Name that Hitch Hiker! *Updated*

Maybe a Feather Duster? The Images I have seen online are more white?

Edited by Ackbar - May 27 2012 at 12:57pm

looks like a feather duster to me as well. I have a variety of colors in my tank. Mainly shades of white, a couple yellow, and I once had a small cluster of hot pink, red and black striped ones! pretty cool!

Yes it is, I have a lot of them in my rocks. I think they are pretty neat:)

Looks like I have another extra on the Scene. I dont think this one is a "good guy" thought...

I'm also not sure what we are looking at in that pic, but did you know that 99.9% of the 1000's of species living in our tanks are beneficial? We know how to deal with the major few that are a problem.
Here is the list we watch out for along with the easy/not so easy solutions:

Ich Parasite - properly prepare tank for each new fish, acclimate and use a Garlic Oil that works per instructions in Reefkeeping Tips below; quarantine and treat everything for 2 months
Aiptasia Anemone - Peppermint shrimp; Butterflyfish; chemical spot treatment
Majano Anemone - avoid at all costs; don't buy any rock with them; Butterflyfish; chemical spot treatment
Hair and/or Bubble Algae - avoid by keeping sufficient snails and herbivorous fish; control after infestation via instructions in the Reefkeeping Tips
Rock Crab - baited jar catches them easily; Triggerfish
Flatworm - inspect source tank to avoid; freshwater dip or medicated dip of all LR/base of new coral; Wrasse; Mandarin; chemical eradication with Lavamisole or Flatworm Exit per instructions in the WMAS Reefkeeping Tips
Bryopsis Algae - avoid by keeping sufficient snails and herbivorous fish; control after infestation via elevated Mg levels or removing rock and treating with Hydrogen Peroxide
Zoanthid Nudibranch - Medicated dip; Wrasse
SPS Red Bug - avoid by dipping all new SPS in a medicated solution; chemical eradication with the veterinary medication Interceptor

I tried to place them in order of their severity and/or the frequency that we hear about them here.
The likelihood is rare that you will stumble upon anything outside of this list.

I recently learned of another organism that lives in the sand. Supposedly it has a large population in the ocean so I imagine it's in our tanks as well. It's an almost microscopic crustacean. I'm adding this to my long list of beneficial bugs and worms that live in LS as the major biofiltration.

I agree.
Isopod was actually my first thought, but not all are harmful to fish or even survive in our tanks.
Personally I'd just be fascinated with it and watch it closely to see if it looks like it's going to cause harm.
I tend to leave more things to live in my tanks than some hobbyists.

Thanks! Ill keep an eye on him, hopefully it will just end up being a snack for something else in the tank.