Related FAQs: Corallimorphs, Mushrooms 2, Mushrooms 3, Mushrooms 4, Mushroom Identification, Mushroom ID 2, Mushroom ID 3, Mushroom ID 4, Mushroom ID 5, Mushroom ID 6, Mushroom ID 8, Mushroom ID 9, Mushroom ID 10, & Mushroom Behavior, Mushroom Compatibility, Mushroom Selection, Mushroom Systems, Mushroom Feeding, Mushroom Health, Mushroom Disease 2, Mushroom Reproduction, Stinging-celled Animals, Related Articles: Cnidarians, Water Flow, How Much is Enough, /A Diversity of Aquatic Life Corallimorphs! Mushrooms and More!

By Bob Fenner

            Whether you call them Mushroom Anemones, Coral Anemones, False Corals, even just Mushrooms, Corallimorpharians are standard favorites of reef aquarium hobbyists worldwide; and for good reason. They’re beautiful color and shape wise, interesting behaviorally, generally hardy, easily propagated and readily available for a reasonable price (most). They do have some noxious properties that can be of consequence; and we’ll have much to state concerning this issue.

Systematics:

            Mushrooms, Order Corallimorpharia are members of the Phylum Cnidaria; the stinging-celled animals; and considered by hobby aquarists as “corals”; though scientists only commonly label the soft corals (Order Alcyonacea) and stony corals (Order Scleractinia) strictly as such. Some of the group’s higher taxonomy is:
Kingdom:        Animalia
Phylum:           Cnidaria; Anemones, corals, sea fans, jellyfishes, sea pens...
Class:               Anthozoa; Polyp stage only, stomach divided in numerous compartments.
Subclass:         Hexacorallia; Multiples of six tentacles.
Order:              Corallimorpharia, erected by Stephenson 1937
Families we’ll leave out of the discussion, but pertinent, used genera include Discosoma (subsuming Actinodiscus), Rhodactis Ricordea, and Corynactis. And we’ll have a mention of Amplexidiscus and Pseudocorynactis as well.

Corallimorphs appear similar to Anemones; being short-bodied cylindrical, with bumps and/or tentacles arranged in radiating rows on their wide oral (facing up) disc surfaces. They are narrow-columned and lack true tentacles of the namesake Actinarians (true anemones).
Some species do look like stony coral polyps superficially, but of course, Mushrooms lack a stony skeleton.

Species Variety: For most Corallimorphs, description to genus is best.

Genus Actinodiscus/Discosoma are the common mushroom or disc anemones; Three to eight cm. across, they have smooth to pebbled to larger pseudotentacles covered oral discs that may be smooth around the edges or emarginated. Actinodiscus include the hardiest, most commonly offered species of Corallimorphs, including metallic varieties; their species identification is problematical, but what is stated for the genus applies to all. They can do well under moderate illumination and circulation; and accept all formats of foods.   Some examples of colors and textures of Actinodiscus below.

 

Genus Ricordea; simply called Ricordea Mushrooms can grow to about three inches across and resemble small carpet anemones, with bulbous tentacles covering their oral surface. Mostly browns, greens and tans, some stocks include the spectrum of mixed in warm and cool colors. Care is much the same as for Actinodiscus. Below; some Ricordea florida in captivity and one in Grand Turks.

 

Ricordea yuma is a Pacific species offered as wild-collected and cultured at times. It too occurs in a variety of mixed colors. Below, at a Los Angeles distributor, and lower, in the wild in N. Sulawesi.

 

Genus Rhodactis are the “Hairy” Mushrooms; and called just that. Their oral surfaces are covered either in finely branching tentacles of knobby projections. They occur in various browns and yellows; and metallic greens and blues. Not only do they grow larger (up to 30 cm.) than the previously mentioned genera, Rhodactis are aggressive species, burning other Cnidarians and consuming small unwary fishes if they venture too close. Some Rhodactis examples below: A yellowish colony in Fiji; a close-up of a polyp in N. Sulawesi and Rhodactis rhodostoma in the Gulf of Aqaba, Red Sea.

 

Corallimorpharia Not Usually Sold in the Trade:

Metarhodactis, with one species (M. boninensis, Carlgren, 1943); with its papilliform tentacles covering the oral disc appears similar to Actinodiscus… but due to possessing a type of mastigophore, and gaining larger size; the genus is definitive. Sold in Europe at times (de Jong site); the “Elephant Ear Mushroom” gets too large for home hobbyists; as does:

Amplexidiscus; also monotypic (A. fenestrafer) is also called a/the Elephant Ear Mushroom, and is the largest of the group, with polyps exceeding 40 cm. in diameter. This is a beautiful animal, but tricky to keep with other reef life, as it is known to engulf fishes and mobile invertebrates, digesting them in its enclosing mouth. A grouping shown below in Palau Redang, Malaysia.

 

Pseudocorynactis: are usually solitary and though hobbyists don’t usually know it, can get quite large; up to 15 cm. in diameter. Regarded more as pests than assets, most Pseudocorynactis just “show up” on tropical west Atlantic live rock. Some are quite beautiful, though very aggressive; stinging and consuming fishes. They are sold into the trade at times though; mostly as “Orange Ball Anemones” or such. One shown below in an aquarium.

 

 

Corynactis are principally cool to cold water species. Sometimes sold into the trade as “Strawberry Anemones” they won’t live long or well unless kept in a chilled system. The tropical Corynactis tend to be non-descript and cryptic; hiding from view. Shown, C. californica at the SIO Aquarium, San Diego, CA.

