Mixed day.  Good news first.  Found out I have at least 3 baby brittle stars crawling around my tank.  Blue colored nudi looks like it has grown about 50%. 

However I found what was left of my lettuce nudibranch in my filter...   He decided to crawl into the overflow tube, and was then sucked through the siphon tube screen and run through the power head.  I found him stuck in one of my bioballs as a green nudibranch looking mass.  Was going to throw it out, but to my amazement it is/was still alive.  We'll see what happens in the next few hours.  If it dies so be it, if not...  dang he's tough!

Nate

My Lettuce Nudi got himself partially pulled into a powerhead screen one day.  When I found him I cut power to it and let the Nudi take care of himself.  I didn't want to hurt him trying to get him out.  A couple hours later most of him was on the side of the tank, but he left a small piece of his backside in the powerhead.  He seemed to be OK after that, but about a week later he was nowhere to be found.  Haven't seen him since.

Hope yours is OK.  Let us know if he makes it.

He was still moving around last night, only about 1/2 long now.  I could still see him this morning, but won't know until after work today if he made it.  We'll see.  I hope so.  I thought he was really cool.

11/20---as of last night what was left of my nudibranch was no longer to be seen.  I figure he crawled off somewhere but won't know until I see him again someday-- or he's just gone.