SPS feeding on phytoplankton

[nomsmon]

It seems to be generally thought that stony corals do not feed on phytoplankton, but rather zooplankton.

I've been seeing some amount of research from the last 5-10 yrs indicating that might not be true. However, this has all been with species I don't believe are commonly kept in reef keeping.

I finally found some research that seems more relevant; various acropora species feeding on phytoplankton.

Elucidating an optimal diet for captive Acropora corals
https://www.sciencedirect.com/science/article/abs/pii/S0044848619310282
Tldr; they found various acropora species grow well on Isochrysis galbana.

I can't find a public/free version of the paper, but I might have to pay up for access.

I am curious whether they were feeding live phyto and if/how they measured the consumption rates.

 

[jda]

If you want to read with free stuff, Google and search ReefCentral for when it was widely thought that you could not hardly run an effective reef tank with using a live phytoplankton supplement like DTs, or making your own. DTs was a tri blend, but had Iso in it. You will read about all kinds of awesome stuff that people thought that they saw and the good things that it did. However, have you even heard about it much lately? While not science, these anecdotes can teach a lot.

Like many foods-of-the-day, they are through to be all kinds of great but quickly turn into a punch line as nobody can tell the difference. This happened to DTs Phyto along with their Oyster Eggs, Cyclopeeze, Essential Elements, Marine Snow, etc. The current supplements of today will soon be a punch line too.

If you decide to look at this, look for the subtle details that make all the difference. There are certainly some filter feeders and other inverts that most definitely can make use of phytoplankton, but also plenty that cannot. So a glowing review from a NPS keeper should not be used by an acropora keeper. :) Also be sure not to just look at one specific study as gospel... more sure things have many, many that all come to the same conclusion. I once had a professor in college who told us that he could commission a study that could "without a doubt" prove on the surface that your mom might be your dad and that your dad might be your mom... but it would not mean much once you dug in, applied scientific processes and all of that (which was the purpose of his class). What I learned the most in that class is that a LOT of studies are all about the process, and mostly following it, and not so much the results or what the results mean.

 

[nomsmon]

If you want to read with free stuff, Google and search ReefCentral for when it was widely thought that you could not hardly run an effective reef tank with using a live phytoplankton supplement like DTs, or making your own. DTs was a tri blend, but had Iso in it. You will read about all kinds of awesome stuff that people thought that they saw and the good things that it did. However, have you even heard about it much lately? While not science, these anecdotes can teach a lot.

Like many foods-of-the-day, they are through to be all kinds of great but quickly turn into a punch line as nobody can tell the difference. This happened to DTs Phyto along with their Oyster Eggs, Cyclopeeze, Essential Elements, Marine Snow, etc. The current supplements of today will soon be a punch line too.

If you decide to look at this, look for the subtle details that make all the difference. There are certainly some filter feeders and other inverts that most definitely can make use of phytoplankton, but also plenty that cannot. So a glowing review from a NPS keeper should not be used by an acropora keeper. :) Also be sure not to just look at one specific study as gospel... more sure things have many, many that all come to the same conclusion. I once had a professor in college who told us that he could commission a study that could "without a doubt" prove on the surface that your mom might be your dad and that your dad might be your mom... but it would not mean much once you dug in, applied scientific processes and all of that (which was the purpose of his class). What I learned the most in that class is that a LOT of studies are all about the process, and mostly following it, and not so much the results or what the results mean.

Just to be clear, I'm not making any recommendations about how people should care for sps (or any other coral).

I agree that a single study isn't conclusive proof of anything. It is supporting evidence for uptake of phytoplankton in SPS corals; something that hadn't been studied much until recently.

While this is the only acropora study I've found; there are a number of studies out there investigating the consumption of various phytoplankton species by various coral species.

The general trend of these studies seems to be "coral species x will consume phytoplankton species y, but not phytoplankton species z". Some coral species were not observed feeding on any of the tested phytoplankton species.

So, while it may be true that SPS coral do feed on phytoplankton it would probably require more research to find appropriate phytoplankton species for each species of coral.

