An underwater rose....the egg mass of a Redmargin spanish dancer (Hexabranchus pulchellus)

This is a Gold lace nudibranch (Haigerda terramtuentis), one of the prettiest dorids you'll ever see. This amazing translucent nudibranch is only found in Hawaiian waters.

Another look at H. terramtuentis...you can see in this photo that the gill tuft can be retracted for safety.