What's the secret to make Xenia pulse?

[stingythingy45]

I know this subject has been beaten to death.But there seems to be a lot of non-relevant info about why it pulses in the first place.
I've had a patch of(elongata) xenia( seperated on a rock of coarse)for at least 6 months.When I first got it the stuff pulsed really slow,nothing like the wild pulsing in the fellow reefer that I got the stuff from.It seems to be growing fine,looks healthy and is stretched way out.It just never pulses anymore.
Love it or hate it,it's much more interesting when it pulses than just moving in the current.
Here's my water parameters:

SG 1.026
Alk 10 DKH
Temp. 76 deg.
PH 8.0
Calcium 420
Mg. 1275

I have 260 Watt JBJ PC lighting
I dose B-Ionic and Randy's 2 part
Also drip kalk during the evening to help maintain PH

Just wondering if Iron or maybe Iodine might get something going.I'm also beginning to wonder if the lighting intensity is not enough.

[spike78]

My zenia really slowed down in my display. I ended up moving it to my refuge where the flow is much lower and now it pulses like crazy. This is of course anecdotal, but flow seemed like a key element to the change in behavior.

[psteeleb]

I have some of the red sea variety so yours may be different. Mine seemed to respond to Iodine dosing, a slightly higher Ph and low water movement.

[stingythingy45]

I dosed some Iodine last night(Kent).
I followed the dirstions and dosed 1 cap per 50 gallons of system water.I generaly do that every other week as most of my tank is softies.
As for flow I have 1 maxijet mod that pushes 1600 GPH but it's on the same side as the xenia.I have a Maxijet 1200 pointed upward at the surface on the other side of the 55.This causes the xenia to gently move and wrap around in the current.If I shut the Maxi mod off the xenia just falls down and sags.

[psteeleb]

When in a flow mine just got lazy. I guess they only pulse if they have to to get nutrients. If it's blown on them why bother, just my observation.

They respond fast but poorly to a lot of chemical issues. Not so much as the Alc, Ca but if my carbon was getting old they would sometimes start to wilt or slow down. HTH

[stingythingy45]

I just read an article that mentioned keeping PH at around 8.0 nightly and 8.4 during the day.Also this article stated the xenia was under 10 watts per gallon.Sounds like a lot for a softy.
When I seen it pulsing like crazy it was under T5s, 4 -55 watters.

[eshagha]

I have the same question. For me it seems to depend on the specimen.

[jadams7]

In my case, flow had everything to do with it. Koralias come in to play = no more pulsing.

[MThompson]

I notice flow affects mine. I shut the return pump and canister (for carbon) off when I feed artemia and molly fry.....this always results in my xenia retracting for a minute or so and then extending fully and pulsing. Once the pumps are back on, the xenia extends only about 3/4 and pulses a lot less.

I'll see if I can find some science stuff about the needs/reasons for pulsing.

[stingythingy45]

Maybe I need to shut down the Maxijet mod and maybe put just a regular 1200 in it's place for a while.The maxi mod seem to pull the xenia towards it even tough it doesn't really push water at it.

[Apparition]

I had about 1/3rd of my 55 gallon covered in Red Sea pulsing xenia and from my experience flow didn't affect it. While some with little flow pulsed, the ones right in front of the outlet of my maxijet getting totally thrown in the current would still pulse too. For me, mine has never stopped pulsing no matter my water quality. When I broke down the tank and they were in a holding bin with probably poor water quality from the sand movement and such, they still pulsed. Hoping I have the same luck when I set the tank up again, though this time with better planning to keep it contained.

[stingythingy45]

I'm pretty sure this is Elongata.
It's long and thin/pink color with whitish stalks.
Who knows,maybe it's putting all it's energy into expantion of the Empire.I have it seperated on one rock with some yellow colonial polyps.They sting it sometimes but it lives through it.

