Is this invert okay for my tank?

[Smith's]

Hello I am a new to the salt water world and have had my tank for about 2 weeks. Lots and lots of questions. What an amazing project. I recently found this amazing creature and hope it is safe for my tank.
http://i133.photobucket.com/albums/q61/hsmith5/DSC05854.jpg

[greenbean36191]

It's safe, but probably won't last long. It's a predator of specific sponges, which probably don't grow in any abundance in your tank. Without being able to tell what species of nudibranch it is (which I can't from the pic) I can't really begin to guess what sponge it might feed on.

If you could answer a few questions it would help ID it. First, do you have any idea what part of the world it might have come from? Does the slug have a velvety texture or is it smooth? Do the gill tuft or "antennae" retract if you disturb it?

Another pic might help too. Try getting one of it in a shallow bowl of water looking straight down on it.