ok, I'm thinking that this is a nudibranch but not for sure

[DEADFISH1]

I have 2 of these, I acquired them at 2 separate times, they were on the Fiji I bought from the LFS, their jet black with 2 short antennas, they have a slit down their backs that is bright white and it,(the slit) opens up wider when they bend over rocks, they have a wavy skirt around them, and when their on the glass you can see that their mouths look just like a snails mouths, they kind of look likes skunks, they don't seem to harm anything, any ideas?

 

[Anonymous]

Nope, it's not a Nudibranch, you have a Scutus. sp ( a Sea Slug ) which feed on algae, diatoms and some sponges.
Here's a pic of one:

Regards,
David Mohr

 

[DEADFISH1]

hey, that's it, cool thanks, I have some sponges, but I havent noticed any harm too them so far.

 

[DEADFISH1]

I used the name you provided and found this link, some more info.

http://www.seaslugforum.net/scutus.htm