Please help me identify this thing..

Looks to be a Polychaete. Common bristleworm. First and foremost. DONT TOUCH IT. With or without gloves. It will sting you, and it sucks.

 

Bristle worms are probably the most common, yet misunderstood hitchhikers in the reef tank. One reason for this is that they are scavengers of meaty foods. If something dies in the tank such as a clam or fish for whatever reason, the Bristle worms will move in and start to consume the body. The hobbyist sees the dead animal and the Bristle worms eating it and assumes they are the reason for it’s demise which wasn’t the case at all.


Bristle worms will reproduce readily in the reef tank. They can experience population explosions and become somewhat unsightly, but their numbers are controlled by the amount of left-overs in the tank. If you have a population explosion, it is a pretty sure sign that you are overfeeding the tank and in this regard, they are a pretty good barometer of your feeding regimen.


The last concern with the common Bristle worm is that they have bristles. These are very sharp and can easily pierce the skin much like a miniature porcupine quill. The bigger the worm, the bigger the bristles, the bigger the concern this is. Large ones can also have fairly large jaws which can potentially bite. The main lesson here is to not touch them with your bare hands. If you do get bristles stuck in your skin, you can try using the sticky side of tape to pull them out.


Bottom line for the common Bristle worms typically seen in a tank are that they are excellent scavengers and are good to have in a tank as part of the left-over food clean-up-crew. They are typically less destructive than many of the hermit crabs that are sold in the hobby.


Having said all that, there are larger predatory versions of Bristle worms that can be destructive. These tend to be fairly uncommon in reef tanks, so it is usually safe to assume you have the more harmless variety unless the worms start to grow very large or you catch them in the act of attacking other live animals in the tank.

 

Good response Zach. I consider bristleworms part of the CUC and leave them be (if my wife had her way we'd get rid of as many as possible!). I can also attest to not handling them as I've inadvertently picked up bristles a few times - almost always when moving coral and they were hiding underneath. Here is a picture of one of my "lessons learned" in this respect - and Zach is right - the sticky tape trick works pretty well for getting them out - I prefer duct tape as it seems to be a bit stronger:

 

Ouch!!!!!!!


As Dave said - they hide everywhere, so be especially careful when you pick up a rock, they can easily be on the bottom or crawl out a tiny hole in the bottom of the rock even if you don't see them initially.

 

Hmmm.....There are a couple of techniques that can be used. Removal can be difficult as they tend to be secretive and nocturnal, hiding within the rock work during the day. When they are out and about, they usually have their posterior anchored in a hole into which they can quickly retreat if they perceive any danger.

I am not sure in the sump will work.. maybe fresh water dip for an hour. One strategy is to place a rock with a hollow in it in the bottom of it in the tank in the evening on the sand. A piece of shrimp or similar can be placed into the hollow to act as bait and with the hollow side down so that only worms can get to the bait. The next day, the rock can be removed and the worms will either come out with the rock since they collected in the hollow or they will be on the sand bed under where the rock was where they can be netted out. There are also Bristle worm traps that you can buy, but I am not sure of their effectiveness.

Biological control is another possible option. Coral Banded Shrimp and Arrow Crabs are reputed to eat Bristle worms, though I have not seen this activity in the specimens I have kept. Some fish such as Wrasses may also eat them. In any case, they would probably only eat the smaller worms and not touch larger worms which are the only ones that you might have a reason to be concerned about.

 

Bottom up, Coralline algae is an entrusting micro algae. Things like Penicillus, Halimeda, Haliptilon, Chlorodesmis, Udotea, Botryocladia, and chaeto aremacro algae. Theseplaya part in filtering out nitrates and phosphates. Doping the live rock will cause die off from the whole rock, and I would imagine te wormsare going to be a little more resilient than we think.


With that being said. Bristle worms are a self managing system in a marine aquarium. They will bloom if you are or feeding, and once you get that corrected, they will die off and go away. They Helton stir up the substrate and are awesome detritivorse. Overall they are helpful, just be sure to wear gloves when working in your tank, which you should be anyway.


If you really want to eliminate all of them boiling the live rock will do it for sure but then you will need to start your tanks cycle again.

 

The best way I found is to cut the top off of a 20oz pop bottle right above the label now flip it over and stick it back in where you cut it off now super glue it back together so you'll end up with a funnel into the pop bottle kinda like a minnow trap you will also want to poke a little hole somewhere else in the bottle I do it towards the bottom so air can escape put a brine shrimp cube in the bottle or some sort of food stick it in the bottom of your tank and when the lights go out the worms will crawl in and not be able to get out just simply dig it out in the morning and throw it away but if you have small fish double check it first it might take you a couple nights but I usually have success after the first try and only do it if I have a lot of them