So which is it? Crystallized agar? Microscopic plastic? Or sponge skeleton? The majority guessed it was spicules of a sponge…and you were indeed right!
Spicules are tiny, needle-like structures that mesh together in a network to construct a sponge’s skeleton. Some spicules are made of silica, giving them a glass-like appearance. In fact, recent research suggests spicules from a deep-sea sponge act like glassy, fiber optic cables. They can trap and transport light into the sponge and even contain “lenses” that help focus light in dark conditions. While scientists theorize that this light could allow symbiotic algae to grow or even could attract nearby shrimp into the sponge, the real reason for this phenomenon remains unknown.