Sponge

Summary

Sponges, the members of the phylum Porifera (pəˈrɪfərə; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have complex nervous, digestive or circulatory systems like humans. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were possibly the first to branch off the evolutionary tree from the last common ancestor of all animals, which would make them the sister group of all other animals. Etymology The term sponge derives from the Ancient Greek word σπόγγος ( 'sponge'). Ove

Official source

https://en.wikipedia.org/wiki/Sponge

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Here we present a processing route to produce multi-structured ceramic foams based on the combination of particle-stabilized foams with polymeric sponges to produce positive and negative templating structures. Polyester sponges are infiltrated with freshly produced calcium aluminate–alumina foams and upon sintering either positive templating structures are produced when wetting the sponges, or negative templating foams with a percolating pore network are obtained when completely filling the sponges. Additionally, by combining different layers of these particle-stabilized foam infiltrated sponges, various different structures can be produced, including sandwich structures, pore size gradients, and ceramic bone-like structures applying to different types of bone. The particle-stabilized foams used were in situ self-hardening calcium aluminate cement enriched alumina foams to obtain crack-free samples with pore interconnections and tailorable pore sizes.

Elsevier Sci Ltd2013

Biomineralization in living hypercalcified demosponges: Toward a shared mechanism?

Melany Melissa Gilis

Massive skeletons of living hypercalcified sponges, representative organisms of basal Metazoa, are uncommon models to improve our knowledge on biomineralization mechanisms and their possible evolution through time. Eight living species belonging to various orders of Demospongiae were selected for a comparative mineralogical characterization of their aragonitic or calcitic massive basal skeleton. The latter was prepared for scanning and transmission electron microscopy (SEM and TEM), selected-area electron diffraction (SAED) and X-ray diffraction (XRD) analyses. SEM results indicated distinctive macro- and micro-structural organizations of the skeleton for each species, likely resulting from a genetically dictated variation in the control exerted on their formation. However, most skeletons investigated shared submicron to nano-scale morphological and crystallographical patterns: (1) single-crystal fibers and bundles were composed of 20 to 100 nm large submicronic grains, the smallest structural units, (2) nano-scale likely organic material occurred both within and between these structural units, (3) {1 1 0} micro-twin planes were observed along aragonitic fibers, and (4) individual fibers or small bundles protruded from the external growing surface of skeletons. This comparative mineralogical study of phylogenetically distant species brings further evidence to recent biomineralization models already proposed for sponges, corals, mollusks, brachiopods and echinoderms and to the hypothesis of the universal and ancestral character of such mechanisms in Metazoa. (C) 2013 Elsevier Inc. All rights reserved.

Academic Press Inc Elsevier Science2013