Any idea on this

[yagerboy]

Was on glass when lights came on.  About 1/2 inch maybe a little more with 1+ inch antennae.

[ranger]

20 years ago out of the blue all my acros would not grow at all.......they didnt rtn/stn just no growth.

Took a flashlight at night and saw a ton of little clear what i belive to have been sea spyders.

After sucking them out over a month everything went back to normal.

Long of it i would look at night at any lps/sps and see if these thing are on them otherwise there are

 most likely hundreds of creatures rooking at night we never sea.

Always seems like a good idea to have some type of wrasse that eats pest if you dont already.

[yagerboy]

Thanks!  I have 3 wrasses.  Sixline, Melenarus and Coris so hope they do their job

[Squishie89]

My best guess is a spaghetti worm

[lowlizard]

you can try this site.

 https://chucksaddiction.thefishestate.net/hitchworms.html

[yagerboy]

Thanks

[DaJMasta]

Hard to tell from the pic but the sort of feathery look suggest some kind of polychaete worm, not sure if I know any with antennae like that, though.  I had sort of suspected vermetid snail out of its shel, but it turns out those are really snails and not worms, so their body doesn't look like that.  Wouldn't be surprised if it was a tube/hole dwelling worm and the antennae are its feeder appendages.

[yagerboy]

Thanks

[DFR]

That looks like a spionid worm (has the trademark “antenna”/palpi).  It’ll eventually settle in a lower flow area on the sand and build a tube around itself using the grains of sand.  The wrasses I’ve kept never seemed interested in them, but YMMV.  They don’t multiply quickly nor bother corals, so I wouldn’t worry too much about them.

[yagerboy]

Thanks.  That makes a lot of sense