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 "gravity-sensor" that pulled him toward the safety of the dark seafloor. ascidian tadpole
The is a tiny, free-swimming larva that represents a fleeting moment of mobility in the life of a sea squirt. Though it measures only about 1 mm and lives for just a few days, it possesses complex features—like a primitive spinal cord (notochord) and a simple brain—that it will eventually digest to become a stationary adult. The Great Descent of Pip Pip did not eat
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: A "gravity-sensor" that pulled him toward the safety