BGSO Spring Symposium

The Biology Graduate Student Organization Spring Symposium was held March 19, 2011. This year there were 24 presentations; 11 were MS students, 7 from the PhD in Ecological Sciences, and 6 from the PhD in Biomedical Sciences program. Obviously, with this number of students the topics were wide and varied, this made judging difficult; there was a tie for 3^rd place in the PhD student category.  Below are summaries of the top place finisher’s presentations

Top Presentations by a PhD student (Faculty mentor):

1.    Matthew R. Semcheski (Dr H. Marshall)

Dirty Little Secrets: An introduction to one of the most important, yet overlooked primary producers in Chesapeake Bay.

Primary production by microphytobenthos (MPP) is trophically important to a variety of micro- and macroheterotrophs in marine and estuarine habitats. In Chesapeake Bay, MPP facilitate survival and development of ecologically and economically relevant vertebrate and invertebrate fauna. MPP rates have been measured in habitats from sandy bottoms to tidal mudflats worldwide. However, productivity measurements in Chesapeake Bay are lacking, with few published studies in the last 30 years. This project aims to quantify microphytobenthic primary production rates in intertidal areas of lower Chesapeake Bay in relation to water column (phytoplankton) primary production (PPP). Eight sites throughout lower Chesapeake Bay were identified for measurements of PPP and MPP rates. Seasonal variations in community composition are examined in addition to MPP and PPP fluctuations.  MPP and PPP samples were processed for productivity following a ¹⁴C-incubation protocol. After one year, MPP and PPP varied among and between stations, with PPP showing much higher production rates per volume than MPP. Cell densities in the benthos were several orders of magnitude higher than those in the water column. Phytoplankton and microphytobenthic community composition fluctuated both seasonally and between stations, with phytoplankton production and composition consistent with historical Chesapeake Bay data.

2.    Amanda Ackiss (Dr. K. Carpenter)

Assessing the Population Structure of an Artisanal Fishery, Caesio cuning, in the Philippines and Indonesia

The redbelly yellowtail fusilier, Caesio cuning, has a tropical Indo-West Pacific range that straddles the Coral Triangle, a region of dynamic geological history and the highest marine biodiversity on the planet. Caesio cuning is a reef-associated artisanal fishery, making it an ideal species for assessing regional patterns of gene flow for evidence of speciation mechanisms as well as for regional management purposes. We evaluated the genetic population structure of Caesio cuning using a 382bp segment of the mitochondrial control region amplified from over 620 fish sampled from 33 localities across the Philippines and Indonesia. Phylogeographic analysis showed that sites in Western Sumatra formed a single population, resulting in pronounced regional structure between Western Sumatra and the rest of the Coral Triangle (FCT = 0.4596, p<0.0031). The species’ range and measures of genetic diversity at these Indian Ocean localities point toward low effective population size west of Sumatra and indicate that historic changes in sea level and ocean currents during periods of Pleistocene glaciation may have led to the divergence seen between Caesio cuning populations west and east of the Sunda shelf. East of Sumatra, there were additional significant genetic differences between the central sites sampled from the Philippines south to Java and Nusa Tenggara and the sites west of Halmahera to the edge of our sampling range at Cenderawasih Bay. Detected haplotype frequency differences in these sites may have arisen as a result of present-day ocean currents. These signatures, particularly the linage divergence between Western Sumatra and all other sampled sites, corroborate other studies in this region, indicating region wide mechanisms for lineage divergence across multiple taxa.

