Identification help needed

[Reefkeeper]

Out of the blue today I noticed what appears to be two identical sea slugs/nudibranches gliding over my live rock today. Up until now I have never seen them even though this is a 1 piece tank. (1 larger piece of LR vs. multiple smaller pieces) I find this interesting because I have been watching my tank carefully to see what if any critters had hitched a ride in on the rock. Up until now it had only been a snail and some white worm. On top of this, when they arent stretched out they are 1.5" in length although when one was stretched out on the glass it appeared to be almost 3"+ inches in length.

At this point I havent put in any corals yet so if it may present a future problem I can eradicate them.

Here is the picture:

http://www.lemonizer.com/upload/uploadsMarch/DSC00042s.jpg


In the picture you can see that the body is translucent greenish body with spots and then it has a ripple pattern with reddish edges on its back.

I tried to find what they were by doing a couple of searches and the closest thing appeared to be a Elysia ornata or Ornate Sap Sucking slug.

Edit: Sorry about the original size, hopefully I fixed it before anyone noticed.

[bgoode]

I agree it looks a lot like Elysia ornata, the lettuce sea slug. Thats pretty cool you got it as a hithchiker.

[Reefkeeper]

I have at least 2 of them which are both a decent size. There also appears to be something moving around in the back of the tank where I cant get close enough to get a good look at it. Thus far I can only make out that it appears to have eye stalks.