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Old 08/15/2015, 08:33 PM   #1536
34cygni
Registered Member
 
Join Date: Mar 2013
Posts: 59
Wow.

I read the entire thread. It's an epic. I totally feel DNA's pain.

Maybe I can help you guys make sense of what you're seeing...

The thing about mixotrophic dinos is that they're predators that acquired the ability to photosynthesize, not autotrophs that evolved into predators. That's why if you treat O. ovata like algae, you lose.

The big mystery is where are dinos getting their nutrients from? Especially in a ULN system?!? Even scientists seem perplexed...


Quote:
Originally Posted by Ecology of a bloom of Ostreopsis cf. ovata in the northern Adriatic Sea in the summer of 2009
Recent studies have provided increasing evidence of a link between nutrient enrichment and harmful algal events (Hallegraeff 2010). However, in our study, although peak abundances coincided with a decrease in nutrient concentration, we did not observe a clear relationship between the bloom and nutrient concentrations; an observation supported by other studies (Vila et al. 2001; Shears and Ross 2009).
The reason nobody can correlate nutrient levels with dino blooms is that the dinos aren't operating in autotrophic mode. Ostreopsis ovata can do that if there are enough nutrients in the water...


Quote:
Originally Posted by Cell Growth and Toxins' Content of Ostreopsis cf. Ovata in Presence and Absence of Associated Bacteria
This investigation shows that the removal of bacteria associated to O. cf. ovata unaffected cell yield algal cultures, while it appears to confer a higher cell number at mid stationary growth phase. This finding is in agreement with previous results reported for other toxic dinoflagellates (e.g. Uribe & Espejo, 2003; Green et al., 2010 and references therein), and it is reasonably due to the lack of bacteria-algal competition for nutrients, together with the absence of algal degradation by bacteria.
...but obviously that's not what's happening in our reef tanks. When O. ovata (or any dino) is nutrient-limited, it solves the problem the same way we do: by eating something. That's what's happening in our reef tanks.

Think about it. What do you guys know about dinos?


Quote:
Originally Posted by Surly
I've read that there are a number of symbiotic bacteria hosted in the dinos' mucilage.
Quote:
Originally Posted by Adrnalnrsh
Dinos and Cyano have a symbiotic relationship
Remember the evolutionary history of the enemy: mixotrophic dinos are predators that acquired the ability to photosynthesize. These bacteria, the cyano... They're food. Dinos are no more symbiotic with them than people are symbiotic with cows. I mean, yes, we protect cows and we feed cows and we want cows to be fruitful and multiply, but that's because we eat cows. On paper, domestication is a big win for cattle -- there are lot more cows in the world than there would be if cows were free to gambol and frolic in a natural landscape filled with predators and diseases -- but the only benefit an individual cow derives from its relationship with humans is in the abstract philosophical sense that existence is better than nonexistence. We're the ones who benefit from that relationship, as dinos do from theirs.

Heterotrophic bacteria are rich in phosphorous; diazotrophic cyanobacteria can fix nitrogen and are rich in iron. That's the hat trick -- the big three limiting nutrients in aquatic ecosystems, right there.

This isn't my idea. It popped up in a scientific paper on red tides from 2010 and so obviously applied to O. ovata in a ULNS reef that my jaw dropped open when I read it.


Quote:
Originally Posted by Growth, Feeding and Ecological Roles of the Mixotrophic and Heterotrophic Dinoflagellates in Marine Planktonic Food Webs
Dinoflagellate predators often have considerable grazing impact on and sometimes control the natural population of prey including heterotrophic bacteria (Seong et al. 2006; Jeong et al. 2008), cyanobacteria (Jeong et al. 2005b), nanoflagellates (Jeong et al. 2007b), diatoms (Jeong et al. 2004d; Yoo et al. 2009), other dinoflagellates (Jeong et al. 2005c), and ciliates (Smalley and Coats 2002). ...

By combining the results of Jeong et al. (2005b) and Seong et al. (2006), I propose a possible mechanism of the outbreak and/or the persistence of offshore or oceanic red tides (Fig. 9); many MTDs [MixoTrophic Dinoflagellates] such as K. brevis, P. donghaiense, and P. minimum are able to feed on Synechococcus sp. and heterotrophic bacteria. Therefore, if the MTDs feed on some cyanobacteria which can conduct nitrogen fixation (e.g. Mitsui et al. 1986) and heterotrophic bacteria which usually have high P : N ratios (e.g. Tezuka 1990), the MTDs are able to obtain nitrogen and phosphorus simultaneously for their growth in offshore or oceanic waters.
Red tide dinos aren't benthic, of course, but O. lenticularis is...