3.    Brian L. Stockwell (Dr K. Carpenter)

The species-area relationship and marine reserves: no reserve is an island

The argument over the effectiveness of a single large or several small (SLOSS) reserves has been continued for decades, yet analyses have focused on terrestrial examples. This study examined the effects of marine reserve area and networks on fish diversity.    Diversity from six mainstream reef fish families was collected from 28 no-take marine reserves within the central Philippines.   Diversity was plotted against reserve area, number of reserves within 10km, and area of reserves within 10km.  Regression analyses were then run to evaluate the strength of these relationships.   The linear regression analysis of diversity versus reserve area and diversity versus years of protection were both non-significant while the regression of diversity versus the number of marine reserves within 10km  and area of reserves within 10km were both strong (r² > 0.75) and highly significant (p < 0.001).  The greater diversity in networked reserves suggests a connection through larval dispersal.    The current system of many small but closely spaced marine reserves in the Philippines appears to be an effective strategy for improving and maintaining reef fish diversity.

·         Rachel Wigton (Dr. I. Bartol)

Turning Performance in Cuttlefish Sepia pharaonis

Using complex motions of fins that extend along the length of the mantle and pulsed jets that are directed through a flexible funnel, cuttlefishes are capable of making frequent turns when hunting for prey, evading predators, and navigating complex habitats. While cuttlefish appear to be quite adept at making rapid, tight turns during these maneuvers based on field observations, turning performance has not been quantified to date in any species of cuttlefish.  For this study, we recorded a variety of turns performed by cuttlefish Sepia pharaonis from lateral and ventral perspectives using two high-speed video cameras.  Various landmarks on the cuttlefish mantle, funnel, arms, and fins were tracked and parameters, such as minimum radius of the turning path (a measure of maneuverability) and angular velocity of turns (a measure of agility) were calculated using Matlab routines.  Arm movements, asymmetric fin motions, angle adjustments of the mantle and arms, and funnel movements all were employed to minimize the radius of the turning path, whereas vigorous jetting and/or rapid fin waves were closely correlated with the highest angular turning velocities.  The extensive repertoire of mantle, funnel, fin, and arm movements displayed by cuttlefish facilitates their ability to achieve high levels of maneuverability and agility. 

Top Presentation by a MS student (Faculty mentor):

1.    Robyn Nadolny (Dr H. Gaff/Dr R. Rose)

Survey of Ticks in Hampton Roads: Tick Populations

Ixodid ticks are vectors of emerging diseases throughout the southeastern United States, including Lyme disease, Rocky Mountain Spotted Fever, and erlichiosis. In order to understand which areas are most at risk of expressing high prevalence of these and other diseases in human populations, it is imperative to first have an understanding of the tick populations. We have begun a comprehensive long-term sampling effort to understand the distribution and composition of tick populations in the Hampton Roads area. 24 locations at 10 sites throughout Hampton Roads were sampled, and we collected more than 13,000 individual ticks during the summer of 2010. We found established populations of four ixodid tick species, including one species not previously known to have been established in Virginia. With this data we can identify populations that are at high risk of a tick encounter and provide insight as to which times of year are most risky for contracting a tick-borne disease. We are in the process of analyzing our collected ticks for disease so that we can identify areas where disease is endemic in the tick populations at high rates.

2.    Toufic Mayassi (Dr C. Osgood/Dr D. Gauthier)

Imaging biofilms on the Frontiers of Microscopy

Bacterial biofilms are dynamic systems that change over time and in response to changes in the environment.  Mycobacterium marinum are a type of nontuberculosis mycobacteria (NTM) known to form unique biofilms characterized by their cording morphology.  M. marinum can cause granulomatous infections in various fish species leading to financial hardships for affected fisheries.   M. marinum are also capable of infecting humans and have been isolated from commercial water sources, making them an interesting and relevant microorganism to study.  The work presented focuses on better understanding the biofilm growth of M. marinum using scanning electron microscopy (SEM) and atomic force microscopy (AFM).  Escherichia coli was used as a model system for growing biofilms and imaging with SEM and AFM.  Imaging of M. marinum with SEM was able to demonstrate the dynamic nature of biofilms with respect to time and exposure to different levels of nutrition, while also revealing their characteristic cording morphology.  The MBEC assay system was used to further investigate M. marinum biofilms along with the effect of different fixatives on the preservation and stability of the biofilms.  M. marinum biofilms imaged with SEM revealed extensive extracellular polymeric substances (EPS) when fixed with glutaraldehyde as opposed to formaldehyde.  Novel web-like EPS ultrastructure, which may play a structural role in maintaining biofilm stability, was also observed.  The MBEC assay system also allowed for the first images of M. marinum biofilms using AFM.  The results from this study provide groundwork for live cell imaging of M. marinum biofilms with liquid cell AFM in hopes of better understanding the structures of these systems in nature.

