Long white flat worm ID

[AV corals]

I found this worm last week. I took him out because I just thought “flat worm” must be bad. However, I’ve been seeing more of them now and need to know friend or foe and if I have a bigger problem on my hands.

Any help or insight would be appreciated!

iPhone video of worm

 

[AV corals]

 

[exnisstech]

@ISpeakForTheSeas is good at IDs

 

[Tinnerito]

I found this worm last week. I took him out because I just thought “flat worm” must be bad. However, I’ve been seeing more of them now and need to know friend or foe and if I have a bigger problem on my hands.

Any help or insight would be appreciated!

iPhone video of worm

Looks rather similar to a planarian flatworm but also kind of different... bump!

 

[EnterName]

I'm quite bad at identifying flatworms, but this could be a Rhabdocoela?

The small ones around it are maybe just ghost flatworms. They are still a plague and eat copepods which is annoying.

Treatment might be challenging as it involves a lot of manual removal at first. I would keep a close eye on all corals, snails, and clams.

 

[AV corals]

Thank you guys so much for taking the time to reply! I've been looking through the forums, and some say to get a wrasse to help with flatworms; however, I have a snowflake eel. In terms of corals, I have hammers, torches, and acros, but they seem to be unharmed at this time.

 

[ISpeakForTheSeas]

@ISpeakForTheSeas is good at IDs

I'm late and the video won't play for me on my phone, but with the moderately elongated body shape that tapers at the "tail," my first thought - which could definitely be wrong here- would be a Prosthiostomid flatworm of some variety (the taper is not seen in al species); regardless, there really aren't many (or really any at this point) flatworms that would be keepers.

 

[EnterName]

I'm late and the video won't play for me on my phone, but with the moderately elongated body shape that tapers at the "tail," my first thought - which could definitely be wrong here- would be a Prosthiostomid flatworm of some variety (the taper is not seen in al species); regardless, there really aren't many (or really any at this point) flatworms that would be keepers.

To get the videos running, don't use the app. Click the share button on a post and copy the URL. Then open your phone's webbrowser and insert the link. The videos work in webbrowsers. The R2R staff is currently working on fixing this issue as far as I know

Edit: Nevermind the linked video is not available (404 error page) and not hosted directly on R2R. Still works for other videos though.

 

[AV corals]

 

[EnterName]

The branching lines radiating from the center towards the sides are probably "anastomosing intestinal branches", which is literally the origin of the name "Polycladida" meaning "many branches". So it's most likely a Polyclad.

This fits ISpeakForTheSea's suggestion of a Prosthiostomid, which belong to the Prosthiostomidae family. These are known as Acropora-eating flatworms (AEFW) in the reef tank community (not all might eat acropora but the family includes AEFWs).

Polyclads mostly reproduce sexually but some can reproduce asexually through fission (splitting their body similar to Asterina starfish). If there is more than one flatworm, chances are there are eggs somewhere and you will need a repeated (or prolonged) treatment to ensure all flatworms will be treated after hatching if a treatment of eggs is not possible.
The issue is, that I see is the large amount of smaller flatworms (probably Amphiscolops sp. or Heterochaerus sp.), and I don't know if a treatment like Salifert's flatworm eXit would cause a huge amount of toxins to be released if you cannot manage to reduce their numbers through manual removal beforehand.

Maybe @ISpeakForTheSeas knows if treating ghost flatworms or Acoel flatworms releases toxins, a question that will become important to me as well soon. I might send in a Oceamo Organo-MS test to check, but I would like to know before I poison my own tank


If we are really dealing with something different (another Polyclad), I was only able to find these three that have at least some similarities, but I doubt that they are a match:

• Armatoplana reishi
• Euplana gracilis
• Notocomplana acticola (this one likes colder water though)

Either way: Most likely a bad guy, it should be removed