ID this Worm?

[gpodio]

What kind of worm is this?

Thanks
Giancarlo

 

[wade1]

At a glance, it actually appears to be a string of eggs or waste... certainly doesn't look like a cohesive worm. But then again, I'm a toxicologist, not an invertebrate biologist.... maybe someone else can shed more light?

 

[fishfanatic2]

Looks more like eggs to me. Almost like little shark or ray eggs. :?

 

[wade1]

Actually, they look mostly like little whelk eggs. Capsules strung together by a tough thread between them.

Have you seen or do you have any odd snails or whelks in the tank?

 

[gpodio]

But this thing is moving around just like a worm. The only place I have seen it on is this goniopora, every time the goni is closed up completely you can bet it's because this 'thing' is crawling on it. Seems to do it regardless of day or night and moves very slowly, but several photos taken minutes apart clearly show it moving around, I haven't disturbed it yet so I'm not sure how fast it can move when it needs to. I have more photos of it at home if they can help, but for sure it moves around and I've seen it there 3-4 times now on different occasions. Haven't seen it anywhere else however.

BTW, this goni would have made a perfect addition to this month's Reefkeeping's top 10

Thanks
Giancarlo

 

[wade1]

Very intriguing. Maybe Matt or John can chime in with some ID assistance... I'm at a loss. Be very cool to find out what it is though.

 

[gpodio]

I'm reluctant to try and get it out until I know what it is, it looks very fragile. It's very thin and about 4" long. I guess it's cool when it's in someone elses tank ;-)

Giancarlo

 

[gpodio]

Here's a couple more pictures, I looked carefully last night and realized this worm crawls around the goni even when it's extended, I didn't realize that before, perhaps he's been there the whole time? I noticed it moving much like an earthworm, not sure how that's called but it contracts and expands as it pulls it's way around the goni.

Hope someone knows what this is. I found an old post here regarding a similar situation where someone was asking about a worm that seems to live on the goniopora but there were no photos or suggestions as to what it may be. I'm curious to see if by removing it the goniopora extends it's polyps out more than usual, but I'll wait to know what it is first seeing it's easy to locate now that I know where to find it.

Thanks
Giancarlo

 

[John_Brandt]

Wow! Never seen anything quite like it.

I have a hunch that it's not a worm, but rather a synaptid (think sea cucumber). It is somewhat camouflaged by the coral, but that it fully exposes itself during daylight might be a hint that it is not a worm. Worms are a primary food source for a great number of reef fish species. Exposing its body this way is a terrible life strategy for a worm. But synaptids are toxic and can afford to do this.

Deductive reasoning to support my guess, but I really don't know what it is. Can you see a set of tentacles at the 'head'?

 

[gpodio]

Thanks John, that's quite interesting, I looked it up in google and found this page with some photos, the last one kind of looks similar don't you think?

http://www.wildsingapore.com/chekjawa/text/c621.htm

So far I haven't been able to see any kind of tentacles on it's head, actually I'm having a hard time distinguishing any head features at all, seems like it comes to a point on both ends. But now that I know what I'm looking for I will give it a close inspection over the weekend and let you know.

Sooooo.... I guess I don't need to worry about this thing right now correct? I mean it's not posing any danger to the goni or other inhabitants of the tank right? I wouldn't mind it at all if he'd find a new home but I guess it's better there than on my clam.... Wife will also be happy to know it's not a worm... if she actually believes me ;-)

Thanks again
Giancarlo

 

[John_Brandt]

Giancarlo,

I'm not confident that it isn't a worm yet. Regardless, it probably isn't harmful to the coral. It may be feeding on mucus or particulates trapped in the mucus.

It's markings seem to mimic the coral texture. So this species may have a relationship to the coral. I bet a Goniopora researcher could say something more.

 

[John_Brandt]

How quickly does this thing move? Do you know the real-time duration of the excellent .gif that you posted?

 

[gpodio]

The gif was 4 photos taken 10-20 seconds apart, I did it because I wasn't sure myself if this thing was moving or not initially. I left it alone for about 30 minutes and found it on the other side of the goni, lost track of it after another 30 minutes which I 'guessed' it had moved on into the substrate or something...

Last night however I did see it "pull" it's mid section in an eartworm-style motion and I certainly didn't need any help in seeing that, it was rather slow and graceful but definetly faster than I have seen it move to date. I've yet to see it move around in any hurry, I'd say it's quite slow.

I will likely get better shots of it over the weekend, I'll wait till the goni is fully retracted after lights out so it can't hide. I may try to harass it a little with a small squirt of water to see if it does move any faster when it needs to, but I won't touch it seeing it looks so delicate.

Thanks for the help
Giancarlo

 

[HClH2OFish]

Not really sure, but does google Nereis vexillosa and see if it looks similar...

Most segmented worms tend to be bristleworms...and I don't see bristles on this guy...

sp. gpodiosum?

 

[gpodio]

Last night I made the goni close up so I could see this guy a little better, it certainly moved faster last night than I had seen before, however still relatively sluggish. The head shows no features at all and is thin and pointy, the tail end on the other hand is fatter, I also think it's a little longer than what I had originally thought, but I've yet to see the entire thing at once. Here's a video showing both head and tail and how it moves around:

http://www.gpodio.com/posts/worm.wmv (10mb)

Sorry for video quality, I reduced it in favor of file size.

Thanks for the help
Giancarlo

 

[John_Brandt]

I'm now thinking that it is a worm.

 

[gpodio]

I had a chance to view the tank during the day when the goni is completely opened up, it seems the worm lives on the goni and when not moving it's wrapped around a couple of the polyps. I thought the goni was closing up because of the worm but I think I was wrong, the goni was fully extended even with the worm crawling all over it, it's just that he's more visible in the evening when the goni is partially closed, and that's usually when I get to see the tank.

Definetly no tentacles or feet on this worm, just a thin pointy head and a big butt

So you think it could have some sort of relationship with the goni? You'd think the worm would wonder elsewhere though, even at night it seems to never leave the goni. I wonder why my fish are ignoring it being a worm and all...

Giancarlo