Quote:
Originally Posted by Associated Bacterial Flora, Growth, and Toxicity of Cultured Benthic Dinoflagellates Ostreopsis lenticularis and Gambierdiscus toxicus
The genera of bacteria found with Ostreopsis clone 116 did not change during the course of these studies, suggesting a selectivity in the dinoflagellate-bacterial association similar to that reported in other algal-bacterial systems (11, 19). ...

The total bacterial cell/dinoflagellate cell ratio remained essentially constant through the initial 28 days of culture growth. Following this period, there was a steady, significant increase in the total bacterial cell/dinoflagellate cell ratio through 49 days of culture growth. The percent total bacteria directly associated with the dinoflagellate cells was high (above 70%) in the inocula used to initiate the dinoflagellate cultures in this study. This percentage decreased significantly (to values below 10%) during the first 7 days, followed by sharp increases (60 to 80%) at 21 to 35 days of culture growth. ...

The dinoflagellate cells appeared to exercise some control on both the total density and distribution of the bacterial populations present in the respective culture flasks. Peak dinoflagellate culture growth rates (first 4 to 7 days of culture, Fig. 1) were associated with reduced numbers of bacteria directly associated with the dinoflagellate cells (Fig. 2), while peak relative dinoflagellate cell toxicity (Fig. 2, shaded area) was associated with a significantly increased fraction of closely associated bacteria. Later stages of culture growth (35 to 49 days) were marked by reductions in dinoflagellate cell toxicity and relatively uncontrolled increases in the total bacterial cell/dinoflagellate cell ratio. Increases in bacterial population densities associated with the decline of phytoplankton blooms have been reported elsewhere (10, 36).

Results presented here show that bacterial genera associated with 0. lenticularis grown in clonal laboratory culture are not toxic when grown individually in pure culture. Marked increases in the proportion of these bacteria directly associated with the surfaces or extracellular matrices of these microalgal cells were correlated with the development of peak dinoflagellate toxicity during the static phase of their culture growth. Subsequent declines in dinoflagellate culture density and toxicity corresponded to uncontrolled increases in the total bacterial cell/dinoflagellate cell ratio and decreasing proportions of bacteria directly associated with Ostreopsis cells. These results suggest that associated bacterial flora may play a role in the phasic development of toxicity in laboratory growth cycles of these algal-bacterial consortia.
In other words, not only are the dinos eating heterotrophic bacteria, they're farming their preferred food species of heterotrophic bacteria!


>The total bacterial cell/dinoflagellate cell ratio remained
>essentially constant through the initial 28 days of culture
>growth. Following this period, there was a steady,
>significant increase in the total bacterial cell/
>dinoflagellate cell ratio through 49 days of culture growth.

That means that the dinos were running the show for the first month or so, but then they lost control and the system shifted to a state in which bacteria were ecologically dominant. What happened?


>The percent total bacteria directly associated with the
>dinoflagellate cells was high (above 70%) in the inocula
>used to initiate the dinoflagellate cultures in this study.
>This percentage decreased significantly (to values below 10%)
>during the first 7 days, followed by sharp increases (60 to
>80%) at 21 to 35 days of culture growth. ...
>Peak dinoflagellate culture growth rates (first 4 to 7 days
>of culture, Fig. 1) were associated with reduced numbers of
>bacteria directly associated with the dinoflagellate cells
>while peak relative dinoflagellate cell toxicity was
>associated with a significantly increased fraction of closely
>associated bacteria.

The dinos start off with plenty of food (over 70% of the bacteria in the flask) and eat their way through it in the first week, reproducing rapidly while their food bacteria drop to 10% of the bacterial population. The dinos respond to this crisis by producing poison to suppress competing bacteria and encourage the growth of their food bacteria. They're like farmers spraying weed killer to prevent competition for nutrients in the soil and maximize the growth of their crops, and the population of the dinos' bacterial "symbionts" rapidly recovers over the next two weeks to over 60% of the total bacterial population, preventing a crash in the dino population.

