The sea squirt is a strange creature. Found attached to rocks and shells, it looks like a soft plastic tube waving with the current. Drawing its nutrients from the passing water, it lives a passive life far removed from its once active youth.

The sea squirt starts life as a tadpole with a primitive spinal cord and brain that helps it find food and avoid harm. As a juvenile it spends its days exploring the ocean, but something happens when it reaches adulthood. Settling on its rock, it stops exploring and growing. In a macabre twist, it digests its own brain.

Spineless,…