Anthellia is soft coral that looks somewhat similar to Xenia, except it doesn't pulse. Polyps extend from a mat during the lighted-period, and withdraw into themselves during the night like inverted tube socks. I'm not a fan of this easy-to-keep coral, because it tends to grow very fast and spread onto neighboring corals so quickly that those become smothered. It can be manually removed from the rockwork, but attention to detail is important if you want to avoid its return. It is a filter-feeder and requires normal reef-tank parameters with quality lighting.