Before starfish embryos look like starfish, they resemble little beads spinning around in the water. MIT researchers now report that when the tiny embryos get near each other on the surface, they come together to create a kind of "living crystal" structure. The scientists determined that tiny hairs on the embryos move the surrounding water in such a way that it pulls other embryos closer. Eventually, a better understanding of this natural phenomenon could inform the design of robots that self-assemble into swarms. From MIT News:
"It's absolutely remarkable — these embryos look like beautiful glass beads, and they come to the surface to form this perfect crystal structure," says Nikta Fakhri, the Thomas D. and Virginia W. Cabot Career Development Associate Professor of Physics at MIT. "Like a flock of birds that can avoid predators, or fly more smoothly because they can organize in these large structures, perhaps this crystal structure could have some advantages we're not aware of yet." …
In their new study, she and her colleagues fertilized thousands of starfish embryos, then watched as they swam to the surface of shallow dishes.
"There are thousands of embryos in a dish, and they start forming this crystal structure that can grow very large," Fakhri says. "We call it a crystal because each embryo is surrounded by six neighboring embryos in a hexagon that is repeated across the entire structure, very similar to the crystal structure in graphene."