Please help ID? Octopus?

[rwsunrx]

While looking in my tank at night with a red LED, I noticed a fleshy creature that was moving over the surface of some live rock. This animal was crawling out of a small (1/2") hole in the live rock and somewhat slowly across the surface of the rock. It didn't react much to the red LED light I was using, but as soon as I turned on a bright white LED and used my iPhone to take this photo, it very quickly recoiled into the same small hole in the live rock. Could this be a small octopus that entered my tank as a hitchiker? My tank is 150g with a lot of live rock. But this is the first time I've ever see this critter and I haven't added anything other than some small SPS frags during that last year. So it must have been in my tank for quite some time. In this photo, I've highlighted the animal. It appears to be about 2 or 3 inches by about 1.5 inches. Its skin is about the same color as the coraline algae on my rock work and the skin has some lighter colored spots, maybe like an octopus. BUT I could not see any tenticales. So what do you think?

 

[Slickcg33]

I believe you have a FLATWORM in your tank, more specifically Pericelis sp.

I believe they are predators of snails and clams, you should remove it immediately if possible. A google search of the name will give you more information

https://www.google.com/search?q=Per...CZK08AT5r4Bw&ved=0CAoQ_AUoAA&biw=1920&bih=948

http://seaslugs.free.fr/flatworm/planaire/pericelis_sp2_a.htm

 

[rwsunrx]

YES! I think you're right. After looking at google photos as you suggested, I think that's what I have. Now for the hard part - getting rid of it. I have a 150g tank with lots of rock work and I've only seen this once in the last 1.5 yrs since I added any rock or significant corals. But I'll try to catch it with a trap.

Thanks Slickcg33!