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CURRENT LAB MEMBERS
Cecilia Boutry, Ph.D.
candidate Integrative Bioscience, began spring 2006 ,
graduated spring 2011
***Congratulations, Cecilia has graduated and is moving to a postdoc in
Doug
Fudge's lab***
Cecilia is studying how
individual level plasticity in the mechanical performance of spider silk
is related to variation in web architectures and the environment. She is
particularly interested in testing the hypothesis that spiders can
actively control the structural and material properties of silk. Cecilia
is also interested in relating variation in silk performance to
functional differences between webs during prey capture. Her research
has been highlighted by
National Geographic. Cecilia has degrees in Biology from
Université des
Sciences et Technologies de Lille and from
Université François-Rabelais Tours.You
can read more about Cecilia's research
here.
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Boutry C.*, Řezáč M. & Blackledge T.A. 2011. Plasticity in major
ampullate silk production in relation to spider phylogeny and
ecology. PLoS One. 6(7):e22467.
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Boutry, C. & T.A. Blackledge.
2010. Evolution of
supercontraction in spider silk: structure-function relationship
from tarantulas to orb-weavers. Journal of Experimental Biology.
213:3505-3514.
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Boutry, C.,* & Blackledge, T.A. 2009. Biomechanical variation of
silk links spinning plasticity to spider web function. Zoology.
112:451-460.
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Blackledge, T.A., Boutry, C.,* Wong, S.C., Baji, A., Dhinojwala, A.,
Sahni, V. & Agnarsson, I. 2009. How super is supercontraction?
Persistent versus cyclic response to humidity in spider dragline
silk. Journal of Experimental Biology. 212:1981-1989. (cover
article featured in Inside JEB, New Scientist,WKYC-TV)
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Agnarsson, I., Boutry, C.*, Wong, S-C., Baji, A., Sensenig, A. & T.A.
Blackledge. 2009. Supercontraction forces in spider dragline silk
depend on rate of humidity change. Zoology. In press. (cover)
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Agnarsson, I., Boutry, C.*, & Blackledge, T. A. 2008. Spider silk
aging: Initial improvement in a high performance material followed
by slow degradation. Journal of Experimental Zoology 309A:494-504.
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Boutry, C.* & Blackledge, T. A. 2008.
The common house spider alters the material and mechanical
properties of cobweb silk in response to different prey. Journal of Experimental Zoology
309A:542-552. (featured in National Geographic News and
Outside JEB)
Sam Evans, M.S. candidate,
began fall 2010
Sam came to the lab from
Miami University where he worked on the ecology of wolf spiders in
agro-ecosystems. He is broadly interested in evolutionary biology. Sam
is investigating the fitness consequences of plasticity in orb web
architecture using both theoretical modeling and empirical field
studies.
Mohammad Marhabaie, M.S.
candidate, to begin spring 2011
Mohammad joins the lab
from Isfahan University, Iran. He is interested in the evolution of web
building spiders and recently participated in an EU funded study of
eresid spiders. Mohammad is investigating the role of different proteins
in the material properties of orb spider silk.
Undergraduate Researchers
2011
| Dakota Piorkowski |
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| Jared Harris |
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| Stephen Cross |
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Kettleen Esperance
NSF REU student |
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Summer/Fall 2010
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Sean Kelly |
Sean is studying energy absorption in spider webs during
prey impact. His work involves a combination of high speed video
and mechanical testing of individual silk threads. This work
seeks to understand how individual silk threads work together to
stop the tremendous energy of flying insect prey. |
Orb webs distribute the energy of prey impacts across many
different threads. |
|
Sara Suva |
Cherec Dickey |
 Sara and Cherec are investigating how spiders utilize silk
safety lines during falls. Orb spiders possess muscled valves in
the spinning ducts of their major ampullate glands that they can
use as a "brake" to clamp down on threads during falls. This
musculature is reduced or absent in other evolutionary lineages
of spiders so Sara and Cherec are using high speed videos to
analyze how diverse behave during falls.
