ID on these tiny things

Veljko

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These are very very small, to the naked eye barely visible as just blacks/dark brown dots. Once zoomed in you can see the "tentacles" in the flow.
 
Do they retract if you touch them? If so, I'm not ready to rule-out apitasia yet. There are many species. If this 30 year old memory is correct, I recall poking anemones that look like that in the Caribbean. I had a blast watching them disappear when I touched them.

Do the tentacles look to have any frills on them? That would make me lean away from aiptasia.
 
There are one or two of these things retracting extremely fast in the video. Aiptasia can retract fast but this looks near instantaneous.

There also is no visible stem/neck and the tentacles have a uniform thickness which doesn't match an anemone either.

The video compression seems to be causing a lot of detail loss... Can you take a photo or two so it's possible to see the base these tentacles are retracting into?

I only see black spots but don't know if they are all sitting in holes in the rock or have some kind of shell or tube they retract into.
 
Gonna sound weird cause they all kinda look the same but some of them remind/look like barnacles; which fits the speed.
 
Brother, I have bad news for you

IMG_2996.png
 
There’s already a couple, and if you cut one there’ll be a couple more… and then you’ll have your answer 😅 not serious advice
 
There are one or two of these things retracting extremely fast in the video. Aiptasia can retract fast but this looks near instantaneous.

There also is no visible stem/neck and the tentacles have a uniform thickness which doesn't match an anemone either.

The video compression seems to be causing a lot of detail loss... Can you take a photo or two so it's possible to see the base these tentacles are retracting into?

I only see black spots but don't know if they are all sitting in holes in the rock or have some kind of shell or tube they retract into.
These things are so small that if I wasn't taking a video of something else and zoomed in all the way, I would never see these with a naked eye.
The only reason I can even take this video is because the rock is almost touching the glass. The lens is literally 1/4" from them.
You do not see the "tentacles" with the naked eye. Once you know where to look, maybe, just maybe you can see black dots.
Tentacles are absolutely not visible without the macro lens.

Yes, they retract instantly. They are all pretty much the same size and there is a bunch of them.

Would aiptasia just pop up so uniformly and in large numbers like that?

Hydroids?

I doubt I can take a decent high res photo but I will try.

I took another video.
I think what seem to be larger ones are actually groups of smaller ones. Because they kinda retract separately.


There are one or two of these things retracting extremely fast in the video. Aiptasia can retract fast but this looks near instantaneous.

There also is no visible stem/neck and the tentacles have a uniform thickness which doesn't match an anemone either.

The video compression seems to be causing a lot of detail loss... Can you take a photo or two so it's possible to see the base these tentacles are retracting into?

I only see black spots but don't know if they are all sitting in holes in the rock or have some kind of shell or tube they retract into.
 
There are one or two of these things retracting extremely fast in the video. Aiptasia can retract fast but this looks near instantaneous.

There also is no visible stem/neck and the tentacles have a uniform thickness which doesn't match an anemone either.

The video compression seems to be causing a lot of detail loss... Can you take a photo or two so it's possible to see the base these tentacles are retracting into?

I only see black spots but don't know if they are all sitting in holes in the rock or have some kind of shell or tube they retract into.
These things are so small that if I wasn't taking a video of something else and zoomed in all the way, I would never see these with a naked eye.
The only reason I can even take this video is because the rock is almost touching the glass. The lens is literally 1/4" from them.
You do not see the "tentacles" with the naked eye. Once you know where to look, maybe, just maybe you can see black dots.
Tentacles are absolutely not visible without the macro lens.

Yes, they retract instantly. They are all pretty much the same size and there is a bunch of them.

Would aiptasia just pop up so uniformly and in large numbers like that?

Hydroids?

I doubt I can take a decent high res photo but I will try.

I took another video.
I think what seem to be larger ones are actually groups of smaller ones. Because they kinda retract separately.


There are one or two of these things retracting extremely fast in the video. Aiptasia can retract fast but this looks near instantaneous.

There also is no visible stem/neck and the tentacles have a uniform thickness which doesn't match an anemone either.

The video compression seems to be causing a lot of detail loss... Can you take a photo or two so it's possible to see the base these tentacles are retracting into?

I only see black spots but don't know if they are all sitting in holes in the rock or have some kind of shell or tube they retract into.
Colonial tube worms.

