Common Name: Vermetid Snail, Tube Worm
Scientific Name: Vermetid
This creature exists in most aquariums and was encountered by every aquarist at some point or another. They are relatively diverse with over a hundred known species. Vermetids live in a hard tube like structure with brown-red-purple coloration that grows away from rocks and other hard surfaces. They vary in size but the ones seen in the aquarium are mostly small up to a centimeter in size. These tubes release a slimy web like substance into the aquarium while thy feed, this can be seen in its full effect during aquarium feeding. A few of these creatures will not hurt the aquarium but one must keep an eye on them as if they are left untouched they can grow uncontrollably and harm the coral in the tank with the slimy web they release when feeding, this web is known to irritate and even kill some coral. If you decide to leave it be make sure to keep an eye on it and occasionally kill them to block their growth.
these animal are quite small making their discovery and treatment quite difficult. It in important to remember that a small amount of these will not harm the aquarium as long as they are not left to breed uncontrollably. To mitigate this problem one can break the tubes off carefully, or plug their holes with a small amount Superglue (the gel kind) or other aquarium safe glue.
Some fish and animals in the aquarium hobby are known to prey on this animals. these include Copperband butterfly fishes, some hermit crabs (usually the bigger ones)
Besides the two options above, one more common solution is to remove the rock they are nesting on from the aquarium and treating it separately in a quarantine tank. Some take the drastic approach of boiling the rock or getting rid of it completely.
Common Opinion: USE WITH CAUTION