Mushroom Corals

Mushroom Corals or Corallimorphs are great beginner corals because they are some of the easiest species to care for. I recommend mushroom corals for hobbyists at any level. They are hardy, tolerant of some less than ideal reef tank parameters or conditions, will grow in areas of lower light, and can be easily fragged or will reproduce on their own.

This mushroom coral colony was one of my first corals ever purchased

Mushroom coral care quick facts

• Common names: Mushroom coral, Mushroom anemones, Bounce coral, False coral, Ricordea
• Scientific names: Corallimorpharia, Actinodiscus, Discosoma, Rhodactis, Ricordea
• Care level: Most species are easy, a few of the more rare mushrooms require moderate care
• Light level: Most require low to moderate light intensity/quality, a few of the brightest color varieties do need higher intensity light
• Flow level: Most require low to moderate water flow
• Aggression: Mostly Peaceful. No stinging sweeper tentacles, but it will try to outgrow and grow over any nearby corals.
• Where to place: Bottom of the tank, will generally thrive in lower light than most other corals, will also thrive in moderate light

• Light: Mushroom corals thrive in low to moderate light because their symbiotic zooxanthellae efficiently provide energy even under subdued lighting. In high light, mushrooms may bleach (expel zooxanthellae), shrink, or lose color. Too little light can result in stretching and pale coloration. Their tolerance for lower light makes them suitable for shaded or peripheral tank areas where other corals might struggle.
• Flow: Low to moderate water flow is preferred. Excessive flow can cause mushrooms to detach from their substrate, curl up, or experience tissue damage. Insufficient flow may lead to detritus buildup and poor gas exchange. Their ability to tolerate variable flow is greater than many stony corals, but extremes should be avoided.
• Aggression: While mushrooms lack stinging sweeper tentacles, they can overgrow and smother neighboring corals by expanding their tissue. If placed too close to other sessile invertebrates, mushrooms may encroach and outcompete them for space and light. This slow but persistent encroachment is their main form of aggression.
• Placement: Mushrooms are best placed on the bottom or in shaded areas of the tank. They tolerate less-than-ideal water quality better than most corals, which is why they are considered beginner-friendly. However, if placed in high light or high flow zones, they may detach, bleach, or fail to thrive. Watch for signs of stress such as shrinking, detachment, or color loss, and move them to a more suitable location if needed.

Natural habitat

Mushroom corals are generally found in lower light, nutrient-rich environments, which makes them somewhat ideal inhabitants in a mixed species tank including fish and coral, and easier to care for than some of the most finicky coral species. They have symbiotic photosynthetic zooxanthellae and require low to moderate light, are not picky about flow, and can be kept in less than pristine conditions.

What’s in a name? (Taxonomy and common name confusion)

All Mushroom corals are Corallimorpharians, which is the taxonomic ORDER they belong to (Corallimorpharia). Within this order, there are several families, genera, and species, leading to a variety of common names such as False corals, Disc corals, and Mushroom anemones. These names reflect their appearance and biology:

• Mushroom anemones or Disc anemones: Many mushrooms resemble small anemones or discs, hence these names. Their disc-like shape and sometimes tentacle-like structures can cause confusion with true anemones.
• False corals: Unlike other corals, Mushroom corals lack a skeleton. Even true soft corals have sclerites (tiny bone shards) embedded in their tissue, but mushrooms do not, which is why they are sometimes called “false” corals.

The overlap in appearance and biology has led to a mix of common names, but all refer to the same general group of corallimorphs.

Mushroom anemones or Disc anemones

Take a look at the image below and you can see how they have earned the common name mushroom anemones. Many of them do, in fact, look a lot like anemones.

On the left is an image of a “True” Carpet Anemone and on the right is a group of Ricordea

False corals

Unlike other corals, Mushroom corals don’t have a skeleton. Even true soft corals have the remnants of skeletons, called sclerites, which are tiny bone shards/slivers embedded in their tissue. But Mushroom corals do not, hence the justification for calling them False corals.

They also don’t have long, retractable feeding tentacles to capture prey (Borneman 2004). These are at least two of the reasons they have earned the common name, False corals.

Mushroom corals

In lower light environments, the individual polyps from any species of mushroom corals will stretch upward in the water column, creating a mushroom-like appearance.

Amazing to see them stretch towards the light like this–this growth form and behavior is not unique to a particular species, but rather characteristic of the entire group under lower lighting conditions

Disc corals

In normal-to-higher light environments, the polyps lie flat along the substrate and take on a discoid shape.

Red Actinodiscus mushrooms

Mushroom coral types (families) and identification guide

There are three popular families of Mushroom corals available in the Aquarium trade.

