What would sessile organisms do with information provided by the light from “their meals?” Just because spicules on a sea sponge transmit photons doesn’t mean that that’s their function.

David Contey
Boulder, Colo
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Each Euplectella sponge houses a pair of bioluminescent shrimp. The researchers speculate that the spicules transmit the shrimps’ light into the sponge’s surroundings.