uhh-- just noticed him like last week-- he moves around like a nudibranch or something - but I haven't seen him on the glass or anything-- so far just on the rock-- he was on a xenia rock (the type of xenia's that are tiny and feather-like) yesterday and freaked me out-- I don't know if he ate anything or not-- he looks like some sort of slug with antennae like things on his head and a cream/white/tan line on his back-- he's not so small-- maybe the size of the tip of my finger . . . he's up and about during the day-- uhh-- I haven't bought anything in like three months so it's kind of wierd . . .
his speed is about that of a nudibranch . . . I just went to look at him and he just came out from inside of a crevice and it looks like the white line can disappear-- from the first time I sent this message he was in the back of the tank-- he had a white line-- now he is in the front of the tank and his line has appeared to disappear-- some sort of camouflage mechanism-
no shell then I would go with a type of nudibranch. if you have corals I would keep and eye on them and make sure they are not getting munched. now if it has a type of shell I would of guessed almost an egg cowrie and they prey on corals. either way I would keep an eye on him you never know. the closest nudi that matches yours is a blue stripe and they are great at eating flatworms. but I would keep a very close eye on your corals and softies in the tank.
I don't know-- maybe that black cover is some sort of shell-- the antennae appear to come out from under it-- if so-- it's unlike any shell that I have ever seen-- if the covering is shell like it's pretty flat-- I don't really know-- I would touch it but I'm scared-- hahaha (recently battled a mantis shrimp)
if it has a type of shell then I would go with egg cowrie and then I would get him out of the tank they are veracious predators on corals. if your not sure I would take him out and if you have a sump put him in there. have you noticed any bad signs on corals and softies????/ If so I would yank him