Discosoma sp. (Mushroom Polyps)

The ultimate starter coral might have to be the humble Mushroom Polyp. It is nigh indestructible and should be proof to any newbie that corals are not inherently difficult to keep. Whereas most of us have killed one or two (or many) houseplants, there has literally never been a Discosoma that has died, ever.

That may be an exaggeration, but only slightly so.

This heartiness likely stems from the ecological versatility of Discosoma. Specimens can be found in all your favorite coral reef environments, usually tucked into the shaded nooks and crannies surrounding other corals, but youll also find it in heavily silted habitats, such as intertidal sand flats or deeper muck sites like the Lembeh Straits. About the only parameter that they dont seem to cope well with is excessive amounts of flow.

Discosoma neglecta

Rather, Mushroom Polyps seem particularly well-suited to stagnant condition and may even benefit from any sediment that settles onto their oral disc. They are equally unconcerned with lighting and have been known to survive quite well in the most barebones of systems. In fact, they often seem to do best in neglected, underfiltered, underlit tanks.

Feeding Discosoma is widely presumed to be unnecessary. Unlike with the greedy Rhodactis species, the smooth-bodied Discosoma dont show much effort when food (pellets, shrimp, etc) touches them. Perhaps these are adapted for a finer diet of bacterial flocculents or perhaps they simply get all they need from their zooxanthellae. Essentially nothing is known about the metabolic needs in these corals.

Discosoma sanctithomae

Equally unknown is the true nature of their biodiversity. Eleven species are presently recorded as being valid (and Platyzoanthus mussoides is essentially a weird, colonial twelfth), but nobody has actually done the necessary research to confirm the TRUE number out there. The Atlantic species (carlgreni, neglecta) seem distinct, but those in the Indo-Pacific are far more uncertain. A recent genetic study (Nilkerd et al. 2014) found that all of their Indo-Pacific Discosoma specimens represented a single variable species. This means that all the common morphs (Reds, Blues, Greens, Pinwheels, the Ricordea-likes ones, Jawbreakers) may be essentially the same coral.

This also means that it is safe to combine these different morphs together side by side; however, this does not hold true for other corallimorphs, like Rhodactis, which have a surprisingly strong sting in their marginal tentacles. Place a Rhodactis in contact with a Discosoma, and the Discosoma will not be pleased by the situation.