the secret to colorful,healthy corals....obvious to some,elusive to many

This thread = mind blown.

I'm a total noob but I understood all be basic concepts behind reef keeping. Nitrogen cycle, photosynthesis, nutrient export etc. I had assumed that only trial and error would help my thick head get around some of the concepts clearly and succinctly explained in this thread. Having read it almost cover to cover I really feel some of the trepidation ebbing away.

Thanks to the RC community for sharing so many great insights.
 
Just one question to clarify and confirm- Assuming the organic nutrients are such that the coral are healthy and thriving, the job of your export methods is to remove the inorganic nutrients (or stop organic nutrients breaking down in the tank). One of the side effects if this is not happening could be unwanted algae growth(?).

So in addition to exporting inorganic nutrients, an efficient algae-scrubber could also out compete the algae in a DT?
 
elegance coral said:
Aquacultured SPS corals have not "evolved" at all. They are all genetically identical to the coral that was their "wild ancestor".

They can make small changes, like pigmentation, or changes to zooxanthellae density, or even total zooxanthellae clad exchanges, but that's not evolution. When we begin "breeding/sexually reproducing" these corals, then we can talk about how they are evolving. As of right now, all reproduction with these corals, in this hobby, is asexual. There is no mixing of genes through asexual reproduction. We are not seeing evolution in these corals.

Peace

EC
Click to expand...


http://www.aims.gov.au/docs/media/f...ssisted-evolution-versus-genetic-modification


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Those are interesting ongoing projects, none of which has anything to do with the claim that aquacultured corals in the hobby are "selected" or "evolved". As was correctly pointed out, all propagation in the hobby is by asexual means. Every coral in a hobbyist tank is genetically identical to a coral that was pulled out of the ocean sometime within the last few decades.
 
EMeyer said:
Those are interesting ongoing projects, none of which has anything to do with the claim that aquacultured corals in the hobby are "selected" or "evolved". As was correctly pointed out, all propagation in the hobby is by asexual means. Every coral in a hobbyist tank is genetically identical to a coral that was pulled out of the ocean sometime within the last few decades.
Click to expand...


This is a bit off topic and mods feel free to move or delete this as you see fit, but, @EMeyer I politely disagree, as I discuss below.

1) the assumption that clonal reproduction does not lead to genetic change / evolution is not correct. There are many animals, plants and prokaryotes that asexually reproduce, yet they still experience evolution (=genetic change over time). Case in point; antibiotic resistant bacteria; they 'evolved' resistance despite being clonal.

Mutation is always occurring. Mutations arising in coral polyps kept in captivity can spread and fix. Every time a polyp duplicates its DNA prior to cell division, there is a chance of genetic mutations arising because of errors in DNA replication the escape repair. A polyp with a new mutation, will clone this new mutation into daughter polyps and so forth. Because captivity does not stop mutation, it does not stop evolution.

Have a look at this for an example of evolution in a colonal organism
News story - https://www.sciencenews.org/article/scientists-watch-bacteria-evolve-antibiotic-resistance
Peer reviewed paper
http://science.sciencemag.org/content/353/6304/1147

2) the idea that the 'gene pool' of aquacultured corals and wild corals are identical is also unlikely to be correct. Imagine a specific species of coral in the wild. Let's call it species x. Species X likely contains a substantial amount of genetic diversity; differences in genetics between individual and populations of the same species.

This study on an Acropora suggests that genetic diversity is Huge
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831158/ ; there is an average of approximately 1 genetic difference every 60 bases of DNA between any two individuals chosen at random. For humans, it's about 1 difference in every 1000 to 2000 bases.

So now imagine a species that has a lot of genetic diversity; a few collectors collect a small number of frags; these frags will have a small proportion of genetic diversity that was initially found in the species (= a population bottleneck). Now imagine that these few frags are now put into a tank.
Some of the frags may have some specific mutations that allow them to survive aquaculture for some reason or another. This amounts to 'artificial selection' which changes the genetic makeup of the aquacultured population.
So the initial collection bottleneck combined with artificial selection plus subsequent mutations in the aquacultured population can all lead to genetic differences between aquacultured and wild populations. The magnitude of these difference may be very small or very large, depending on the levels of standing genetic diversity in wild populations, the size and frequency of the collection bottlenecks, strength of artificial selection and generation time in captivity.

Hope this post offers a few thoughts to consider. For the people inclined to disagree; please resist the temptation to send a quick angry reply. Instead, read and dwell over the arguments presented, and try to think of counter evidence that support your views.

