Siliceous spicules and skeleton frameworks in sponges: Origin, diversity, ultrastructural patterns, and biological functions

  title={Siliceous spicules and skeleton frameworks in sponges: Origin, diversity, ultrastructural patterns, and biological functions},
  author={Mar{\'i}a Jes{\'u}s {\'U}riz and Xavier Turon and Mikel A. Becerro and Gemma Agell},
  journal={Microscopy Research and Technique},
Silica deposition is a fundamental process in sponges. Most sponges in the Classes Demospongiae and Hexactinellida secrete siliceous elements, which can subsequently fuse, interlock with each other, or form three‐dimensional structures connected by spongin. The resulting skeletal frameworks allow sponges to grow upwards and facilitate water exchange with minimal metabolic cost. Several studies on sponge skeletogenesis have been published. We are beginning to understand the mechanisms of spicule… 

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Sponges, the most primitive multicellular animals, are able to concentrate and precipitate three mineral elements: iron, calcium, and silicon. Iron forms small granules deposited on and within the

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