New acro worm parasite

[hoosierpat]

Mesenterial filaments are the same things that anemones use to digest their prey once it is their body cavity. If you ever poke an Aiptasia repeatedly you will likely see it expell filaments through its body wall as a defense. As I recall, they are covered in nematocysts and provide a pretty formidable defense. It is pretty unlikely though that they could survive detached from their parent flesh long enough to wriggle around, much less survive in the oral cavity of a small polyped coral. As I understand it, mesenterial filaments are a property of more developed polyps and less common in small polyped corals. The only delicate, skeleton-building corals that I have ever seen attack with mesenterial filaments is Hydnophora sp. which are not actually a small polyped coral but more of an LPS to use crude terminology. I would have to think that these are actually parasitic worms, unfortunately.

 

[jbundas]

E. Borneman's response from his Marine Depot forum:

"Those look like extrusions of mesenterial or acontial filaments, not worms. Can you remove them from the coral without breaking them? If not, your coral is stressed by something and is extruding them through the coenosarc. Pretty common response."

Based on what I've seen so far and the discussion here, this is latest theory:

Stag - The Ca and Alk drop that started 3 weeks ago was gradual enough not so shock any corals but eventually caused this relatively fast growing stag's skeleton to start decalcifying and breaking apart . The loose shards of skeleton started to work their way through the coral tissue causing the rough appearance and tissue recession. Most of the affected areas were on vertical surfaces or the undersides of horizontal stalks. Handling frags and rolling them around in the microscope dish irritated them, causing the mesenterial filament defense response. All told, I probably spent a couple hours peering through the microscope. If there were any alien parasites, I would have seen them. The fact the the skeleton damage occurs before the tissue damage indicates it's probably not something coming in from the outside.

What's left of the stag in the isolation tank still looks good. I'll take a few photos tonight to compare to the initial ones. I'm pretty confident that it's not hosting a plague that requires quarantine from the rest of the system. Provided the chemistry in the main tank is back on track, it should have an easier time recovering in there than in the little 3 gallon it's in now so I'm planning on putting it back tonight.

ORA Yellow Fuzzy - This guy got beat up bad after the nose dives into the favia. I don't have any reason to suspect there is a parasite issue with this piece either. It's already back in the main system. The tissue recession on it hasn't progressed much if at all during the last week, so given good flow and low to moderate light I'm hoping it will recover. There are a couple small sections that have a more full greenish color to the tissue so I think it's heading the right direction. As long as a couple polyps make it through, it'll grow back.

 

[Leeroy]

jbundas, I had what I thought were worms on one of my acro's a while back. Under magnification, I could see them moving under the corals tissue, and also going through the tissue wall as well.
They were mesentery filaments as well.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=916518

Good luck.

Regards,
Lee

 

[jbundas]

Lee - Yup looks like the same thing I saw. It's tough to tell from your pics, but did you have a similar abnormal skeleton issue that I was seeing?

 

[Leeroy]

jbundas, the base of the acro was pale in patches, which made me inspect it more closely.
I didn't really notice the skeleton at the time, as I was more concerned of the possible worms at the time.
Going back through my records, the week leading up to my post, alk was 9.6 - 9.9 and Ca was steady at 400 (a bit low).
Not really sure what stressed it, but at the time I split the colony and both have been fine since.

Cheers

Lee

 

[danfrith]

jbundas- So do you think that it was just a coincidince that both these corals had these mesenterial filaments out at the same time, and the two acros problems werent related in anyway?

 

[Ladipyg]

If the coral is sending out mesenterial filaments as a defense mechanism or a type of "scouting party" to see if it's a good time for expansion (as in kill any close corals so that it can grow without competition) or even a response to something secreted into the water by another coral, be it SPS or LPS. Do you think running carbon and increased water changes might help alleviate the problem or at least knock down the response.
I have a set up that allows me to do frequent water changes every other day...even an SPS that has fallen onto a favia I had recovered with no problems.
I would think that if you have an incidence of one coral falling or touching another, an increase of water changes and carbon would be called for. Since a diatom filter works so well that it even filters out the ich parasite, maybe running that would take some of the floaters out of the water.
Just a thought...interesting thread