Rhodactis

The Rhodactis mushrooms can be identified by the fuzzy or texture on the disc cap

Note the fuzzy or ‘hairy’ texture classically associated with Rhodactis mushrooms

Actinodiscus

The Actinodiscus mushrooms sometimes have a bumpy texture or stripes, but they also somehow look smoother/shinier than either Rhodactis or Ricordea

Actinodiscus

Ricordea

Ricordea, by comparison, are generally distinguished by a more uniform, bulbous appearance

The bulbous texture of the Ricordea mushrooms

What do mushroom corals eat?

Many mushroom corals will get a significant amount of their nutrition from their symbiotic zooxanthellae, which are small photosynthetic sugar daddy’s (almost literally). They will also absorb nutrients from the water. Each polyp also does have a mouth and is capable of ingesting small meaty foods, as well. Larger species, like the elephant ear, can be fed meaty foods just like an anemone.

Supplemental feeding: While most mushroom corals can thrive without direct feeding, offering small meaty foods (such as mysis shrimp or finely chopped seafood) can promote faster growth and more vibrant coloration, especially in larger species. However, overfeeding can lead to excess nutrients in the water, fueling nuisance algae and degrading water quality. Signs of overfeeding include increased algae, cloudy water, or mushrooms shrinking away from uneaten food. Underfeeding is rarely an issue unless mushrooms are kept in very low light or nutrient-poor systems. Feed sparingly, and remove uneaten food to maintain water quality.

Where to put: ideal placement in the aquarium

Mushroom corals do best in the lower region of the tank, largely the bottom 25%, including on the substrate or bottom glass. They are a great addition to add color, texture and interest to those quieter and darker corners where other more fussy corals will not thrive.

Can mushroom corals move?

Yes, mushroom corals can move and probably will move about your tank, to the location they prefer the most. Resistance, on the part of the aquarium-owner, is generally futile. I have had mushrooms move from back to front, front to back, side-to-side, everywhere except where they are supposed to be, even to the point where they vanished, only to be seen again, in a completely new place, a few months later.

How and why mushrooms move: Mushroom corals move by slowly creeping their basal disc along the substrate, a process similar to how anemones move. Common triggers for movement include seeking more favorable light or flow, avoiding irritation from neighboring corals, or escaping suboptimal water conditions. Mushrooms may also detach entirely, drifting to a new location—sometimes ending up in pumps, overflows, or undesirable spots in the tank.

Implications for aquascaping: Because mushrooms can move unpredictably, they may overgrow or shade other corals, or detach and settle in hard-to-reach areas. To minimize unwanted movement, place mushrooms in areas with stable conditions and avoid placing them near prized or slow-growing corals. Physical barriers or isolated rocks can help contain their spread.

How do mushroom corals reproduce?

Like most other corals, mushroom corals are able to reproduce sexually and asexually. Sexual reproduction involves the release of gametes into the water (eggs and sperm). Fertilized eggs become embryos and the corals then settle, with half of their genetic information from mom and pop. This occurs normally on ocean reefs but is rare in the home aquarium.

Asexual propagation and overpopulation: In reef tanks, mushroom corals most commonly reproduce asexually by budding, splitting, or fragmentation. While this rapid propagation is an advantage for filling out a tank or trading frags, it can also become a problem: mushrooms may quickly overrun rocks, crowd out other corals, and become difficult to remove. Signs of overpopulation include mushrooms spreading onto neighboring corals, forming dense mats, or appearing in unintended areas.

Managing overgrowth: To control mushroom populations, regularly remove unwanted individuals by gently peeling them from rocks or cutting them at the base. Limiting excess nutrients and maintaining moderate lighting can slow their spread. Consider placing mushrooms on isolated rocks or islands to prevent them from encroaching on the main aquascape. If mushrooms become invasive, manual removal is often the most effective strategy, but persistence is required as small remnants can regrow.

The more common reproductive method in the reef tank is asexual fragmentation through either budding, splitting, both of which are natural and performed by the coral itself, or active fragging by the tank owner.

Budding

Budding is a process where the coral extends a small portion of their foot or stalk out beyond where the rest of the base is located. It then attaches to the rock further away from the base and then detaches from the original base, leaving that little piece of its foot out in front. That tiny piece of the foot then starts to transform into a fully formed, genetically identical mushroom coral clone.

Splitting

Splitting is a process where the corallimorph actually forms a second mouth and bifurcates down the center, essentially cutting itself in half—while each half re-grows to full size. It looks a little like cell division, in slow motion. The two halves will space themselves out, once completely split–and just like in budding, the two split halves are genetically identical.

Eventually, the lobes of this large mushroom cap will pinch completely and split into two separate colonies

Fragging

Technically, the word fragmentation or fragging could apply to any of these methods of asexual reproduction by breaking off a tiny piece of the parent, including budding and splitting, as described above. But in the context of this hobby, the word is generally used to refer to the process a human takes to actively exploit (not in a bad way) this amazing natural ability to create tiny clones of their corals, for the purposes of aquascaping and filling out their tanks with more corals or to trade to the local fish store or to other hobbyists.