I thought the acropora one was of particular interest because
1) acropora is common is reef keeping
2) I. Galbana is commonly available in phyto supplements

 

[nomsmon]

Couple of the other studies I mentioned

Accumulation of 13C-labelled phenanthrene in phytoplankton and transfer to corals resolved using cavity ring-down spectroscopy

Coral feeding on microalgae assessed with molecular trophic markers

 

[C. Eymann]

If you want to read with free stuff, Google and search ReefCentral for when it was widely thought that you could not hardly run an effective reef tank with using a live phytoplankton supplement like DTs, or making your own. DTs was a tri blend, but had Iso in it. You will read about all kinds of awesome stuff that people thought that they saw and the good things that it did. However, have you even heard about it much lately? While not science, these anecdotes can teach a lot.

Like many foods-of-the-day, they are through to be all kinds of great but quickly turn into a punch line as nobody can tell the difference. This happened to DTs Phyto along with their Oyster Eggs, Cyclopeeze, Essential Elements, Marine Snow, etc. The current supplements of today will soon be a punch line too.

If you decide to look at this, look for the subtle details that make all the difference. There are certainly some filter feeders and other inverts that most definitely can make use of phytoplankton, but also plenty that cannot. So a glowing review from a NPS keeper should not be used by an acropora keeper. :) Also be sure not to just look at one specific study as gospel... more sure things have many, many that all come to the same conclusion. I once had a professor in college who told us that he could commission a study that could "without a doubt" prove on the surface that your mom might be your dad and that your dad might be your mom... but it would not mean much once you dug in, applied scientific processes and all of that (which was the purpose of his class). What I learned the most in that class is that a LOT of studies are all about the process, and mostly following it, and not so much the results or what the results mean.

Are you proposing Acropora do not feed on particulate matter and /or bacteria from the water column?

- There was never really a widespread mentality of "you can't have a successful reef without dosing live phytoplankton"

-Oystereggs, cyclops, marine snow etc etc a "punchline"? and not used anymore? huh?


Acropora do indeed capture food items and bacteria from the water column, if not why would their axial polyps have a much larger ratio of nematocysts : zooanxthelle than radial corallite polyps?

other than "coral -coral warfare and anti predation" why have nemtocysts at all? why have mouths? why have gastic cavities?

I debated this with you shortly after I migrated from RC onto this forum about a year ago, and you disputed that axial polyp extension was strictly for "gas exchange" and had nothing to do with food capture.
Id be glad to post articles/links that reinforce this again, not to throw stones, but a few months ago, in Chaswoods Sunday driver thread, it seemed you didn't really know what an axial or incipient axial corallite was at all ?


Just saying, its brash of you to post on here about this topic in a matter of fact type of way, claiming many widely used coral foods and supplements are just a "phase" or "trend" and are essentially useless in that the coral cannot utilize these supplements for benefit at all..

While I do agree gathering reliable data concerning their effectiveness/benefits would be difficult considering all the variables in a closed reef system.

However, it seems like this post was you claiming every coral food supplement out there is a sham and that sps coral, acropora in particular receive zero nutritional value from food capture?

did I understand that right?

 

[jda]

I never said that. I said that acropora only NEED to use their polyps for gas exchange. This is also why they are out more at night and not to catch some magical food that only appears in the dark. I never said that they cannot catch food, or even try and digest it... only that there is no evidence that they get anything from it. The biologist in the Coral Sea told us that the water there was so pristine out in the open ocean that acropora could not live there if they need to catch food to live... the lagoons and near shore was different and other types of coral were different.

Maybe I miss them, but when is the last time that you saw somebody suggest DTs or cyclopeeze over Reef Roids, Acropower or the like? Would people stop using stuff that actually worked well and would they be secrets? What have you seen in the past that I have been wrong about... todays magic supplement is tomorrows punchline... when has this not been true? What supplement was awesome three decades ago when reefing got hot and is still hot now? Essential Elements? Zoe? Selcon? Zeo has stuck around the best, but this is a metrology as much as a supplement. Purple Up is still kinda around, but also a punchline at the same time. Aminos are the rage right now and have replaced rages of the past. If history has taught us anything, the rage will change soon... if not, then we recalculate.

FWIW - I have seen some evidence that some certain aminos can penetrate tissue of some corals and provide some building blocks for them. Acropora for sure. However, we don't know what aminos are in any of the supplements since nobody will tell anybody anything. Also, since single celled algae (waterborne) and bacteria (surface and especially waterborne) also will absorb this stuff very well, it is unknown if any of it even gets to the coral.

In the end, what have you every seen that leads you to believe that acropora get anything out of feeding? Too many people who excel at this hobby with acropora have no use for any of them and not for a lack of trying the stuff.

