Acropora Growth Captive Vs Wild.

[MammothReefer]

Now we all agree, that things just aren't going to be 100% the same in our tanks as the wild.

Today I was looking over my tank, and I was pleased to see a fair bit of of "white tips", signs of new growth however as look at the pieces one thing I noticed is all the new growth well.. it pretty much looks the same. Milli, "efflo", hyacantis, stags, etc.. Eventually they colour in and assume the normal shape of the rest of the coral but at first the new growth all is white and some what "blocky" when compared to the rest of the coral. This isn't always the case I have a milli that on when end is doing the encrust thing and as it does it it has full colour, but on the other end is doing the "white tip" thing, and have a few corals that never seem to do this however on the ones that do it always strikes me as a bit odd. As I have yet to see or recall a single wild or maricultured piece coming in with "white growth tips".

Have you?
Why is that?

We would have to assume that things in the wild are growing. What is different between ours tanks and the ocean to cause the coral to grow in a manner where it will grow a skeletal structure, polyps, and skin faster then it can populate it with symbiotic zooxanthellae. Why does it take so much longer for this component that is required to give the coral it's pigmentation and ability to photosynthesize in that new grown area to appear? What are we missing that isn't allowing this to happen, or is it the opposite is our super saturated above sea level parameters instead causing the coral to grow quicker then we can grow the zooxanthellae? This is all of course based on that the theory that I think I understand what is going on in my tank..ha

What are your thoughts?

 

[robs.mark]

amazing, im going to keep an eye on mine and see if i get the same results..

 

[acro-ed]

Wild/maricultured SPS (usually) don't come in with white growth tips because, simply put, they are not growing. They are not growing because they do not take to being taken from a lagoon to a holding tank and then to your tank as well as captive pieces take to being taken from one person's tank to yours. Those wild pieces likely had very nice white growth tips the day they were pulled from the lagoon, but over the course of days, weeks, and months before you got it the growth has ceased. I have seen first hand that SPS corals in the wild have extensive white growth tips that far exceed what is attainable in an aquarium.

-Ed

 

[karsseboom]

I have noticed the same thing with some wild pieces. They don't show the new white growth tip like the home grown stuff and I know there growing because i take before and after shots an the growth is clearly there.

 

[Allmost]

I have seen wild colonies [pics not in person] in ocean, with growth tips.

when it gets yo me and you, it has stopped growing, due the so much change ans stress.

 

[acro-ed]

I have noticed the same thing with some wild pieces. They don't show the new white growth tip like the home grown stuff and I know there growing because i take before and after shots an the growth is clearly there.

The "white growth tip" signifies rapid growth. The corals you see that are "growing" but without the "white tips" are growing, but the growth is slow enough that the zooxanthellae has time to populate the skeletal structure before the "white tips" are noticed. In a nutshell...the wild pieces aren't growing as fast.

-Ed

 

[ange062]

I've noticed this exact thing with my Bali mariculture yellow millie. Aside from the color changing over time, the white growth tips are up to 1/4" in length and a different, blockier shape then the tips when I first got it. There is still PE on these tips, just no color. It almost looked unhealthy to me at first, but it's still growing and the base still looks great.

I haven't noticed this with my other Bali pieces though, and definitely not on my ORA frags.

 

[MammothReefer]

Wild/maricultured SPS (usually) don't come in with white growth tips because, simply put, they are not growing. They are not growing because they do not take to being taken from a lagoon to a holding tank and then to your tank as well as captive pieces take to being taken from one person's tank to yours. Those wild pieces likely had very nice white growth tips the day they were pulled from the lagoon, but over the course of days, weeks, and months before you got it the growth has ceased. I have seen first hand that SPS corals in the wild have extensive white growth tips that far exceed what is attainable in an aquarium.

-Ed

I don't think that's the case. I should have qualified that I have spent years picking threw corals at the wholesalers even helped unpack fresh shipments and have yet to see (or recall) a piece coming in with white tips. Maybe I just wasn't paying attention, but I don't think so. I also don't think If I took a piece of mine that was growing well (and had white tips) and did something to stunt it's growth that it would then colour up perfectly (as the pieces appear when they arrive) instead it would brown/bleach/die. On top of that, I have yet to see any "white growth tips" in any pictures of wild, or at least not in the same manner of growth that we in our tanks? Granted just because I haven't seen it doesn't mean it's not happening.

Allmost do you recall where you saw that?


As soon I get a moment I'm going to hunt threw the sdmas coral site see if any of veron pictures has white tips.

 

[acro-ed]

 

[acro-ed]

...and yes, I have seen wild/maricultured come in from the trans-shipper with white growth tips. I have never seen them actually sustain the growth though, and the tips quickly fade to a typical "slower growth" coloration (i.e. blue, purple, pink, etc.).

-Ed

 

[Confuse]

I've noticed this exact thing with my Bali mariculture yellow millie. Aside from the color changing over time, the white growth tips are up to 1/4" in length and a different, blockier shape then the tips when I first got it. There is still PE on these tips, just no color. It almost looked unhealthy to me at first, but it's still growing and the base still looks great.

I haven't noticed this with my other Bali pieces though, and definitely not on my ORA frags.

I was in the same exact situation with my yellow mille as you! At one point, I thought it was bleaching since the white part was so long that I almost clipped it. My mille will grow in that same manner where it will extend out with white tips and branches and then slowly color up over time. Seems like the growth isn't as much slow and constant, but sporadic and rapid.

What are ya'lls experience with retaining wild acro colors?

