Green Mushroom, Mushroom CoralActinodiscus nummiformisPhoto © Animal-World: Courtesy David Brough
This Purple Mushroom or Green Mushroom is a great variation to the usual Actinodiscus varieties, because they can get much larger!
The Actinodiscus nummiforme species is a lesser known member of the Actinodiscus group and is generally known as simply a Mushroom Coral. But these beauties have a very pretty blurring of colors and a larger size, that makes them a wonderful addition to the reef aquarium. While most Actinodiscus mushrooms typically reach only 2-3" (5-8 cm), this corallimorph can can grow to 4-5" (10-13 cm).
These mushroom corals come in green, brown, light pink to a reddish brown, and dusky violet, thus the names Purple Mushroom or Green Mushroom.They have little pimples on the surface of their oral disc, rather than the long feeding tentacles used by sea anemones and stony corals for capturing prey. Although those pimples do hold several types of stinging cells, they primarily feed off micro particulate foods from the water column.
The A. nummiforme is a great coral for beginners to advanced aquarists. It.is easy to care for and does not like or need high levels of light. They should be kept in shaded areas in tanks with high output lamps, if not they turn all brown and fail to thrive. LIke other mushrooms, this one does not care for fast currents either. They can handle higher levels of nitrate than SPS and LPS corals.
The Purple Mushroom or Green Mushroom propagates easily in captivity, though after splitting the clone mushroom doesn't necessarily always resemble the "mother" mushroom. They are semi-aggressive if they are near another coral. They will cause other corals to loose tissue, recess, and possibly die. Acroporas will not grow in aquariums with large mushroom populations. A. nummiforme have very few predators if any.
Species: Actinodiscus nummiforme
Mushroom Coral Information: The Mushroom Coral Actinodiscus nummiforme was discovered by Ruppell and Leuckart in 1828. Some names they are known for are Purple Mushroom, Green mushroom, Disc Anemone, and Mushroom Anemone. Some general common names they are known by are False Anemone, Shrooms, and Mushrooms..
As far as current taxonomy, the A. nummiforme is listed under Actinodiscus and not Discosoma, according to the 2007 taxonomy list. The taxonomical identification of mushroom corals has a history of limited and dated information which is often of dubious value and sometimes incorrect. Mushrooms corals have no fossil records and studying the physical aspects has proved to be not very reliable for identification. Modern methods using DNA and RNA testing to deduce the sequence of genes, though more reliable, is not readily available.
Where Mushroom Corals Are Found: The Actinodiscus nummiforme are found in the Indo-Pacific Ocean, and have recently been seen in the Red Sea as well.
Mushroom Coral Habitat: Purple Mushroom or Green Mushroom are found on outer reef slopes at times, but prefer shallow lagoons and tide pools. They like to grow on dead corals, rubble, and between coral heads. They feed off micro particulate foods in the water column. A. nummiforme propagates easily in captivity, which can contribute to preserving the wild populations. Even after splitting, the clone mushroom doesn't necessarily always resemble the "mother" mushroom. They have very few predators if any.
The Actinodiscus nummiforme is not on the IUCN Red List for endangered species
What do Mushroom Corals look like: These Coral Mushrooms Actinodiscus nummiforme are basically a coral without a skeleton and their internal structures are the same as stony corals. The top of their body or the upper surface is called the oral disc. The stalk area, which is very small, is called the column and it is located just above the pedal disc, which is where they attach to surfaces.
The A. nummiforme can be green, brown, light pink to a reddish brown, and dusky violet, and they can be slightly fluorescent. The darker specimens occur in shallow waters..They have little pimples on their surface. They lack long feeding tentacles to capture prey, although those pimples do hold several types of stinging cells.
They can actually warp the surface of their oral disc to change the water flow over them to direct particulate and flocculent material toward their mucous center for absorption. At times they will make a trumpet shape. This is thought to be formed when they are needing nourishment, or if the light level is low, or is of low quality due to age.
Mushroom Coral Life Cycles: This Coral Mushroom can grow to 4-5" across (10-13 cm), but their life span is unknown.
Mushroom Coral Care: The Purple Mushroom or Green Mushroom is easy to care for and does not like or need high levels of light. They should be kept in shaded areas in tanks with high output lamps. If they are not shaded, they turn all brown and fail to thrive. Some will just float around the tank until they find a nice shaded area or have an unpleasant encounter with a pump. They can handle higher levels of nitrate than SPS and LPS corals, but they cannot handle high water flow.
