Bonellid Echiuran Worm
Late at night, I saw this strange creature stretched out across the substrate. It looks like a plant, but this is actually the proboscis of a Bonellid Echiuran Worm. I've never seen the body of the worm, but the tendril will reach out quite far. In this shot it was out at least 12" from the source in the rockwork. According to Dr Ron Shimek, it is a harmless detrivore. If you want to see one in your tank, look while the lights are off, using a dim flashlight. As soon as light is sense, it pulls back in quickly. The above was taken with a flash. More images and discussion Reef-safe.