20th International Congress of Arachnology

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DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
20th International Congress of Arachnology
peacock spiders provide two striking examples. Here, we
show how tarantula blue is produced using specialized
hairs with complex hierarchical structure that greatly
reduces iridescence—which has been a key obstacle to
the production of synthetic structural colorants without
the shimmering effects. On the other hand, the strikingly
iridescent scales of the rainbow peacock spider (Maratus
robinsoni) can produce every color of the rainbow, and
may hold the secrets for future optical device miniaturiza-
tion. We used an interdisciplinary biomimetic approach to
investigate both questions by including techniques such
as: morphological characterization (SEM/TEM), phyloge-
netic analysis, spectrophotometry, optical simulation, and
rapid prototyping by 3D nano-printing. Particularly with
the rapid prototyping capability, we can create engineer-
ing models to test biological hypotheses in a controlled
manner that may not be feasible with the living systems.
Hence, biomimicry is not only taking what we learned
from natural systems to practical human applications,
but it is also providing insightful feedbacks and ideas to
deepen our understanding of the biological system subject
matter during the process.
Keywords: structural color, biomimicry, Theraphosidae,
Salticidae, Maratus
Oral presentation
Multiple convergences in pholcid spiders:
problem and promise
Bernhard A. Huber1, Alejandro Valdez-Mondragón2,
Dimitar Dimitrov 3
1Alexander Koenig Research Museum of Zoology,
Bonn, Germany; 2Instituto de Biología UNAM,
Municipio de Santa Cruz Tlaxcala, Tlaxcala, Mexico;
3Natural History Museum, University of Oslo, Norway
Based on our upcoming molecular phylogeny of Pholcidae
(currently 380 species, 61 genera) we explore multiple
convergences at three levels: ecology (microhabitats),
ultrastructure (spinning apparatus), and sexual dimor-
phism (male ocular area modifications). In tropical
forests, pholcid spiders occupy a wide range of microhabi-
tats, such as the leaf litter, large sheltered spaces, and the
undersides of live leaves. Most species are restricted to
one specific microhabitat, and most are adapted to their
microhabitat in terms of body shape and coloration. Here
we focus on leaf-dwelling which is often associated with
conspicuous adaptations in morphology and behavior. Our
results suggest that leaf-dwelling has originated ~30 times
independently, mostly in the supposedly ‘modern’, humid
tropical subfamilies Modisiminae (8) and Pholcinae
(~21). The evolution of the pholcid spinning apparatus is
characterized by multiple convergent losses of one specific
set of spigots. Male ocular area modifications have evolved
about 20 times independently in pholcids. Such multiple
convergences are not only examples of ‘noise’ in phyloge-
netic analyses (the problem) but can guide future research
on the macroecology, behavioral ecology, and functional
morphology of the respective taxa (the promise).
Keywords: convergence, Pholcidae, microhabitat-shifts,
leaf-dwelling
Poster presentation
Multiple convergent evolution of male sexual
‘head’ modifications in pholcid spiders
Bernhard A. Huber1, Alejandro Valdez-Mondragón2,
Dimitar Dimitrov 3
1Alexander Koenig Research Museum of Zoology,
Bonn, Germany; 2Instituto de Biologia UNAM,
Municipio de Santa Cruz Tlaxcala, Tlaxcala, Mexico;
3Natural History Museum, University of Oslo, Norway
Sexual modifications of the male ocular area (‘head’)
occur in a wide variety of pholcid genera, in particular
in the subfamily Pholcinae. These range from simple
median or paired processes to exaggerated eye-stalks,
conspicuous turrets, and curiously waxed brushes
of hairs. As a first step towards understanding the
evolution of these modifications, we summarize all
known cases and map them on our current molecular
phylogeny of the family (380 species, 61 genera).
There is strong evidence that male ‘head’ modifica-
tions originated at least 20 times independently within
pholcids. Similar to linyphiids, the copulatory position
of pholcids is a likely explanation for this multiple