I believe that is a very beautiful specimen of Platygyra.
They tolerate a really wide range of lighting so if it is growing you are good on the sand bed (i think they prefer lower lighting but they can adjust to intense lighting). Just give it room to grow, they throw massive sweepers.
Yes it does have these long things at night come out with like a round tip on the end. Its sitting about 8 inches from the bottom on a rock so i guess ill leave it there tanks is only 20 inches tall..Thanks for all yalls help ,This is by far the best forum out there cause so many people like yall reply..