Good or bad nudibranch???

[cpreefguy]

I found this little guy surfing the current in my tank. Im not sure if he is good or bad so if someone can help out with an ID Id appreciate it. Lil dude is exiled in a red cup til then.

[cpreefguy]

[cpreefguy]

Perhaps?
http://www.seaslugforum.net/display.cfm?id=4822

[Instar]

Most Elysia sp. are quite small and the ones I've seen hitch hike in on sponges are green to gold and eat only algae.
What color is it? (Hard to tell from your purple pictures.) Color and close observation will help ID what it eats as
well as the species. What did it come on? If it came with zoo rocks or a gorgonian, don't let it in your tank if you
have zoos or gorgonians and watch for hatchlings.

[cpreefguy]

The purple is from the red cup's outside... but it is kind of greenish brown with two eyespots on its head, and an orange lining on its back

[Instar]

What did you get it with or on? Normally their color is a simple concentrate from the food they eat and many Elysia are mostly algae eaters.
Make a cool nano for him and put some things in there and see if he leaves them alone. He many hide in something but you have to really watch
with a lense to see if it eats the algae from the surface or more. I've had them from time to time and unless its bothering the macro in my refugium
I let this genus stay in the main tank. To be safe, if you choose that too, be sure you verify it does eat algae first unless its easy for you to get it
back out.

[cpreefguy]

Im not sure what it came in on, It could have come in on some colonies oz zooanthids, or on some of the ~60lbs of
LR I just put in it

[Instar]

There are many zoo hitch hikers that are not good. If its the same or similar color of the zoos, keep it in a nano and see if it will eat
a zoo polyp that is colored similar to it. Its hard to tell from the pictures but it looks like it has a double spiked tail and
those kind eat zoos and if thats the case, there are so many nudibranch species to go through its hard to tell what family and
genus its in without going through a lot of research.

[cpreefguy]

i looked through the sea slug forum for about an hour. Im not one to chance it for a little nudi.
Unless anyone wants him...