are britle starfish agresive

My britle starfish is wrapping around my feather dusters... also i got a new firefish and came in this morning and cant find him... this has happened a few times before with other fish the only other fish in the tank are 2 clown fish and the britle starfish... thought they were all comunity fish any help on what is going wrong thanks

I had a large serpent star that would catch fish when they were sleeping.  

Is it a green brittle star or black? The green have been known to eat fish and be aggressive. The black are docile and I've never heard anyone report a problem with them.

Also welcome to the board Nisha!

If he ate your fish his disk should be huge.  It is amazing how big their disk gets after a big meal. Should look like a golf ball.

Ok. Sounds like you could have a couple of problems not related to the starfish. Like i said, they're opportunistic and they can smell something dying off pretty quick.

3 Things come to mind to check. The first thing would be your water parameters. It would be helpful if you post them and a full tank shot to see if we can spot something you might be missing.

The second thing would be your acclimation process. If you are losing fish within the first couple of days then you might not be acclimating them properly.

The last thing would be, where are you getting your fish? Local reefer? Fish store? If you get them from from a fish store it's important to know how long they have had the fish and if the fish is eating. Sometimes they get them in from the supplier who just got them from Hawaii and the poor thing is stressed to the max, then you buy him and he doesn't make it....

I had a red and black brittle star mangle my yasha haze goby, I had to pull it out of its arms.  The goby lived, but died a couple days later from injury.  He was a perfectly good health before, but he chose the wrong hole to call his home.  In my experience they are definitely opportunistic feeders.