Maximum measured toxicity comes at week 4, corresponding to a decline in the population of the dinos' associated bacteria to about 50% of the total population. The dinos have hit a point of diminishing returns. Metabolic waste products and the physical remains of dead dinos and bacteria are piling up in the mucilage -- all the stuff the dinos' bacteria can't eat -- and more and more poison is needed to keep unwanted bacteria away from that growing food resource, but now it looks like that strategy is failing and their food supply is threatened.


>Later stages of culture growth (35 to 49 days) were marked
>by reductions in dinoflagellate cell toxicity and relatively
>uncontrolled increases in the total bacterial cell/
>dinoflagellate cell ratio. ...declines in dinoflagellate
>culture density and toxicity corresponded to uncontrolled
>increases in the total bacterial cell/dinoflagellate cell
>ratio and decreasing proportions of bacteria directly
>associated with Ostreopsis cells.

At week 5, the dino population is declining. Interestingly, the population of dino-associated bacteria rebounds to over 80% of the total bacterial population -- in all likelihood by eating dead dinos. Even more interestingly, the dino population doesn't rebound along with their food supply, but instead continues to dwindle in weeks 6 and 7... Obviously, something has changed.


Quote:
Originally Posted by Montireef
Dinoflagellates are so delicate and easy to kill...it's only that in ideal conditions they reproduce very fast (both sexual and asexual) and can suffocate any system.
The shift from a system dominated by dinos to a system dominated by bacteria resulted from eutrophication. In a weird way, it looks like ostis are in the same boat as we are -- they're battling eutrophy, too -- and I suspect this explains why "the dirty method" of dino control works. Getting a little sloppy with the housekeeping just helps nature take its course, moving up the eutrophic tipping point where opportunistic bacteria and protists can invade the mucilage and overrun the ostis' bacteria farm.

And speaking of opportunistic bacteria...


Quote:
12/30/2014, 09:42 AM #554
karimwassef
What did you add? Food? Live rock? Love sand? Salt? Additive?


12/30/2014, 09:45 AM #555
Montireef
two kgs live rock and 2 litres skimmate


12/30/2014, 10:41 AM #557
Montireef
Yes, my system was too ULNS and noticed important bacterial growth in the skimmate so I dumped the whole cup. Corals got very happy and extended polyps. One week later I noticed ostreopsis mucilage turning white and on the microscope I see millions of these microorganisms thriving.

I have also been dosing large amounts of Ca(OH)2 keeping pH around 8,7 and put off CO2 input to the Ca reactor.

Live rock was from Indonesia


12/30/2014, 05:59 PM #577
karimwassef
So you're cultivating bacteria in your skimmate for a week and then adding it back in?

That's the first I've ever read or heard of this. Anyone else?


12/30/2014, 07:16 PM #578
cal_stir
I've checked my skimmate under the microscope, seen some microbes and some dinos but never microbes attacking dinos, but I never let it culture for a week.
I will let it culture and take another look.


12/30/2014, 11:43 PM #580
Montireef
Originally Posted by karimwassef
So you're cultivating bacteria in your skimmate for a week and then adding it back in?

That's the first I've ever read or heard of this. Anyone else?

Not only bacteria but many other microorganisms like nematodes and ciliates. Skimmate is mainly water plus a Ca and Mg insoluble carbonates. It has no nitrate and little phosphate but can have SH2.

Snails keep pooping black crap for almost a week, that's the main drawback. Lol


12/30/2014, 11:45 PM #581
Montireef
Originally Posted by cal_stir
I've checked my skimmate under the microscope, seen some microbes and some dinos but never microbes attacking dinos, but I never let it culture for a week.
I will let it culture and take another look.

You will be surprised of the amount of life you will find. LPSs love it


12/31/2014, 10:21 AM #582
karimwassef
My skimmate is ugly sludge that smells like feces. It varies from brown water with black sludge to yellow water with brown sludge depending on how wet I run it.

Are we talking about the same thing?

Isn't the skimmate what we're using to export the dinos and is primary intended to remove DOCs?


12/31/2014, 10:28 AM #584
karimwassef
Do you let it settle and just pour the yellow liquid? Do you throw the brown chunks in? Break them up first?

Monti - I'm not doubting you. I've just never heard about it so I want to know more.


12/31/2014, 11:19 AM #585
Montireef
Yes, the same nasty stuff.

I poured it in two times, one litre in the morning and one litre in the night, only the liquid, avoid solid chunks.

What we want are the bacteria and microorganisms, not the solid inert stuff.


