Any Idea?

Nice ID.

 

I just found a couple of these a few weeks back in my tanks. Never really noticed them until staring at the sandbed of my nano. They come out of the sand and rock nooks and basically fish. They throw their tentacle out there and jerk it in slowly, pulling in water ever attaches to their tentacle. Very interesting to watch.

 

are they ok? ill have to do some reading up on them

 

wow i just rearanged my rocks and i guess i stirred those guys up in my tanks 7 months i have never seen them, sounds kind of cool, so i guess their ok

 

The movement you're describing would be a ctenophore. Those are harmless (actually fun to watch). Digitate hydroids have a powerful sting.

 

Don't the digitates hydroids have a fishing movement too?

Mine look just like the ones melev mentions....
Melevsreef.com - Digitate Hydroid

 

If something irritates them, they will sometimes retract but they don't fish for particulates. Benthic ctenophores do "fish" for particulates.

 

Here's a video with 4 or 5 benthic ctenophores

 

I'll have to check out that vid when I get home....

So is melev incorrect with his description?

"If you watch Digitate hydroids for any length of time, you'll realize this is a thinking creature that is filter feeding similar to Fly-Fishing. The fuzzy end will sway in the current, and the worm will reel it in in short jerks, only to release it again. It is extremely dilicate in nature, and interesting to observe. It can become a problem in some tanks, but it hasn't in either of mine. Reef-safe-ish. " -melev

image from his site....