Is my star fish dying? or splitting? Infected?

[MassiveCaC]

So I picked up a purple star last week and he was great in my 75gal tank.
fish inside are(yellow tang,clown,naso tang, green cromies, porcupine puffer, snowflake eel)
then he started to give off this brown substance from the tips of his arms... then today he lost both his arms!! but they are still in the tank holding onto a rock..
Do you know whats going on?

1ist pick is when he was discharging brown stuff and white bubble on top
2nd pic is star fish on back glass

 

[B-Willz]

Looks like it is dying. Linkas are very difficult to keep alive.

 

[MassiveCaC]

yea I just took it out of the water, it started to fall off the glass.. to bad that was one pretty star