Interesting reports according Darwin's Paradox

[jda]

The few papers that I have read that separate the different types of P have all indicated that the host prefers the poly/meta since it can store it for later and use some of the other things that are bound as trash cans to export waste from the host. Next is organic P and then ortho. This really sucks since it is hard to search for since poly, meta, complex and a few other words are used like synonyms - even harder if the articles need/are translated.

To your point, we probably don't know much and who knows which is right and there are not many of these papers.

My gut tells me that since ortho is the last stop for P and that people can easily test for it that some might be assuming too much. The assumption all along is that plankton is the missing link in the wild where ortho has very low numbers, but many studies have shown that most of the coral that we keep are not great at catching zooplankton (some are really good at it which gets overgeneralized into "coral.") The missing link could be other type of P and it seems not well enough studied. The marine biologist from the coral sea that we met said that there are not the nightly swells of plankton like Veron has written about in other parts of the world, nor are the acropora reefs close enough to land to have terrestrial help. The only abundant thing is fish and inverts that eat the algae near the acropora reefs.

 

[Lasse]

P have all indicated that the host prefers the poly/meta since it can store it for later and use some of the other things that are bound as trash cans to export waste from the host.

Yea could be true but this is a total other story. Animals (and the host in corals are animals) can´t use (take up) phosphate as orthophosphate from the outside as plants, algae and probably some bacteria can. Animals must have their P as inorganic or organic P from food. The zooxanthellae can´t either take up inorganic P as polyphosphate - it must be in the form of orthophosphate. Inorganic polyphosphate in the water can be broken down to orthophosphate by bacteria and maybe also by equilibrium processes.

When the animal finally gets P through the food, some is stored as polyphosphate, As an example - the famous ATP molecule is an organic polyphosphate with three phosphate groups

Sincerely Lasse

 

[DanyL]

Inorganic polyphosphate in the water can be broken down to orthophosphate by bacteria and maybe also by equilibrium processes.

Are you suggesting that the heavy import/export methodology where you have spikes of PO4 getting bound and released across the day may benefit the inorganic-orthophosphate conversion through the equilibrium processes?

 

[Lasse]

benefit the inorganic-orthophosphate conversion through the equilibrium processes?

If there really is a significant equilibrium process your thoughts of "overfeed" / "starvation" are interesting - I understand where you're coming from. Honestly - I did not thought of that possibility. But I´m not sure there is a non biological equilibrium process between orthophosphate and polyphosphate - I wrote it - as we in Sweden say - as a "brasklapp" Difficult to translate but it is like a reservation if it exist, which I do not know but it can be a possibility.

Sincerely Lasse

 

[Randy Holmes-Farley]

If there really is a significant equilibrium process your thoughts of "overfeed" / "starvation" are interesting - I understand where you're coming from. Honestly - I did not thought of that possibility. But I´m not sure there is a non biological equilibrium process between orthophosphate and polyphosphate - I wrote it - as a we in Sweden say - as a "brasklapp" Difficult to translate but it is like a reservation if it exist, which I do not know but it can be a possibility.

Sincerely Lasse

There's not a nonbiological way for orthophosphate in seawater at room temperature to spontaneously make any significant amount of polyphosphate. The reverse (hydrolysis of polyphosphate) does happen

 

[Lasse]

Thanks



Sincerely Lasse

 

[taricha]

TLDR: We talk about N-fixation as though it's important process sometimes. I'd love to know if anything in our systems actually bothers to do a notable amount of it.

This notion of N-fixation is perplexing.

Several types of cyanobacteria were also found associated with the coral, and may be providing fixed carbon and nitrogen to the coral. In addition, an abundance of fungi were associated with corals, including those involved in nitrogen cycling, indicating that fungi may be fixing nitrogen and making it available to members of the coral holobiont (Wegley et al. 2007).

It gets talked about a lot. And the genes responsible for N-fixation can be sequenced from coral organism communities- but I've never seen any successful accounting of how much N budget a coral can meet by N-fixation of its associates. I have seen such accounting done for cyano mats in the Caribbean and some of them could Fix enough N from N2 to actually grow well on.
I'm not convinced the corals can get any but a barest trace of N this way. And I'm ambivalent as to whether N-fixation is a useful path for anything in our systems.
But I can argue both sides:
N-fixation is the absolute most energy expensive way to get N. Breaking N2 is such a huge energy expenditure that literally every other form or source of N would be more practical. So why would this be a big pathway in reefs/ our aquariums?
Other side: A coral in a N-depleted system being blasted with sunlight or strong tank lighting has energy to burn and so why not use some of that sugar-excess to feed some N-fixers on the side? What if it's a tank with tiny N and a significant carbon dose. Then N-fixation may start to look like a not-crazy proposition.

The OP study in this thread - the corals that just got light and tank water looked awful - if they could have fixed N2 they would have. Maybe they did and that didn't save them - or it was the P starvation that got them.

 

[BZOFIQ]

There's not a nonbiological way for orthophosphate in seawater at room temperature to spontaneously make any significant amount of polyphosphate. The reverse (hydrolysis of polyphosphate) does happen

Things are just better here when you have a resident genius involved.

Your post are out of my field but I love them still. Thanks for putting smile on my face.

