20th International Congress of Arachnology

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DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
fitness. Traits such as locomotor performance and
endurance capacity may determine an animal’s success
in tasks such as obtaining resources, evading predators
and determining the outcome of intraspecific interac-
tions. Morphological traits may potentially contribute
towards, or impede, multiple performance traits. At the
same time, variation in performance capacity between
individuals may result in different individuals adopting
different behaviours in order to achieve similar levels of
fitness. Therefore, whole-organism performance capacity
may be central to understanding why animals behave the
way that they do. We will present the results of a series of
studies examining different whole-organism performance
traits in spiders and their relationships with 1) morphol-
ogy, 2) other performance traits and 3) fitness related
tasks such as mating success and predator evasion.
Keywords: whole-organism performance, locomotion,
morphology, sexual selection, mating success
Oral presentation
Neural responses to airborne pure tones
from the brains of jumping spiders,
fishing spiders and net-casting spiders
Gil Menda1, Jay Stafstrom2, Paul Shamble3, Tsevi Beatus1 ,
Itai Cohen1, Eileen Hebets2, Ron Hoy1
1Cornell University,W213 Mudd Hall, Ithaca, NY
14853 USA; 2School of Biological Sciences, University
of Nebraska - Lincoln, USA
It has been known for over a century that spiders are
very sensitive to acoustic stimuli such as substrate
vibrations and airflow. We report neural recordings
from the brains of jumping spiders (Salticidae),
fishing spiders (Dolomedes) and net-casting spiders
(Deinopidae). We present single unit recordings from
the sound-processing regions of the brain in response to
airborne pure-tone stimuli. These airborne pure tones
were broadcast from a loudspeaker placed 3 meters
from the spider, with neural units showing responses
to amplitudes as low as 55 dB (SPL), and sensitivity to
species-specific frequency bands between 50 and 5 kHz.
These findings raise very interesting questions about the
sensory ecology of these species—especially regarding
the sensory systems and cues used for the detection of
predators and prey.
Keywords: neuroethology, recordings, acoustic, jumping
spiders (Salticidae), wolf spiders (Lycosidae), net-
casting spiders (Deinopidae)
Student - oral presentation
Investigating the complex relationship
between female state and courtship in
Schizocosa ocreata
*Timothy Meyer, George Uetz
Department of Biological Sciences, University of Cincin-
nati, PO Box 210006, Cincinnati, OH 45221-0006, USA
The courtship of male brush-legged wolf spiders
(Schizocosa ocreata Hentz 1844) involves both visual
and vibratory signals, which are initiated upon contact
with cues in female silk. Studies have found that males
appear able to assess a female’s maturity, mating status,
and feeding history from silk alone, and that variation
in male response indicates differential courtship invest-
ment. However, these studies examined single factors,
and males are likely to encounter multiple females with
different combinations of states under natural condi-
tions. In order to investigate how males might assess
more complex aspects of female life history, males were
exposed to silk from females varying in feeding history
and mating status, and behaviors of these males were
analyzed for indicators of courtship investment (rates
of characteristic foreleg tapping and cheliceral strikes).
Results suggest the presence of multiple factors and
variation in the amount of experience with female cues
may have an interactive effect on male behavior, with
some combinations resulting in differentially reduced
courtship. Additional results also show that females
with varied feeding and reproductive states behave
differently during male courtship, i.e., becoming less
receptive or more aggressive, which suggests a relation-
ship between male investment and female behavior.
Keywords: Schizocosa ocreata, sexual conflict, sexual
selection, courtship
20th International Congress of Arachnology