How to frag a mushroom coral

At its most basic level, fragging any coral involves the following steps:

1. Cutting or breaking off a piece of the coral from the parent/original colony
2. Attaching that piece to a frag plug, piece of live rock rubble, shell, or another substrate

Where it can become a little bit more complicated is when you factor in the individual needs and challenges of the corals involved. For example, one of the positive factors that make life easier, when fragging a mushroom coral vs. a plate coral, for example, is that any frag or piece of the Corallimorph that you slice away from the original is capable of forming an entirely new colony. Larger pieces will form larger frags, but all you have to do is manage to slice of any piece and you should be fine.

The trickiest aspects in learning how to frag a mushroom coral are:

• How to cleanly/easily free the sliced piece from the live rock
• How to attach the new fragment to your preferred substrate

Freeing your frag from the live rock

Remember, the mushroom coral is attached to the live rock by a tiny foot and stalk. The easiest ways to make a frag are either to:

1. Slice off the entire cap, with a horizontal slice, leaving the foot and stalk behind, if you can easily get under the cap to make the cut, or
2. Slice down to cut off a large lobe, using an angle that cuts away from the food.

It is worth repeating–you can cut just about any piece of the mushroom off to create a frag. The reason I advocate for one of the two angles above is that the foot can sometimes be really well attached to tiny crevices in the live rock. I have had some challenges, in the past, removing my frag, once sliced, if my frag had too much of the foot attached to an irregular, natural surface.

Attaching it to a substrate

The next challenge in how to frag mushroom coral is figuring out how to attach your new slice of shroom to your coral plug or rubble. Mushroom corals are notoriously slimy escape artists. My preferred method is to put a bunch of rubble or plugs in a small plastic container (the kind you would save food in), place the frags inside, and cover it with a plastic mesh (from fruit, onions, or bridal veil), and then place that container in an area of low flow for about a week.

The fragments will settle and attach to the rubble in the container. Once they do that, you can remove them and attach them where you want them.

Fragging troubleshooting and tips:

• Common problems: Frags may fail to attach, “melt” (tissue disintegration), or develop infections. Causes include high flow (which can dislodge frags), poor water quality, or handling damage.
• Why low flow and mesh? Low flow prevents frags from being blown away before they attach. Mesh holds them in place while allowing water circulation and gas exchange.
• If frags detach: Simply return them to the container and re-secure with mesh. Persistent detachment may indicate too much flow or poor frag health.
• Signs of stress: Mushrooms that shrink, turn pale, or develop a foul odor may be stressed or infected. Remove unhealthy frags promptly to prevent spread.
• Best practices: Use clean, sharp tools; minimize handling; and maintain stable tank parameters during recovery.

Learn more about how to frag mushroom corals and other corals

There are two places I strongly recommend to learn more about how to frag corals:

1. Check out this series of articles that starts with: Introduction to fragging corals
2. Download this definitive guide on Amazon, book 4 in the Reef Aquarium Book Series

A few final care tips

• If you plan to keep these corals with smaller saltwater fish, avoid large mushroom species like the ‘Elephant Ear’ or ‘giant cup mushroom’, which will snack on unsuspecting smaller fish who get too close. These large mushrooms are opportunistic predators and can trap and digest small fish or invertebrates that rest on them.
• Not all Mushroom species are for beginners. If you consider yourself an intermediate or advanced aquarist and want to add a more challenging mushroom to your tank, consider adding a mushroom from the Genus Ricordea.
  • The two most popular species in the aquarium hobby are Ricordea florida and Ricordea yuma. These species require more pristine conditions and generally have a higher light requirement. Ricordea are more sensitive to poor water quality, rapid parameter swings, and can suffer tissue loss or color fading if kept in suboptimal conditions. They also prefer moderate, stable flow and benefit from targeted feeding. For best results, maintain stable alkalinity, calcium, and magnesium, and avoid exposing Ricordea to aggressive corals or high-nutrient environments.

What to read next

Learn more about some of the other popular types of corals:

• Zoanthids
• Soft Corals
• Small Polyp Stony Corals (SPS)
• Large Polyp Stony Corals (LPS)
• Torch corals

Or switch over and see some of the most popular saltwater fish species, like:

• Yellow tang
• Ocellaris clownfish

References:

Borneman, Eric H. Aquarium Corals. T.F.H. Publications. New Jersey 2004.

Ulrich III, Albert B. How to Frag Corals. www.SaltwaterAquariumBlog.com Publications 2015

Ulrich III, Albert B. The New Saltwater Aquarium Guide. www.SaltwaterAquariumBlog.com Publications 2014.