My Hammer Has New Appendages

[Crazy fishes]

My hammer coral today has a new appendage. The center of the coral has opened up and a brown clear tentacle like thing is projecting from the opening. It tapers towards the free end and is uniformly coloured. No other fetures are present. The picture shows exactly what it looks like.
Any ideas what this is???

Regards

 

[SkiFletch]

Nope, when hammers lash out with sweeper tentacles, they modify the tentacles they normally have. Basically they make them long, stringy, flexible, and pack them with nematocysts. Then the elongated tentacle hits something and digests it on the spot with the extra nematocysts.

What you're seeing there looks like the expulsion of zooxanthellae algae. Euphyllia will often do this when brought into an appropriately lit home aquarium. Chances are, your lights are more powerful than those at the LFS (at least at the surely shallow depth of the nano) and as such, the coral gets more light. With more light, the zooxanthellae do not have to do as much work of photosynthesis to sustain the coral, so the coral doesn't need them. And when it senses that it doesnt need that many zooxanthellae, it expels some. This is a very common behavior in newly bought hammers/frogspawn/torches. You may also notice a deflating of the tissue and a widening of the mouth when it expels the algae. This too is normal, so long as the coral re-inflates (usually between 30-60 mins later).

 

[steelhealr]

The dumping of zooxanthellae is another way of using the term bleaching. The coral does it under stress..it is a survival technique. Agree with the sweeper tentacle comments by Ski. SH

 

[Crazy fishes]

I don't understand how my tank with it's puny little 72 watt power compacts could be producing more intensity than the LFS double metal halide unit? If I was that coral I would think that I would want to hold on to all the Zooxanthellae I had! Isn't life strange..... oh well there was me worrying that my lights might not be powerful enough.

Regards

 

[Musho3210]

i think (not 100% sure) if the intensity lowers, they expel the zooxanthellae and get new ones that are more adapted to the light. The old ones are used to high light and expect a lot of light to be fed, when not given enough, they die. When they die, new ones, that can survive in the lower light conditions then take the old ones place.

 

[Crazy fishes]

I am interested since I can see the top of the hammer coral. It reminds me of a mint corneto icecream (with tentacles slayed far and wide). That is good right it means the coral is expanding fully. It's NOT translucent at all.

Many thanks

Regards

 

[steelhealr]

Zooxanthellae are separate organisms that live within the coral and provide food. When your coral was under the halides, it was cranking out 'food'. When the coral was placed under PC lighting, the food production 'halved' or, whatever. The coral 'kicks out' the algae saying 'hey...there ain't enough for all of us'. Go figure....biting the hand that feeds you. SH

 

[SkiFletch]

Do remember, a coral a few inches under the water even under PC lights can be getting more light than the same coral over 2' under the level of the water despite it being under halides. Remember, light energy useful for growing corals is measured in PAR (photosynthetically available radiation). In my own 65g tank with twin 175 halides over it, I get a mere 90-100PAR down on the sand bed (2' down). In my nano tank (which I've since used as QT) with twin 18watt PCs over it, I get 100PAR a few inches below the surface...

 

[Crazy fishes]

Ok my hammer is about 12 inchs max from the water surface. Three heads are good; fully extended and swaying in the current. The other looks like that in the picture. I have posted it before but I believe this is dead or well on the way; should I leave it or remove it from the remained heads???


Regards

 

[SkiFletch]

In this specific case, because the affected head is so far removed from any nearby "sister" heads, I'd just leave it be, and cross my fingers. If the flesh of the "shriveled" head is in contact with the head of a non-shriveled head, then I'd consider fragging. But since you clearly have full separation of the two heads here, I'd just leave it be. It's highly likely that the shriveled head will die here , but it is also highly unlikely that it will transfer any infection/immune response to the healthy heads.

 

[Crazy fishes]

That shrivelled head has begun to decay, a big cloud of brown gunk surrounded it. I aspirated it all with a syringe earlier today and it has begun to reaccumulate. I was wondering if all that dead material in such close proximity to the sister head is going to have an affect?

Also yesterday I found that bloody little sea slug it was going after the hammer; I have since removed it. The attached picture is it out of the tank (sorry about the red background it was the only thing to hand). They are surprisingly fast!! Anyone know what it is; it doesn't look like the images of nudibranch I've seen. They are all a lot more colourful and this guy is just dull orangey-brown.

How many hours lighting do you give your tank? I am running them 12 hours at the moment since that is what I read was required but a few people have said that 8 hours is sufficient.

SH, you have a 24g d&d with standard 2x 36watt lighting right? and you have a hammer/ancor coral on the substrate? So it can get sufficient light down there too. Mine is about 6 inches from the surface so should have ample light??

Is this lighting sufficient for a open brain? I read that they require placement on the softer substrate and to avoid the rock. It can damage their delicate tissue.

Regards

 

[SkiFletch]

Brain corals are a risk in nano tanks, open or closed. Some varieties can really get aggressive with sweeper tentacles in the alleopathic soup known as a nano reef. Some are safe, but I don't reccomend them in mixed nanos

 

[Crazy fishes]

I think I will skip the open brain for the time being. When I move my reef to the 180L then I will think about it (At the moment the freshwater fish inhabit that tank). I think the other LPS that I am going with is Euphyllia Divisa (Frogspawn coral). I popped into the LFS today to just see what corals they have and ask about the hammer. I am really surprised because the other hammer frag which was in pretty much the same shape as mine is practically dead. It has one dead head and the other three are well on the way to being the same way.
My hammer: I aspirated the last little bits of the dead material today and the sister heads are looking good; fully extended and getting their colouration back. Phwwwww!! I thought the nearest sister head was also going to die because it had assumed that 'pull myself in as much as possible' posture but has emerged fully all day!! My clown fish are interested in maybe setting up home in the tentacles; they keep circling it. Hopefully they will or at least one will; it is the epitome of the coral reef, a hosting clown. Oh by the way that slug in the picture is known as a 'half shelled sea slug'.

One question for now:

1) How many hours should the lighting be on each day?


Regards

 

[SkiFletch]

8-10 hours seems to be a good happy medium for most people

 

[CageUK]

8-10 hours seems to be a good happy medium for most people

I must admit to leaving our lighting on about 14hrs per day and sometimes a little more if I forget to turn off. I have done this as a deliberate act in order to help the PH. I have not noticed any adverse effects. I was hoping that a reverse cycle on some chaeto in the rear chambers would have meant I could stop the PH dropping in the night but it makes little or no difference. I am lighting the chaeto using two 'Marina' white led lights (one in each of the two chambers containing the chaeto). I suspect that due to the fact I have only a small amount of the stuff (small chambers) plus the weak lighting means I can't hope to compensate for the natural PH drop overnight. I now have it on a 24hr cycle instead.

Using this lighting schedule I tend to get a PH of around 8.30 ish by the evening and 8.16ish in the morning. I have an digital PH meter continually monitoring so I can see a minute to minute picture of what the PH is doing (subject to any inaccuracy in the meter).

I doubt that this cycle should be a problem, because certainly in the summer in the tropics, it is usual to get longer days although admittedly the light at the beginning and the end of the day is a reduced strength and quality although as always am always willing to listen to more sage advice.

I use moonlight LEDs at night.

Cheers