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Brittany Lesher |
Almost all spiders produce silk attachment disks to secure
threads to the substrate or to one another. For her honors
thesis, Brittany is studying the morphology of these attachments
to elucidate common patterns in their production across
evolutionarily diverse spiders.
|
Silk disk used to attach draglines to surfaces. (light
micrograph) |
|
Sarah Wright |
Sarah is an engineering student from CalTech who visited the
laboratory for the summer. She worked to develop techniques to
use high speed to analyze the behavior of individual glue
droplets as they stick to surfaces. |
single thread of capture silk pulling away from surface |
| Loué Nasar |
Loué is investigating the biomechanics
of caterpillar silk. Most research is confined to domesticated
silk worms even though many diverse species use silk not just to
produce cocoons but also to build shelters, to fold leaf tents,
to provide nighttime resting "threads" and to provide signals
for trail following by kin. Almost nothing is known about how
the properties of caterpillar silks may have changed during the
evolution of these different behaviors.
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| Johnny Grebenc |
Johnny is investigating the effects of water on the
properties of spider silk. This work has implications for
understanding how spiders form solid silk fibers from liquid
protein "dope" and for the application of silk as a biomimetic
muscle. |
Our 2009 undergraduate research
assistants: Kim Lorentz and Sean Kelly are investigating the
biomechanics of energy absorption by orb webs during prey impact. Taylor
Gondek and Johnny Grebenc are studying how silk interacts with water and
the potential application of spider silk as a biomimetic muscle.
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image coming!
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Johnny |
Taylor |
Sean |
Kim |
Our summer 2008 undergraduate
research assistants were Kim Lorentz (Biology), Taylor Gondek (Biology),
Chad Rooks (Psychology), and Rachel Stevenson (a post-bac. student, now
at Denison University).
Our summer 2007 undergraduate
research assistants were Jaclyn Stenger (from
Xavier University), Marlena
Abraham (UA), and Sarah Anderson (UA)
LAB ALUMNI
Milan
Řezáĉ, Postdoctoral Scholar, Ph.D. 2007 Charles University in
Prague
Milan spent a year in my laboratory investing the relationship between the morphology of silk
glands and the material properties of silks. By comparing silk
production apparatuses across evolutionarily diverse species of spiders,
he hopes to gain insight into key innovations in silk spinning. Milan
returned to the Crop Research Institute in summer 2010.
 Andrew
Sensenig, Postdoctoral Scholar, Ph.D. 2009 University of Maryland
Andrew's expertise is in the functional morphology and biomechanics
of arthropods. He characterized locomotion in harvestmen for his
master's research. More recently, Andrew's Ph.D. focused on
hydrodynamics during gill movements in mayflies. His work in the lab
focused on functional mechanics of silk. Andrew is now faculty at
Tabor College.
Sensenig, A., Agnarsson, I. & Blackledge, T.A. 2010. Behavioral
and biomaterial coevolution in spider orb webs. Journal of Evolutionary
Biology. 23:1807-2029 (cover)
Sensenig, A., Agnarsson, I., Gondek, T.M. & Blackledge, T.A. 2010. Webs in vitro and in vivo: Spiders alter their orb web spinning
behavior in the laboratory. Journal of Arachnology. in press.
Ingi Agnarsson, Postdoctoral
Scholar, Ph.D. 2004 George Washington Univ.
Ingi is trained in the
systematics and evolution of spiders, particularly spiders that express
cooperative web spinning and prey capture behaviors. More generally,
Ingi's research interests span shore ecology, morphology, taxonomy,
biodiversity, sociality, inbreeding and phylogenetic theory. His work in
the lab focuses on the evolution of silk biomechanics in orb-weaving
spiders. You
can find out more about Ingi's research at this link.
Congratulations! Ingi began a faculty position at University of Puerto
Rico Autumn 2008!
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Agnarsson, I., Kuntner, M., Coddington, J. & T. A. Blackledge.
