The Great Zoanthid Experiment

[digitalreefer]

There seems to be a great deal of information not known about zoanthids. Some say the number of species is 300 others say it's closer to 60. No one seems to be sure which species host palytoxin and which ones do not. Unfortunately, I can not study these things, but I can study the effects of food on zoanthids.

I am considering starting an experiment to prove the effects of regular feedings on various zoanthid colonies. The experiment would consist of two tanks set up identically with numerous zoanthid colonies of equal polyp count in each tank. Nutrient levels would be monitored on a daily basis to avoid a disparity in nitrates, phosphates, etc. On a set schedule, one tank will be fed a specified amount of food (likely baby brine shrimp), the other tank will be left unfed.

I'd like to see what everyone else thinks of this idea and what I should watch for to maintain control over the experiment. If this does come together, any help putting together 2 identical systems would be great. I'll need ideas as to what the systems should contain, equipment, and probably some local help to monitor things should I not be able to make it one day.

If everyone thinks I'm insane, maybe I won't bother, but if I get a positive response, I feel like I should do this. Thanks in advance for your input everyone!

 

[Aqua Pro Builder]

I can contribute 2 20G long tanks but will need them back when your experiment is finished.

 

[digitalreefer]

I can contribute 2 20G long tanks but will need them back when your experiment is finished.

Wingo that would be amazing! That was around the size I was thinking for the experiment. What do you think of the idea?

 

[Aqua Pro Builder]

I will PM you.

 

[Deanos]

Which known species are you studying? My personal experience tells me that Protopalythoa sp. will eat anything that will fit in its mouth, including cyclop-eeze, mysis, adult brine, etc while many zoanthus sp. won't react to other meaty foods offered.

Also, when you say 'various colonies', do you mean as determined by color morph? That would be a loss of experimental control. On the Marine Depot forum, coral expert Eric Borneman states, "As far as is known, there is no validity to color morph as a sole determinant of species designation."

Since you said last night that you've been doing alot of research into zoanthids, I'll limit my links on them to these three; you may have already read them.

Zoanthids - Eric Borneman

Zoanthids - Julian Sprung

Sea Mats - Blane Perun

 

[LeslieS]

To be sure they are the same species, you could frag the same colony/color/right next to eachother groups and put some in each tank.

 

[Deanos]

To be sure they are the same species, you could frag the same colony/color/right next to eachother groups and put some in each tank.

Very true! But as the articles above states, some species are known to eat, while others ignore offered foods. Those that ignore offered foods tend to absorb their required nutrients directly from the water column. As I said to digitalreefer on the Reef Graffiti last night, these particular zoanthids wouldn't be fed directly by his feedings, but indirectly via the water column once the uneaten food is broken down by other biological processes. If that is the case, all his experiment would prove is that feeding "a tank" would suffice in naturally propagating most zoanthids; something many people believe anyway. It would also prove that feeding zoas that do eat orally, is beneficial to their survival. Another no-brainer.

 

[jiggy]

u see that guys post on rc where he used a syringe to take color pigment out of one type of zoa and injected it into another

 

[nanoreefer22]

My only question/problem with the set up is how he is going to get 2 seperate tanks to have the exact same water quality/levels? With 2 seperate bodies of water wont that be near impossible?

 

[fishguttz]

I would think it impossible to have the same parameters especially if one tank has a higher bioload of daily feedings!

I also think you should only test one species of Zoa at a time if you want an even more accurate test. Otherwise; what would you conclude if some of the species of zoas in the feeder tank grew and some crashed?

 

[Craig]

I agree with nanoreefer. can you setup 1 tank with a divider?

 

[Deanos]

I agree with nanoreefer. can you setup 1 tank with a divider?

A divider won't separate water. Since zoanthids are able to absorb nutrients directly from the water, those on both sides of the divider would benefit.

 

[ShaunW]

u see that guys post on rc where he used a syringe to take color pigment out of one type of zoa and injected it into another

Would you have a link to that thread, I am very interested in reading it! THANKS!

 

[digitalreefer]

There are a lot of details that need to be worked out obviously, but even if the results aren't 100% conclusive, it would tell us what the effect of food (even if it is broken down) is on zoanthid growth.

I am not a scientist, I am simply looking to experiment with this. With good skimming and very regular large water changes I feel I can keep residual nutrient levels to a very low level when I am not intentionally feeding. As an alternate method, the zoanthids could be kept in the same tank, and moved for feedings. In order to avoid stressing only one colony, the other would be moved to a non feeding tank. Both the feeding and non-feeding tank would be made fresh for each feeding with RO/DI water so that all nutrient levels are identical. After feeding the zoas would be moved back to the main tank together.

As I said, there are many details to work out, and help organizing the details is appreciated.

 

[meschaefer]

My only question/problem with the set up is how he is going to get 2 seperate tanks to have the exact same water quality/levels? With 2 seperate bodies of water wont that be near impossible?