 

[blasterman]

Even if Acropora have the biological capacity to grab phyto and perhaps larger organic particles from the water column......so what?

Looked at the average phosphate and nitrate levels in a captive tank vs the open ocean? No wonder SPS might need to grab protein from the water column in the wild given the scarcity of organic molecules.

Phyto and similar products have extremely limited suspension time in captive tanks before they are swallowed by skimmers and decay into basic proteins and convert to nitrate and phosphate. If you are running a hyper ULN tank and start dumping crazy Larry's phyto in it and your corals color up please connect the dots.

Too many SPS tanks out there not dumping this junk in tanks to verify another in vitro coral white paper written by a get my MA and run expert that proves nothing. On one side of the tank we are running cheato and skimmers and anti fertilizer reactors and on the other we are dumping dead micro fauna. #ritalin

 

[flampton]

Corals feed in every aquarium end of story, now whether it helps to add more food on top of the fish food depends on your management style.

Every added free organic will end up in bacteria first. Then hopefully those bacteria are consumed by something larger e.g an acropora polyp. The tricky part is that they have food preferences so hopefully your added organics will reach the correct picoplankton that is accepted. It is also clear that some symbiodinium can also consume bacteria, however that experiment was in culture so not sure if they are also actively bacteriovorus within the so called holobiont.

So added food as phyto useful for SPS. Not imo unless it is an acceptable picoplankton.

 

[C. Eymann]

In the end, what have you every seen that leads you to believe that acropora get anything out of feeding?

I work at a large coral farm that specializes in the aquaculture of acropora 40 hrs a week. A large part of my job is testing/maintaining water chemistry, feeding and QT protocols. and from my observations feeding suspended coral foods, mostly a blend of phytofeast, oysterfeast and rotifeast, increase growth rate and coloration, its very evident. Especially comparing systems that aren't able to get fed on their regular schedule due to high volumes of coral getting shipped out, with strictly broodstock systems that are able to be fed regularly.

Are food additions needed to keep acropora successfully?
I don't believe its absolutely necessary, they will do fine with an aquarium stocked with fish that are being appropriately fed.

Can suspended coral food supplements help optimize health, growth and coloration?
again From my daily observations - absolutely!

If they didn't make any difference we wouldn't be dumping hundreds of dollars Reef Nutrition and Benereef foods in our systems every week.


Good nutrient export = enables more feeding

As far as blastermans argument of corals coming from very low nutrient warers in the wild, sure thats true, but when diving on reefs, the water column is filled with potential food items!

One of the big things our home aquariums lack is that constant availability of prey/food items in the water column that they have available to them consistently.

 

[jda]

I appreciate the experience and observations. I do not agree, but I also have not worked at a large coral farm. I have also heard of some other farmers with greenhouses feeding yeast with what they call good results, but when they were on vacation and nobody fed, they will admit that they saw no difference.

One of the local stores feeds some not-unsubstantial dollar amounts of supplements ever week to sell a thousand dollars worth. It works for them in a financial way. In the end, he figures at at a minimum, he gets some backend P out of it and maybe some ammonia to feed the corals as other stuff eats it. This cannot be underestimated if you are not feeding fish a lot... the corals maybe never caught or directly used any of it, but they got some benefit in unintended ways.

I still do not know if something from a AQ farm will translate to a home reef tank. I still have not seen enough high quality reefers with in-home reefs have anything positive to say about the experience of supplementing over the past few decades.

I won two jugs of reef roids - I used them to see if they helped. When they were all gone, nothing changed either way. They did not seem to help anything, but the also did not hurt anything (they would make my clams close sometimes), so it is not like there is any risk unless your residual building block levels are already too high.

 

[Big E]

I work at a large coral farm that specializes in the aquaculture of acropora 40 hrs a week. A large part of my job is testing/maintaining water chemistry, feeding and QT protocols. and from my observations feeding suspended coral foods, mostly a blend of phytofeast, oysterfeast and rotifeast, increase growth rate and coloration, its very evident. Especially comparing systems that aren't able to get fed on their regular schedule due to high volumes of coral getting shipped out, with strictly broodstock systems that are able to be fed regularly.

Are food additions needed to keep acropora successfully?
I don't believe its absolutely necessary, they will do fine with an aquarium stocked with fish that are being appropriately fed.

Can suspended coral food supplements help optimize health, growth and coloration?
again From my daily observations - absolutely!

