Mushroom Corals: Discosoma vs Rhodactis vs Ricordea

Mushroom corals are the piece almost everyone buys first — cheap, tough, and forgiving of the mistakes every new reefer makes. The catch is that three very different corals all get sold as “mushrooms,” and telling them apart is the difference between a smart first purchase and a tank someone regrets.

The three mushrooms, and why it matters which one you buy

Nearly every soft mushroom in the hobby is one of three genera: Discosoma, Rhodactis, or Ricordea. They share the same basic body plan — a fleshy oral disc with a central mouth, no hard skeleton — but they differ in surface texture, care, aggression, and price. The single most useful skill for a mushroom buyer is reading that surface texture, because it tells you the genus, and the genus tells you almost everything else.

Discosoma: the smooth one you should start with

If you’ve ever seen a reef tank with a rock that’s slowly disappearing under a carpet of flat, colorful discs, that’s Discosoma. They’re the definition of a beginner coral: they tolerate low light, imperfect flow, and the nutrient swings of a young tank, and they multiply by splitting and by dropping little “daughter” discs that crawl off and settle nearby. Give them a shaded spot low in the tank, moderate flow, and leave them alone — they’ll do the rest. Colors range from the electric blues and neon greens to deeper purples, and the same colony can shift shade depending on your lighting. The only real complaint with Discosoma is that they can be too successful — a happy colony will spread onto neighboring rock and shade out corals you’d rather keep. That’s a good problem for a first coral to have.

Rhodactis: bigger, hungrier, and a little bit sneaky

Rhodactis take the mushroom body plan and cover it in short, branching, finger-like bumps called papillae, giving them a fuzzy, almost furry look. They get larger than Discosoma, take brighter light, and — this is the part people don’t expect — they actively feed. A big Rhodactis will fold its disc around meaty food, and the largest specimens (the elephant-ear types) have been known to close over and eat small fish or shrimp that settle on them overnight. It’s rare, but if you keep a large Rhodactis, don’t pair it with tiny gobies or expensive shrimp that sleep on the rockwork. They’re still a beginner-friendly coral — hardy, colorful, fast to spread — just with a bit more personality. The “Frankenstein” and “wagon wheel” morphs are Rhodactis, and they’re some of the most striking mushrooms in the hobby.

Ricordea: the one people actually collect

Ricordea are where mushrooms stop being a beginner throwaway and start being a collector’s item. Their discs are covered in tight, round, bubble-like vesicles that catch the light like beads of glass, and under blue spectrum lighting the fluorescent morphs are some of the most vivid animals you can put in a reef. There are two you’ll see: Ricordea florida, the Caribbean species we hand-collect here in the Keys, and Ricordea yuma, the Pacific species with larger, more pronounced vesicles and often wilder color. Yuma tend to be the pricier and slightly fussier of the two. Ricordea want a bit more than the other two — moderate, stable light and clean water — but they’re not difficult, just less bulletproof. They spread more slowly, which is part of why a nice piece holds its value. If you’re going to spend real money on a mushroom, this is the genus to spend it on.

How to keep any mushroom happy

The good news is that all three genera want broadly the same thing, and it’s an easy list to hit: A mushroom that won’t open is almost always telling you one of two things: too much light, or too much flow. Move it lower and to a calmer spot and give it a week. They’re slow to react but very forgiving.

So which mushroom should you buy?

If it’s your first coral, start with a Discosoma — cheap, smooth, bulletproof, and it’ll teach you how corals behave. If you want something bigger and more dramatic that still forgives beginner mistakes, step up to a Rhodactis. And once you’ve got a stable tank and want a piece that holds its value and stops people at the glass, that’s when you buy a Ricordea. All three are mushrooms. Knowing which is which is what makes you a smarter buyer.

The Underwater Gardener grows and hand-collects corals in Key West, Florida (FL Aquaculture Certificate #AQ0254072). Questions about a mushroom for your tank? Reach us at jamie@theunderwatergardener.com or (305) 850-9949, or visit us at 2816 N Roosevelt Blvd Suite 1, Key West, FL 33040.