New acro worm parasite

[jbundas]

Maybe this isn't a new siting, but I haven't seen any reports of this parasite yet. Here's the story:

I noticed some "rough" patches on an otherwise thriving healthy stag variety acro. I inspected it further out of the water, noticing that some of the rough spots gave way to cavities through the coral tissue into the skeleton but still couldn't see any culprits. When I touched the rough sections with a toothpick, they crumbled leaving a large cavity in the skeleton.

I tried to wash some of the affected section off in a clear glass container but found nothing. Not having any type of magnification equipment at home, I bagged the whole colony and brought it to work this morning and put pieces under a stereoscope.

The rough sections of the coral appear so because the calcium skeleton is very irregular and thin, with blade sharp edges poking through the outer membrane of the coral tissue. The skeleton below the tissue in these areas is so sparse and thin, it just disintegrates when touched.

After enough searching, I found what appears to be some sort of worm parasite living beneath the coral tissue. They are not the no infamous AEFWs. Once affected areas are disturbed they retract quickly into the skeleton under the tissue. They look very similar to the cloudy clear spaghetti worms that live in liverock and substrate but way smaller. These guys are about the size of a hair and the same cloudy clear so they're impossible to see without a microscope, maybe a nice mag glass if you're good. Since they disappear once they know you're onto them, they're even tougher to spot. I did manage to separate one from the coral and it continues to squiggle around on the bottom of the glass.

Unfortunately, I don't have a camera hooked up to the microscopes here but I'm going to try to find someone in the are who does.

Any other experience with this sort of thing out there.

 

[jbundas]

The acro pieces have been marinating in the dish under the scope for while and the little guys are showing up around the edges of various coral polyp openings. Not being a biologist, I'm making a mildly educated guess based on what I've seen so far. It looks like the worms generally live in the coral polyp cavity and extend out to collect food (similar to a spaghetti worm), as opposed to directly feeding on the coral tissue itself since I'm finding rather large worms together with healthy polyps surrounded by healthy tissue and skeleton. It appears as the presence of the worm eventually screws up the calcification process in the area, resulting in the abnormal formation of the thin irregular skeletal structure, and possibly the decalcification of previously well-formed skeleton. The actual damage to the coral results from the extreme skeletal deformation either collapsing or causing the tissue to tear and recede.

Still working on the microscope camera to get some pics here. If anyone wants to play around with some of this, drop me a pm and I'll ship out a piece or two.

 

[jbundas]

This guy's been stewing in a bag of his own filth all day but surprisingly still looks pretty good. Here's a shot showing a slightly infected area.

You can see the "rough" sections where the underlying skeletal structure is all disorganized but the color and tissue still look fine.

 

[jbundas]

Here's another one:

You can seen the normal skeleton towards the upper right, but the area in the lower middle is deformed to the point where shards are starting poke through the outer tissue.

 

[jbundas]

Even more pronounced here:

Touching this area with a toothpick or such would cause it to crumble into a mush of coral tissue and flakes of skeleton.

 

[jbundas]

And finally, a section where the skeleton has collapsed and the tissue has torn, leaving open cavities:

Working on some microscope shots....

 

[NuReef]

ANy one else witnessed this in thier tanks?
Ricky

 

[Dog boy Dave]

Wow. Thanks for posting that one. Just one more reason for a quarantine tank.

 

[jbundas]

Here come the close-ups. These were taken with a Cannon S70 through the eyepiece of a B&L stereoscope. I was amazed that this actually worked.

Here's a bad section where the tissue opened up:

...closer:

You can see the sharp pieces of skeleton that have poked through the tissue.

 

[jbundas]

A good shot showing normal growth, then where things started to go wrong:

 

[jbundas]

Another similar situation:

 

[jbundas]

One more area of roughness:

 

[jbundas]

Now for the long awaited worms. There's one here coming right out of the middle of a polyp. It's the P-shaped clear noodle right in the center:

To help you pick it out, here's the same worm after it moved a little:

 

[jbundas]

Another one - it's the tornado twister shaped thing in the center of the pic:

There's no way you could see these guys without the microscope.

 

[jbundas]

I finally found a good one all the way out, hanging onto some acro slime:

 

[jbundas]

I was able to pull it off the coral with a bamboo skewer. It's still holding onto the slime string which also has some pieces of decalcified/deformed coral skeleton in it:

 

[jbundas]

I finally isolated it and threw in a piece of hair to a sense of size:

 

[jbundas]

These last two shots used a supplemental Maglite for a little more juice:

The bright pointy piece near the top is a chunk of coral skeleton:

 

[jbundas]

I got this coral from another reef-keeper over 3 years ago. I had fragged it and gave a piece to a friend when my sps were having trouble in general (1-1.5 years ago). Ultimately, I lost my original piece but the fostered frag flourished, growing into multiple large colonies.

I got a nice piece back about 6 months ago - the one shown here. I also have another smaller piece that looks totally fine.

This is the first time I've seen anything like this, in my tank or others, including the now parent colonies of this coral.

I have this infected colony in an isolation tank. I'd like to see how this progresses. If anyone has any ideas or suggestions of a treatement, I'm all ears. If anyone wants a piece to experiment with, let me know and I'll send one to you.

 

[mpoletti]

Wow, those pics are intense. I will be tagging along.