Help! Euphyllia sweeper tentacles or pest?

Hulzare · Jul 1, 2025

Apologies for the poor resolution. I added this hammer to my tank last week and I noticed these long, very thin tentacles coming from the base of the skeleton.

This is my first Euphyllia. I initially though they were the famed ‘sweeper tentacles’, but not I’m starting to wonder if they are a pest or detritus worm.

Please could someone help me ID?

This is my first R2R post so I apologise if this ends up in the wrong area.

Saltyreef24 · Jul 1, 2025

definitely not sweeper tentacles. Not sure what it IS though. maybe some hind of algae? is your hammer just stuck into the sandbed? if so, pick it up closer to the glass and turn it around under white light to get a clearer photo. there are lots of insightful reef experts on here who could probably help you identify that with a clearer picture

Bigfishy1 · Jul 1, 2025

I can’t tell from the picture what it is. But that is not a sweeper

Hulzare · Jul 1, 2025

Saltyreef24 said:
definitely not sweeper tentacles. Not sure what it IS though. maybe some hind of algae? is your hammer just stuck into the sandbed? if so, pick it up closer to the glass and turn it around under white light to get a clearer photo. there are lots of insightful reef experts on here who could probably help you identify that with a clearer picture

Here’s a slightly better photo, haven’t tried picking it up yet as didn’t want to disturb if this might provide an ID. Usually opens up big, just closed as lights are off.