Evolving Corals?

[NaH2O]

With all of the frag trading and coral propagation in the hobby today, are the corals evolving in order to deal with "tank" conditions? There is such a difference, IMO, between the natural reef and our closed systems....even though we attempt to replicate it, there are so many factors involved....I think we have a difficult time recreating the environment as on the reef. Have "tank" corals started to adapt to their confined environment through the captive generations (even though they are frags)?

If returned to the ocean what would hapen to them...would they be able to survive, or is their biology such that they wouldn't have a problem? Better yet, what would happen to the natural reef if we introduced captively propagated corals? Eeek...the last question scares me....

 

[Curtswearing]

I think we have a difficult time recreating the environment as on the reef.

Yup...I don't think we are even remotely capable of recreating reef conditions which are low in nutrients and high in Oxygen. As you mentioned, our tanks are closed systems and are very high in nutrients when compared to a reef.

Actually, this is an interesting topic. It's my understanding that more than one dinoflagellate can live in a coral. I wonder if some strains are better suited for reef aquaria. Since the dino's are the major food source of most corals, I do wonder what would happen if we put corals from a high nutrient reef tank with dino's accustomed to high nutrients back in the ocean.

I gotta stop ramblin' on here. I'm just thinkin' (typin') out loud. Maybe we should compare the major differences between our reef tanks and a real reef. Then we can drill down and think about possible changes in corals in reef aquaria. Then we can decide if re-introducing frags is good or bad.

 

[wrightme43]

That is a very good question. It is my understanding that a frag is a exact clone (genetic) of the parent coral. Every animal has in its d.n.a a broad spectrum of adaptations it can draw on to live in different enviroments. If all we are able to do is frag our corals, you would think if they were returned to the ocean it would be o.k. however if we are able to get them to reproduce sexually, in our aquariums, we would be selecting for captive life. My example for this is clownfish. If I trap and keep a wild clown in its anemone in my system and then return them to the wild the only risk would be parisites, if I breed them and then return the ones that live, I would of selected for captive life. If they were to breed with wild stock, it could damage the gene pool. I welcome any comments that would help me to understand where I am right or wrong in your opinion. Thanks Steve

 

[MikeS]

Very interesting topic...

I'd say yes...corals can "evolve" and adapt to tank life...

Especially corals and inverts like clams that can reproduce sexually I think will have the best sucess. "Survival of the fittest"...those corals and inverts that are best suited for survival in tank conditions will survive to pass on their genes, and this will be compounded generation after generation...

MikeS

 

[NaH2O]

Wow - good responses. Village idiot? Curt....that title is reserved for mom's that can't remember what they were doing when walking into a room.

OK - to address Curt's point....we should compare the major differences between our reef tanks and a real reef. Obviously we can mimic high flow and current with things like actuators, wave devices, surges, etc....but that water isn't a different temperature rushing through. I don't know how much a cooler current effects a coral's health or survival, but on hot - sun blazing days it has to help. We also don't have storms - even though blasting our rocks with a powerhead may provide a similar effect? High nutrients, as Curt mentioned, is another issue. Predation of the corals may not be the same in our reef tanks...at least we try to not have our corals harmed.

Good points, Steve on captive breeding. As for DNA - I can see that, it is the same DNA, but would environmental conditions effect it? Would zoox strains even come into play?

Mike, for sure sexual reproduction would lead to a survival of the fittest, and would continue provided they kept reproducing sexually (corals).

One of my concerns about putting captively raised corals back to the reef is disease and/or parasites...maybe one type of nuisance algae hitches a ride on the coral. Am I out of my mind with this?

 

[Curtswearing]

Here's an article that indicates that the varying degrees of irradiance controls which dinoflagellates thrive and which ones don't.

Click Here and here's and another LINK

 

[wrightme43]

NaH20 I would worry about algae as well. The parasites that reproduce in our systems have had enough generations to adapapt to our systems. They could be very troublsome to wild corals. This is a awsome subject. How in the heck can we make sure we are doing the right thing. We all want to conserve the reefs. We all want to repopulate reefs that have been damaged by people. Do we just put frags out and see what happens. That could be terrible or wonderfull or just mediocre. You would think we could try with a reef that is dead and isolated. But sometimes my best thinking is the worst thing I can do. On the subject of you being out of you mind, do normal folk spend their money and time on little green critters that live in water? ha ha.

 

[NaH2O]

Zooxanthellae Rule!

I am going to apologize in advance for my post being disorganized. I've been having trouble getting my thoughts on what I want to say in any coherent form, so this post is me thinking out loud.