 

[MammothReefer]

Thanks Ed. I'm not so sure about that photo. Corals often have a different coloured growth rim. It's really hard to say if that is the same thing that is being discussed without a closer up photo of the coralites. However it is possible. I'm going to have to keep a closer eye next time I go to the wholesalers.

 

[acro-ed]

I'm sure there are plenty more pics, and I'm telling you I have definitively seen it in the ocean first hand while diving. There is even a video (can't remember the name) that is a time lapse of a staghorn type acro showing the explosive growth with the white tips and the zooxanthellae slowly "chasing" the growth up to the tip of the skeletal structure. It was on one of those Ocean/Nature type HD Video series'....the white tips appeared to be an inch or two long....pretty neat! Maybe I can find a link to that clip...

-Ed

 

[MammothReefer]

Thanks Ed,
I would really like to check out that video.

 

[Finland]

This is an interesting video of coral farming. Some have growth tips some don't, all with great growth.http://www.youtube.com/watch?v=IjGUoR-CLK0&feature=related

 

[MammothReefer]

Hey Finland,
I've seen that video a few times. I hate to sound arguable here, but I'm just not seeing the "white growth" tips in it all. Just to be clear this is what I'm talking about.

Normal growth (Had this piece for some time in this picture)

White Growth

Again with this piece.. Showing some signs of white growth but not much

Then..

Notice how not only does the coral for a little while loose it's colour, but also the growth shape. All "white growth" tends to take on a similar "blocky" look.

 

[Allmost]

Ive seen it in reef restoration programs and ...

like this :

 

[Finland]

Hey Finland,
I've seen that video a few times. I hate to sound arguable here, but I'm just not seeing the "white growth" tips in it all. Just to be clear this is what I'm talking about.
.

I was at work at the time and couldn't elaborate. I agree, it seems every pic or video I have seen of corals growing in the ocean had some color on the tips. Not the bone white we see in our aquariums. The growth tips on the video I posted all had color it seemed. That was what I was trying to point out. Some didn't look like growth tips, as we know it, the corals just got bigger, and stayed full color. I wish I knew why that is. I would imagine it is a combination of thing we can not reproduce in our tanks.

 

[MammothReefer]

Ya it gets me wondering if we some how can't reproduce zooxanthellae at the same rate that can be done in the ocean, but we are able to grow the coral at equal (if not some times better rates?) I wonder what the missing things are to promote faster zooxanthellae growth/reroduction.

 

[acro-ed]

I came across this pic today at liveaquaria. The tips aren't bone white, but they are much paler and show the "blocky" tips that are typical of recent growth. This pic is of a maricultured coral, and without the actinic light I'm sure the tips would be nearly white.

Axial corallites are always paler than the rest of the branch. Sometimes this structure is pure white and other times it is a different or paler shade of the existing tissue. In nature it may depend on the species, and it may also depend on the conditions present.

The purest explanation of what you are seeing is that the zooxanthelae has not colonized the recent skeletal growth at a density sufficient to see it as having any color. The "blocky" growth tips are typical of axial corallite growth. The pure white tips could be unnatural to some degree in our tanks due to less efficient zooxanthelae reproduction, but it is also seen in nature, so it is a condition that occurs based on the parameters. We are just supplying artificial parameters, hence my statement that it is unnatural.

I can offer two explanations for why this might occur:

(1.) The zooxanthelae in your tank might be slightly less efficient at colonizing the new growth due to an imbalance in the symbiotic relationship between the Acro host and the zooxanthelae (ZX). The ZX is supposed to supply the host with simply carbohydrates (sugar) along with amino acids, and the host is supposed to supply the ZX with CO2 and nutrient in the form of waste. There is a possibility that by dosing artificial amino acids and carbohydrate dosing (vodka, etc.) we are deliberately creating an imbalance in the interaction between the ZX and the coral host. This also occurs in nature, so it is also possible that during certain periods of growth (in certain species) there is also an imbalance (inefficiency) in the asexual budding of the ZX within the host's tissue.

(2.) An alternative explanation is that this condition occurs due to oxygenation within the coral tissue. The ZX, being an algae, produces oxygen. The host is able to suppress and even expel the ZX when it produces too much oxygen. This is known as coral bleaching. It would seem logical that in higher flow areas where the exposed edges of the coral are in direct contact with the rapidly moving water, that the ZX is able to increase its efficiency and is producing excess oxygen within the host's tissue. The host reacts to this condition of excess oxygen by deliberately suppressing the asexual budding of the ZX in the areas where the condition is occurring. We would then observe the coral having white tips as it suppresses the ZX reproduction.

Both of these hypotheses are not scientifically proven (or if they are, I am unaware of it). I am simply speculating based on my knowledge of reef biology, my observations diving, and my 15 years experience with reef tanks.

I wanted to reply again to this thread because I think the topic is thought provoking and I am always striving to learn more. Hopefully someone else may have some more insight.

Finally, here are some recent pics of some of my corals that are also exhibiting varying degrees of low ZX production in the axial corallite structures.

Here is an "Acropora nana." Note that most of the tips are purple, but the very tip of the axial is bright white.

Here is an A. Millepora (yellow with brown polyps) - Bright white axials like this seem to be more typical of this species.

Here is an unknown Acropora, the axials seem white but are actually just a very very pale sapphire color.

Here is an Acropora Efflorescens / Solitaryensis (unsure) that shows pale growth edges (reduced ZX density), but are not pure white.

Here is a different Acropora Efflo. / Soly. that has much higher ZX density at the growth edge.

Hopefully someone finds this worthwhile...lol....it took me a bit to look through my pictures.

Thanks,
Ed