 

Occurrence in the Wild:

Most all Mushroom Anemones are tropical and live in shallow water of a few to tens of meters depths; attached to hard substrates. Some are solitary, although the majority are colonial; at times exclusively covering large expanses of rocky reefs. Polyps are generally small; one to two inches across; though Amplexidiscus can span more than a foot.

 

Conservation Status:

            Mushroom species are not challenged in the wild as far as I’ve seen first-hand and in pertinent references; but are rarely abundant. More singular species, like Ricordeas are only found here and there; and colonial ones like Actinodiscus are really only common in a few places. This being stated, folks who collect them in the wild are careful to always only take a part of what they find; realizing that in time, under the particular conditions where they were found, these animals will reproduce, and repopulate the area.

 

Captive Care Guidelines:

            Mushroom Anemones are popular for aquarium use worldwide; in part due to their hardiness and equally, their beauty. They are easy to take care of given a few simple considerations.

 Acquisition: Corallimorphs can be purchased on-line, from stockists, and traded amongst hobbyists as friends of clubs or “frag fests”; gatherings of reef aquarists.

Introduction: Is best done using an intermediate isolation zone for a week or two; to assure the health of the new specimen. Most all Mushrooms are sold attached to rock, and this should be placed WITHOUT the shipping water in the main-display tank.

Placement: This is a very important issue; to avoid physical and chemical mal-interaction (allelopathy), make sure and put your Mushrooms on bommies, rock arrangements of their own. Though some do and learn to get along with other life, it is best to keep your Shrooms stranded on rocks of their own; not allowing them to migrate over to other sedentary livestock.

Lighting: Corallimorphs are photosynthetic, contain endosymbiotic Zooxanthellae, and hence require “reef” like illumination to do well. They do celebratedly “get by” on lower illumination than stony corals and true anemones, with PAR/PUR readings in the few to several tens. Metallic appearing colonies do better with PAR nearer 100.

            These are spectacular organisms, particularly the “metallic” species, under actinic/blue lighting. Very nice to have some lamps to mix in when guests are over, and/or transitioning to night/lights off time.

 Flow: In the wild, Corallimorpharians are almost always found in low-current settings. In captivity they like the same, but will tolerate non-linear water movement up to the point where it turns their edges up.

 

Feeding: As stated, ‘Shrooms are photosynthetic organisms; deriving part of their useful energy from conversion of carbon dioxide into sugar via light. They also feed themselves directly, both through absorption through their tissue wall, as well as feeding on particulates and small life; gathering them in mucus threads that get passed to their circular mouths.

Towards the chemical needs ends you are urged to not make Nitrate (NO3) or soluble Phosphate (HPO4) absolutely zero; and to stock your system with some other organisms (fishes) that by their feeding will small foodstuffs. Certainly, the best mechanism for providing nutrition to your system all the way around is to have a tied in “living sump”, i.e., a refugium with a Deep Sand Bed; a space where various micro-and macro-organisms can populate and contribute to this function.

 

Compatibility: As noted in the genera/species review, there are some Corallimorphs capable of capturing and consuming small fishes. What is more concerning is this group’s capacity for chemical allelopathy. Along with some Zoanthids, soft and stony corals; Mushrooms, if and when “upset” can release toxic chemicals and slime that can trigger breakdown of other life present. How to avoid such overt situations is simple: Maintain an optimized, stable environment; and isolate probable contenders on their own real estate.

            Though they should not be placed adjacent to other Cnidarian groups, some Mushrooms (especially of the genus Actinodiscus) get along with other Corallimorphs of the same genus.

“You gotta keep ‘em separated:”  At right a Ricordea colony has been placed too near a Bubbletip Anemone (Entacmaea) that is showing the worse for the association. Below; a Rhodactis colony is outcompeting (burning) an adjacent Porites.

 

Propagation: Mushrooms are amongst the easiest of Cnidarians to propagate. With the exception of Ricordeas, most Mushrooms are quick growers, readily split (fission) or leave a piece behind (pedal laceration) when they move. The Order does reproduce asexually in the wild as well as sexually.

            As with fragging Zoanthids, you are cautioned to be extra careful when handling; especially cutting Corallimorpharians. Their slime contains some noxious chemicals so by all means DO wear long-sleeve shirt, gloves and eye protection. Larger pieces, cuts through the mouth are best, result in higher rates of survival and faster recovery. Cuttings can be acrylate secured to hard substrate, placed directly on same in calm settings. DO take care to do all handling, cutting OUTSIDE your main/display, and allow the cuttings to convalesce in an isolated system. TAKE CARE to discard any water that has been used in the fragging process; and of course, clean your cutting tools thoroughly and allow to air dry.

 

Health:

            The vast majority of disease issues with these animals are environmental in nature. Like all Cnidarian life in captivity, they require high and stable pH, adequate alkalinity, sufficient biomineral content…

Below: Bleached out Mushrooms; ones that have lost their pigment and Zooxanthellae; possibly due to too-strong lighting. Some authors suggest that the use of a trace element commercial supplement containing iron and manganese can aid in retaining and recovering health of these endosymbiotic algae. I strongly advise the weekly administration of iodide-ate with keeping all Cnidarians; and its multi-dosing in the case of perceived health issues.

 

Cloze:

            Mushroom Anemones have a great deal going for them; requiring little specialized care, being appealing in appearance and available in many colors, patterns and textures, and being aquarium-hardy. Their one downside, and it can be important, is their penchant for over-population and allelopathy. Confine yours to designated rock formations, and do your best to not offend them physically, chemically or biologically; especially if you’re trying your hand at asexual fragmenting them to make more. Much better to provide propitious conditions and be patient; even slow-growing varieties like Ricordeas will split and make more of them in time.