Sea sponges pushed through a fine mesh separate into individual cells that then crawl back together over hours and reassemble into a functioning sponge, an extreme case of whole-body regeneration that biologists have watched under microscopes since 1907

Sea sponges pushed through a fine mesh separate into individual cells that then crawl back together over hours and reassemble into a functioning sponge, an extreme case of whole-body regeneration that biologists have watched under microscopes since 1907

Push pieces of a living red encrusting sponge through a fine mesh and the animal disappears into a cloudy suspension of cells. Thousands of tiny bodies settle across the bottom of the dish, separated from the canals, chambers and surfaces that made them part of a sponge. Within minutes, some begin extending probing projections and moving towards their neighbours. The scattered cells start gathering themselves back into an animal. Over the follow…