Hi! Since spotting this alien-looking thingie, it's been haunting me. So if you can help me identify it, I would be most grateful I saw it on a night dive off the coast of Sabang, Puerto Galera, Philippines in december 2011. It's huge, i couldn't even fit it in the picture. At least a meter long and 30 cm in diameter. Colours are pretty well represented in the photo of the front end (or back end?).
NFRDI | National Fisheries Research and Development Institute As you state that it was about a meter long...it rules out being a commercial type of Cucumber. It appears to be a very, very old prickly cucumber of the pine apple variety. When looking at it's mouth raised up..he looks like an old Grandpa Prickly. I submit his pricklies are not as pronounced as the years that small fish nibbled away on them. IMHO (no puns now)