worm and coral?

[Mihai]

Hi,

Those two things (I'm guessing a coral and a feather duster) came with come Carribean LR and resisted incredible hardships (from me too: >4ppm ammonia, 2.037 sg).

Now I'd like to keep them happy, but I don't know the first thing about them (i.e. what's the species/class/family, what they want in light, food, flow, etc.).

My guess for the coral is based on the fact that a few of the small polips (on the right side of the picture) are dead and white leaving behind a
white bony structure.

Thanks for the help,
Mihai

 

[paats]

I don`t know about the coral,but that`s not a feather duster on the bottom.It looks like an anemone

 

[Mihai]

After looking long and far last night, the coral
looks more like a zooanthid than like anything else
(it also correlates on hardiness).

Regarding the duster/anemone, how can I tell?
I'm pretty sure that it's not apatsia as its arms are very thin (like those of a duster) rather than plumpy...

Thanks,
Mihai

 

[John_Brandt]

Mihai, your coral looks like Madracis sp. And that does not look like a featherduster worm.

Would you please provide more photos that are in focus, so that we may do a better job of helping identify these animals?

 

[Anonymous]

Mihai,
I have the same stuff on my gulf rock, or at least it looks the same. Given a little light (even NO will do) and frozen food both will do well. I don't know what either one is, but I do make sure that they get something to eat. The one that you think was a featherduster, will it hold onto a piece of frozen food? If yours is the same as mine, it should.

 

[Mihai]

The focus thing is killing me! I used a tripod, manual focus, focus bracketing, shot like 30 pictures and still unable to get that coral into focus (best shot is now coral2, but it's still bad). It's true that the manual focus on my Canon G3 is crap, but I never had such a problem with it (macro, or no macro didn't make any difference).

On the other hand I got a good shot of the "worm". To get an idea of the
sizes of those guys: the polips on the coral are about 5mm in diameter, and the duster is slightly larger (7mm or so). I don't think that the duster can hold onto anything: it hides immediately in its base (completly) if it sees anything moving fast in front of the aquarium. I will try to target feed, but I doubt that it will stick around.

If getting the right focus is so difficult with worms and corals, I have no hope to get a fish (or even a hermit crab) ever! This is discouraging.

I'll try to move the coral rock closer to the front of the tank maybe I can get a better focus.

Thanks,
Mihai

 

[John_Brandt]

Mihai, don't worry about the focus. I know it's driving you nuts. Be confident that your coral is Madracis sp., as all signs point to this even without sharp focus. It is a hardy stony coral.

The 'other' animal may be a tubeworm, but I am having difficulty pinning-down its identification. Please look very closely at it. Do you see tiny 'feather-like' pinnae that come out each side of each 'tentacle'. I'm using the word 'tentacle' at this point only for convenience. There are nine of these on this animal. In your first photo I can barely see what appears to be pinnae on the 'tentacle' at about 8 o'clock.

Are you seeing this too?

 

[Mihai]

I looked at the tentacles from really close (5cm), and I unable to see
any pinae steaming away from it. They seem to have no little branches.
The only strange thing about the tentacles is that they seem to be
something like an articulation at about 1/5 from the tip: when they
bend due to the water current, they'd don't bend for the entire length
of the tentacle, but rather only the top 1/5 or so. Have a look at the
second picture I posted, at the tentacle that is at 1:00. All of them
seem to bend at that point at one time or the other.

Anyway, I don't necessarily want to know exactly what species it is,
if you know family or genus, that'll do: I just want to know if it's a
pest, if it is not what to do to keep it alive and happy, and
eventually if I can help it reproduce (as I like it, and I'd like to
have more like it).

Now, about the Madracis: is it doomed to die under 4 x 40 NO
fluorescent lights? If not, what can I do to make it happy? Propagate?

Thanks a lot for the help,
Mihai

 

[John_Brandt]

Oh I would be happy myself with a generic identification of this "tentacled" animal! I suspect that this is not a worm, but rather is a Cnidarian - and probably a Hydroid. I think we can rule out Octocoral because those characteristically have eight tentacles while this one has nine. I am very weak in identifying specific hydroids. There is no need to fear it being a pest, at least if it does not reproduce explosively and spread throughout the aquarium. I am going to seek other references to try to get closer to identifying your animal.

I think your Madracis coral will do well with your lighting (please position it to get maximum exposure) but will probably have a slower growth rate than if you had a brighter situation. This coral will encrust (as yours is) and then may begin to form columns. You could presumably propagate it once the columns reach a size that can be broken off from the main colony.

 

[Mihai]

Thanks a lot for your effort. The Hydroid can "see" me if I move in front of the glass too fast, and it hides in its leg which is very small compared with the tentacles (some 5mm long), it must have some more space in the rock (or it folds itself )

M.

 

[Anonymous]

Well that's unusual. As far as I know hydroids don't really have the ability to do this. Are you saying it responds to light? Try waving your hand over it without touching the tank in any way, and see if it retracts. If so it might just be some type of worm.

 

[John_Brandt]

This animal has the ability to feel minute vibrations transmitted by your movements into the aquarium, even from a considerable distance. This could give the impression that it "sees" you, when actually it "feels" you.

Hydroids do construct a "tube" that they live in, and this may be much shallower than you might expect. They collapse into their tube by reflexively expelling water from their body, of which they are almost entirely composed (imagine a deflating balloon).

 

[Mihai]

Matt, John is right, and I was wrong: it was not "seeing" me, but rather feeling my movement
(through the floor and stand). So it can still be a
Hydroid. What does it eat? Anything special for it?

M.

 

[Anonymous]

Trust me, you won't need to treat it special for it to grow and reproduce, at least if it's anything like the hydroids I have dealt with. They're very easy to simply rip off rock if they get out of hand, but do it early.

 

[Mihai]

Why would I rip it? It is so cute (when you only have LR and 3 dusters, the hydroid is the highlight of your tank ). Do they harm anything? I was actually thinking not to put hermit crabs to avoid harming the hydroid (but I'll try them anyway ).

Also, does it reproduce asexually? I don't see any other hydroid in the tank...

M.

 

[Mihai]

John, after moving the rock in front of the tank and 1/2 h of trying really hard, the autofocus decided to make me a surprise and got it right.

See attached pictures, now the mistery will be cleared...
The other picture is how the coral looks at night when it goes to sleep (retracts its polips). The coral is doing clearly much better than before: the polips are larger, more plump and darker in color. Still would be nice to know what it is.

Thanks a lot,
Mihai

 

[John_Brandt]

Excellent shots of Madracis coral.

 

[Anonymous]

Wow, that is a good shot! It looks like the polyps are getting buried by sand though!

Mihai,
Assuming that it *is* a hydroid, you should try and kill it as quickly as possible. The easiest way I've found to do this is to remove the entire rock they are on, and scrape/pull them off. There are no easy biological controls for hydroids, AFAIK. Hydroids have very potent stinging cells and will kill some adjacent coral polyps eventually. They will spread very nicely as well. If, later on down the road, you have guilt from removing a hydroid from your tank....trust me, I can provide you with some to replace them

 

[shr00m]

lol see how cute you think it is when your tank is full of them... matt is right get it out now.

 

[Baianotang]

i agree