Hitchhiker sea slug

[tizzite]

I found this guy crawling in my tank, he's about 1/4 inch long. This isn't my picture but it looks just like the one in my tank, I want to say it's a nudibranch but I'm not sure.

 

A few of my corals (torch, zoas and birdsnest) died recently, but I'm not sure why. I don't think it was predation because my zoas don't look great either- most of them are in hiding. I'm doing gradual water changes. My xenia, ricordea mushrooms and gsp are looking fine.

 

Is this thing reef safe?

[Christopher Marks]

It's hard to know for sure, it might have an appetite for only some things. It may be best to contain it until you decide whether it should be removed permanently.