20th International Congress of Arachnology

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70 DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Cushing
several characters proposed as the setae present on
the legs on this genera, setae on the metasomal keels,
hemispermatophore structures and trichobothria on the
pedipalp, additionally presents new characters as the
vesicular glands and the subaculear serrations (LAS) on
a phylogenetic analysis.
Keywords: high lands, systematics, speciation, ende-
mism, biodiversity
Student - poster presentation
Display architecture across social contexts
in the amblypygid Paraphrynus laevifrons
*Tyler B. Corey, Eileen A. Hebets
School of Biological Sciences, University of Nebrasca-
Lincoln, 323 Manter Hall, Lincoln NE 68588, USA
Using a likely similar toolset for signal production and
signal perception, conspecific animals communicate
with each other across social contexts. In amblypygids
(Class Arachnida, Order Amblypygi), previously studied
species have been shown to use distinct ritualized
displays in intra– and intersexual interactions. In this
ongoing study, we explore how selection for effective
intraspecific communication across contexts might
facilitate and/or constrain signaling system architec-
ture. Specifically, we examine, describe, quantify, and
compare the behavioral repertoire of Paraphrynus
laevifrons in intra- and interspecific contexts to assess
display similarities/differences. Preliminary results
suggest that adult males and females use distinct
types of antenniform leg vibrations (ALV) in intra-
sexual interactions, and that sex-specific ALVs are also
employed in intersexual interactions. ALVs used by male
P. laeivfrons are additionally compared to signaling
systems in other known amblypygid species. An assess-
ment of juvenile interactions thus far reveals no similar
behaviors, suggesting that the form of these displays
may change over ontogeny in these relatively long-lived
arachnids.
Keywords: Amblypygi, communication, signal evolution,
social context
Student - oral presentation
Silk gene expression profiles of male
versus female cob-weaving spiders
*Sandra M. Correa-Garhwal1 , R. Crystal Chaw1 , Thomas
H. Clarke III 1,2, Nadia A. Ayoub2, Cheryl Y. Hayashi1
1Department of Biology, University of California,
Riverside, CA 9252, USA; 2Department of Biology, Wash-
ington and Lee University, Lexington, VA 24450, USA
Spiders have multiple types of silk glands that are specialized
to produce an array of task-specific silks. Studies have shown
that spider silks are largely composed of proteins encoded by
members of the spidroin gene family. Most of these studies
have been conducted on females; thus, little is known about
silk production by males. To shed light on silk use by male
spiders, we compared silk gene expression profiles of mature
males and females from three cobweb-weaving species
(Theridiidae). We de novo assembled male-specific as
well as species-specific (male and female) transcriptomes
for Latrodectus hesperus, Latrodectus geometricus, and
Steatoda grossa. Based on the presence of silk spigots in
both sexes, we expected gene expression for aciniform (domi-
nant component of prey-wrapping silk), major ampullate
(dragline silk), minor ampullate (web construction silk),
and pyriform (attachment disc silk) spidroins in males and
females. Furthermore, we did not expect males to express silk
protein genes associated with egg-case and aggregate glue
production. Because males desert their prey-capture webs
and become cursorial to search for mates, we expected males
to have a higher expression of major ampullate spidroin
genes than other silk genes. Our expression profiling results
show that both sexes express aciniform, major ampullate,
minor ampullate, and pyriform spidroin genes, as predicted.
The most highly expressed silk genes in females of all species
were tubuliform, major ampullate, and aggregate spidroins.
Counter to expectation, we found that the most highly
expressed silk genes in Latrodectus males were the
minor ampullate spidroins. In Steatoda males, however,
major ampullate spidroins had the highest expression.
These findings suggest that Latrodectus males use more
minor ampullate silk than Steatoda males.
Keywords: differential gene expression, male spiders