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55
DENVER MUSEUM OF NATURE & SCIENCE
REPORTS
|
No. 3, July 2, 2016
Alopecosa
(PJ, April),
Schizocosa
(PJ, June and August),
Pardosa
(PP, June and August), and
Varacosa
(PP, April
and October). MDS based on taxon and abundance
showed good separation of the two habitats (MDS 1),
and of abundance levels correlated with precipitation
(MDS 2). These lycosid species show strong habitat fidel-
ity, suggesting that if the PP habitat becomes more like
PJ as is predicted,
Pardosa
and
Varacosa
species will
likely decline.
Alopecosa
occurred mostly in the spring; a
warmer climate may also reduce its numbers.
Schizocosa
is the only species likely to continue in its current pat-
terns of high summer abundance in PJ woodland.
Keywords: climate change, ecology, community struc-
ture, Lycosidae
Oral presentation
Burrow adoption and navigation in the desert
grassland scorpion,
Paruroctonus utahensis
Brad P. Brayfield, Douglas D. Gaffin
Department of Biology, University of Oklahoma,
Norman, OK, USA 73019
bbrayfield@ou.eduAnimals have many navigation tools, including path
integration, polarized light detection, optic flow tracking,
magnetoreception, and others. Unlocking the physiological
mechanisms of navigation has been difficult because many
acclaimed navigators (such as bees and butterflies) are too
small for researchers to monitor their neural activity. We
think that sand scorpions make good models to study navi-
gation. They are long-lived, are easily maintained in the
laboratory, are accessible to electrophysiological record-
ings, and fluoresce under UV light. Most importantly, they
home to burrows and are easily tracked by video. Scorpions
also have ground-directed organs called pectines with
dense fields of peg-shaped sensilla that possess chemo- and
mechano-sensitive neurons. We hypothesize that scorpions
use their pectines to sense the chemical and/or textural
aspects of the substrate around their burrows and use
this information to get home. Testing this chemo-textural
familiarity hypothesis requires an efficient homing
assay; here we report the development of such an assay.
To encourage burrow adoption, we confined individual
scorpions to a small area containing a man-made burrow
within a larger, sand-filled arena. We then removed the
barrier and monitored activity in the entire arena for six
days. During days 1–3 post burrow adoption, the propor-
tion of animals that returned to or remained inside the
burrow increased from 63% to 89%. During days 4–6, the
scorpions were presented with two additional burrows in
the large arena. Fidelity to the originally adopted burrow
subsequently decreased to 52%, 32% and 47% during these
three days. While some animals returned to their burrows
during darkness, most animals returned after initiation of
daylight. After roaming the arena, some animals appeared
to efficiently navigate to their home burrow, while others
engaged in systematic searching behaviors. Our assay
should allow for testing hypotheses about specific naviga-
tional mechanisms.
Keywords: pectines, homing, burrow, fidelity
Poster presentation
Descriptions of two new genera of the spider
family Caponiidae (Arachnida, Araneae) and
an update of
Tisentnops
from Brazil
A. D. Brescovit, A. Sánchez-Ruiz
Laboratório Especial de Coleções Zoológicas, Instituto
Butantan, Av. Vital Brasil, 1500, Butantã, São Paulo,
São Paulo, Brazil, 05503-900
antonio.brescovit@butantan.gov.brNew members of the spider family Caponiidae from Brazil
are presented. We described two new Brazilian species of
Tisentnops
(
T. mineiro
sp. n. and
T. onix
sp. n.), a genus
known only from its damaged type species. These two new
species allowed us to complete the information on the
morphology of the genus, and also allowed us to extend its
distribution range and know a little more about its natural
history. Additionally, two new non-nopinae Brazilian
genera are proposed:
Nasutonops
gen. n. including three
new species from northwestern of Brazil and
Carajas
gen.
n., known only from the type species from North of Brazil.
Both new genera are non-nopinae that have tarsi entire,
rather than sub-segmented. Among all these findings, we
are describing the first known blind caponiids in the world:
Tisentnops mineiro
sp. n. from State of Minas Gerais and
20
th
International Congress of Arachnology