2010. Shifting continents, not behaviors: independent colonization of
solitary and subsocial Anelosimus spider lineages on Madagascar (Araneae,
Theridiidae). Zoologica Scripta. 39:75-87..
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Agnarsson, I., Dhinojwala, A., Sahni, V.*, & Blackledge, T.A.. 2009.
Spider silk as a novel high performance muscle driven by humidity.
Journal of Experimental Biology. 212:1990-1994. (cover
article featured in Inside JEB, WKYC-TV, WOSU, New Scientist,
Popular Mechanics)
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Blackledge, T.A., Boutry, C., Wong, S.C., Baji, A., Dhinojwala, A.,
Sahni, V. & Agnarsson, I. 2009. How super is supercontraction?
Persistent versus cyclic response to humidity in spider dragline
silk. Journal of Experimental Biology. 212:1981-1989. (cover
article featured in Inside JEB, New Scientist,WKYC-TV).
-
Agnarsson, I., Boutry, C.*, Wong, S-C., Baji, A.*, Sensenig, A. &
T.A. Blackledge. 2009. Supercontraction forces in spider dragline
silk depend on rate of humidity change. Zoology. 325-331.
(cover)
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Agnarsson, I. & Blackledge, T.A. 2009. Can a spider web be too
sticky? Tensile mechanics constrains the evolution of capture spiral
stickiness in orb-weaving spiders. Journal of Zoology.
278:134-140. (Featured in Cosmos Magazine).
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Blackledge, T.A, Scharff, N., Coddington, J., Szüts, T., Wenzel, J.W.,
Hayashi, C.Y. & Agnarsson, I. 2009. Spider web evolution and
diversification in the molecular era. Proceedings of the National
Academy of Sciences. 106: 5229-5234. (featured in Associated
Press article)
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Blackledge, T.A, Coddington, J. & I. Agnarsson. Fecundity increase
supports adaptive radiation hypothesis in spider web evolution.
Communicative & Integrative Biology. 2(6):459-463. (cover)
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Agnarsson, I., Boutry, C.*, & Blackledge, T. A. 2008. Spider silk
aging: Initial improvement in a high performance material followed
by slow degradation. Journal of Experimental Zoology
309A:494-504.
Raphael Royaute, visiting
researcher summer 2007
 Raphael
came to UA from Ecole
Nationale Supérieure d’Agronomie de Toulouse in France for a summer
research internship to learn about spider behavioral ecology. Raphael
studied the energetic costs of cobweb construction. Working with
Peter
Niewiarowski, Raphael used respirometry to measure the behavioral
costs of web spinning (spinning silk and assembling it into a web) and
calorimetry to measure the material cost of the silk itself. We are
currently analyzing the data for publication. Raphael is starting a PhD
on spider ecology at McGill University!
Jacki Zevenbergen, M.Sc.
Biology, graduated summer 2006
Jacki is studying how organisms can adjust their behaviors to respond
adaptively to selective pressures from both predators and prey in their
environment. Her research focuses on the cobwebs spun by black widow
spiders. These spiders dramatically alter the shapes of their webs
depending upon how much food they capture and Jacki is currently testing
the effects of these different web shapes on how black widows capture
prey and defend themselves against their own predators. Jacki received
her B.S. in Biology from U. Akron in 2005. Congratulations to Jacki for
her successful thesis defense in spring 2006! Jacki's thesis was
published in
Animal Behaviour summer 2008 and the article was highlighted by
New Scientist.
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Zevenbergen J. M.*, Schneider N. K.**, Blackledge T. A., 2008. Fine
dining or fortress? Functional shifts in spider web architecture by
the western black widow Latrodectus hesperus. Animal
Behavior. 76:823-829. (featured in New Scientist, Nature.com)
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Blackledge, T.A. & J.M. Zevenbergen.* 2007. Condition dependent web
architecture in the western black widow spider. Animal Behaviour.
73: 855-864.
