If a sea urchin survives the incredible tumult of youth, it’s nearly immortal

Sea urchins are members of a tube-footed sea creature family that includes sand dollars and starfish. To reach maturity, they must brave treacherous, extraordinary journeys. Conceived in the open sea from sperm and eggs released by adults, sea urchin larvae develop small, spaceship-shaped exteriors to help them float to a more permanent home. When the time is right to settle down, the spherical larvae turn themselves inside out, revealing a small, many-legged adult that has been growing inside. Part of KQED’s science documentary series Deep Look, this stunning high-definition video chronicles one of nature’s most spectacular transformations.