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traits are key innovations. Until recently, the favored
phylogenetic hypothesis included the clade Orbiculariae,
which was composed of two groups that include orb-web-
weaving spiders: Araneoidea and Deinopoidea. It implied a
more recent evolution of the orb web. Under this hypoth-
esis, the sister group of Orbiculariae was the RTA-clade,
a megadiverse group named by the retrolateral tibial
apophysis (RTA) structure of the male genitalia. The RTA-
clade includes spiders that build sheet webs or that have
abandoned web-construction altogether. Recent evidence,
however, suggests that Deinopoidea is sister to the RTA
clade, implying either an earlier, more ancestral evolu-
tion of the orb-web with multiple losses, or less likely two
separate origins of the orb-web. Both of these hypotheses
make mutually exclusive claims about the morphologi-
cal and phylogenetic characteristics of the silk systems
of these three clades. Our understanding of deinopoid
and RTA-clade silk systems, however, is poor compared to
those of araneoids. To approach this issue and add to our
understanding of deinopoid and RTA-clade silk systems,
we combined morphological, histological, and non-tradi-
tional phylogenetic (comparing silk genes as opposed to
housekeeping genes) analyses of deinopoid and RTA-clade
silk systems to test the claims of these two hypotheses and
clarify the evolution of spiders
Keywords: RTA-clade, phylogenetics, orbweb
Student - poster presentation
Influence of age and environmental
enrichment on tarantula (
Grammostola
pulchripes
) personality
*Samantha Malley, Dr. Cara Shillington
Eastern Michigan University Department of Biology,
Ypsilanti, MI 48197, USA
smalley@emich.eduPersonality in arachnids is increasingly being studied,
but the majority of work has been with social species
within colonies. Tarantulas, which are traditionally
thought of as solitary, have been studied in the context
of personality even less. Our project examined the impact
of environmental enrichment and age on tarantula per-
sonality. Personality was assessed on a spectrum of bold
to shy behaviors; measurements included latency to prey
capture and exploratory behavior. Tests of these behaviors
were performed three times over a six month period using
arena prey capture trials and video tracking of explor-
atory behavior in a novel environment. Two age groups
were used — spiderlings and juveniles — and split into
separate environmental types: simple and enriched. The
simple environments held only coconut substrate, and
the enriched environments had the addition of artificial
plants. Juveniles were found to be significantly more active
in their explorations, and most likely to spend time away
from the periphery of the arena, which corresponds with
bold behavior. Surprisingly, no differences were found
between tarantulas housed in the two types of environ-
ments. Similarly, latency of prey capture was alike between
age and environmental groups. These results suggest that
age may play an important role in personality, while envi-
ronmental enrichment appears to have no effect.
Keywords: Tarantulas, personality, environment, age
Oral presentation
How far is far? Spatial variation in the
structure of spider communities in the
Udzungwa Mountains, Tanzania
Jagoba Malumbres-Olarte
1
, Christina Brylov Henriksen
1
,
Luis Crespo
2
, Pedro Cardoso
3
, Tamás Sz
ű
ts
4
, Wouter
Fannes
5
, Thomas Pape
6
, Nikolaj Scharff
1
1
Center for Macroecology, Evolution and Climate, Natural
History Museum of Denmark, University of Copenhagen,
Copenhagen, Denmark;
2
Biodiversity Research Institute,
Department of Animal Biology, Universitat de Barcelona,
Barcelona;
3
Finnish Museum of Natural History, Uni-
versity of Helsinki, Helsinki, Finland;
4
University of West
Hungary, Szombathely, Hungary;
5
Royal Museum for
Central Africa, Tervuren, Belgium;
6
Zoological Museum,
Natural History Museum of Denmark, University of
Copenhagen, Copenhagen, Denmark
Jagoba.Malumbres.Olarte@gmail.comUnderstanding the mechanisms behind community assem-
bly is no trivial task. One must consider processes such
as adaptation, speciation and movement, and use data
on the ecological and evolutionary relationships among
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DENVER MUSEUM OF NATURE & SCIENCE
REPORTS
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No. 3, July 2, 2016
Cushing