3.    Stephen Rice (Dr. R. Rose)

Patterns of transiency, sex bias, and body weight in open-habitat rodent populations.

Rodents belong to the most abundant and diverse order of the Class Mammalia, and as such have served as a common basis for study and modeling biological concepts.  Rodents are presumed to be philopatric with minimal vagility, except for the notion that juvenile males are the most probable subgroup to disperse.  To test these assumptions weight, reproductive status, and previous captures were evaluated to determine departure from unity, examine the proportion of each group in trappable populations, and identify differences between residents and transients.  Long-term data sets from CMR studies in Kansas and Illinois combined with trapping efforts in eastern Virginia were coded to evaluate the patterns of transiency, sex bias and body weight in six species of open-habitat rodent populations.  Preliminary analysis of Sigmodon hispidus from Kansas indicates male biased populations for residents and transients as expected.  No discernable difference in body weight was detected; however the total population consisted of 51% transients.  Further analysis is ongoing for populations and species in eastern Virginia, Kansas, and Illinois.

Converging for the Birds!

This post was written by Rachel Jabaily, currently a post-doc in the lab of Assoc Professor Tim Motley, about the current display in the Kaplan Orchid Conservatory.

Converging for the Birds:

The plant families Orchidaceae (the orchids-25, 000+ species) and Bromeliaceae (the bromeliads- 3200+ species) are not closely related.  But both have a group of species (genus) in the New World with uncannily similar general flower shape and colors. 

In our living collection we have specimens of the orchid genus Stenorrhynchos, a group of ~7 species found in the SW United States, the Caribbean, Central America, Brazil and much of the Andes.  Notice the red, narrowly opened flowers, each protected by a big bract.

Compare the orchid with these pictures of the bromeliad genus Pitcairnia.  This genus is also only found in the New World tropics but has several hundred species.   See how outwardly similar it appears to the Stenorrhynchos inflorescence (branch of flowers)? The similarity is only skin-deep, though; the bromeliad flower’s reproductive parts (pistil and stamen) do not fuse into a column, which defines the orchid family.

This is a great example of convergent evolution, in which lineages of unrelated organisms evolve in similar ways to similar evolutionary pressures.  In this case, the plants evolved to attract hummingbirds as pollinators, which love red, tubular flowers with lots of nectar at the base.

Interestingly, only ~3% of the world’s orchids are pollinated by birds, with the majority of species using bees, wasps and flies as pollinators. Many orchid species have an extremely specific pollinator relationship with a single insect species.  Bromeliads generally utilize much more promiscuous hummingbirds, and may have fewer species than the orchid family because of it!

We have many other examples of living bromeliads in the Kaplan Conservatory- look UP on the pillars and walls for examples of epiphytes (plants that grow on top of other plants in the rainforest) and DOWN in pots by the entryway for larger specimens that have overlapping leaf bases which hold water like a vase for the plant to use later- also an important water source for many animals!

Here are a few more examples from unrelated plant families that have converged on the hummingbird floral syndrome in the New World tropics…

Text and photos by Rachel S. Jabaily, 2011 except photo of Stenorhhynchos: Golden Gate Orchids, and Pitcairnia: J.M. Manzanares

Dr Meredith Kintzing, PhD.

