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caused flaccid paralysis with an effective paralytic dose
of 3.9µg/g. Altogether, these data provide an important
contribution to comparative venom analyses, fill in
another piece of the phylogenetic puzzle among hap-
logyne spider venoms, and address the myth of daddy
long-leg spider venom potency.
Keywords: venom, astacin metalloprotease, neurotoxin,
cDNA library, mass spectrometry, bioassay
Oral presentation
Retinal specializations and the architec-
ture of visual signals
Daniel B. Zurek, Sebastian A. Echeverri, Nate I. Morehouse
University of Pittsburgh, Department of Biological Sci-
ences, 204 Clapp Hall, 4249 Fifth Avenue, Pittsburgh,
PA 15260, USA
dbz1@pitt.eduOne widespread feature of visual systems is regional-
ization of visual competency across the visual field,
including regions of heightened motion sensitivity,
spatial acuity and/or color vision. Animals compensate
for this regionalization with gaze movements that aim
specialized retinal regions at areas of interest within
the visual scene. These movements determine what
animals see when they interact with visual stimuli.
However, we know almost nothing about how animals
use their gaze to evaluate communicatory displays. We
know even less about how visual displays have evolved
to effectively capture, retain or manipulate the gaze of
signal receivers. We have begun to explore this critical
aspect of visual signaling in the jumping spider genus
Habronattus
. The extreme regionalization within their
modular visual systems, and their diverse courtship
displays combined with a well-characterized phylogeny
enable us to investigate how female gaze interacts with
male displays, both during courtship signaling and
over evolutionary time. By employing gaze-tracking,
video playback, and signal manipulations, we are
approaching three questions: 1) Where do jumping
spiders focus attention when viewing complex displays,
and how do visual systems influence the evolution of
visual signals? 2) Conversely, how do visual signal traits
act on the evolution of the receiver’s visual system? 3)
How are multiple visual functions (e.g., color vision,
motion detection) integrated during active display
evaluation? Our data from
H. pyrrithrix
reveal discrete
distance-dependent dance motifs that match regional
competencies of the female visual system, and show that
females pay specific attention to subsections of the male
display. Analysis of other
Habronattus
species with
distinct visual environments, coloration, and courtship
dances offers a tantalizing opportunity to deepen our
understanding of visual signaling, and reveal principles
that may be applicable across taxa.
Keywords: Salticidae, color vision, communication,
sensory drive, courtship
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DENVER MUSEUM OF NATURE & SCIENCE
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No. 3, July 2, 2016
Cushing