What kind of coral is this?

Its got thorns all around the top of it and when the coral opens up it goes over the thorny areas

 

A brain coral. I have one of those. If I put oyster feast in the tank, it opens to feed. They have small, subtle tenticles. Very cool to watch.

 

Any idea on how these grow cause it seems to be just confined to its place but there is what look like a tumor on the side of it. The bottom part is about 4 inches in length all around.

 

It is definitely a brain coral. Looks to be a red open brain to me, one that has not been kept in the best conditions for a while.

Nurse it back to health and it will be big an beautiful again

 

I bought it out of the live rock tank at my lfs for a few bucks cause of its weight. They must of thought it was some weird rock or something, its definitely looking better then it once was but just slowly gettin better. I have had it about 8 months already. I'll try to take some more pictures of it if I can.

 

Uggh.... brain coral is used for like 20 genus of corals, not a wise one to suggest

It's most likely a Lobophyllia sp.

 

And they can potentially get very large. It takes years though. So nurse it and you will be happy. Mine has stayed the same size under PCs for months. When I upgraded to T5s, it started looking healthier, so growth should commence. And I agree, it is a Lobo brain.

 

Thanks Gresham, K+

 

Hard to say what kind it is yet, hence my generic brain coral term. It was pretty obvious the OP had no idea what kind of coral it was, so I narrowed it down quite a bit for him.

 

It's a Lobo, 99% sure on that on

It's not that narrow of an ID though if you consider how many corals are labeled "brain coral". If you help the posters by giving a true species, genus, etc, they'll be educated and most likely won't resort to using those ancient inaccurate common names. On export lists they love to call nearly 1/4 of their corals some sort of "Brain" or "gem stone". Heck, they even call porites a brain coral *and* a gem stone.

FWIW an easy ID website is Coral Identification and information at Coralidea.com and it's downloadable to your smartphone, iphone, Ipod, etc