Can you solve the mystery of the moving coral? Carrie Straight 05.03.01 Corals are animals, but like plants, they are sessile (“stay in the same place”). But some scientists from Monaco noticed that the coral Lobophyllia hemprichii in their marine aquarium had moved up to 16 cm during the night. The coral moved from its original place and was attached to a rock. The scientists removed the coral and put it back in its original location. The next morning the coral was back on the rock. They put the coral back 21 times, and 21 times found that it had moved by the next morning. The scientists had a mystery on their hands: How did the coral move? To answer this question they filmed the aquarium at night. Filming under normal light did not work. When they filmed with bright lights, the coral did not move. So, they then used an infrared camera. Infrared cameras detect differences in temperatures of objects, and do not need any light source to take pictures. They filmed a small worm coming out of hiding each night. Each night the worm pulled the coral back to the rock. The worm was attaching the coral to the rock. Attached to the rock, the coral made a great hiding place for the worm.  Chisholm, J.R.M. and R, Kelley. 2001. Worms start the reef-building process. Nature 409: 152. ©2001 The Aurora Collection, Inc. All Rights Reserved. Site Development by: Interactive Multimedia. Inc.