Curt - thanks for the links. Some of the information was new to me. On the point of irradiance: If we introduce a coral that is used to a particular irradiance and the zoox can't handle it - they get kicked out, so a zoox that is more suitable to a particular environment will habitate. The corals in the system all have zoox that are suitable for the current environment and are surviving otherwise we would have a white coral. What happens to the zoox that is kicked out....it wouldn't be useful to another coral because it is unsuitable for the environment, so it gets picked up by the skimmer? In essence would all of the corals in a particular system have the same zoox? I understand that corals can have different zoox strains in themselves, but would these strains be shared throughout the corals? Maybe not - I haven't thought through this yet. In the second link, there is a statement about corals mid-day renewing or releasing certain numbers of zoox on a daily basis. I can see that it would be easy to swap zoox. But, how long do these guys stay floating around? With a strong protein skimmer and high flow, I'm having a difficult time seeing this. Color changes of corals....different lighting or swapping zoox?

Along the same lines, since we are discussing zoox....I read a Review by Delbeek about a study conducted on flow and coral bleaching. Here is a link to the article: Media Review. Basically, what they found were areas that had high flow exhibited less bleaching by aiding the removal of derivitaves through enhanced diffusion. A pretty interesting read. In the conclusion, Delbeek indicates to help prevent bleaching ...increase flow: if your tank gets too hot; if you get a new brighter lighting system or new lights; if introducing new specimens from dimmer aquaria or place these in areas with greater water flow.

wrightme - I don't know that we could find an "isolated" reef to attempt a study, as the ocean is all tied together. Introducing an algae or parasite that isn't normally found in a location would, IMO, lead to a horrible outcome (thinking of the Simpsons episode where Bart brought a frog to Australia?).


OK - I think this was long enough....let's see how I did

 

[wrightme43]

NaH20 Good point, on the isolated reef. I had never really thought about the zoox, now I've got something else to sit and ponder. I keep reading all of this stuff, and discovering how little I know. I am very glad you are all here. So let me make sure I understand. The zooxanthe are interchangable, the coral decides how much, and what kind, based on light, current, temp, and nutrient levels. They can release and aquire new zoox, from and to other corals.

 

[wrightme43]

Nikki, I looked in one of my books, on adaptation (genetics) it is called the Runaway Brain the evolution of Human Uniqueness, by Christopher Wills. It discusses enviroment as a factor of evolution. Here is my understanding of what it says. All life has a broad base of genitic features, and the more it has the more succeding generations can adapt. For example Pygmy Mammoths existed on a small island because food was very limited and not able to support a large animal. rather than die off small 3 to 4 feet tall mammoths survived and had babies. What it says is because of lack of food this happened to some of the first babies born there, then because the genes were activated for small size the next generation had more small babies. On the flip side of the coin, the corals have lived in the stable ocean for a very long time, do you think that they have become rigid (geneticly) or can they still rapidly adapt to new enviroments. Along those lines Acropora has like 6 or 7 different growth forms depending on light, current, nutrients, and God only knows what else. All of it is able to survive. grow, and reproduce, with each of the other forms. Then on top of that, my book on Corals by Eric Borneman says they can crossbreed as well. I want to understand, but sometimes I think I never will.

 

[NaH2O]

Interesting on the Pygmy Mammoths....we can use giraffes' necks as an example, as well. The thing with evolution on that magnitude it is takes a long time. Corals have adapted in the ocean environment for many many many,etc. years. I am unsure of "coral evolution" through the changes in ocean environment - how different are they from fossilized records. One thing about evolution in the genetic sense - is it takes reproduction to alter the genes. How many people experience their corals sexually reproducing in a tank, as opposed to being a clone? I'm sure there are some, but are the conditions such that it is impossible (sexual reproduction) to occur (thinking of a heavy duty skimmer)? So, we wouldn't get a genetically altered coral. Perhaps the corals don't do anything but be themselves, and it is all related to the best environment we can give them to survive.

 

[ScottT1980]

Just to go back a bit (I skimmed, so I apologize if this has been covered):

As far as corals evolving in our tank, I would say no, only because evolution takes time and mutagenosis (if we are talking about Darwinian evolution...Lemarkian is a whole different ballgame), at least from what I can recall. However, natural selection is occuring (now I am starting to confuse myself).

In other words, we provide an environment that is tough on some corals, great for others. Of course, it is difficult to speak in general terms since my system is completely different from your system, etc... However, most of us think things like xenia, star polyps, colts, leathers, shrooms, etc... grow quite well in our tanks, perhaps moreso than in the natural environment. Why? Because we have removed natural predators, have an environment with far more nutrients, etc... So, this is where natural selection comes into play, this is where we are "God's" controlling our own environment.

In order for actual evolution to take place, a coral that at one time could not survive our tank's environment would have to mutate in order to adapt. Is anyone aware of this occuring?

I do have a buddy doing transgenics at UNC that has considered getting into transgenic corals, although upon researching this proposition he has found that the costs (fiscal and otherwise) might greatly outweigh the fiscal benefit. This brings up another huge issue, especially if transgenic corals found their way back into our oceans (see glo-fish/glo-rabbit/glo-anything debate).

Crazy stuff...wait...what was the question???

