Care
The Elephant Ear Coral is a formidable predator which mimics anemones, in particular attracting and then consuming clownfish. These deadly cnidarians are a giant among mushroom-type corals and possess prominent bead-like verrucae spaced sparsely across the surface of the expansive oral disc. Although it is possible that more species exist in this genus, A. fenestrafer is by far the most common import, and currently the only described species. The name Amplexidiscus means 'enfolding plate' in allusion to the way this coral can quickly close and envelop prey; indeed this fearsome mechanism is complete in under 3 seconds. Fenestrafer is Latin for 'windowbearer' and refers to the smooth, translucent border that is free of verrucae, near the edges of the coral. It is this bare margin that differentiates Amplexidiscus from the similar genera Discosoma and Rhodactis. In the wild, Elephant Ear Corals are found in relatively shallow waters in sub-tidal coral reef lagoons that may be anywhere from quiet to turbid. Here they are found growing solitary or in clusters on dead corals and rocks in a vertical formation. As an aquarium animal, Elephant Ears are somewhat specialist and are really only suitable for very specific set ups, where no small-medium-sized fish, shrimps or crabs are present. Some aquarists like to maintain them in a coral-only tank because they wish to observe these fascinating cnidarians, yet are not inclined to take the risk of endangering any fish or other livestock. Having said this, most fish do tend to stay well clear of Elephant Ears, but it can be difficult for some (such as clownfish) to differentiate them from a welcoming host anemone, or, when the Elephant Ear is in a rolled-up position, a snug cave. As soon as prey lingers on the surface of the oral disc, it triggers an instant feeding response, the coral quickly closing up in a ballooning draw-string purse formation, from which there is no escape from the opening mouth. The 'purse' then contracts, and the prey item is ingested. For most, understandably, these corals are simply not worth the risk. Elephant Ear Corals are normally beige, brown, green-grey, or ivory, and whilst they are not particularly flashy, they are very distinctive. Although carnivorous, these hardy corals are primarily zooxanthellate and derive a lot of their dietary needs from nutrient-rich surroundings, but do provide supplemental feeding every few weeks (see feeding section, below). Provide moderate light intensity and gentle water movement - ideal placement is just above the substrate. Interestingly, it is estimated that a single mature Elephant Ear Coral can enclose up to 4 litres of water upon drawing up and together whilst feeding. May also be seen on sale as Giant Cup Mushroom or Elephant Ear Anemone, although the latter is somewhat of a misnomer as they are not true anemones. In fact, they are not true corals either, but further studies are needed to determine exactly what they are. It is quite likely that they will end up in a different genus entirely.
Feeding
Zooxanthellate, but benefits from supplemental feeding with small pieces of fish/clam/crab/shrimp once every few weeks, preferably just before the lights dim. This should be placed on or near the central mouth area with tongs, and this will usually trigger the feeding response mechanism. If for some reason, the food is not consumed, remove the item carefully and try again a few days later. If the coral refuses food continually, it may be unhappy in its current position and would benefit from being moved to an area with different light intensity and water movement.
Propagation
Most commonly reproduces via asexual cloning (longitudinal fission).