If they didn't make any difference we wouldn't be dumping hundreds of dollars Reef Nutrition and Benereef foods in our systems every week.


Good nutrient export = enables more feeding

As far as blastermans argument of corals coming from very low nutrient warers in the wild, sure thats true, but when diving on reefs, the water column is filled with potential food items!

One of the big things our home aquariums lack is that constant availability of prey/food items in the water column that they have available to them consistently.

Are these acropora systems? How many fish are there? The real question is---are the corals eating the foods or just benefitting from the results of having the end products of Po4 and No3?

This isn't the same as a reefer's tank. There are many more fish that are fed well .....corals benefit from the direct uptake of ammonium/urea from the fish, Po4 in poop and also small particles and juices from fish food.

I'm also sure a display tank has available gut filled bacteria, micro plankton ect.

This is more apples and oranges comparison as runway systems aren't display tanks that are growing frags into large colonies over many years.

I agree-- Good nutrient export = enables more feeding, but there's no real proof this has to be "coral food"

 

[Potatohead]

Is it not possible that some acropora, out in the open ocean have adapted over millennia to utilize light more and/or better than others that are in regions with more food available?

I know in my tank some acros really prefer lower nutrients, they grow faster and show better colors and polyp extension while some others are the opposite and prefer them a bit higher. It is somewhat of a compromise to make them all mostly happy.

It seems to me that extra feeding would probably have the same type of "some like it/need it and some don't" results.

 

[SeaDweller]

The easiest way is to set up two tanks: one as a control without the extra feedings of phyto, roids, oyster feast, etc etc, and the other with it; keep everything the exact same except the food and see if the tank with the feedings does better. Problem solved.


or even have a third tank, with no fish and just feed; see what happens.

 

[C. Eymann]

Are these acropora systems? How many fish are there? The real question is---are the corals eating the foods or just benefitting from the results of having the end products of Po4 and No3?

This isn't the same as a reefer's tank. There are many more fish that are fed well .....corals benefit from the direct uptake of ammonium/urea from the fish, Po4 in poop and also small particles and juices from fish food.

I'm also sure a display tank has available gut filled bacteria, micro plankton ect.

This is more apples and oranges comparison as runway systems aren't display tanks that are growing frags into large colonies over many years.

I agree-- Good nutrient export = enables more feeding, but there's no real proof this has to be "coral food"

The systems I am referring to are mostly acropora, but they are also stocked with fish similar load as one would see on a home aquarium.
Other than size, there is not a big difference to a home reef aquarium.

While I sometimes use increased fish food feeding or sythesis (urea, free nitrogen) and potassium phosphate to maintain or increase N/P in the systems, 90% of the time I use coral foods to do so because of increased growth and coloration to be had, another over looked result from regular suspension feeding is polyp extension, which I believe for some species such as tenuis can equal better coloration development of polyp tissue as more tissue is exposed to intense lighting.
When people come visit the farm, one of the first things they ask is "how do you get such ridiculous polyp extension on your acropora"

Answer- regular 2-3× a week of coral food additions in addition to maintaining stable water chemistry.

Does coral food count as "small particles?" if so, then you agree there are benefits to be had?


Look at the vast majority of animals that are unfortunately still collected for hobby and are bound to doomed in home reef aquaria due to lack of available suspended foods, crinoids, certain sponges, scallops, delicate gorgonians etc etc,

One of the things we cannot reproduce in our closed systems is the constant suspension of food items reef animals/ corals have available to them in the wild.
When you go diving on a reef, the water is filled with planktonic critters.
The main goal of reefkeeping husbandry is to mimic their natural environment , technology has afforded us hobbyists to become pretty proficient at doing so, however, we fall short on the endless availability of food/prey items in the water column on wild reefs.

Do you think captive coral breeding/reef restoration projects feed coral foods because they do nothing? the supplemental nutrition from food items helps with gonad development and primes them to spawn successfully in a captive environment.

There has also been growth studies on sps coral and increased feedings equated to an increase in growth. One study with stylophora showed calcification rates doubled after 8 weeks of zooplankton feeding.
Increased feedings =increase of zooanxthelle densities each coral cell, increased densities= higher photosynthetic capacity---->more chemical energy available for growth


Again, I do not believe coral foods are necessary to have a great looking, successful sps reef aquarium, but neither are amino acid additions.