Congratulations to Dr Kintzing who triumphed over personal tragedies to graduate with her PhD in Ecological Sciences in Dec 2010. Meredith joined the PhD program in 2004 under the mentorship of Dr Mark Butler. Meredith's studies involved traveling up and down the east coast from her home here in VA to her main research site in the Florida Keys where she spent the summer, or entire semesters immersed in her "lab". In addition, she was able to fit in classes, trips to scientific meetings and other exotic research sites, as well as the occasional marathon or half marathon. Currently Meredith is a post-doc in the biogeochemistry lab of Chris Martens in the Marine Sciences Department at the University of North Carolina at Chapel Hill.

From Meredith:
Being a graduate student in marine ecology is challenging, exciting, and rewarding. As a graduate student at ODU I had the opportunity to dive the coral reefs of the Florida Keys and Belize while conducting research that addressed interesting scientific questions that also had applications to managing this resource. Like any graduate program it involved a lot of hard work, but on any given day I might see a sea turtle, manatee, or shark in addition to the invertebrates that were the focus of my research. When your “office” is the ocean every day is an adventure.

Research: Human activity has stressed the world’s oceans. Nowhere is this more evident than coral reefs, especially those of the Caribbean. Caribbean reefs began experiencing declines in coral cover in the early 1980s attributable to a number of factors including overfishing, pollution, disease, and loss of key herbivores. I am interested in coral reef communities particularly determining the causes and consequences of their decline. My research focuses on trophic interactions, or who eats whom, on the coral patch reefs of the Florida Keys. My dissertation focused on how the spotted spiny lobster altered patch reef communities. I found the spotted lobster has a broad diet that includes several important herbivorous, or seaweed eating, invertebrates. In addition to consuming herbivores, the spotted lobster also alters the behavior of herbivorous sea urchins causing them to consume less algae. This has important implications for coral reefs as algal overgrowth associate with the diseased induced die-off of this sea urchin is one of primary causes of reef decline in the Caribbean. By gaining a better understanding of how organisms interact on coral reefs we will be able to better preserve and protect them for future generations. 

 http://marine.unc.edu/people/Faculty/martens

SCHEV Outstanding Faculty Award

Congratulations to Professor Mark Butler who this past week was recognized as one of the SCHEV outstanding faculty for 2011.  See the full ODU story here.  His hard work and dedication is appreciated as evidenced by this award and the numerous others he has had over the years. For more information about Dr Butler's research check out his web page.

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Brief Bio provided by Mark Butler:

Mark Butler is Professor and Eminent Scholar in the Department of Biological Sciences at Old Dominion University, where he teaches marine ecology and biostatistics and has been a faculty member since 1989.

Professor Butler received the Hirschfield Award for Faculty Excellence and the "Most Inspirational Faculty" Award from the ODU College of Sciences. His dedication to science education has attracted the attention of the National Science Foundation, which has appointed him to numerous review panels to select the recipients of various institutional science education grants, as well as graduate research fellowships for the nation's top doctoral students.  

An internationally known marine biologist, Professor Butler has published more than 100 scientific articles and book chapters, and has been awarded more than 50 grants totaling over $8 million, many being prestigious grants from the National Science Foundation.  He has two current NSF grants: one exploring the effects of fishing and climate change on disease in Virginia's blue crabs; the other uses Caribbean lobsters as a model system for understanding how pathogen dispersal in the sea influences disease dynamics. He also spearheads a community-based project to restore sponge-dominated hard-bottom habitat in the Florida Keys.

Among other professional service activities, Professor Butler has been an advisor to fishery management agencies in Florida, the Caribbean, Australia, and the Galapagos Islands and has trained coral reef managers in Mesoamerica.  In 2008, he co-authored a policy brief for the United Nations on improving coastal marine management and last year led a conservation assessment of lobsters worldwide. Here in Virginia, he has served on the Blue Crab Scientific Task Force and is a member of the Suffolk Wetlands Board.

"My students and I get wet and dirty when studying marine ecology and I wouldn't have it any other way", writes Professor Butler. "Few will become marine biologists. Yet, whatever careers they pursue, I want to help them gain a truer understanding of how knowledge is generated and hope they become more responsible stewards of our watery, blue planet."