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Blackledge, T.A. & J.M. Zevenbergen* 2006. Mesh width influences
prey retention in spider orb webs. Ethology. 112: 1194-1201.
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REPRESENTATIVE STUDENT RESEARCH PROJECTS
Chad Eliason "Mesh width and
energetic gain in orb spiders" - Biological Problems Summer 2006
Chad investigated how the spacing between rows of the
sticky silk (mesh width) in orb webs affects the biomass of prey
captured by spiders. By removing every other row of sticky silk from
webs, using a hot wire, we were able to compare the prey capture of two
spiders of the same species - one with an intact web and the other with
half as much sticky silk. Preliminary analysis suggests that an increase
in the mesh width of orb webs does not affect the probability of
capturing prey. However, spiders with closely spaced spirals of silk in
their webs were more likely to capture exceptionally large prey. This
suggests that the capture of rare, large prey has played an important
role in shaping the evolution of orb web architecture. The results of
this project are published in
Biology
Letters. Chad is now a PhD student in the Integrated Bioscience
program.
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Blackledge, T.A. & C.M. Eliason.* 2007. Functionally independent
components of prey capture are architecturally constrained in spider
orb webs. Biology Letters. 3:456-458.
Burhan Dahir "Development
of cobwebs in the common house spider Achaearanea tepidariorum"
McNair Scholar Summer 2006
 Burhan
worked in the lab through the
McNair Scholars
program at U Akron. He investigated how the cobwebs spun by the common
house spider change as spiders mature. Burhan's project included
characterizing the shapes of cobwebs and examining how the structural
and material properties of spider silk change as spiders age. He found
that both the mass of silk in webs and the sizes of individual silk
threads scale strongly with increases in body mass as spiders age. The
numbers of sticky gumfooted threads in webs, which are used to trap
prey, varied inversely with spider condition. This suggested that
well-fed spiders may reduce investment in the prey capture elements
within cobwebs even as they maintain an overall high level of investment
in silk.
Hannah Koppleberger "The
Use of Operant Conditioning and Positive Reinforcement in Training an
American Alligator (Alligator mississippiensis" Honors
Thesis 2006
Hannah is an intern at the
Cleveland Metroparks Zoo and is
working on her Honors Thesis there. Hannah is testing the utility of
operant conditioning through positive reinforcement to modify the
behavior of an american alligator to facilitate its care in captivity
and to provide behavioral enrichment to the animal. Hannah received
second place for her research at the 2007 Biology Undergraduate Research
Conference and and is moving to a research internship at the National
Zoological Park in Washington, D.C.!
Jacki Zevenbergen and Steve
Schulz "Condition dependent web architecture in the western black widow
Latrodectus hesperus" Biological Problems Spring 2005
Tradeoffs between prey capture and predator defense
commonly cause changes in behavior. For instance, starved orb-weaving
spiders sometimes construct larger webs, using thinner silk threads,
than fed spiders. Within the Theridiidae, the orb web has been
transformed into seemingly chaotic cobwebs, which depend upon tangled
sheets and gumfooted threads to capture prey. We hypothesized that
cobweb spiders with more food resources would invest more silk in webs
than starved spiders and that the allocation of silk to gumfooted
threads versus the sheet would change with resource availability. To
test these hypotheses, we initially fed one group of black widow spiders
for eight days while starving a second group. We then quantified web
architectures and switched the feeding regimes between groups for a
further eight days before repeating the quantification. We found that
black widow spiders with more food resources were heavier than starved
spiders and that heavier spiders invested more silk in webs than lighter
spiders. We also found that starved spiders invested more silk in prey
capture elements, sheets and gumfooted threads, while fed spiders
directed resources into the three-dimensional tangle. We suggest that
fed spiders are allocating silk resources toward the spinning of a
defensive three-dimensional tangle, while starved spiders allocate
effort toward foraging. This research is published in
Animal Behaviour.
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Jacki Zevenbergen |
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Steve Schulz |
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