What's this white anemone-looking thing in my tank?

[Thermal]

I was looking through my tank earlier and found alot of these really small, white circles on the roots of the salvinia plants. They looked like anemones, with tiny white tendrils or tentacle thingies waving around, and everytime I would poke it, the thing would close. I got rid of most on the roots but I'm seeing more and more on the hardscape and rooted plants. Can anyone identify what these are, and if theyre a threat to anything in the tank?

 

[Donya]

Sounds like freshwater hydroids. Whether they're a problem depends on what else is in the tank - they aren't a threat in most cases but can sometimes be a problem for very tiny things like fish fry and small inverts. If you are breeding shrimp in that tank you will want to remove the hyrdoids. You will also want to control their food source, which is tiny particulates - so water changes without stirring up the substrate and feed the tank inhabitants very sparingly.

EDIT: sorry I somehow read this as that you had these in a shrimp tank, but apparently the ony place where "shrimp" appears is in the forum the post is in! I need more coffee today. If you're not breeding anything in the tank and just have fish the hydroids will look messy but won't be harmful.

 

[WhistlingBadger]

Interesting. I want some!

 

[Ceez]

I'm wondering if it's food that got mold/fungus and stuck to the roots there?

 

[Thermal]

Update: I observed them for a few more days, and concluded that they are infact alive. I see them floating around in the water and when they land on something they just stay there and start opening up again, exactly like anemones. I did a little bit of research and found Vorticella? They do look similar, but the ones I'm seeing in my tank are always clumped together in a dandelion shape. I'm still considering some type of hydroids or vorticellla, but I'm not really sure yet. I'm not planning on keeping any shrimp here, but I'd still want to get rid of them since they aren't pleasing to look at. The tank is fairly new so I believe that they did multiple from all the organic particles in the water, I recently did a replant too so there's tons of detritus. Thanks for the advice though, I'll be doing more water changes for now. I'm curious if fish like guppies would eat them? maybe raising the tank temp will get rid of them, or maybe just tannins?

Here are some more pictures

 

[Ceez]

Update: I observed them for a few more days, and concluded that they are infact alive. I see them floating around in the water and when they land on something they just stay there and start opening up again, exactly like anemones. I did a little bit of research and found Vorticella? They do look similar, but the ones I'm seeing in my tank are always clumped together in a dandelion shape. I'm still considering some type of hydroids or vorticellla, but I'm not really sure yet. I'm not planning on keeping any shrimp here, but I'd still want to get rid of them since they aren't pleasing to look at. The tank is fairly new so I believe that they did multiple from all the organic particles in the water, I recently did a replant too so there's tons of detritus. Thanks for the advice though, I'll be doing more water changes for now. I'm curious if fish like guppies would eat them? maybe raising the tank temp will get rid of them, or maybe just tannins?

Here are some more pictures

I wonder if you spot treat them with hydrogen peroxide if that will kill them like algae?

 

[Thermal]

I've been thinking about trying that too, but I'm not sure if it's safe for the plants or other microfauna? I also don't know how much dosage, I have a hydrogen peroxide bottle here and this is what's on the bottle:

120ml bottle
3% w/v (10 volumes)
TOPICAL SOLUTION
Antiseptic/Disinfectant

Each 100ml contains:
Hydrogen peroxide - 3 grams

 

[rebe]

Does this look like hydra to you?

I'm a bit concerned because it's popped up suddenly in my 5 gallon with the beckford pencilfish fry

www.fishforums.net

Does it look like these to you? Maybe they're something similar

 

[Thermal]

Does this look like hydra to you?

I'm a bit concerned because it's popped up suddenly in my 5 gallon with the beckford pencilfish fry

www.fishforums.net

Does it look like these to you? Maybe they're something similar

yep that's it

 

[Ceez]

I've been thinking about trying that too, but I'm not sure if it's safe for the plants or other microfauna? I also don't know how much dosage, I have a hydrogen peroxide bottle here and this is what's on the bottle:

120ml bottle
3% w/v (10 volumes)
TOPICAL SOLUTION
Antiseptic/Disinfectant

Each 100ml contains:
Hydrogen peroxide - 3 grams

Theres a ton of videos on youtube. Most everyone uses exactly what you have, 3%. They spot treat with a syringe in small doses and it works great for the algae. I guess it sucks oxygen from the tank so a lot of these guys are draining the tank down and spraying the algae and refilling it afterwards. I've also seen them removing the plants and spraying them with peroxide and than replacing them in the tank afterwards. Worth checking out if you want to try and rid your tank of these using peroxide. Don't know if it'll work but it's worth a shot

 

[Uberhoust]

I cannot think of anything that you describe that would hurt your fish. I would leave them alone and allow yourself the opportunity to view another type of animal. If I found them in my tank I would leave them as is.

I guess it sucks oxygen from the tank

It kind of looks like that but Hydrogen Peroxide carries an extra oxygen atom in with it (H2O2), this breaks down to water and oxygen. Adding peroxide to a tank can increase the dissolved oxygen in the water. The extra oxygen is a strong oxidizer which can work as a disinfectant. The absence of oxygen can kill but so can too much oxygen.