20th International Congress of Arachnology

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DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
to uncouple potential depth cues (e.g., absolute and rela-
tive size differences, retinal expansion, motion parallax)
and test their relevance independently. First experiments
confirm the important role of motion parallax for the
preference of close objects.
Keywords: vision, behavior, depth perception, Virtual
Reality, learning
Poster presentation
SpiderVR: A virtual reality setup to
investigate visually guided behavior in
untethered hunting spiders
Martin Streinzer, Maximilian Hofbauer, Axel Schmid
Department of Neurobiology, University of Vienna,
Althanstraße 14, 1090 Vienna, Austria
Cupiennius salei serves as important model in neurobi-
ology, neurophysiology and neuroethology. It is equipped
with well developed eyes which are used in various biolog-
ical contexts, such as orientation, object detection, object
discrimination and visual learning. Traditionally, behav-
ioral experiments were performed in large arena setups,
where single or multiple target objects were presented and
the spider’s behavior was recorded. To overcome limita-
tions of these real-world setups, minimize handling time
between trials and to permit presentation of non-static
objects, we designed a Virtual Reality (VR) setup that
can be used to study visually guided behavior in freely
moving large hunting spiders. The spider walks on top of
an actively driven sphere that compensates for its move-
ment. The spider’s position is tracked using computer
vision, which feeds into the motion compensation and the
recording of the walking path. Virtual environments are
presented on a circular screen using four video projectors
that produce a seamless image of 360° horizontal and
50° vertical extent. The virtual scene is rendered for the
current viewpoint of the spider and updated in real-time.
Repetition of previously performed real world experiments
in the virtual environment confirmed that SpiderVR can
serve as alternative for the traditional approach.
Keywords: vision, virtual reality, behavior, computer
vision, motion compensation
Oral presentation
Can genomic approaches resolve the
phylogeny of Argyrodinae (Araneae:
Theridiidae)?
Yong-Chao Su
National University of Singapore, 14 Science Drive 4,
Singapore 11754
Spiders in the subfamily Argyrodinae (Araneae: Theri-
diidae) are known for their web invasion behaviors to
the web of other spiders. These host-parasite associations
include two forms: araneophagy and kleptoparasitism.
Although the behaviors of argyrodine spiders have been the
interest of behavioral ecologists for a long time, the lack of
a robust phylogenetic treatment of this group has hindered
the study of the evolution of these behavioral traits. Su and
Smith (2014) reconstructed the first molecular phylogeny
of the subfamily Argyrodinae and conducted several com-
parative analyses to test the evolutionary association of
group-living behavior and host use. An updated molecular
phylogeny showed the increase in species diversification
rates in Argyrodinae is related to the origin of web inva-
sion behavior and the origin of kleptoparasitism. However,
these molecular phylogenies based on Sanger data could
not resolve several deep nodes thus made the inferences
of the behavioral evolution unsettled. Therefore, genomic
approaches could be the solutions toward a robust phylog-
eny of Argyrodinae. I compared two genomic approaches,
restriction enzyme associated DNA sequencing (RAD-seq)
and targeted sequence capture methods (specifically,
ultra-conserved element sequence capture, or UCEs) and
discussed the feasibilities of using genomic approaches
for Argyrodinae phylogeny. The preliminary results of the
genomic approaches showed that RAD-seq approach is
suitable for species group or genus level phylogenies. The
number of homologous loci dramatically dropped when
filtering the DNA fragments for constructing the phylogeny
among genera. The UCEs approach is promising for a fully
resolved phylogeny for Argyrodinae.
Keywords: phylogenomics, restriction site associated
DNA sequencing, ultra-conserved elements, probe
design, character evolution
20th International Congress of Arachnology