Just found this on my palys

[richiet]

It's about a quater of an inch long and frills coming off of its sides are bright red under blue leds. Any ideas

 

[richiet]

I guess I found out what it was

This guy in the first pic
http://aquamarinediscovery.blogspot.com/2008/09/sea-slugs-part-2.html

Should I toss it or keep it?

 

[ColaAddict]

If it's the same color as your paly, that means it's a nudibranch that only eats your paly's.

 

[richiet]

Well the paly was green and this thing is bright red. Could it be off it's diet?

 

[BlakeT]

I'd say better safe than sorry. I would flush it and dip the coral it came off of. Cool looking little guy, but they are usually harmful.