Best,
t


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DNA is amazing. The manifestation of that DNA is situational and you're only seeing those traits that have been triggered, but the data storage that is latent is amazing.

They were able to take a chicken and by triggering latent strings - got it to grow teeth - like its ancestors had...
 
The idea that all of the top sps tanks are grown from frags from tanks which is why they are nice is kind of dramatic. There are thousands of brilliant tanks grown from wild and maricultured sps. The only difference I have noticed is some wild and maricultured corals take a little longer to aclimate to tanks and start growing. While a few require much more demanding conditions. Frags grown in tanks for years might be easier to grow but most of these are easier space to keep from the get go. Keeping the wild equivalent of these corals is just as easy.
It bothers me when people try and say wild corals just die and turn people who are not aware of how to keep them away from buying them. Keeping wild corals is all some people in certain areas can keep. Most everyone's tanks in these regions are started from wild corals since there is no market for tank raised fragments. You don't hear about people saying wild and maricultured sps is hard or not worth it around these regions.
Keeping wild sps is all about knowing how to choose healthy corals, since most deaths are because of shipping stress and or stress from being held at local fish stores or wholesalers. Even if the coral dies weeks after purchase.
I have not seen much of a difference in tank raised and wild corals when I take in consideration the above.
 
Wild corals do just as well as frags from tank raised corals IME, with a two to four week quarantine and treafmet treatment for potential pests as necessary in either case.
 
I find wild corals more hardy but also more demanding in light and flow.
Tank raised are more "pampered". They prefer softer conditions.

Both can grow well once acclimated.
 
95% of my SPS are wild collected specimen (almost 90 different species) and they all do just fine.
 
Hkgar we have Bengal cats, here is our webpage. www.graffitispotbengals.com

Thanks for chipping in on my thoughts on wild coral guys. On another website similar to this the idea that wild corals are pest filled and will just die is pushed more than the topic is brought up. Sorry to get a little off topic too.
 
EMeyer said:
Those are interesting ongoing projects, none of which has anything to do with the claim that aquacultured corals in the hobby are "selected" or "evolved". As was correctly pointed out, all propagation in the hobby is by asexual means. Every coral in a hobbyist tank is genetically identical to a coral that was pulled out of the ocean sometime within the last few decades.
Click to expand...
I have no idea if you are correct about coral evolution but the claim that every propagated coral is the same genetically to what it was taken from doesn't ring true.

Each coral consists of hundreds (thousands?) of polyps. Different types of polyp animals reproduce differently but many are sexual. It is possible that the frags of frags of great, great grandfather frags are generically different to the original due to reproduction after fragging.

Of course it's just as likely that the corals adapt. The textbooks say than two members of one species on the same reef can look like entirely different species due environmental factors like water turbidity, flow, competition etc.

Great topic

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Punchanello said:
I have no idea if you are correct about coral evolution but the claim that every propagated coral is the same genetically to what it was taken from doesn't ring true.

Each coral consists of hundreds (thousands?) of polyps. Different types of polyp animals reproduce differently but many are sexual. It is possible that the frags of frags of great, great grandfather frags are generically different to the original due to reproduction after fragging.

Of course it's just as likely that the corals adapt. The textbooks say than two members of one species on the same reef can look like entirely different species due environmental factors like water turbidity, flow, competition etc.

Great topic

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Click to expand...
Do a search on epigenetics and do some reading. In the short term (thousand of years) frags will be identical in their genetic makeup. Short term adaptation has to do with specific bits of genetic code being triggered by changes in the environment to change the way proteins are folded.

Over much larger periods of time, populations of fragments that become geographically separated can become genetically different because of replication errors, or even because bits of foreign genetic material have been incorporated. The latter is something that has been verified in bacterial populations.

Edit: here's a good link: https://www.whatisepigenetics.com/what-is-epigenetics/
 
Coral Growth Slow

Coral Growth Slow

I am a heavy feeder including Reef Chili with strong lighting and good flow. Phosphates and nitrates are low but more than zero. I believe my skimmer and Rollermat takes out enough nutrients before they become NO3. PO4 comes out with GFO. Have brown algae on glass but no hair algae ever. I have a refuge/pod tank which grows Cheto very slowly. Target KH is 8.5, Temp 78, Salt 34. PH 8.1 to 8.3. Using a calcium reactor and other parameters are stable and in range. I am dosing Amino acids.

Color is not bad, but growth is slow. Any ideas? Not a lot of Coraline Algae for a one year tank rebuild either.
 
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