Login to your account

Password *
Remember Me

porifera.net lab

@ Friedrich-Schiller-Universität Jena, Germany

Dr. Jörg U. Hammel

Dr. Jörg U. Hammel, Dipl. Biol. (t.o.), is a postdoc member of porifera.net lab after finishing his PhD as a fellow of the Studienstiftung des Deutschen Volkes.

Jörg U. Hammel


Address: Dr. Jörg U. Hammel
Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum
Erbertstr. 1
D-07743 Jena
 Telephone:  +49 3641 949173  Visit the ResearcherID profile of Jörg Hammel
 Fax:  e-Mail contact form



Comparative functional morphology and hydrodynamics of sponge aquiferous systems.

S_lacustrisAs sessile filter feeding organism sponges particularly rely on a highly efficient and effectic fluid transport system. Generally three different organisational types of the aquiferous system can be distinguished, from which the leucon-type represents the architectureal most complex one. The high number of choanocyte chambers, which are the flow generating units in the system, are distributed throughout the entire mesohlye of sponges. They are connected the the incurrent canal system via a highly ramified system of canal segments. In a similar manner the excurrent canal system can be discribed as a highly ramified three-dimensional canal network as well. 

In this project I will address functional morphological aspects of sponge aquiferous systems in an integrative and comparative approach. Sponge leucon-type canal systems show a higher complexity of architectural patterns than previously assumed. In this context the present model of flow in sponges is regarded to be to simplified. As sponges are sessile filter feeding organisms all major physiological processes are dependent of the water processed within the canal system. Most of these processes are diffusion limited (e.g. oxygen transport). Therefore, a interdependence of specific canal system architectural patterns and growth form in sponges is expected.
Corrosion CastBy means of analyzing morphometric parameters, the interdependence of canal system architecture and sponge growth form will be studied. In combining morphological data, experimentally determined flow velocity data and computational fluid dynamic results, the present theoretical standard model of flow in sponges will be refined and expanded to fit our deeper knowledge on the higher complexity of canal system architectures. Following a modeling approach the project will bring forth information on the distribution of nutrients and gas in sponges. The overall resulting expanded knowledge on sponge canal system functional morphology will lead to a deeper understanding of sponge physiology in general and thus support still ongoing efforts to establish sponge cultivation methods which are an important prerequisite for marine biotechnology and applied natural product research on sponges.




Functional morphology and molecular biology of coordination- and effectorsystems in early evolved Metazoa

Already in early evolved metazoan animals, like in sponges (Porifera), distinct motions can be observed. These events clearly seem to be coordinated. However these animals lack sophisticated coordination- and effector systems as represented by the later evolved muscles and nervous systems. I use the tropical sponge Tethya wilhelma as a model organism, because this species shows a remarkably pronounced contraction- and moving-attitude. I´m interested in fundamental questions connected with the evolution of complex muscles and nervous systems in metazoan animals. My focus are the cellular effector systems and control mechanisms needed for such coordinated reversible attitudes, as well as the functional characterisation of their molecular basic modules. In this context my investigations will subsidiary also help to understand the evolution of muscles and nervous systems in the rest of the Metazoan lineage.
By combining classical morphological methods with new techniques like synchrotron radiation based micro tomography (SRµCT) and RNAi-techniques I will address morphological, biomechanical, physiological and molecular biological interrogations in an integrative manner.
This aims to contribute in completing the fundamental gap in the understanding of evolution of essential metazoan-systems. Also this work will for the first time establish the RNAi-technique in sponges and will be helpful for further functional interrogations in sponges


Academic career:

since 02/2012 Associated Researcher at the Universitet van Amsterdam, Section Computational Science
since 08/2010 Postdoctoral researcher at Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum
04/2007 - 06/2010: Doctorate at Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum, PD Dr. M. Nickel (until November 2007 at Biologisches Institut, Universität Stuttgart)
10/2006: Diploma `Diplom-Biologe (technisch orientiert)
10/2000 - 10/2006: Study of `Technische Biologie´, Universität Stuttgart

Research visits:

07/2012: Lab of Prof. G. Bavestrello, Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università degli Studi di Genova, Genua, Italy
02/2012 - 05/2012: Lab of Prof. J. Kaandorp, Section Computational Science, University of Amsterdam, Netherlands  
03/2011: Station Biologique de Roscoff, France
04/2010: Lab of Prof. J. Kaandorp, Section Computational Science, University of Amsterdam, Netherlands 
06/2004 - 08/2004: Arctic Station, University of Copenhagen, Qeqertarssuaq, Disko Island, Greenland
05/2004: Zoological Museum, University of Copenhagen, Denmark

Academic management activities:

since 08/2013: Project manager according to German genetic engineering law (Projektleiter nach Gentechnikgesetz) at Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsbiologie
2003:  Elected member of faculty council `Bio- und Geowissenschaften`at Universität Stuttgart, Fachschaft 

Honours and awards:

2008:  Poster award of `Division of Invertebrate Zoology´ at the`Annual Meeting of the Society for Integrative and Comparative Biology´
2007: Poster award of `Fachgruppe Morphologie´ at 100. Jahresversammlung der Deutschen Zoologischen Gesellschaft
2005: `Preis der Technischen Biologie´ 

