*Symphon amphora*. A sponge adapted to colonize — and create — air pockets.
1. Amphora-shaped structure Like all sponges, the amphora requires constant flow through its pores to survive, but it pumps air rather than water. Contraction and expansion forces moist air through the sponge's pores. Absorbent surfaces harvest water and carbon dioxide from the air. Waxy coating helps prevent water loss.
2. Radiolytic metabolism The soft blue glow of the sponge is bioluminescence fueled by radioactive minerals in the sponge's vanes (the structures growing from the anchoring rhizoid). This radiation splits water into hydrogen and oxygen. The gases gather in the cave ceilings the amphora prefers to colonize, creating pockets of knallgass (unmixed hydrogen and oxygen). Though breathable, this air is highly flammable and an explosion risk. The sponge's symbiotic bacteria feed on the hydrogen and oxygen, producing energy and water. The sponge uses this energy to fix carbon from the air and grow, as an Earth plant would.
Assessment: a remarkable step. The amphora sponge may evolve an entire lineage of dry-land sponges, colonizing niches filled by plants and fungi on Earth.
Indicates the presence of an air pocket. Swim up to breathe. Do not ignite flares or discharge electrical devices in the pocket.