12/31/2014, 11:21 AM #586
Montireef
The next day I watched cristal clear water, higher redox and many black poop from my turbo snails (they love it). Corals extended awesome polyps two days after pouring it.
Turning skimmate into probiotic tea?!?!?!? Pure genius. Thanks, Montireef!

But DNA provides us with counterexamples...


Quote:
Originally Posted by DNA
I have a 400g system
On day 1 the skimmate was 7 days old.

Day 1: 0,5 liters of skimmate added in the morning.
Day 2: 0,5 liters of skimmate added in the morning.
Day 3: 0,5 liters of skimmate added in the morning.
Day 3: 0,5 liters of skimmate added in the afternoon.

2 liters in all added over 3 days.
No reduction or increase was noticed in the dino population on the sandbed.

In the last round I emptied the cup right after adding the skimmate.
In less than an hour the skimmer had gathered around 0,5 liters of skimmate of similar transparency.

My results:
Skimmate alone does not help against Ostreopsis dinoflagellates.
If skimmers are really effective at removing an organism that prays on Ostreopsis, it's likely it can multiply in the skimmer cup so further tests are in order.
Right now I 'd like to see if this will work with added live rock.
Quote:
Originally Posted by DNA
It's been two weeks since I added more live rock and sand.
Since there was no visible sign of anything positive after a week I did another test.

I added a dead shrimp in a plastic mesh to the tank and let it rot.
That has been going on for a week and now I'm on my second shrimp.

This was done to see if the dinos disliked the additional ammonia.
They don't seem to care at all, but there is a pleasant side effect going on.

The rest of my SPS, fingernail sized brown leftovers, are showing their polyps for the first time in months.
There is some color also showing in their tissue.
I'm so sorry, DNA. I thought you had a chance.

It looks to me like heterotrophic bacteria are the foundation on which ostis build. These bacteria are rich in phosphorous. Dinos are P-rich organisms, as well, but less so than the bacteria, so there's excess phosphorous in their diet. This waste phosphorous is used to recruit cyano, which is also P-rich, but less so than the dinos. And now the dinos have access to P from the bacteria and N and Fe from the cyano. Sky's the limit.

I thought Montireef outcompeted the ostis' bacteria by triggering a minicycle when he added LR. A cycling bacterial biofilter is basically a series of overlapping bacteria blooms, during which nutrient demand is very high. Montireef's experience suggests that slowing the reproduction of the food bacteria by giving them some competition can cause an established dino population to eat itself out of house and home in a matter of days. The addition of a massive dose of heterotrophic bacteria and protists -- Montireef's probiotic zoom juice -- to the system thus seems like the perfect follow-up: the dinos, stressed and perhaps turning on each other because of the sudden scarcity of food, couldn't fight off the invasion. A combination of starvation, hungry protists and microfauna, and "algal degradation by bacteria" apparently overwhelmed the dinos. In essence, Montireef artificially tipped his system into a state where it was dominated by heterotrophs... It's the dirty method without the dirt.

But DNA couldn't repeat the experiment. I wonder... Montireef reported snails pooping black for almost a week. Did your snails do that, too, DNA? I'm wondering if Montireef's skimmer was off when he dosed, and if you left yours on just that one time you checked the skimmate cup less than an hour after dosing, or if it was on every time...?

The example of O. lenticularis suggests that benthic dinos secrete poison at least in part to control the population of bacteria around them to favor their preferred food species. If O. ovata is doing the same thing, then parachuting in a zillion tiny globs of colloidal organic carbon infested with heterotrophic bacteria and protists seems like it would be absolutely the last thing it wants.




Ecology of a bloom of Ostreopsis cf. ovata in the northern Adriatic Sea in the summer of 2009
http://www.researchgate.net/profile/...95e5000000.pdf

Cell Growth and Toxins' Content of Ostreopsis cf. Ovata in Presence and Absence of Associated Bacteria
http://www.researchgate.net/profile/...0f93000000.pdf

Growth, Feeding and Ecological Roles of the Mixotrophic and Heterotrophic Dinoflagellates in Marine Planktonic Food Webs
http://hosting03.snu.ac.kr/~hjjeong/...%2045%2065.pdf

Associated Bacterial Flora, Growth, and Toxicity of Cultured Benthic Dinoflagellates Ostreopsis lenticularis and Gambierdiscus toxicus
http://aem.asm.org/content/55/1/137.full.pdf


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