Silver Monos Not Eating

[Nelson]

I have two large silver monos (brackish) that I bought four days ago and they're extremely skittish and I haven't seem them eat since I put them in their tank.  Water parameters are the same as the tank they came from (BA-east).  They were trade-ins so I suspect there may be some stress involved.  Tried bloodworms, brine shrimp, marine flakes and beefheart.  Any ideas what the problem may be?