Thought I'd drop in and shed some light on these
Discosoma sanctithomae. They aren't in fact ricordea, but a species of Discosoma, that come from the Caribbean. We collect many of them in the Florida Keys for our company
Coral Morphologic. They are excellent corallimorphs for all aquarists, and very hardy. They are not very aggressive, and show stress very easily. They appear very delicate because as was previously mentioned their tissue is practically see through, and they will puke out their guts (mesenterial filaments) at the slightest disturbance. When we ship them, people often think that they are going to die because of all the guts that they spew out in the bag. However, as soon as the stress is removed and they are settled into their new home, they will pull all their guts right back in again and recover in no time. They are very hardy animals.
We have a few of these mushrooms that are over 7" in diameter, almost as big as dinner plates. They are truly magnificent. They come in a wide variety of colors from yellow-green, neon green, aqua, blue, purple, brown-red, cream, and very rarely fluorescent red (sometimes with fluoro green undertone). The vesicles (warts) on the surface of the polyp can range from perfectly spherical to very branched and warty. There can also be a range of white variegated spots throughout the colored disc. Because of their "delicate" tissue, you can almost see right through them which provides a nice contrast to other more "saturated" coral tissues in the tank. Lots of morphological variation worthy of collecting.
They can handle low to high light. We are growing ours in a 4'x4' vat under a single 400 w metal halide that is raised about 30 inches above the water surface. However, you can easily keep them under much lower lighting. The colors tend to "pop" much more under bright light though.
They also don't need too much water flow. A gentle current just enough to cause the polyp to "sway in the breeze" is best.
I would keep them from overlapping any other corals, or in a place where they might get stung by sweeper tentacles. The aggression isn't always immediate, but when placed next to
Ricordea florida, they will both sting each other and cause stress over time.
Ricordea yuma seems to be more potent than
D. sanctithomae from our experience.
They seem to not be bothered (or bother) by other
Discosoma sp. corallimorphs.
For the most part they reproduce by asexual cloning through pedal laceration (They send a piece of tissue off the "foot" that forms a new polyp). I have seen them divide in half like a
Ricordea florida, but I think that this is pretty uncommon. They reproduce much slower than Indo-Pacific Discosoma, but once settled into the tank, will spit off new baby clones every couple of months at least.
Hope that this helps. We are getting ready to feature a wide variety of sanctithomae as WYSIWYG polyps on
Coral Morphologic this coming week. I'll also post some pics of our collection here so you can see the variety of morphs.
Cheers,
Colin
Coral Morphologic