Assertion: sponge's structure | /r/Synonym | spicule
Facets:
Source sentences:
text: They make spiny or bristly structures called spicules, made out of a mesh of protein, spongil, and calcium carbonate, as a defense against predators.
text: Their skeletons are made up of structure known as spicules.
text: Their bodies are supported by a skeleton which is made up of structures called spicules.
text: The body of many sponges is supported by tiny rods or star-shaped structures called spicules (SPIH-kyoolz).