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Zoomorphology

, Volume 121, Issue 2, pp 109–121 | Cite as

Dynamic structure of the mesohyl in the sponge Chondrosia reniformis (Porifera, Demospongiae)

  • F. Bonasoro
  • Iain C. Wilkie
  • Giorgio Bavestrello
  • Carlo Cerrano
  • M. Daniela Candia Carnevali
Original Article

Abstract 

The common demosponge Chondrosia reniformis possesses the capacity to undergo an unusual creep process which results in the formation of long outgrowths from the parent body. These shape changes, which have been interpreted as adaptive strategies related to environmental factors, asexual reproduction or localised locomotor phenomena, are due mainly to the structural and mechanical adaptability of the collagenous mesohyl. This contribution describes the morphological correlates of mesohyl plasticisation in C. reniformis. The microscopic anatomy of the mesohyl was examined when it was in different physiological conditions: (1) standard ”resting” condition, (2) ”stiffened” condition and (3) dynamic ”creep” condition. In this last case four representative regions of the sponge body were analysed: the parent region, the elongation region, the transition region and the propagule region. The results show that the histological modification of the sponge mesohyl during plasticisation is limited and localised. The most significant structural changes involve mainly cytological features of specific cellular components characterised by granule inclusions (i.e. the spherulous cells) and the arrangement and density of the collagenous extracellular framework, though the integrity of the collagen fibrils themselves is not affected. Morphological and functional aspects of mesohyl plasticisation invite comparison with the mutable collagenous tissue of echinoderms. Possible functional analogies between these two tissues are hypothesised.

Keywords

Collagen Fibril Asexual Reproduction Parent Body Collagenous Tissue Cytological Feature 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • F. Bonasoro
    • 1
  • Iain C. Wilkie
    • 2
  • Giorgio Bavestrello
    • 3
  • Carlo Cerrano
    • 4
  • M. Daniela Candia Carnevali
    • 1
  1. 1.Dipartimento di Biologia ”Luigi Gorini”, Sezione di Zoologia e Citologia, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy e-mail: bonasoro@mailserver.unimi.it Tel.: +39-02-58354787, Fax: +39-02-58354781IT
  2. 2.School of Biological and Biomedical Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA, UKGB
  3. 3.Istituto di Scienze del Mare, Università di Ancona, Via Brecce Bianche, 60131 Ancona, ItalyIT
  4. 4.Dipartimento per lo studio del Territorio e delle sue Risorse, Università di Genova, Corso Europa 26, 16132 Genoa, ItalyIT

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