2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

11. Morphology POSTER
����111 David Altrock
Dynamics and functional morphology of contraction and expansion in the
calcareous sponge Clathrina clathrus
Authors: David Altrock 1 , Christopher Arnold 1 , JörgHammel 1 , Felix Beckmann 2 ,
Alexander Ereskovsky 3 , Michael Nickel 1
Affiliation: 1 Institut für Spezielle Zoologie, Friedrich-Schiller-Universität Jena; 2 Zentrum
für Material- und Küstenforschung, Helmholtz-Zentrum Geesthacht; 3 Institut
Méditerranéen de Biodiversité et d‘Écologie, Aix-Marseille Université, France
The body of the calcareous sponge Clathrina clathrus (Schmidt, 1864) (Porifera,
Calcarea, Calcinea, Clathrinidae) consists of an anastomosing network of even tubes.
Like most sponges, C. clathrus is contractile, however its contractile strength exceeds
most other species by far. This enormous shrinkage of the body in contracted animals
was already observed in first in situ studies during the last century and where
misinterpreted as necrotic events.The contraction-expansion cycle, however, takes
much more time than in most demosponges (comparative data for other calcareous
sponges is not available to date). The aim of our project is to characterize the
dynamics and functional morphology of contraction in C. clathrus. Further on we will
compare it to data on well-studied demosponges, like Tethya wilhelma. We used
time-lapse imaging, histology, SEM and SR-µCT to characterize body dynamics as well
as anatomical traits in 2D and 3D. Our preliminary results confirm the hypothesis of
pinacocyte contractility with a clear body shape change from extended thin
pinacocytes in expanded stage to t-shaped pinacocytes in contracted stage. However,
in contrast to demosponges, the mesohyl displays prominent changes during
contraction, too. Surprisingly, the mesohyl increases in thickness during contraction,
while the canal lumen almost collapses completely. Whether the volume of the
mesohyl is altered by incurrent water (swelling = volume increase) or thickening is
simply an effect of an overall 3D deformation of the tube walls due to overall
shortening will have to be proven.
����113 Christoph Bleidorn
Immunocytochemical investigations of anterior regeneration in Chaetozone caputesocis
(Cirratulidae, Annelida)
Authors: ChristophBleidorn 1 , Michael Weidhase 1 , Conrad Helm 1
Affiliation: 1 University of Leipzig, Institute for Biology, Molecular Evolution and
Systematics of Animals
A remarkable characteristic of many annelids is their ability to regenerate lost body
parts. It is also known that many taxa are capable of regaining their anterior body
after decapitation. Although this ability is known to be present within many members
of the Annelida, only few investigations deal with distinct regenerative patterns
concerning the re-development of different organ systems so far.
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