20th International Congress of Arachnology

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82 DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Cushing
avoidance, will result in energy loss, and a probable reduc-
tion in fecundity or possible injuries and death. Here we
investigate the incidence of autotomy in Nephila clavipes
in the tropical rainforest of Costa Rica. Additionally, in a
repeated measures design, we test for behavioral plasticity
of simulated prey capture events before and after induced
autotomy (of one leg I) using a combination of MANOVA
and behavioral sequence data. We found that 18 of 59
spiders observed at La Selva Biological Station had one or
more legs missing (~31%) in the field, with leg II being
the most frequently lost. We also found that N. clavipes
altered their resting body position following autotomy,
changing the angle of legs I (on the intact side), and legs
II, and III on the autotomized side relative to the prosomal
midline. In addition, autotomy appeared to significantly
hinder the spider’s ability to detect prey, with the odds of
reaction being 7.8x less following leg loss. Taken together,
N. clavipes demonstrated marked behavioral plasticity
following autotomy in order to compensate for the loss of
sensory perception organs during prey capture.
Keywords: autotomy, Nephila, behavioral plasticity
Oral presentation
Biogeography of Caribbean arthropods
Lauren A. Esposito, Sarah C. Crews
California Academy of Sciences, 55 Music Concourse
Drive, San Francisco, CA 94118, USA
For the past 50 years the Caribbean has been a bastion for
research on island biogeography. None the less, unifying
patterns of biogeography for the region have remained
elusive. A complex geologic history and the close proxim-
ity to major continental landmasses have resulted in a rich
biodiversity, but one that is relatively understudied for ter-
restrial arthropods. This study synthesizes, for the first time,
every published dataset on terrestrial Caribbean arthropods
providing clarity into the mode and tempo of Caribbean
diversification, clarifying the driving historical forces that
have resulted in the incredibly diverse fauna present
in the region today. Molecular datasets from insects and
arachnids were used to generate time calibrated phyloge-
netic hypotheses of relationships. Various hypotheses of
dispersal and vicariance were then tested under an assort-
ment of constraints based on various geologic scenarios.
In elucidating the historic patterns and processes that have
led to the present day diversity of the Caribbean biodiversity
hotspot, we hope to inform future conservation efforts.
Keywords: Caribbean, biogeography, phylogeography,
islands, vicariance, dispersal
Student - Poster presentation
Resolving deep relationships within
jumping spiders
Samuel C. Evans 1, Wayne P. Maddison1,2, Christopher
Hamilton3 , Jason Bond4, Alan R. Lemmon5, Emily
Moriarty Lemmon6
1Department of Zoology, Biodiversity Research Centre,
University of British Columbia, Vancouver, BC V6T 1Z4,
Canada; 2 Department of Botany & Beaty Biodiversity
Museum, University of British Columbia, Vancouver,
BC V6T 1Z4, Canada; 3Florida Museum of Natural
History, University of Florida, Gainesville, FL; 4Depart-
ment of Biology, Auburn University, Auburn, AL
36849; 5Department of Scientific Computing, Florida
State University, Tallahassee, FL; 6Department of Bio-
logical Science, Florida State University, Tallahassee, FL
Recent advances in cost-effectiveness of genome-wide
sequencing has made feasible addressing long-standing
questions of deep relationships among major spider groups.
Within the 5800-plus species of jumping spiders (Araneae:
Salticidae), we have yet to resolve relationships among
basal lineages, we lack confident support of some large
clades within the salticines, and we are still unable to
discern placement of groups such as the agoriines and
eupoines. Therefore, we used anchored enrichment (AE)
sequencing to obtain hundreds of unlinked “anchor”
regions throughout the genomes of 32 salticid species and
one philodromid outgroup, yielding a dataset of over 90 kb
and 400 loci. Our resulting maximum-likelihood phylogeny
confidently supports the Hisponinae as sister to the Saltici-
nae, reinforces the monophyly of the Saltafresia, succeeds
in placing the agoriines within the Saltafresia, and
resolves many relationships among the amycoids. We are