[MThompson]

Science Editor's Note:

Dr. Yehuda Benayahu is among those with a great deal of knowledge on the Xeniids. He began a talk to an audience of aquarists with the statement, "Please don't ask me why they pulse. I don't know." The point is that no answer to pulsatility has been conclusively demonstrated. Anthony mentions a number of points that are indeed anecdotal to the behavior. I would like to expound on a few points.

As mentioned in the article, the Xeniids have dramatically reduced feeding apparatus. In particular, they almost totally lack the ability to capture prey or particulates, and their mesenteries are reduced to the point where intercoelenteric digestion is rudimentary to non-existent. However, they are capable of dissolved nutrient uptake directly across the epidermal tissue surface. Pulsatility has been suggested to be related to this ability. In strongly coordinated pulsing, the contraction movement is much stronger than the movement of the relaxation extension, and this results in a net efflux of water through the colony. In other words, water is drawn from around the colony, through the colony, and outwards from the center of the colony. This has been hypothesized to be related to the facilitation of dissolved nutrient uptake. It also correlates well with anecdotal observations of many Xeniids that display a coordinated and strong pulsing in nutrient poor tanks and a cessation of pulsing in high nutrient tanks. Of course, there are exceptions, as Anthony mentions in the article.

Additionally, pulsatility has been found to be affected by a number of other factors. This is a coordinated neuromuscular response, and the pulsing can vary from single pinnule bending or flexing, to isolated uncoordinated pulsing, to rhythmic, coordinated, forceful, colony-wide pulsing. The behavior requires ATP, a cellular energy source, and without adequate energy, pulsing cannot occur or may occur in a less vigorous manner. Furthermore, the effects of various agents on pulsing has been demonstrated rather comprehensively in Red Sea Xeniids almost fifty years ago by H.A.F. Gohar in laboratory experiments in Ghardaqa, Egypt. He used a variety or stimuli, including electricity, drugs, temperature, and chemicals to determine their effect on pulsatility. He found that some stimulated and some inhibited pulsatility, as might be expected from a neuromuscular response. Interestingly, in light of Anthony's discussion of temperature, is that coordinated pulsing took place in a range of temperatures, with the extremes of the temperature treatments (both hot and cold) causing inhibition or cessation.

Likewise, I think many of the anecdotal observations in various tanks relate to any number of these type factors. Pulsatility is not determined or controlled by one factor, but can be affected by many factors, some of which may or may not be the case in individual aquariums.

Eric Borneman

Editorial References:

Gohar, H. A. F. and H. M. Roushdy (1956). "The neuromuscular system of the Xeniidae (Alcyonaria). I. Histological." Publications of the Marine Biological Station Ghardaqa (Red Sea) 10: 63-81.

Gohar, H. A. F. and H. M. Roushdy (1959). "On the physiology of the neuromuscular system of Heteroxenia (Alcyonaria)." Publications of the Marine Biological Station Ghardaqa (Red Sea) 10: 91-144.

[psteeleb]

Interesting read that doesn’t end up saying a lot. I guess the only thing I picked up out of that, is there appears to be more evidence that they pulsate to create flow, rather then to actually try and consume anything

In the end I learned something new, and that's always good. Thanks for that post.

[MThompson]

That was a science content addition to A. Calfo's article To Pulse or Not to Pulse? Identification and Behavior of Xeniid Corals (http://www.reefkeeping.com/issues/2004-02/ac/feature/index.php) from a few years back. I have yet to find any scientific journal articles about their movement, only some stuff on physiology.....there is probably something in some obscure Japanese journal, so I will keep searching.

[stingythingy45]

Well,I ditched the Maxijet mod for a while to see if it's too much flow.Added a regular maxijet 1200 in it's place.One thing I've found is 55 gallons ae very har to direct flow in.Also took a frag of it that was growing on an old snail shell and put it in the refugium.Figured I would see if this did anything different in there.I upped the drip on the ole kalkwasser.
See if that makes a difference.