Inflates with water to feed and collapses to a rag when the current stops.
A soft coral growing as a branching tree in pink, red, orange, white or purple, with clusters of polyps at the branch tips and translucent spicules visible through the tissue. It has no symbiotic algae and depends entirely on capturing plankton, which is why it grows where current runs rather than where light is good, and why it is often the dominant life on a wall or a wreck rather than on a reef top.
The colony has no skeleton. It inflates by pumping water into its tissue, which is what makes it open, upright and photogenic; when current stops it deflates to a limp fraction of its size, and a colony a diver saw at slack water is not the one photographed on the run. The candy crab lives on it and takes its colour and polyp shape, and several nudibranchs feed on it. Recorded from about 5 to 45 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
