It is not due to stress or touching, bulbing also has nothing to do with stress or light as stated in another discussion on this fourm. I have raised anemonies for 6 year. Half my 125g is full of them. Somethings they bulb and sometimes they don't. None really knows why or why not, lots of theories, but no proof. The same thing as when they are stringy or fat tenicles. I have 6 RBTA and 1 large GBTA. Some of my observations over the years. First off, even thought thy touch each other in a nem forest, the clowns will only host the GBTA, which was my first. The green is usually flatter and stringier then the reds. Some days the RBTA are very bulb up and other times nothing. The green never bulbs. They rarely get fed. They were kept under 2x250 MH
lighting for years, and about 18 months ago, switched to Maxspect 2x160 with no effect on them. But about 2.5 years ago my T5 HO
that I had on the very back of the tank for supplemental and color went out, so I put in a power compact temporary while I order parts, the RBTA split 4 times in 3 weeks. But once I put the T5 back in, it never split again. But had no issues switching from MH
's. Some are high in the tank, some are low in the tank, seems to make no difference. It also appears that when one of the RBTA bulb, all the RBTA bulb. Mine have never moved in 6 years.