Mushroom corals, 'corallimorphs', are a group of small soft corals which possess no remnants of a coral skeleton at all. Mushrooms are excellent corals for beginners and advanced hobbyists, as they are especially easy to keep, generally require low - moderate light and are very tolerant of higher nutrient water. There are three main genus' available in the hobby, including Actinodiscus, Ricordea and Rhodactis, of which there are many colourful varieties of species available.