A colossal iceberg the size of Chicago has broken from a floating glacier in Antarctica, and like a retractable roof at a stadium, the drifting structure has opened up ... A solitary hydroid drifts in ...

A solitary hydroid drifts in currents about 380m below sea level. "Solitary hydroids are related to corals, jellyfish, and anemones, but do not form colonies," SOU said.