Nature’s first fiber optics could light the way to internet innovation

In a discovery that blurs the line between biology and technology, scientists have found that heart-shaped clams use fiber optic–like structures to channel sunlight through their shells in a lot the identical way that telecommunications company use fiber optics to deliver high-speed information superhighway connectivity into homes.

This innovation, a first known example of bundled fiber optics in a living creature, helps to explain how heart cockles (Corculum cardissa) — a marine bivalve found in shallow waters across the Indian and Pacific Oceans — harness sunlight to nourish symbiotic algae living within, while protecting them from harmful ultraviolet rays. In return, the algae provide the clams with sugars and other very important nutrients.

The finding highlights an evolutionary adaptation that parallels human technological ingenuity, and offers potential insights for the development of bioinspired optical systems within the very long time, researchers report November 19 in Nature Communications.

Heart cockles are small, walnut-sized bivalves best known for their distinctive shell shape. But a detailed look reveals the shells are pockmarked with “windows” — minute, transparent structures that allow light to move through.

This unique architecture is rooted within the special properties of aragonite, a crystalline kind of calcium carbonate (SN:1/21/03). These aragonite crystals are arranged in micron-sized tubes that function like fiber-optic cables, guiding light with extraordinary precision, while filtering out harmful ultraviolet radiation which may damage the clams’ symbiotic algae or their own delicate tissues.

Evolutionary biophysicist Dakota McCoy, of the University of Chicago, and her colleagues performed microscope experiments demonstrating that the sun-facing side of the shell permits more than twice as a lot photosynthetically useful light to penetrate within as it does harmful, DNA-damaging ultraviolet light.

Per McCoy, this light-filtering capacity likely helps in the reduction of the chance of bleaching, a deadly phenomenon affecting both corals and clams alike which is currently being exacerbated by climate change (SN: eight/7/24).

Computer simulations in an analogous fashion demonstrated that the arrangement of the fiber optic–like structures represents an evolutionary trade-off, finely tuned to balance the shell’s mechanical strength with its ability to efficiently transmit light.

“Sooner or later, somebody has truly worked this out,” says Jingchun Li, an evolutionary biologist at the University of Colorado, Boulder, who studies the symbiotic relationship between heart cockles and their algae.

The heart cockles aren’t by myself in channeling sunlight to symbiotic algae. Other marine creatures, equivalent to giant clams, do that too (SN: 6/22/18). But whereas these massive, ridged bivalves place self assurance in really expert cells to attract in an grand suggestion sunlight, heart cockles, with their shells shut tight, take benefit of of their unique aragonite architecture.

“They’re the use of minerals of their shells to do that and now now not biological structures,” says Sarah Lemer, an evolutionary geneticist at the Leibniz Institute for the Analysis of Biodiversity Change in Hamburg, Germany, who became now now not involved within the study. “It’s indubitably neat.”

McCoy and others now envision leveraging the properties of aragonite or its intricate lattice structures to create new materials with superior optical performance — potentially revolutionizing wireless conversation technologies and advanced measurement tools.

One quality they hope to copy is aragonite’s ability to channel light without reflective coatings. Such coatings are needed on telecommunications cables to confine light signals, but aragonite naturally possesses its own optical containment features.

“By mimicking the bundled fiber structures found in heart cockles, we may develop systems that offer enhanced light collection,” says Boon Ooi, a photonics researcher at the King Abdullah University of Science and Technology in Saudi Arabia.

“Billions of years of product design have gone into this,” McCoy points out. Tapping into the guts cockles’ shell design, she says, may bring about unmatched light-transmission capabilities — leaving the human end-users of those technologies as happy as clams.