Mushroom Coral Feeding: The Purple Mushroom or Green Mushroom is a carnivore. In the wild, these corallimorphs are well equipped with nutritional alternatives for their well-being. They derive nutrition from their symbiotic algae, zooxanthellae, that dwells within their tissues and they eat suspended micro particles out of the water column. They can actually warp their surfaces to change the water flow over them to direct particulate and flocculent material toward their mucous center for absorption.
In captivity you can feed your A. nummiforme newly hatched artemia once in a great while. But really, it is the nutrient level in your tank that they will thrive in, and not direct feedings.
Water changes of 10% bi-monthly or 20% a month are typical. Provide a reef environment with proper magnesium levels. Some claim proper iodine levels are beneficial also. Due to their toxins, active carbon is a good idea with larger colonies of mushrooms. Do not over skim since the A. nummiforme need nutrients to survive on and will not do well in a pristine environment.
A typical live rock/reef environment is what is needed for your Purple Mushroom. Provide rubble or dead coral and live rock for them to have something with which to attach their pedal disc. They do not do well with strong water movement, so direct the power heads and intake nozzles away from them. As they can float around when looking for a place to settle, it's a good rule of thumb to have all of your pumps covered. Most good quality pumps have guards on them.
- Minimum Tank Size / Length: Nano tank of 1 gallon or more
- Marine Lighting: Low.
- Temperature: 72° - 83° F (22° - 28° C)
- Salinity / Specific Gravity: 1.023 to 1.025
- Water Movement: Low / weak
- Water Region: Bottom of the aquarium
The Purple Mushroom or Green Mushroom is semi-aggressive if they are near another coral. They will cause other corals to loose tissue, recess possibly die. Acroporas will not grow in aquariums with large mushroom populations. Make sure to leave 6 - 8 " between your mushrooms and other corals. Watch the growth rate since the A. nummiforme will overgrow and kill any nearby corals.
Mushroom Anemones will tolerate their own species and usually other Mushrooms. In the wild many species of Mushroom Corals occur together in large groups. In captivity the A. nummiforme will get along with their own species, but may not tolerate mushroom species outside their colony. Even in one genus, if the color is different or a different species, the weaker mushroom will detach and find another location. Strong water movement will cause them to detach as well.
No sexual difference in appearance is known.
- Mushroom Coral Reproduction:
Corallimorphs reproduce in 4 different ways. The first three ways, asexual budding, laceration, and division/fission, are successful in the aquarium as most hobbyists soon discover. Budding is where individuals are formed from particles divided off from the pedal disc. Similar to budding, laceration happens when they move slowly over the surface and leave behind small pieces that will eventually form into mushrooms. Division or fission is where an individual divides down the center and forms two animals.
Sexual reproduction is where eggs and sperm are released into the water column. They unite and form free-swimming larvae which are initially plankonic, and them settle and adhere to the substrate. Sexual reproduction has not been well documented, and has not been observed in captivity. Presumably modern filtration methods are inhospitable to free swimming larvae.
- Mushroom Coral Propagation:
Mushroom corals can be easily propagated in captivity by cutting individual polyps into several pieces. Placed the pieces on a gravel substrate with low water flow. They will attach themselves to pieces of gravel. Later they can then be super glued to a suitable substrate such as a reef plug. It has been stated that the warmer end of their temperature spectrum encourages reproduction.
For details on how to propagate your mushroom corals see Mushroom Corals: Mushroom Coral Propagation
The A. nummiforme are disease resistant, and only affected by improper husbandry. Problems for the most Corallimorphs are pretty minimal unless your lighting, water movement, feeding and water quality are improper for these animals. A sign of this is if your coral mushroom detaches to look for "better conditions" to settle in. They have very few predators if any.
Mushroom Corals for Sale: The Purple Mushroom, Green Mushroom, or Mushroom Coral A. nummiforme are not always easy to find online but you may be able to get some from reef clubs, coral frag groups, or by special order from your local pet store
- Animal-World References: Marine and Reef
- Eric Borneman, Aquarium Corals : Selection, Husbandry, and Natural History , TFH Publications, 2001
- Anthony Calfo, Book of Coral Propagation, Volume 1 Edition 2: Reef Gardening for Aquarists, Reading Trees; 2 edition, 2007
- Ronald L. Shimek, Guide to Marine Invertebrates: 500+ Essential-to-Know Aquarium Species, Microcosm, 2005