What is this?

[DaScubaSteve]

Found just one in my sump... tried to peel It off the glass it fell to the bottom and kind of curled up like a rolly bug we find under rocks in the yard. Is it a flat worm? I removed it in the end but will be on the look out for more.

 

[X-37B]

Lools like a chiton to me. I have them in my systems and they are harmless.

 

[Uzidaisies]

Hard for me to say without seeing the top

 

[JGT]

Agree on chiton. Looks too oval to be limpet but top view would confirm. Either are good herbivores.

 

[Uzidaisies]

Lools like a chiton to me. I have them in my systems and they are harmless.

think that’s a good bet.

 

[HeyLookItsCaps]

Chiton! Super lucky, I paid 8 bucks each for mine (6) just because they are super weird and unusual and I can’t resist that.

 

[DaScubaSteve]

Thanks that's a relief!

 

[WheatToast]

Lools like a chiton to me. I have them in my systems and they are harmless.

Agree on chiton. Looks too oval to be limpet but top view would confirm. Either are good herbivores.

Second! They are harmless algae grazers.