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Dr. Romi Burks

Dr. Burks in the Field

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B.S. Biology, magna cum laude, Loyola University Chicago (1995)
B.A. English, magna cum laude, Loyola University Chicago (1995)
Ph.D., Aquatic Ecology, University of Notre Dame (2000)

Research Interests: food web interactions, invasion biology, predator-avoidance behavior, chemical ecology

The Present:

Since my arrival at Southwestern, my lab has been taken over (somewhat literally!) by an exotic, invasive applesnail, Pomacea insularum. We have been studying this snail for nearly 7 years and still have much to learn! Receiving my Ph.D. in the lab of noted exotic species authority Dr. David Lodge at the University of Notre Dame has helped me focus my current research emphasis to questions associated with invasion biology. In particular, I collaborate with student researchers to investigate multiple aspects of basic life history of this new invader. In addition, the work has expanded to include an international collaboration in Uruguay and Brazil where native applesnails occur.

A Little History:

I am an aquatic ecologist interested in how organisms interact within and impact shallow lakes and ponds. My graduate work focused on looking at predator-avoidance behaviors in an important aquatic herbivore, Daphnia. In temperate systems, this large-bodied zooplankter migrates horizontally and seeks refuge in the complexity offered by aquatic plants and my research has examined what mechanisms regulate the frequency and amplitude of this behavior. In particular, Daphnia respond to the presence of chemical signals from both predators and plants that influence the extent to which they migrate. They also seek refuge in aquatic plants. Apple snails eat aquatic plants so it is not difficult to connect the dots. Thus, my interests have always included a strong focus on invertebrates and I've just moved up in size!

The Questions:

In my lab, students have the opportunity to work on any of the life stages (egg, hatchling, juvenile, adult) of this invasive applesnails that we collect from the Houston area and maintain in the lab. Some of the work has directly involved behavioral investigations or experiments and other work focuses more directly on basic ecological questions. Below I list a timeline of our work.

  • ROUND 1 RESEARCH (2004-2007): We examined basic trends in fecundity, growth and feeding. The first four alumni of the lab (Rebecca Marfurt Fordham '05, Matt Barnes '06, Brandon Boland '07 and Abby Youens '07) contributed to the first set of publications.

  • FOR ROUND 2 RESEARCH (2007-2009): We narrowed our focus a little more to examine how snails interacted with specific exotic plants through either consumption with the work of Sarah Hensley '08) or through behavioral choices in terms of oviposition in the lab or the field Colin Kyle '09 and James McDonough '09). Current senior Alexis Kropf '12 also completed oviposition an experiment during Summer of 2009 that showed that medium-sized snails can produce more eggs than their larger counterparts. Additionally, Scott Manusov '09 also developed a method to look at aggregration of juvenile snails during this period of lab history.
  • The majority of this work has finally now been published.

  • FOR ROUND 3 RESEARCH (2009-2010):
  • Having an good estimate of apple snail fecundity, we turned our attention to factors that could influence hatching efficiency. Student collaborators Matt Trawick '10 and Megan Rice '11 collectively completed a set of experiments that tested how water stress influenced hatching efficiency, quality and survival with clutches of different ages. For these questions, we have the research completed....and now need to recheck our analyses and get to writing.

  • FOR ROUND 4 RESEARCH (2010 to present):
  • With much experience behind us, current students in the lab have diversified their interests and now pursue a number of projects. Senior Tracy Day '12 and Junior Allyson Plantz '13 have been working on projects for just over a year. Newcomers Kevin Burge '12, Katie Gibson '12 and Manuel Ortegon '13 worked during the Spring of 2011 to develop their project ideas. Brandon O'Connor '12 did some predation work during this first summer in the lab and wants to continue a focus on hatchilngs. Some current ideas include:

  • Do riparian predators, such as red-eared slider turtles, consume apple snail eggs or hatchlings (Allyson)?

  • Can we determine the trophic position of Pomacea insularum using stable isotopes and experiments? (Tracy)

  • Does Pomacea insularumexhibit behavioral responses to predators typical to other snails? (Katie)

  • What factors influence hatchling survival and growth? (Kevin and Brandon)

  • How does temperature affect consumption and survival of island apple snails? (Manuel)

  • The Context:

    The genus Pomacea possesses a history of global invasion. P. canaliculata made the top 100 list of the world's worst invasive species with substantial impacts on Asian rice. Very recently, colleagues at the University of Hawaii (link to Ken Hayes's website - and Florida International University (link to Tim Collin's and Tim Rawling's website determined that a new species, Pomacea insularum, occurs in Texas, Georgia and has recently invaded the Everglades. Very little information exists on this species, although it is closely related to the better-known global invader.

    To further add to the complexity, P. insularum competes with a native Florida applesnail, P. paludosa, that serves as food for an endangered raptor. In addition, the aquarium trade may facilitate the introduction, establishment and spread of P. insularum by selling another applesnail species, P. diffusa, which only eats algae but, at small sizes, closely resembles the species that we study. These aquarium snails are sometimes called 'mystery snails' as it is a mystery as to what you actually bring home.

    Philosophy of Collaborative Research with Students:

    To maximize productivity for both students and myself, I continually recruiting students to work on some aspect of applesnail ecology.I want to build a stair-step lecture in the lab where the most senior member helps out the newcomers and new students form their own ideas by helping out senior students on developed projects. Although we want to focus on efforts on this study organism, the diversity of questions that can be explored remains endless. I work directly with the student to develop his/her own research question that includes a reasonable degree of "personal ownership or investment." To get the most out of the research process, students need to work on questions that pique their own interests. When first embarking on a research projects, students review primary literature and then draft a proposal that includes a rationale, hypotheses, and proposed methods for developing experiments. We spend substantial time developing the context of the research and determining the appropriate methods (not many ecology project have established specific protocols). After executing the experiments, students participate directly in data analysis and dissemination through poster nd oral presentations and, hopefully contributions to a scientific paper.

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