Take er easy
Scott T.

 

[ScottT1980]

Also, here is a link explaining the difference between Lamarck's evolutionary theory and Darwin's. People often times confuse the former with the later. I did have a physics proffesor in undergrad. who was believed in Lamarckian evolution, and could actually make it sound pretty convencing.

Take er easy
Scott T.

Edit: BTW, I can't spell...consider yourself warned

 

[mojoreef]

Interesting topic. In regards to Zoox transfer, its pretty tough for that to happen in our closed enviroment, it once again becomes a recruitement problem. As in thier isnt enough of the stuff coming inot the tank and being constantly available for it to make any impact, however thier is a slight possibility that some may occur.
As we know some corals and clams use zoox as a control function for food delivery. For corals they will regulate the ammount of zoox population with in them based on their nutritional needs. The zoox popluation will regulate itself based on the ammount of availble food. Zoox population is based on the ammount of nutrients the coral transfers back to it, this is a control feature, however if the surrounding water is nutrient laidened, through absorbtion the zoox would e subjected to more food and thus would begin to bloom with in the coral. This would be one of the reasons corals turn brown (Zoox is brown). In this case the coral would expell as it only requires so much food.
Zoox populations are all subject to the dominance theory, as in the enviroment will dectate which strain becomes the most dominant. This also occurs with in the pigment strains of the coral (which is what dictates the color the coral will turn).
Thier is no reason why corals could not be put back into the wild as long as they are a native species, thier ability to adapt would not take them long to be back in biz. Humans have been putting corals and reseeding them into the wild for decades and it is done by countless orginisations and countless countries. Jeauberts monaco's aquariums whole original setup was to reseed the caribean with Acropora.

Mike

 

[NaH2O]

Thanks for jumping in Scott - I knew there was something about my genetics classes I was forgetting. Great link, too.

Crazy stuff...wait...what was the question???

LOL - I started this thread, and I have a difficult time remembering myself!

Thier is no reason why corals could not be put back into the wild as long as they are a native species

Mike, what about tanks that have corals from different areas? A hitchhiking parasite from one coral jumps on the other from a different location. Introduce the coral with the new parasite back into the wild.....wouldn't you introduce a foreign parasite the new location? Not possible?

 

[mojoreef]

Well with the places and psople that do this repopulating all that is taken into concideration. Enviromntal controls are key in that process and different regions are never mixed. They have to be proffesional and scientific when running these operations. Just ask EricB you got his permit denied, lol

Mike

 

[Curtswearing]

I would still like to discuss this issue further.

However, maybe organizations like Reefballs are doing a good thing if they are careful. Heck, you can even be buried in your own man-made reef by having your ashes mixed into the concrete of a reef ball

 

[NaH2O]

MINI-REEF BALLS - YAHOO!!

Mini-Reef Balls OK....I almost suffocated from laughing so hard at this - tooth brush holder?..... I better order my model reef balls quick before they run out....I think I'll use them to break ice at the party I'm having this weekend.

The mini-reef balls are great because:

........
* Business card holder
* Pen holder
* Candle holder (great for those romantic nights)
* Table centerpiece
* Conversation piece
* Paper weight
* Toothbrush holder
* Desk decoration
* Remote control holder
* "Pet" reef
* Icebreaker for parties
* Doorstop
* Landscape border
* Orchid pot
* A gift for an ecologically minded person

I'm very interested in the reef balls - it doesn't seem as though they put corals or anything on them, so I'm not sure how this is a benefit - I could be wrong. I hope people don't take the corals from their aquariums and glue them on.

Is creating an artificial reef beneficial to the ocean environment or does it not make a difference?

 

[NaH2O]

If we go back to corals' ability to adapt....what ways will the coral adapt to handle its environmental changes?

 

[Curtswearing]

Some experiments are being done on that right now. I don't have access to the full article but here is the abstract.

Previous research has demonstrated that the massive corals Favia speciosa (Dana, 1846) and Diploastrea heliopora (Lamark, 1816) are phenotypically plastic, i.e. the phenotype of these species can be altered by environmental conditions within their life span. Many researchers have suggested that light, water movement and/or sediment can affect coral morphology, but no work to date has attempted to separate these variables in a controlled aquarium experiment. To ascertain whether any of these three factors could induce morphological change in F. speciosa and D. heliopora, fragments (clone-mates) of both species were maintained in five aquarium tanks, representing: high water energy, high sedimentation, and three different light regimes. After 4 months, the architecture of 12 randomly chosen corallites from each fragment was measured. Reaction norms suggest a relationship between corallite morphology and light, but no consistent pattern could be detected for fragments kept in the sediment regime tank or the high water energy tank. Corallites expand, extend and deepen in high light conditions and possible functional explanations for this response are presented. However, more research is necessary to confirm that light is the primary controlling factor inducing small-scale morphological change in F. speciosa and D. heliopora.