Good or bad nudibranch?

[Rutrag]

I think this little yellow guy is a nudibranch. When he's stretched out, he's maybe 3/4" in long, has two antennae like apendages on the ehad end, and two parallel rows of ruffles down his back close to either edge. I found him on some live rock in the tank about a week ago and have had him in a specimen container and he's still alive despite no circulation. I'd like to put him back if he's of the okay sort.

 

[Sniperhank]

Def a nudibranch. I kept the one in my sump for months before it just vanished. I never fed it as it was munching on my blue symphodium so i know what happened to him. Though there are afew reef safe ones, i see nudibranches as fowlr inverts as you can never be sure. Only ones ive ever seen as listed as reef safe were green amd yellow. Id keep yours out of a reef system.

 

[Deep Seven]

If I was you I would google image yellow nudibranch and try and identify the species. Once identified you can try and research it's food and toxic potential. Nudibranchs will often release toxins when dead and usually only eat one type of food and they starve to death after several weeks if they can't find it.

If you think you can feed it and remove it quickly when it dies I'd say go for it. I've never kept a saltwater tank but I've read up on nudibranchs a fair bit and get to observe several different species in the wild as part of my job.