20th International Congress of Arachnology

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conditions with the Invasive Model, while the later shares
20.3% of its climatic conditions with the Native range. We
concluded that C. citricola has the potential for occupy-
ing and expanding into novel climatic conditions when
compared with its native range. This is one of the first
studies that analyzed the potential geographic expansion
of an old word spider in the Neotropics, and set the bases
for measuring the effect on the native spider fauna.
Keywords: niche expansion, invasive, biogeography,
Cyrtophora citricola
Oral presentation
Burmese amber arachnids; biodiversity in
a Cretaceous tropical forest
Paul A. Selden
Department of Geology and Paleontological Institute,
University of Kansas, 1475 Jayhawk Boulevard,
Lawrence, KS 66045, USA, and The Natural History
Museum, Cromwell Road, London, SW7 5BD, UK
Known for many years, but thought to be Cenozoic in
age, there has been an upsurge in interest in amber
from Myanmar in recent years, partly because of its
increased availability (especially now on the Chinese
market), and partly because we now know it is mid-
Cretaceous (c. 99 Ma) in age. A great diversity of biotic
inclusions have now been described. Most arachnid
groups are known from Burmese amber: Araneae, Opil-
iones, Solifugae, Pseudoscorpiones, Anactinotrichida,
Amblypygi, Thelyphonida, Ricinulei, Scorpiones, and
Schizomida. In this talk, I shall briefly discuss the
biodiversity of arachnids in Burmese amber, before
describing some interesting new finds from the amber.
Keywords: paleontology, Opiliones, Tetrablemmidae,
Ricinulei, Schizomida, Mesothelae, Pseudoscorpiones
Student - oral presentation
Are males really so insensitive? Palp mor-
phology of a spider Philodromus cespitum
reveals innervation
*Lenka Sentenská1, Stano Pekár1 , Gabriele Uhl2
1Department of Botany and Zoology, Masaryk University,
Brno, Czech Republic; 2 Zoological Institute and Museum,
Ernst Moritz Arndt University of Greifswald, Germany
Male spiders transfer their sperm via a secondary
reproductive organ called palpal bulbus. Based on several
histological studies, this structure is considered to be
unique among all animal genitalia due to possible lack of
innervation. A recent study, however, reported first evidence
of neurons in the male bulbus in Hickmania troglodytes
from a relict group of spiders. We performed a morpho-
logical study on male copulatory organ of a common
entelegyne spider, Philodromus cespitum , whose males
apply amorphous mating plugs into the female atrium
after copulation. By means of microtomography, light
and transmission electron microscopy we discovered a
nerve-like structure in the bulbus. The cymbium of the
palp is richly innervated. One of the nerves departs into the
bulbus, runs through the whole structure and terminates
at the base of the embolus. Interestingly, the nerve is in
contact with two of three different glands situated in the
bulbus. These glands are connected to the spermophore
and may be involved in transfer of sperm as well as mating
plug material. Our combined behavioral and morphologi-
cal observations on the production of mating plugs in this
species suggest that the male gains information about
the intention of the female to interrupt the copulation
and reacts by promptly extruding the plug material. This
is the second case of bulbus innervation in spiders and
the first evidence for nerves in male copulatory organs of
entelegyne spiders. Our results open the window into the
research of genitalic sensory feedback in spiders.
Keywords: male genitalia, palp morphology, innerva-
tion, mating, histology, microtomography, mating plug
Student - poster presentation
Sexual dimorphism in venom gland
anatomy in a sexually stinging scorpion
Lenka Sentenská1, Franziska Graber2, Miguel Richard3 ,
Christian Kropf3,4
1Department of Botany and Zoology, Faculty of Sci-
ences, Masaryk University, Kotlář ská 2, 611 37 Brno,
Czech Republic; 2Institute of Anatomy, Department
172 DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Cushing