Hyalonematidae

Hyalonematidae is a family of deep-sea glass sponges (class Hexactinellida) comprising five genera. They are known for their unique siliceous spicules called amphidiscs and skeleton structure primarily composed of diactins, large, rod-like megasclere spicules found within the sponge's internal tissue (choanosome). Hyalonematidae have been recorded at depths of up to 6000 meters and have a global distribution, though they have not been documented in the Arctic Ocean. Initially mistaken for corals due to their fibrous base, Hyalonematidae were later recognized as glass sponges and classified wit