Freshwater Corals

[Galilean]

http://www.panda.org/about_wwf/where_we_work/africa/where/mozambique/index.cfm?uProjectID=MZ0020

Very few freshwater corals are known to exist in nature (see above)

Has anyone tried to keep any corals or even corallimorphs in freshwater? I have suspected, since reading Dr. Addey's book Dynamic Aquaria, that it might be possible to keep coral freshwater, but I haven't tried any yet. I was wondering if anyone had any thoughts on it.

I suspect that it may be the pH and carbonate or bicarbonate hardness that is really critical rather than the salinity. I think they can work around salinity and snails, clams, etc. have no trouble precipitating calcium out of freshwater.

Recently I successfully acclimated some cauplerpa serrulata to a specific gravity of 1.012 as a first step. This only took 6 hours and the caulerpa continues to grow as fast as ever under a 65 W compact flourescent. I used this plant to filter a bare 20 gal with 5 reef fish while giving them a low salinity treatment against cryptocaryon irritans. All the ick was gone in 10 days but I held out for 22 days to make sure.

Anyway, this got me thinking about freshwater corals again. Any ideas?

 

[goda]

i always read corals couldent survve in fW.. but then to find that there really are FW coral

anyways maybe what they are calling coral is really just FW jellyfish that are rooted to the bottom i doubt they are anything like sps or anything

anyways iv thought about this as well and wanted to try to drip aclimate a mushroom to FW ( veryyy slow.. several months ... along with a blue danmsal

 

[raaden]

Now this is an interesting topic. My guess is that if it is natural it has occurred over hundreds or thousands of years of adaptation. The area they are talking about is a small inlet off of a large body of water on the Mozambique Border. It may have been connected at one point to the ocean although I am not sure there are any reefs near there. On the other hand if they have somehow adapted SW corals to this environment this could be interesting.

I am setting up a large prop system and this may be the first research project I try. The WWF is good about sharing information and I may try to contact them about this.

I have seen where makeup tank valves have stuck and hyposaline conditions have happened that corals do not survive well, but that is a fast occurrence with little time to react. I can also tell you that closer to the beach there are times throughout the year that salinity will fluctuate greatly but I am not sure it makes it out to reef areas.

 

[goda]

well there are corals everywhere. even up north ( well atleast anenomes.. same thing basicaly) just not limestone producign ones. so there is a reef near there. just not anyhting we would care to display

 

[raaden]

Goda,
Good point about the anemone's, wasn't thinking about that. also I stand corrected on the presence of reefs near there. It seems there is a fairly high density of reefs in the Mozambique straits. Also look up in the Norther British isles area it looks like there is a sizable reef there; whoda thunk it

From this I would lean towards the adaptation idea. It also does not seem that far fetched to believe that corals could potentially live in freshwater. What affects it would have on them and how appealing they would remain would be interesting to see.

Another idea I thought about last night would be to attempt fragging over the course of a year at different salinity levels while maintaining ph stable (could be difficult). It would seem to me that something like a GSP (need a fast grower, and Xenia is too finicky) could be kept at a certain salinity level and then fragged into a few pieces. Then take a few of those pieces and let them grow out at a lower salinity while keeping the original colony and a few frags in the original environment. then keep this going as the lower salinity pieces grow out take a couple of frags and move them down another notch.

With this approach you could be at brackish/nominal salinity levels within a year if all goes well. If it doesn't you could always just continue again from the last successful step and see where you hit a wall. It also seems to me that during the transition feeding would be imperative, but this should not be that hard. There are many microalgae strains that could make the transition as well.

Another thing I thought of last night was the huge limestone deposits you find near temperate FW lakes. Not being a geology major I could only guess at why this is. Erosion/Deposition but what if it isn't :eek2:

If anyone is interested in trying out this theory with me I would love to setup a couple of tanks and compare some notes. I have a few 20T tanks that I can use for this, and if I can get three steps into it I would be willing to get some more to continue.