 

[Lasse]

if they could have fixed N2 they would have. Maybe they did and that didn't save them - or it was the P starvation that got them.

To answer that - you need to run an experiment without adding NO3 but still add PO4.

I´m not sure that cyanobacteria N fixation in our aquarium can be excluded, remember my graphs from my aquarium according NO3 rise when I decrease my denitrification rate. I feed around 40 g frozen artemia and cyclops - protein content around 5 % - it means 2 g proteins a day. 16 % is N = 0,32 g N a day. Around 20 % will be taken up as biomass of the fish - rest around 0,25 g N = 1,3 g NO3 a day - in 310 L it will give 4,2 mg/L NO3 rise/day if all N not consumed by my fish was converted into NO3. My biomass of other organisms than fish is much higher but let us say that 40 % of the added N will be in form of free NO3 in the water column, It give us a theoretical rise of around 2,7 mg/L a day.

I have had two occasions when my DOC dos into the plenum stopped (I dos ethanol) The first 230525 to 230531 - 5 days. Average rise of NO3 was around 4 mg/L NO3 a day. This indicate that some N is probably coming from another source than my feed. I did not measured my feed but I know that I feed a little bit lesser at that time compared with the 40 g I feed with today

The other occasion was between 230624 and 230630 - 6 days result in an average rise of 2,5 mg/L NO3. Did not not the feeds at this occasion either.

I have had cyanobacteria mats in some place when this happen.

Even if it is not totally clear that I have had N fixation (or have) - I can´t exclude it.

Sincerely Lasse

 

[danimal1211]

TLDR: We talk about N-fixation as though it's important process sometimes. I'd love to know if anything in our systems actually bothers to do a notable amount of it.

This notion of N-fixation is perplexing.

It gets talked about a lot. And the genes responsible for N-fixation can be sequenced from coral organism communities- but I've never seen any successful accounting of how much N budget a coral can meet by N-fixation of its associates. I have seen such accounting done for cyano mats in the Caribbean and some of them could Fix enough N from N2 to actually grow well on.
I'm not convinced the corals can get any but a barest trace of N this way. And I'm ambivalent as to whether N-fixation is a useful path for anything in our systems.
But I can argue both sides:
N-fixation is the absolute most energy expensive way to get N. Breaking N2 is such a huge energy expenditure that literally every other form or source of N would be more practical. So why would this be a big pathway in reefs/ our aquariums?
Other side: A coral in a N-depleted system being blasted with sunlight or strong tank lighting has energy to burn and so why not use some of that sugar-excess to feed some N-fixers on the side? What if it's a tank with tiny N and a significant carbon dose. Then N-fixation may start to look like a not-crazy proposition.

The OP study in this thread - the corals that just got light and tank water looked awful - if they could have fixed N2 they would have. Maybe they did and that didn't save them - or it was the P starvation that got them.

I suspect the coral animal itself doesn’t concern itself with where it’s zoox and other microorganism within the holobiont get there N from. More and more it seems the coral animal consumes these herds for its nutritional needs. https://link.springer.com/article/10.1007/s00248-022-02094-6

 

[Randy Holmes-Farley]

Things are just better here when you have a resident genius involved.

Your post are out of my field but I love them still. Thanks for putting smile on my face.

lol, thanks.

 

[Hans-Werner]

Yea could be true but this is a total other story. Animals (and the host in corals are animals) can´t use (take up) phosphate as orthophosphate from the outside as plants, algae and probably some bacteria can. Animals must have their P as inorganic or organic P from food. The zooxanthellae can´t either take up inorganic P as polyphosphate - it must be in the form of orthophosphate. Inorganic polyphosphate in the water can be broken down to orthophosphate by bacteria and maybe also by equilibrium processes.

When the animal finally gets P through the food, some is stored as polyphosphate, As an example - the famous ATP molecule is an organic polyphosphate with three phosphate groups

Sincerely Lasse

I think it is not necessary to think too complicated. To my knowledge, only orthophosphate is taken up.

From both, organic phosphates and polyphosphates, orthophosphate is hydrolysed by the enzyme alkaline phosphatase outside of the organism before uptake. The orthophosphate then is taken up.

Polyphosphates are a storage form of phosphate and energy which is formed in bacteria and microalgae, well, for storage. If the cells are destroyed, the polyphosphates get into the water.

For example a certain kind of sewage bacteria stored much polyphosphate when they were exposed to alternating conditions. If I recall it right it was alternating aerobic and anaerobic conditions.

 

[Lasse]

For example a certain kind of sewage bacteria stored much polyphosphate when they were exposed to alternating conditions. If I recall it right it was alternating aerobic and anaerobic conditions.

Yes - it was all waste water workers wet dream when they was discovered. And in reality - it was a dream - it was difficult to use them as P removal workers - still the precipitating chemicals dominate phosphorus removal in wastewater

Sincerely Lasse

 

[jda]

Get the animal what it needs. It will take care of it's slaves (as Lasse calls them).

 

[Hans-Werner]

Yes - it was all waste water workers wet dream when they was discovered. And in reality - it was a dream - it was difficult to use them as P removal workers - still the precipitating chemicals dominate phosphorus removal in wastewater

Sincerely Lasse

We are living in a technocratic world, not in a world of respect and holistic thinking.