A Fusion of Adjacent Spicules
Video courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts. Download larger version (mp4, 102 MB).

While exploring “Hopscotch” Seamount during Dive 03 of the 2021 North Atlantic Stepping Stones expedition, we encountered several of these rather large glass sponges. The tissues of glass sponges contain glass-like structural particles made of silica. The many tiny siliceous elements of a glass sponge’s skeleton are called “spicules.” Unlike soft sponges, glass sponges produce extremely large spicules that fuse together in beautiful patterns to form a hard structure. These sponges live attached to hard surfaces and consume small bacteria and plankton that they filter from the surrounding water.

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