Dodecaceria sp. (e.g. D. pulchra, D. concharum, ...).

I don't know much about these guys, but they can apparently drill into SPS corals and spread aggressively. They are often confused with boring Spinoid worms (e.g. Polydora sp.), but the dark coloration is more common in Dodecaceria.

They won't kill corals as far as I know, but can become unsightly and frustrating.
 
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Colonial tube worms.

Dodecaceria sp. (e.g. D. pulchra, D. concharum, ...).

I don't know much about these guys, but they can apparently drill into SPS corals and spread aggressively. They are often confused with boring Spinoid worms (e.g. Polydora sp.), but the dark coloration is more common in Dodecaceria.

They won't kill corals as far as I know, but can become unsightly and frustrating.
Thank you. Can't quickly find some images that resemble these specifically but will look more.

Do they stay that tiny?
 
Colonial tube worms.

Dodecaceria sp. (e.g. D. pulchra, D. concharum, ...).

I don't know much about these guys, but they can apparently drill into SPS corals and spread aggressively. They are often confused with boring Spinoid worms (e.g. Polydora sp.), but the dark coloration is more common in Dodecaceria.

They won't kill corals as far as I know, but can become unsightly and frustrating.
Thank you. Can't quickly find some images that resemble these specifically but will look more.

Do they stay that tiny?
Yes they should stay quite small but can grow dense.

Here are a few images:




https://reeflex.net/tiere/12126_Dodecaceria_pacifica.htm (see images at the bottom of the page)
 
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Yes, that's them.
Thank you very much for your help.
I guess they're fine to leave. Not even sure what I would do to them :)
 
Thank you very much for your help.
Always happy to help 😊

I guess they're fine to leave.
You will have to search through the web a bit. Some see them as pest because they drill into corals, and spread fast.

Not even sure what I would do to them :)
If you can take the rock out, a bit of muriatic acid on a toothbrush would probably get the job done. If they are too hard to spot without magnifying glasses when they hide in their tube you could also nuke the whole rock with a bleach bath or hydrogen peroxide. This will effectively make it a "dead rock", but in an established tank it will be filled with life very fast again.
If you have no way to remove the rock and need to treat them within the tank it gets more difficult. I assume Kalk paste or products used for Aiptasia removal might work, as well as simply gluing them shut.
 
What's interesting to me is that they're from northeast pacific and are considered cold water worm (up to 50F). How are they surviving in 79F!? And how did they end up in the tank? :)
 
What's interesting to me is that they're from northeast pacific and are considered cold water worm (up to 50F). How are they surviving in 79F!? And how did they end up in the tank? :)
There exist a variety of different species which will prefer different water temperatures. Dodecaceria dibranchiata for example likes warmer waters and would probably just do fine in your tank. It has been found in Panama and the tropical Rocas Atoll in Brazil.
 
There exist a variety of different species which will prefer different water temperatures. Dodecaceria dibranchiata for example likes warmer waters and would probably just do fine in your tank. It has been found in Panama and the tropical Rocas Atoll in Brazil.
Well, they probably came on tbs live rock.
Can I take more of your time on a few other things I captured on video while looking for these tube worms.
Macro lens in reef tank is scary stuff!

There is a ton of both of these. Worm like things are mostly below the substrate surface while the "bugs" are crawling on the substrate surface.


 
Worm like things are mostly below the substrate surface
I assume these are some flatworms, but it's hard to tell at low magnification. Most flatworms are not considered reef-safe, but as these are living in the substrate I think they are harmless detritus feeders and won't bother corals, fish, or inverts. Not all flatworms are parasitic or corallivore. Even at higher magnification I will probably not be able to tell you the exact species or genus, but Macrostomum species are quite common and some flatworms belonging to the Acoela order can have these elongated shapes as well, even when most people associate acoel flatworms with a broad and short shape (see post #85 on page 5 of my microscopy thread).

[...] while the "bugs" are crawling on the substrate surface.
Can you see if these "bugs" have segments? In that case it could be some isopod, but the movement is weirdly jaggy resembling a tiny hermit crab.

Does it look like some bivalve shell with crustacean feet that's moving around or can you describe it a bit? It's really hard to see any details in the video.

If it's important we can first tag the reefsquad and if that doesn't help we can tag ISpeakForTheSeas, his identification skills are far better than mine.
 

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