SPS's bad worm?

[Myka]

Originally Posted by Aquattro

Looks like mesenterial filaments.

Gold star for proper terminology - even correct spelling!

That one long filament at the bottom is vicious! Mesenterial filaments are used as offensive territorial warfare and have stinging cells in them. They are used to reach over to another coral to maim it. Corals can also release toxins into the aquarium which is referred to as chemical warfare. Since our aquariums are confined, when there is one offensive coral acting up it will often spur others to become aggressive as well. If you see this happening in the future, add a bag of carbon for a day to help absorb some of the chemical warfare that's going on in the tank.