brain confusion

yes, my brain (in my head) is confused about the one in my tank.. when i first bought him, i was told he was an open brain coral.. the second day i had him he swelled up to enourmous proportions (pic 2) since then ive only seen him swell to about where he was in the first pic.. Ive done a lot of research and looking on the net and ive never seen an open brain swollen to even a fraction of what he currently does, let alone what he did the first day.. is he possibly something else? i mean most of the open brains ive seen look rather "hard".. this guys is really fleshy and when i target feed him, little mouths open up all over the place and feed.. by the way, i originally had him on this rock but now have him in the sand, was trying to keep my diamond goby from sanding him over.. thanks..

 

I'm not really sure that it is an open brain. Can you take a picture of the bottom of the coral (its skeletal base). Regardless of what it is, the coral looks fine to me in both pictures and the fact that it's reacting to and eating food tells me that it's healthy

 

yeah not sure myself.. i dont want to turn him on his side cuz he gets upset and emits a lot of slime strings.. but from what i saw when he initially turned over was kinda like a plate corals underbelly.. kinda fleshy but a skeleton there for sure.. he target feeds mysis like a champion, and will take silversides.. strange.. i really dunno?

 

My guess is that it is a Trachyphyllia brain. A cone shaped base is pretty much a dead give away as it develops this to bury its base in the sandy substrate.
Their are different reasons for the brain to become filled with water and thus increase its size. They also have tentacles just on the outside of its oral disk, mainly for feeding purposes.
Better to keep it in sand though accumulation of sand and detritus on it isn't good.

 

wow, good lookin out, im pretty sure thats what he is.. and yeah i think hes in a good spot, if i ever notice any sand on him, i turkey baster it off with the quickness.. thanks for the help Creefer, i was a bit confused there...

p.s. yay, celabration, i have moved up to an astrea snail!! gotta go eat some algae!!