Although optical fiber technology is usually considered to be an excellent example of human innovation and engineering, recent investigations have revealed that silica fibers capable of guiding light are manufactured as well by a simple deep-sea sponge. Indeed, several other “primitive” organisms have already been shown to exhibit sophisticated solutions to complex optical problems. The skeleton of the “Venus's flower basket” (Euplectella aspergillum), a hexactenellid sponge that lives at ocean depths ranging from 35 to 5000 m (115 to 16,400 ft), contains silicious spicules (spiny fibers) exhibiting optical and mechanical properties that are comparable, and in some cases superior, to manmade optical fibers. As such, these spicules may serve the sponge as a fiber optic network for the collection or the distribution of light. A better understanding of these natural silica fibers may lead to improvements in the design, fabrication, and performance of commercial optical fibers.