However, if coral food and /or amino acid additions can help growth, coloration and overall vitality- why wouldn't you use them ?



Just my two pennies...

 

[Big E]

I'm not going to go point for point with you as it will never end. We are not really disagreeing so much as when the application of these coral foods has a benefit.

A prop facility is not the same as a home reef tank and I'll leave it at that.

 

[C. Eymann]

I'm not going to go point for point with you as it will never end. We are not really disagreeing so much as when the application of these coral foods has a benefit.

A prop facility is not the same as a home reef tank and I'll leave it at that.

I guess Ill agree to disagree.

Other than scale, there is no difference between our systems and a well setup home reef aquarium. Our systems range from 300-2300gal
Same principles, same fish load, same equipment thats readily available to hobbyists.

Scale is the only real difference. Our goals are health, hardiness, coloration, growth and sustainability.

We find regular feeding of suspended coral foods helps us achieve those goals more readily.


Other than scale, no difference to a home reef aquarium, we have the same goals as home reef aquarists when it comes to coral.

 

[Naturalreef]

What I have noticed with my acros is that if they are provided quality light, flow and nutrients they give me growth and color. But I feel they didn’t have a reserve if they were subjected to a stressor. When I started feeding my tank Easysps phyto, I seen a change in my SPS. Polyps are always out day and night looking to capture food and mild stressors don’t send them over the edge. I feel like they have a little reserve built in because of their nourishment.

It’s like us eating peanut butter sandwiches all day long vs a vitamin enriched diet. Our immune can handle things better when nourished. Jmo

 

[92Miata]

I guess Ill agree to disagree.

Other than scale, there is no difference between our systems and a well setup home reef aquarium. Our systems range from 300-2300gal
Same principles, same fish load, same equipment thats readily available to hobbyists.

Scale is the only real difference. Our goals are health, hardiness, coloration, growth and sustainability.

We find regular feeding of suspended coral foods helps us achieve those goals more readily.


Other than scale, no difference to a home reef aquarium, we have the same goals as home reef aquarists when it comes to coral.

I guess Ill agree to disagree.

Other than scale, there is no difference between our systems and a well setup home reef aquarium. Our systems range from 300-2300gal
Same principles, same fish load, same equipment thats readily available to hobbyists.

Scale is the only real difference. Our goals are health, hardiness, coloration, growth and sustainability.

We find regular feeding of suspended coral foods helps us achieve those goals more readily.


Other than scale, no difference to a home reef aquarium, we have the same goals as home reef aquarists when it comes to coral.

Why do you feel that scale isn't an important factor?

IMO, the difference in scale between reef tanks and the ocean drives almost every compromise we make in reefing.

 

[Ike]

Incorrect ausation and jumps to false conclusions in this hobby runs rampant. JDA makes some good points. In many cases, dumping x into a tank and leading to improvements in growth and coral health leads to the false conclusion that the corals is utilizing and consuming x, when the reason for improvement is often probably as simple as adding something that can break down into P and or N to a nutrient starved tank will yield positive results. The likely reality is that you could probably toss a dead fish or some poop a tank, and as long is the system can handle the input and not get dangerously high levels of anything you will see improvement. Even something as simple as iodide could be a factor, if it's limited corals won't grow. Add some food source or something that can break down into N and P and you're indirectly adding a food source regardless if if the inhabitant can utilize it directly.

The above is probably why so many falsely believe amino acid supplements are beneficial when then it's likely they're just adding some N to an N limited tank.

 

[BAUCE]

Incorrect ausation and jumps to false conclusions in this hobby runs rampant. JDA makes some good points. In many cases, dumping x into a tank and leading to improvements in growth and coral health leads to the false conclusion that the corals is utilizing and consuming x, when the reason for improvement is often probably as simple as adding something that can break down into P and or N to a nutrient starved tank will yield positive results. The likely reality is that you could probably toss a dead fish or some poop a tank, and as long is the system can handle the input and not get dangerously high levels of anything you will see improvement. Even something as simple as iodide could be a factor, if it's limited corals won't grow. Add some food source or something that can break down into N and P and you're indirectly adding a food source regardless if if the inhabitant can utilize it directly.

The above is probably why so many falsely believe amino acid supplements are beneficial when then it's likely they're just adding some N to an N limited tank.

Sounds like a good idea for an experiment. Keep a full blown sps tank healthy with no feeding or fish but dosing N an P to keep levels up.