Bubble Tip Anemone ????

[Delphinus]

"BTA" aka "Bubble-tip anemone" is just a common name referring to the species "Entacmaea quadricolor." It's just a name and doesn't imply the anemone actually HAS bubble-tips, instead it's more that it's of a species that "can have" them. In reality the actual bubble-tips come and go, more often they go in captivity for reasons not really fully understood (although they can come back for a while if you change lighting or something else.. not really something you can predict accurately, however). Personally I think it has something to do with the ratio of surface-area to volume of a cylinder versus a sphere, and zooxanthellae population density, but that's just a guess. At any rate I can't really see anything in your picture to suggest that it's not an E. quadricolor, so that probably is what it is. Hope this helps!