siliceous spicule

biology

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July 13, 2026

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A siliceous spicule is a tiny, sharp, needle-like structure made of silica. These spicules are a key component of the skeletons of many sponges, particularly those in the class Demospongiae, which make up over 95% of known sponge species.123

Sponges use these spicules for support and protection. They vary greatly in size and shape, making them important for identifying different sponge species. While most siliceous sponges are marine, a few live in freshwater. Some sponges, like the glass sponges, have intricate, lattice-like skeletons formed from siliceous spicules. The term "spiculiferous" means bearing spicules.145

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sponge
Mineral skeletons
Siliceous spicules, found in the Demospongiae and in the Hexactinellida, are made essentially of silicic acid; they also contain some water, a small quantity of other compounds containing sodium, potassium, iron, and chlorine, and a small quantity of organic matter, called spiculin, which forms an…
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Siliceous spicules, found in the Demospongiae and in the Hexactinellida, are made essentially of silicic acid; they also contain some water, a small quantity of other compounds containing sodium, potassium, iron, and chlorine, and a small quantity of organic matter, called spiculin, which forms an…
Read More