Unravelling the mysteries of giant glass sponges

Dive under the Antarctic sea ice near Scott Base into the weird world of cold-water life. Pink sea angels, worms that look like intestines, ocean creepy crawlies that get as big as your hand... and mysterious giant glass sponges. These sponges are one of the strangest, and oldest, animals on Earth: surviving without light, eating bacteria and viruses, and making themselves out of silica they absorb from the water. In most parts of the world, they live at depths too deep to dive, making them tricky to study. But in the cold waters of McMurdo Sound, they can be found in shallower waters. Now an international team of scientists are unlocking some of their secrets.