Can sea sponges become hard

Sea sponges generally have a soft, porous structure composed of collagen and silica, which allows them to filter water and capture food. However, some species can develop a harder exterior due to the presence of spicules, which are tiny, needle-like structures that provide support. While they can exhibit a firmer texture, they do not become truly "hard" like coral or other calcified organisms. Instead, their resilience and structure vary depending on their environment and species.