 

[Glove]

Not really a coral, but the quarry we train in here in Indiana, has some freshwater jellyfish and a species of sponge that can be seen during certian parts of the year. I have also seen some type of polyp at a depth of 40 feet and temps about 50 degrees F. I never have my camera when I run across these polyps though.
The jellyfish have been in decline the past few years and we think the zebra muscle population has played a part in this.

I wanted to try collecting a few of the jellyfish. There seems to be a trend for them to appear about late sept-oct and then they are gone again. I am courious if they have a larval stage they go through.

 

[Galilean]

I think if you get into genetics (or even just breeding) you will find that some adaptations (natural or manmade) can occur much more rapidly even than thousands of years. I respectfully disagree with typical expert opinion on this. Look what has been done with the standard domestic animals (dogs, cats, horses, cows, pigs, etc.). Or think about goldfish, betas, guppies, platys, mollys, etc. I know from experience and reading those with much more experience than me that cichlids and tetras are far more genetically compatible/interchangeable than the taxonomic “splitters” make them out to be. In Scott W. Michael’s books on Reef Fishes it is clear that hybrids exist naturally and manmade between many saltwater fish as well.

I take it as a general principle of genetics that there is much more information in any given animal than is expressed physically. This is why you can get your fish to have long fancy fins, change the size, change the color, and change the personality, etc. by selective breeding. It’s much to fast for new genetic code to be created so the variation must already exist. Only the selection is required to bring it out.

So as this applies to corals… I think that some corals probably already have the genetic capability to survive in freshwater. There is nothing about their basic life requirements that includes NaCl. It’s just a matter of nudging them in that direction.

 

[goda]

wouldent this be better in advanced topics?


btw you are right. the african area has alot of what. african cichleds what do we keep that ph at ? 8.2


this is all about osmosis more then anything else and if it has the mechinism to reverse the way the water is forced..( like mollys do)

 

[raaden]

Probably would be better over there... I am willing to move

Glove,
I would defnitely be interested in seeing/hearing more about the polyps you are referring. I have heard from my dad about strange coral-looking growth in a quarry in Pa he used to dive. Jellyfish definitely have a pelagic larvae period.

Galilean,
Agreed on the adaptation and genetics, my only issue with it is that breeding(spawning) in corals is nonexsitent on a large scale for captive specimens. Therefore the adaptation would be much slower for corals than that seen in fish and other mammals. On the other hand corals are constantly adapting to their environment and changes. Some of this would be on a borderline morphing scale. Also they seem to be equipped with pretty intense defense mechanisms and have lasted for millions of years. These things together tell me that it may be worth it to study it a bit.

On the NaCL- issue from what I understand, when referring to corals, that is much more required for maintenance of the environment and the chemical processes needed than on the animal itself, fish would be a completely different story. In a colonial coral there are no organs to be damaged and if the coral does not store large amounts of water in its tissue there should be little affect to the tissue itself. It seems that if the salinity changes were slow enough there would little affect on a few select species.

Goda,
I am not sure I understand the osmosis thing. Are you referring to the ability to feed/breathe or are you just speaking overall.

 

[Galilean]

Right, the main thing is the calcium and carbonate ions, and this you can easily get in freshwater with off-the-shelf aquarium products. I don't know which trace elements are really critical. You can guess from the relative abundance of each in the animals tissue (listed in Dynamic Aquaria if anyone wants to know). But you can add those independant of the salt as well anyway.

It might be a very novel product to have freshwater coral or other typically salt water creatures acclimated to freshwater. Eventually I expect the husbandry of all of these creatures to advance to the point that they can be selectively bred for color and other "selling-point" attributes.

This is fascinating to me because its something that had not been done. Likewise I am trying to breed lysmata shrimp in a new "hands off" technique. Eventually I hope to automate most of the process so that they can be produced on a commercial scale.

BTW I have no problem with moving the thread to adavanced topics. I assume moderators do that?

 

[goda]

no osmosis of the tissue's

FW fish constantly have FW flowing into them and SW fish have water flowing out of them so the cells need to "drink"

think it throu for awhile and forget about your RO unit