticity in the cortical telencephalon of the squamate brain. Adult male rattlesnakes were radio-tracked for 2 …

Sirtuin-Induced Protein Deacetylation Affects The Heat Shock Response In Blue Mussel Congeners (Mytilus), M. Beam, M. Zuzow, L. Tomanek

Biological Sciences

The warm-adapted Mediterranean blue mussel species Mytilus galloprovincialis invaded southern California during the last century and has since replaced the cold-adapted native M. trossulus from its southern range, possibly due to climate change. Based on previous proteomic analyses, we hypothesized that the more heat-sensitive M. trossulus switches from NADH-producing metabolic pathways that may generate reactive oxygen species (ROS) to NADPH-producing pathways that are able to scavenge ROS during severe heat stress (32°C). We further linked these changes to the activity of the mitochondrial NAD-dependent deacetylase, sirtuin-5, which has been shown to regulate many metabolic pathways. To test the latter hypothesis, …

The Proteomic Response Of Mytilus Californianus To Acute Oxidative Stress In The Presence Of A Sirtuin Inhibitor, H. Chilton, J. Mier, M. Zuzow, L. Tomanek

Biological Sciences

The ribbed mussel (Mytilus californianus) occurs in the in the rocky intertidal zone along the Pacific coast of North America where it experiences greatly varying environmental conditions in terms of temperature and hypoxia, stressors that are known to induce oxidative stress. It has been hypothesized that while under acute heat stress, related Mytilus congeners undergo a shift in redox potential through the reduction of NADH fueled respiration pathways to the production of the reducing agent NADPH as a potential defensive mechanism against the production of reactive oxygen species. In addition, it has been hypothesized that sirtuins (a family …

The Proteomic Response To Acute Heat Stress After Acclimation To Fluctuating Temperatures In The Eurythermal Porcelain Crab, Petrolisthes Cinctipes, Michael A. Garland, Holland Elder, David A. Hurt, Jonathon H. Stillman, Lars Tomanek

Biological Sciences

The porcelain crab Petrolisthes cinctipes inhabits the high intertidal along the Pacific coast between British Columbia and central California and is an emerging model organism to study the effects of environmental stress. In its habitat it experiences not only variability in average temperature but also variability in temperature fluctuations. To investigate the effect of temperature fluctuations, we characterized the heat shock response at 30°C for 6 h by acclimating individuals to three different acclimation treatments: 10°C, 10-20°C (4 h), and 10-30°C (4 h) on a daily basis for one month. We dissected claw muscle and separated proteins by 2D gel …

Proteomic Responses Of Mytilus Congeners To Hypo-Saline Stress, M. Z. Zuzow, L. Serafini, L. Hitt, J. Valenzuela, L. Tomanek

Biological Sciences

The invading Mediterranean blue mussel species Mytilus galloprovincialis requires higher salinity levels than the more hypo-saline tolerant and native M.trossulus,which it replaced from its southern range in California, possibly due to climate change.It is also the warm-adapted congener.Hypo-salinity,due to an increase in extreme precipitation events,has been hypothesized to limit the expansion of the invader.By comparing the proteomic responses of the congeners to acute hypo-saline stress we were trying to identify the interspecific differences that set limits to hypo-saline stress and assess their contribution to the range shifts.We exposed mussels to acute hypo-saline(100%, 85% and 70% salinity)stress for 4h followed …

Proteomic Response Of Tidal-Rhythm Entrained Mytilus Californianus To Acute Aerial Heat Stress, D. Hernandez, M. Schuman, L. Tomanek

Biological Sciences

The rocky intertidal mussel species Mytilus californianus is native to the Pacific coast of North America. It is frequently exposed to temperatures that can induce the cellular stress response due to the tidal rhythm. Instead of acclimating mussels to common conditions in the laboratory for several weeks, we collected mussels from a site with mussel body temperature recordings (specimens’ thermal history) and immediately started experimentation by mimicking the tidal rhythm with different levels of heat stress over multiple low tides and with different recovery periods. By using individuals that were entrained to the tidal rhythm and by maintaining it, we …