Rhodactis bryoides: The shroom that thought it was an anemone!

Thanks to our friend and colleague Joe Rowlett’s book Indo-Pacific Corals new insights were provided on many different coral families. One new development I found particularly interesting concerns the taxonomy of corallimoprh since not much new work has been done on this family in recent time. Among these boneless corals, one particular species has been showing up in the trade on regular basis but is almost always misidentified. It’s time to correct this and shine a light on this really interesting and remarkable species: The Wagon Wheel bullseye mushroom, Rhodactis bryoides.

Wagon Wheel Shrooms have been a classic of the reef aquarium scene for many years, coming in a broad range of coloration but their unique appearance and coloration has not yet risen to the level of being properly identified as a unique species bullseye mushroom.

They can reach pretty large size:

*Rhodactis bryoides* can easily reach over 15-18 cm (5”) wide. As big as a small carpet anemone.

Similarly to the Jawbreakers Shroom, Rhodactis bryoides can reach a pretty decent size sometimes to the point of being mistaken for a small carpet anemone. They can reach a diameter of 15-18 cm (6-7 inches) size making it one of the largest corallimorph found in the ocean, second only to the massive elephant ear Amplexidiscus fenestrater.

Wagon Wheel Pattern:

The Wagon Wheel pattern is really characteristic of Rhodactis bryoides because the radial pattern is not found in many other species except Discosoma sp, and very seldom in Rhodactis indosinensis, but the tentacle shape is very different.

*Rhodactis bryoides* can be readily confused with some Rhodactis inchoata, but tentacle shape is not as elaborate in *R. inchoata* especially on the edges.

Very Characteristic tentacle shape:

Tentacles of *Rhodactis bryoides* are very characteristic with a ‘moss’ like shape

The species name comes from the Greek ‘Bryos’ for moss, and referring to the very fuzzy, fluffy, bushy, moss like shape of pseudotentacles. The numerous, branched, polyp-like shape of the tendrils are unmistakable. Unlike Rhodactis inchoata, the pseudotentacle shape is uniform from center to edge while in R. inchoata, pseudotentacles tend to be less dense and fluffy close to the edge.

Tentacle density is important, especially around the mouth.

A wide range of coloration:

The classic solid red morch, often with a light blue underlying oral disc is a classic.

Like most shrooms, the real asset of these unique polyps in an aquarium setting is their broad range of coloration. All the possible colors are available in polyps of Rhodactis bryoides – red, yellow, green, pink, purple, rainbow, multicolor. In addition to the Wagon Wheel pattern, solid colored morphs of R. bryoides can also be found. Some specimen with very polyp-like pseudotentacles exhibit dual coloration, with the center of the tentacle, like an oral disc, differently colored than the tentacle tips, take a speckled, pearly appearance.

Habitat and Maintenance:

Rhodactis bryoides prefer stiff reef slope, or even drop off, with indirect light, in protected and turbid environment rich in food.

This is what a healthy, fully expended specimen should look like.

Keeping these shrooms is quite easy once they’ve achieved a certain degree of acclimation. They are low metabolism animals, growing slowly, but also taking a long time to recover from stress. They should be kept in dim light for quite a while until they fully open and start feeding and only past this point can the lighting schedule be very slowly increased.

Vincent Chalias

Vincent is a coral passionate aquarist with extensive experience in the industry, travelling the world to learn about corals. His background is a master degree in Marine Aquaculture. He set up the first Indonesian Coral mariculture farms at the beginning of the century and spent over 20 years in Indonesia running them. He's been extensively diving and documenting corals all over the Indo-Pacific.