Bristleworms are numerous in size shape and color, some so beautiful it’s ashamed they can be dangerous to our reef tanks. Most of the time these worms are inadvertently added to via live rock, or coral colonies themselves. Because there are prone to nocturnal predication we often don’t notice them unless they have created some damage. The worms vary in length some reaching over a foot, and others smaller than one inch but regardless of the size some can cause serious damage.
These worms have been documented to consume flesh in both stony and soft coral by means of burrowing into the specimens, and in other cases consuming the tissue itself. Some have preyed on snails and clams by boring into the shell and feeding. Small Fish can even become victim to bristleworms in the evenings but this threat is not likely. The worms that occupy the substrate are actually beneficial, the larger ones like this Fireworm that live amongst the rocks may be a less welcome visitor to the tank.
An ounce of prevention in this and many cases can save you many nights of rest. By quarantining colonies, specimens, and live rock upon arrival you will have a better chance of catching the larger worms. In the first week of your isolation period don’t put any food in the quarantine tank. Without feeding, the worm will become hungry and interrupt it’s natural feeding cycle. The animal becomes more aggressive when it senses food and will take risks. These worms enjoy the safe heaven of rock, and very seldom expose their full body if it’s not necessary.
When you make your first feeding, be careful to position the food far from retreat. Once the worm takes the bait you will have a good opportunity to go for the catch. If your not quick with a net and elect to use your hands make sure you wear gloves, these guy pack a powerful stingers. Like most segmented worms the Polychaeta’s and others have regenerative ability, so merely dicing the worm or breaking half away will not suite your purpose. The worm will simply grow back to it’s normal size in a short time.
Some say introducing a predator is a safe means as well. While this may be true for smaller worms it will most likely present problems for larger ones. The predator fish will not be picky about getting the entire worm and will likely take bites when ever presented the opportunity, you may even end up with two. When all else fails or you have not the luxury of a quarantine system you can result to a commercial or DIY trap. Most traps are concocted from a small tube with one or two removable ends, in which you open to place the bait. Place the trap in the aquarium right before lights out, and after a few days of not feeding the tank typically the worm enters and you can simply take it out of the aquarium.
One last method that has worked well for me it to remove the rock from the aquarium and place it on the floor, most works I have found exit the rock looking for water. This can be done with some coral colonies but not all, so read up before you attempt this method.