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noy
07/31/2015, 01:33 PM
There is a recent article in the July 2015 (Volume XVI) of Advanced Aquarist by Tim Wijgerde. (I seem to get into trouble everytime i post a link).

The article is a report of 2 experiments which was done to study feed/growth in various species of Dendronephthya corals (the species were not identified). The experiments were based heavily on studies done in 1995 by Fabricius, KE, on food intake of soft NPS corals.

The experiment consisted of a controlled setup where Phyto-feast, Roti-Feast, Oyster-Feast and Rhodomonas sp. (micro algae) were dosed in different volumes in a 80 x 40 x 28 aquarium with a total volume of 370 gallons with 8 Tunze stream 6085 powerheads and a DyMiCo (Dynamic Mineral Control) filter which acts as a jaubert system for nitrification and (supposedly) denitrification. (NB I have to say the lack of controls over the water quality in the experiment was a bit surprising). The difference in the two experiments was primarily the volume of foods being pumped in.

Both experiments showed a substantial decline in coral health and eventual degeneration over a 5 month period. Despite the steady decline there was asexual reproduction noted.

I duplicated the conclusion of the report below:

The preliminary experiments presented here reaffirm the prevailing opinion that Dendronephthya corals are highly difficult to maintain in aquaria. Even though water flow rates and patterns closely matched those found in the natural habitat of these corals, significant amounts of plankton were provided and water quality was maintained adequate, most corals quickly deteriorated. It remains to be determined what factor(s) determine the health and growth of Dendronephthya spp. Food quantity and quality remain key variables to be studied in the future. Future experiments may reveal differences in survival rates and growth between species within the Dendronephthya genus, as different polyp morphologies allow them to feed on different food items.

For now, I recommend that aquarists enjoy these corals in their natural habitat, rather than in a home aquarium. Still, if we are to learn more about the biology and husbandry requirements of these corals, especially their feeding preferences, we will have to continue conducting small scale aquarium experiments. One day, we may be able to truly replicate the biodiversity found on coral reefs, with thriving sponges, tunicates, bryozoans, bivalves, crinoids, (a)zooxanthellate corals and many other invertebrates. Such a reef display would be truly inspiring and have great educational value.


In terms of my personal thoughts, I don't find it surprising at all that a feeding regiment of oysterfeast, rotif-feast, phyto and micro-algae would fail. Many home aquarists (including myself) have tried similar feeding regimes on these readily available commercial foods and failed.

I can't say the main thrust of the article was of any scientific significance but there are some interesting collateral points (adverse effect of air exposure, asexual production even during coral decline). Worth a read.

teemee
08/01/2015, 09:44 AM
Hi Noy,
What's your take on Dendronephthya? Do you have any right now?

HPark
08/01/2015, 04:11 PM
I think I contributed all of $50 on their go fund me page to this effort so received periodic updates. Maybe I was just getting the fundraising e-mails but the project seemed to be consistently hampered by finances.

I was a little disappointed with the efforts as I too wasn't sure what they were trying that was any different than a well prepared hobbyist.

noy
08/03/2015, 08:31 AM
Hi Noy,
What's your take on Dendronephthya? Do you have any right now?

Not keeping any right now. I do plan to tackle them in the future but in a dedicated setup with a dedicated rotifer grow setup. I bought 2 in my current gorg tank (just couldn't pass it up) and they made a big mess when they disintegrated. So they didn't make it in a setup where gorgs were thriving. I have couple of projects ahead of that though.

The most "success", if you can call it that, i had was in my 110 where i kept a couple going for about 8-12 months.

They go through the same cycle - polyp reduction, deflation, shrinkage and disintegration. I just don't seem to have a handle on getting sufficient nutrition to these corals. In nature (based on the article) they are one of the fastest growing corals.

noy
08/03/2015, 08:47 AM
I think I contributed all of $50 on their go fund me page to this effort so received periodic updates. Maybe I was just getting the fundraising e-mails but the project seemed to be consistently hampered by finances.

I was a little disappointed with the efforts as I too wasn't sure what they were trying that was any different than a well prepared hobbyist.

I agree. I am a little skeptical about the assertion regarding the high bacterial count without seeing the methodology. Just not seeing it in a new jaubert(DSB) setup without carbon dosing.

Also I would expected any such experiment on foods to analyze the specimens directly to see what foods was actually ingested (using the methods in the paper that was cited).

shred5
08/03/2015, 09:06 AM
Not keeping any right now. I do plan to tackle them in the future but in a dedicated setup with a dedicated rotifer grow setup. I bought 2 in my current gorg tank (just couldn't pass it up) and they made a big mess when they disintegrated. So they didn't make it in a setup where gorgs were thriving. I have couple of projects ahead of that though.

The most "success", if you can call it that, i had was in my 110 where i kept a couple going for about 8-12 months.

They go through the same cycle - polyp reduction, deflation, shrinkage and disintegration. I just don't seem to have a handle on getting sufficient nutrition to these corals. In nature (based on the article) they are one of the fastest growing corals.

As a past fish breeder I am not sure rotifer would have the nutrition.. Maybe with supplemental copepods it could be enough..

What I find funny is how often you see people feeding or test with phyto. Very little phyto has ever been found in the guts of most corals. What is there most of the time they dont even know how it got there, it could have actually been in the gut of like a copepod. I am sure there are some corals that take phyto directly but how many and how much really? How much phyto is really on a reef to begin with? Water is to pure for it.

I do know in some part of the world phyto does play a large role on reefs. Some island are so porous that that a lot bat and bird feces gets in the ocean causing huge phyto blooms making the water look green. The reefs in these areas are fantastic too but those phyto bloom lead to huge copepod blooms. So again the corals are taking in the phyto indirectly.