What kind of Coral?

I received this free with a G.A.R.F order, well maybe it was one I paid for...they gave me 23 corals for 100 + shipping.

Description:

It can go almost straight up and sometimes it hangs so limp it is folded over the reef plug. It is about 4" long by 1/2" wide. I do not know what it eats but I am feeding the tank flake, mysis, cyclop eeze, and marine snow so it is living. It has been in the tank over a month. I will think it is responding to light or dark and then it will do just the opposite one day/night so I do not know that. What have I got on my hands?

Pics:

The tank -



The thing -

 

Maybe a sponge...

 

looks like a sinerlia sorry the spelling I know has to be off. or a leather of some sort.

 

its a sponge

 

I have several sponges in the tank and I have never seen them expand - contract, stand up - go limp.
Perhaps a specific sponge?
I have red ridge, orange fan, and the regulars, orange encrusting, ect...

What is "sinerlia" I googled and I didn't get a word choice, spell check thing.

I will try to capture more images of it in its various states.

 

I would think it was a form of leather. Looks like it has the same texture as a kenya or colt. Could just be a stalk of some softie. I have a feeling you will be able to tell after a month or 2 exactly what it is. I have had colt frags with just one stalk going up and it has looked similar. keep us posted.