Some kind of flat worm?

[MaxM]

It's on the glass. You are seeing the bottom side. The top side doesn't look any different. It's about a quarter inch or smaller and I have only seen the one. It seems to hang out in that area of the tank. It moves fairly fast and hides when the lights come on.

 

[Screwgunner]

That is a snail

 

[MaxM]

That is a snail

What kind? It's topside is also flat. Is it's shell internal?

 

[Screwgunner]

Look again it should have a small shell in the middle on top .

 

[Screwgunner]

 

[Screwgunner]

This one has a shell

 

[Screwgunner]

Stomatella snail it is a hitchhiker.

 

[Screwgunner]

I have 100s of them

 

[Screwgunner]

Flatworms are small look them up.

 

[Screwgunner]

There is a flatworm like that it has brown lines running though it body .

 

[srobertb]

Almost every tank I can think of had a “bloom” of flatworms at one point or another. They rise up then disappear unceremoniously.

but this looks like a stomatella.

 

[Screwgunner]

Red flatworms killed everything in my tank except my clown fish.

 

[BAMatter]

It's on the glass. You are seeing the bottom side. The top side doesn't look any different. It's about a quarter inch or smaller and I have only seen the one. It seems to hang out in that area of the tank. It moves fairly fast and hides when the lights come on.

If no shell, look up euphyllia eating flatworms. Had a couple look like that fall off a torch coral that I dipped after I bought it.

 

[BAMatter]

Red flatworms killed everything in my tank except my clown fish.

How? I’ve had red planaria in every one of my tanks at one point or another and they are harmless. My sump has them currently and my display is kept under control, guessing by my wrasse.

 

[Screwgunner]

I was a beginner did not have internet back then and no wrasses in my tank they covered everything live rock and sand . When I put the flatworm exit in they all released there poison and killed everything in my tank except my clowns. If I had known wrasses eat them I would have been ok.

 

[IKD]

What kind? It's topside is also flat. Is it's shell internal?

Can you get a picture of the top? Could be a stomatella snail but not seeing any antennae from this angle

 

[BAMatter]

I was a beginner did not have internet back then and no wrasses in my tank they covered everything live rock and sand . When I put the flatworm exit in they all released there poison and killed everything in my tank except my clowns. If I had known wrasses eat them I would have been ok.

Dang yea that one hurts.

 

[MaxM]

There is a flatworm like that it has brown lines running though it body .

No lines

 

[MaxM]

Flatworms are small look them up.

I was thinking maybe ghost flatworm, but it doesn't have the twin tails

 

[MaxM]

Stomatella snail it is a hitchhiker.

I'm not seeing antenna or any slime tail trapped grains of sand I see on my other small snails. Zero color and the topside looks like the bottom when I look through the sidewall of the tank.