Planairia flatworm. These flatworms can quickly multiply in number and can be dangerous to other members of your reef aquarium especially coral which it will feed on tissue and smother coral from light.. To make things more confusing, some types of planaria can change color according to what they eat. Unlike other flat worms, planaria have a distinct triangular-shaped head as in your picture. What you want to look for is the cross-eyes. Yep, this shovel-faced pest is also cross-eyed. Well, at least it looks that way. At the tip of the head are what look like two eye balls with pupils facing each other – you can see this in your picture!
planaria reproduce fast. And, all it takes is a single flatworm. You see, planaria can reproduce asexually, meaning that one worm can soon become hundreds.
Black and brown planaria flatworms like yours feast on waste, Biofilm, uneaten fish food and even poop which are tasty meals to planaria. Now that you found this planaria, it may be a sign that you are not maintaining a clean tank. Regular to frequent cleanings will starve them.
Siphoning them up is the best method for removal. Another is addition of 6 lined wrasse or lunare wrasse.
An alternate would be to ue salifert flatworm exit. Flatworm Exit is harmless to all reef organisms, but extreme care must be taken when using this product because of the flatworm’s toxic body juice or in better terms- toxins so again siphon as many as you can see.
After using flatworm exit- Run carbon to detoxify tank.
