Scientists have discovered that heart-shaped clams, known as heart cockles, use fiber optic-like structures within their shells to channel sunlight. This allows the clams to nourish symbiotic algae living within their shells while protecting them from harmful ultraviolet rays. The bivalves harness sunlight to provide the algae with essential nutrients, and in return, receive sugars and other nutrients from the algae. This innovative adaptation is the first known example of bundled fiber optics in a living creature, highlighting a unique evolutionary adaptation that parallels human technological ingenuity.
The heart cockle’s distinctive shell shape is pockmarked with minute transparent structures that permit light to pass through. This unique architecture is rooted in the properties of aragonite, a crystalline form of calcium carbonate arranged in micron-sized tubes that function as fiber-optic cables. These tubes guide light with precision while filtering out harmful ultraviolet radiation. This filtering capacity helps reduce the risk of bleaching, a phenomenon impacting corals and clams due to climate change. Computer simulations demonstrated that the arrangement of the fiber optic-like structures represents an evolutionary trade-off balancing mechanical strength with light transmission efficiency.
Evolutionary biophysicist Dakota McCoy and her colleagues performed microscope experiments showing that the sun-facing side of the shell allows more photosynthetically useful light to penetrate inside than harmful ultraviolet light. Other marine creatures also channel sunlight to symbiotic algae, but heart cockles are unique as they use their shells’ aragonite architecture instead of specialized cells. This innovation could offer valuable insights for the development of bioinspired optical systems in the future. Leveraging the properties of aragonite or its lattice structures could lead to the creation of new materials with superior optical performance, potentially revolutionizing wireless communication technologies and advanced measurement tools.
Heart cockles are not alone in channeling sunlight to symbiotic algae, as other marine creatures like giant clams also do this. However, the heart cockles rely on their aragonite architecture within their shells to filter sunlight and deliver it to the algae. The unique use of minerals in their shells instead of biological structures for this purpose is remarkable. Researchers hope to mimic the bundled fiber optic structures found in heart cockles to develop systems with enhanced light collection capabilities. Tapping into the heart cockles’ shell design could lead to unmatched light-transmission capabilities in various technologies, benefiting human end-users.
By mimicking the heart cockles’ fiber optic-like structures, researchers aim to create systems that offer enhanced light collection capabilities. This could potentially improve wireless communication technologies and advanced measurement tools, revolutionizing the field. The billions of years of product design involved in the heart cockles’ shell structure offer valuable insights for developing new materials with superior optical performance. This innovative adaptation in heart cockles highlights the potential for merging biology and technology to create bioinspired optical systems with a range of applications in various industries.