Professor Butler received a B.A. at Wittenberg University, an M.S. at Ohio State University, a Ph.D. at Florida State University.

Fish Disease in the Chesapeake Bay

DAVID GAUTHIER, assistant professor of Biological Sciences recently received funding from NOAA (Chesapeake Bay Office) and Virginia Sea Grant, through Virginia Institute of Marine Science, for his study “Quantifying the interactive effects of hypoxia, temperature, and mycobacteriosis on striped bass (Morone saxatilis) ; their impact on the energetics and ecology of these fish."

Dr Gauthier is working as part of a collaborative team with faculty at VIMS (Richard Brill, Mary Fabrizio, Wolfgang Vogelbein, Dominique Lapointe) to study the synergistic effects of hypoxia, temperature, and mycobacteriosis on the physiology of striped bass.  Hypoxic "dead zones" occupying Chesapeake Bay through much of the summer are thought to be a potential stress factor leading to development of disease due to Mycobacterium spp. in Chesapeake Bay striped bass, and disease, in turn, may exacerbate physiological stress due to hypoxia or increased temperatures.  With this funding they will be studying the physiological responses of striped bass to increased temperature and decreased dissolved oxygen, and will be examining how disease status affects these responses.  Work will be conducted at the state-of-the-art Seawater Research Laboratory at VIMS.  

Tick expert gets recognized by insect society

The Governing Board of the Entomological Society of America in 2010 elected ten new Fellows of the Society. Among them, Daniel Sonenshine, Old Dominion University professor emeritus and eminent scholar of biological sciences.  The election as a Fellow to the society acknowledges Dan’s outstanding contributions to the study of ticks. The fellows were recognized at the ESA Annual Meeting in December 2010. Two years ago Dan was recognized by the American Society of Tropical Medicine and Hygiene with the Hoogstraal Medal for outstanding lifelong service in medical entomology.

Dan Sonenshine retired from the Biology departments teaching faculty in 2002, after 41 years of service to ODU. Since that time he has remained active in his research program.  After years of field work and physiological studies, he has moved down to the molecular level. Among his latest pursuits are studies of the innate immunity of ticks, the molecular biology of tick reproduction, and tick neuropeptides.  

Dr Sonenshine has published over 200 referred articles in various scientific journals, various monographs and book chapters. However, it is his two volume book set “The Biology of Ticks” that he is probably best known for; although published in 1992-93 it is still the bible for all aspects of tick biology including anatomy, ultrastructure, physiology and tick-borne diseases. He is currently working on an updated version with his close colleague Michael Roe from North Carolina State University; this is expected to be published in 2013.

When he ‘retired’ Dr Sonenshine wanted to make sure he had something to do, working in the lab 8hours a day was not enough….In 2010 under the guise of pseudonym Dan Ailey he branched out of just scientific writing into the realm of Sci-Fi writing when he published Extinction: The Ultimate Holocaust. The Plan to Exterminate Humanity.

Rift Valley Fever modeling

HOLLY GAFF, assistant professor in Biological Sciences has recently received funding from the Department of Homeland Security FAZD (Foreign Animal and Zoonotic Disease defense) Center through subgrants with Georgetown University and Texas A&M University (Texas Agrilife Research) for her studies on the modeling of Rift Valley Fever.

Rift Valley Fever is a viral disease spread by mosquitoes that primarily affects livestock but can be passed to humans, and which is potentially fatal. It is currently found across sub-Saharan Africa, with outbreaks reported in Egypt, Kenya, Saudi Arabia, Yemen and South Africa.  With the fact that diseases can be easily moved around the world in a short period of time, introduction to the USA, either intentionally or accidently, could pose a serious threat to both livestock and humans.

Dr Gaff proposes to enhance the modeling of the impact of climate on the spread of the disease.  Competent vectors of the virus already exist in the US so these would facilitate the spread of disease to both human and livestock populations. Models would involve components including climate (temperature and precipitation), livestock densities, and populations of the vectors capable of transmitting the virus.