Mermaid's Cup, (Acetabularia crenulata), is a popular algae with a parasol like "leaf" that arises from a slender stalk. We get aquacultured specimens, that are attached to a small piece of liverock. It does well in full spectrum lighting, 2-4 watts per gallon, but can tolerate brighter lighting. It is the quintessential tropical aquarium macro algae, but we seem to be the only people who sell it.
Simply place the rock into the tank, and you are done. With this item you will receive about 5 plants of this algae. Multiple orders may be combined on a single rock. If you would like multiple shells for a multiple item order, please let us know, and we will try to accommodate you. This macro is a somewhat delicate shipper, and should be sent via Express Mail. The caps of the algae will likely be white from shipping stress. Nothing to fear. Each sprout of Acetabularia crenulata is actually one cell, (one of the largest cells in nature), the part that matters is the part attach to the shell itself, and while that part is microscopic, if only it survives, the entire plant will do just fine. (The caps don't even matter really). Just give it some time and TLC and it will bounce back. The real indicator of its health when it arrives is whether the caps are buoyant when placed in the water.