58 / 232
57
DENVER MUSEUM OF NATURE & SCIENCE
REPORTS
|
No. 3, July 2, 2016
which to choose. In laboratory trials, non-gravid females
from each species did not differ in thermal preference;
however, gravid
V. electrum
selected higher temperatures
than did gravid
V. cashi
. For neither species did we find a
significant difference between thermal preference of gravid
and non-gravid females. These results suggest that scorpi-
ons actively select among available rock retreat sites, and
that this choice may be influenced by a requirement for a
more stable thermal regime. It also suggests that this choice
is not influenced by a female’s reproductive state.
Keywords: scorpion ecology, Sky Islands,
Vaejovis
electrum
,
Vaejovis cashi
, thermal ecology
Oral presentation
The natural history and thermal biology
of an Arctic pseudoscorpion
Christopher M. Buddle
1
, Susan E Anthony
2
, Brent J Sinclair
2
1
McGill University, Department of Natural Resource
Sciences, 21,111 Lakeshore Rd, Ste-Anne-de-Bellevue,
Quebec, H9X 3V9, Canada;
2
Western University,
Department of Biology, London, Ontario, Canada
chris.buddle@mcgill.caThe pseudoscorpion,
Wyochernes asiasticus
(Pseudo-
scorpiones, Chernetidae), is found in parts of north-west
North America, including above the Arctic Circle, but also
in Siberia and other regions in Asia: it is presumably a
Beringian species, found primarily in regions that were
unglaciated during the last glacial maximum in North
America. Data on the species biology, collected over many
years, illustrates its range in the Yukon Territory, and
fundamental knowledge about its life history is presented:
larger females tend to have higher fecundity, and females
have an average of 10.5 eggs per brood sac. The species
is always found under rocks near rivers that flood fre-
quently. Studies on the species thermal biology suggest
it is a freeze-avoidant species, and immersion in water
shows the species is able to hold oxygenated air around
its body and remain alive after submersion of up to 17
days. Despite many years of study, this small, charming
arachnid continues to hold many mysteries.
Keywords: Pseudoscorpiones, natural history, thermal
biology, biogeography, life history adaptation, Arctic
Oral presentation
Population genomics and geographical
parthenogenesis in Japanese harvestmen
(Opiliones, Sclerosomatidae)
Mercedes Burns
1
, Marshal Hedin
1
, Nobuo Tsurusaki
2
1
Life Sciences North 206 San Diego State University
5500 Campanile Drive San Diego, CA 92182, USA;
2
Tottori University Faculty of Regional Sciences 680-
8550 Tottori Prefecture, Tottori, Japan
mercedes.burns@gmail.comGeographical parthenogenesis refers to the common
association of widely dispersed asexual populations
with more narrowly distributed sexual populations.
Some research supports the adaptive advantages of
temporary or facultative asexuality as a colonization
strategy. Other work points to a non-adaptive rationale
for the association of asexuality to habitat margins,
because parthenogens frequently display hybrid ances-
try, genome duplications often precede parthenogenetic
ability, and admixture of sexuals and asexuals within
populations is expected to be rare. We explore these
competing hypotheses in two Japanese species of har-
vestmen,
Leiobunum manubriatum
and
Leiobunum
globosum
. Reproduction in these species proceeds
with or without male fertilization, and female-biased
localities are common in high-latitude and elevation
habitat margins. Using next-generation sequence
data, we compared genetic distance and differentiation
between females collected at high and low latitude
and elevation in order to evaluate genetic indicators
of adaptation in specimens from marginal habitat.
Preliminary molecular data recapitulates latitudinal
structuring of localities sampled, but both species
display single lineages comprised of individuals from
geographically-distant populations. Ongoing cytological
and mito-nuclear discordance work will serve to eluci-
date reproductive mode and potential gene flow to these
putative populations.
Keywords: population genomics, geographical parthe-
nogenesis, mitonuclear discordance, Opiliones
20
th
International Congress of Arachnology