What is the main role of spicules in sponges?

Spicules play a crucial role in providing structural support to sponges. These small, often needle-like structures are composed of either silica or calcium carbonate, and they form a skeletal framework that maintains the shape and integrity of the sponge. This support is essential because sponges lack true tissues and organs, relying instead on their porous structure to filter water and acquire nutrients. The arrangement of spicules not only supports the body but also aids in the sponge's ability to withstand external pressures and environmental challenges, contributing to its overall stability. This structural function is foundational to the sponge's survival and efficiency as a filter feeder in aquatic environments.