A "light-eye" that told him to swim away from the bright surface where predators lurked.
After twelve hours of frantic swimming, Pip's brushed against a rough, granite ledge. His light-sensitive eye confirmed the spot was shaded, and his gravity sensor confirmed he had reached the bottom. With a final, decisive surge, he pressed his head against the stone and triggered the chemical "glue" that would bind him for life. the swimming larva and its metamorphosis - Nature ascidian tadpole
Pip did not eat. He had no mouth and no stomach. He was a living battery, powered only by the energy his mother had packed into his cells, and he knew—in the way a cluster of neurons can "know"—that time was running out. A "light-eye" that told him to swim away
As he flicked his muscular tail, Pip felt the power of his , a flexible rod that made him a relative of the great whales and humans. His tiny brain, a cluster of only 170 neurons, hummed with data from two specialized organs: With a final, decisive surge, he pressed his