I have an anenome like the one you are describing...I bought it as a long tentacle, and then it kind of changed forms...its top turned white and the base turned orange...It is a host to my maroon clown, and I've had the anenome well over a year and a half. It eats scraps that I and the maroon feed it. I don't think my tank is the best, but it is not the worst. 125 Gallon, Xenia Elongata's love it, 30 gallon refugium, protein skimmer, 300 gallon fluidized bed, salinity 1.025, pH 8.3, alk >3.2 mEq, Ca 400 ppm, nitrates <10 ppm. The tank is light by only (2) 96 watt 50/50 PC's, but this thing changed while in my nano-reef (like 2 inches under a 10K PC), and it has made no movement towards my lights, and the tank gets a pretty good blast of natural sunlight every day. I am trying to get a digital camera soon.....better luck then.