Does anyone know what this is?

[Emi2852]

I just got back from a vacation, and my main display suddenly has thousands of these things on the glass near the sand bed and on rocks. It seems to only be attached to a surface by a little white dot in the centre, the orange part seems to move with the water flow.

My tank has Dragons breath macro algae, sea grape macro algae, Duncan’s, orange ricordia mushrooms, a Kenya tree, purple and green leptoseris, Zoas, and an orange and white unidentified coral.

 

[bushdoc]

Red planaria, generally a foe

 

[Catawba_Valley_Reef]

As stated, red planaria. Generally something you don’t want in your tank.

Some fish will eat them or you could use salifert flatworm exit. Make sure to follow the directions exactly as written if you use it.

 

[bushdoc]

Link to thread about planaria:
https://www.reef2reef.com/threads/red-planaria.1137379/

 

[Tahoe61]

Of note: Red planaria host zooxanthellae which are photosynthetic providing nutrition to the FWs.