Scientific memberships:

Deutsche Zoologische Gesellschaft e.V. (DZG), Society for Integrative and Comparative Biology (SICB), International Society for Invertebrate Morphology, Arachnologische Gesellschaft e.V. (ARAGES)


08/2013 Certificate: 'Sicherheit in der Gentechnik'
12/2010 PhD: Dr. rer. nat. (with honors)
10/2006:  Diploma `Diplom-Biologe (technisch orientiert)'

Projects & Scholarships

 08/2013 - 06/2014: Desy grant I-20130206  'Grating-based X-ray phase-contrast micro tomography at imaging beamline P05: Proof-of-concept pilot study for zoomorphology'
 08/2013 - 06/2014: Desy grant I-20130078  'Functional morphology of the anuran larvae filter apparatus: combining SRµCT imaging and fluid dynamic modelling'
 01/2013 - 12/2013: Desy grant I-20120721  'Integrative functional genetic study of developmental genes in early evolved multicellular animals'
 01/2013 - 12/2013: Desy grant I-20120628  'Effects of ocean acidification on calcifying organisms'
 06/2012 - 05/2014: DFG grant 'Comparative functional morphology and hydrodynamics of sponge aquiferous systems'.
 06/2012 - 06/2013: Desy grant I-20120218 'Computational fluid dynamics of sponge aquiferous systems'
 09/2012: DAAD 'Kongress- und Vortragsreisenprogramm' travel grant
 02/2012 - 05/2012: DAAD PostDoc Program - Research fellowship
 01/2012 - 12/2012: Desy grant I-20110915 'Hydrodynamics of leucon-type sponge aquiferous systems' 
 01/2011 - 12/2011: Desy grant I-20100327 'Topology and functional anatomy of sponge aquiferous systems analysed by corrosion casting and synchrotron radiation based x-ray micro tomography'
 06/2011: DAAD 'Kongress- und Vortragsreisenprogramm' travel grant
 07/2007 - 07/2010: PhD fellowship of `Studienstiftung des Deutschen Volkes´
 11/2005: Travel grant of the `Second International Conference on Arctic Research Planing´organizing committee
 03/2005: Travel grant of `Freunde der Universität Stuttgart e.V.´
 05/2004 - 08/2004: Scholarship of `Landesstiftung Baden-Württemberg´ 


Please consult our Publication database for a full list of references!

Peer reviewed Articles:

Hammel, JU, Filatov, M, Herzen, J, Beckmann, F, Kaandorp, JA and Nickel, M (2012), "The non-hierarchical, non-uniformly branching topology of a leuconoid sponge aquiferous system revealed by 3D reconstruction and morphometrics using corrosion casting and x-ray microtomography", Acta Zoologica, 93: 160-170.
Steinmetz, PRH, Krauss, JEM, Larroux, C, Hammel, JU, Amon-Hassenzahl, A, Houliston, E, Wörheide, G, Nickel, M, Degnan, B and Technau, U (2012), "Independent evolution of striated muscles in cnidarians and bilaterians", NATURE, 487: 231–234.
Rivera, AS & Hammel, JU, Haen, KM, Danka, ES, Cieniewicz, B, Winters, IP, Posfai, D, Wörheide, G, Lavrov, DV, Knight, SW, Hill, MS, Hill, AL and Nickel, M (2011), “RNA interference in marine and freshwater sponges: actin knockdown in Tethya wilhelma and Ephydatia muelleri by ingested dsRNA expressing bacteria ”. BMC Biotechnology 2011, 11:67
Nickel, M, Scheer, C, Hammel, JU, Herzen, J and Beckmann, F (2011) "The contractile sponge epithelium sensu lato - body contraction of the demosponge Tethya wilhelma is mediated by the pinacoderm ", Journal of Experimental Biology, 214: 1692-1698.
Høye, TT and Hammel, JU (2010) “Climate change and altitudinal variation in sexual size dimorphism of arctic wolf spiders”. Climate Research 41: 259-265.
Hammel, J.U., Herzen, J., Beckmann, F. and Nickel, M. (2009) "Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma", Frontiers in Zoology, 6, 1: 19.
Høye, TT, Hammel, JU, Fuchs, T and Toft, S (2009) “Climate change and sexual size dimorphism in an Arctic spider”. Biology Letters 5(4): 542-544.
Nickel, M, Hammel, JU, Herzen, J, Bullinger, E and Beckmann, F (2008) "High density resolution synchrotron radiation based x-ray microtomography (SR µCT) for quantitative 3D-morphometrics in zoological sciences", Proceedings of SPIE, 7078: 7078W.
Hammel, JU and Nickel, M (2008) "Pardosa hyperborea (Araneae: Lycosidae) spreading north in Greenland? First report from Disko Island (West Greenland), with remarks on the biogeography of the species. ", Entomologiske Meddelelser, 76: 41-47.
Heim, I, Hammel, JU, Nickel, M and Brümmer, F (2007) "Salting sponges: a reliable non-toxic and costeffective method to preserve poriferans in the field for subsequent DNA-work", Porifera Research: Biodiversity, Innovation and Sustainability: 373-377.

For Abstracts, Academic publications, and reports see the porifera.net lab publication database.

After hours

Contents will follow