For the last five years, Dr. Pim Bongaerts of University of Queensland’s Global Change Institute has been documenting the lives of corals through time lapse photography. It all happens too slowly for the human eye, but capturing life in a coral reef over longer periods of time reveals much more about their growth, locomotion, and even their violent competition with each other. The video above is from BBC News: Underwater time-lapse shows secret life of a coral reef.
Plus some extra info from NOAA.gov:
So what exactly are corals?
Corals actually comprise an ancient and unique partnership, called symbiosis, that benefits both animal and plant life in the ocean. Corals are animals, though, because they do not make their own food, as plants do. Corals have tiny, tentacle-like arms that they use to capture their food from the water and sweep into their inscrutable mouths.
Any structure that we call a “coral” is, in fact, made up of hundreds to thousands of tiny coral creatures called polyps…
In the archives: more coral.
Updated video link.