I would use a common water source. That way everything is the same, the only thing that is changing is whether the zoas that are being directly feed are doing better. They would both have access to the same organics in the water column. That way if the zoas that are being target feed are growing faster, or whatever, you will know that it is due to the target feeding.

 

[ezee]

Digital,

I think this is a cool project if you are willing to put in the time to set it up. If you apply the right level of detail and coherency to the project, I don't see why people would not be interested in hearing the results. Disclaimer: I was a bonehead and did not read the previous posts carefully and so repeated some of the suggestions. Please forgive my unintended plagiarism

You probably don't want the tanks to be linked to the same water source, what you put in one tank will make it to the other tank. Truthfully, you will not even know what your zoos are eating, whole macro foods or plankton, etc. If they are digging on the micro then the shared water source will skew your results.

Your specimens should probably be fragged from the same colonies with an equal number of polyps. Varying types/species (not color morphs) are a good idea. Furthermore they will need to be placed in exactly the same points in the tank, relative to flow and lighting, as their corresponding sister colonies in the other experimental tank.

The two set ups need to be exactly the same. Lighting, flow, tank size, power head position etc., in order for you to standardize the results from one tank to the other. I also think you should take both sets of live rock from a mature tank and match the amounts you put in. Even try to aquascape the same way.

You will need before and after pictures of your non-fed control and fed colonies. Visuals describe best what is happening. Depending on your lighting, I would say 6 months is a good number for the term of the experiment (maybe excessive) and weekly pictures would be good for you. You could even count polyps and generate a chart.

Finally if you really want to get funky, you can try more than two tanks and compare feeding phyto vs blended fishfood vs live brine shrimp babies etc.

Looked like you were looking for some ideas, hope that gives you some.

E

 

[alti]

there is no question that the fed tank will show some better growth rates. if they eat the food or not they will absorb the nutrients. it doesnt only apply for zoas but for all corals. as long as feeding doesnt adversly affect water parameters it will definately benefit the livestock.

 

[meschaefer]

I think some calrification of the experiment is needed:

As far as I see it there are two different experiments.

1: Zoanathids that are fed vs. Zoanathids that are receiving only light.

2: Zoanathids that are target fed vs. Zoanathids that are only receiving nutrients from the water column

In scenerio 1. you obvioulsy have to have two water sources, as one needs to be "sterile" of added food.


In Scenerio 2: you would want them to be in the same water enviroment, as you want the only variable to be if they zoanathids that are receiving target feedings are doing better. You would need them seperated by some type of filter, as you would not want the food stuffs to mix in with the "non targeted" fed zoanathids. If the "targeted" zoanathids grow, larger, faster or something else then you know that it is the target feeding that is the difference, because they would have the same nutrient load in the water column.

 

[ezee]

Meschaefer,

I think some calrification of the experiment is needed:

As far as I see it there are two different experiments.

1: Zoanathids that are fed vs. Zoanathids that are receiving only light.

2: Zoanathids that are target fed vs. Zoanathids that are only receiving nutrients from the water column

In scenerio 1. you obvioulsy have to have two water sources, as one needs to be "sterile" of added food.


In Scenerio 2: you would want them to be in the same water enviroment, as you want the only variable to be if they zoanathids that are receiving target feedings are doing better. You would need them seperated by some type of filter, as you would not want the food stuffs to mix in with the "non targeted" fed zoanathids. If the "targeted" zoanathids grow, larger, faster or something else then you know that it is the target feeding that is the difference, because they would have the same nutrient load in the water column.

Good points. I especially like the distinction between target fed and tank fed.

On the other point. I could be wrong but I think even with the target feeding you would contribute nutrients to the general shared water column that would contaminate the other tank. Therefore the tank with light only would not really be light only, it would have minute particles of organic matter that the zoos might be able to feed on, skewing your results. I don't think any filter would be able to remove 100% of the food particles/compounds that you are adding to the other tank.

E

 

[meschaefer]

Meschaefer,



Good points. I especially like the distinction between target fed and tank fed.

On the other point. I could be wrong but I think even with the target feeding you would contribute nutrients to the general shared water column that would contaminate the other tank. Therefore the tank with light only would not really be light only, it would have minute particles of organic matter that the zoos might be able to feed on, skewing your results. I don't think any filter would be able to remove 100% of the food particles/compounds that you are adding to the other tank.

E

That is why you need to make the distinction about what your studying. If you are studying target feeding, then the amount of nutrients in the water will not mattter. Both sets of zoanathids would need to have the exact same amount of nutrients in the water. That way the only difference is if they are target fed or not. This is the test in option number two. You would not need a filter to remove all the compounds, only to the extent that it could prevent the food that is being target fed from reaching the control animal before it breaks down. I was thinking of something like filter floss or a sheet of the material that filter socks are made of.

If not, all you are testing is whether feeding generally (i.e tank feeding) is better than not feeding at all and requiring them to get all of their nutrients from photosythesis. This is test option number one. If this is the case, then you will have to have two seperate systems.

There is opition number three. Target feeding vs. Light only. You can't test target feeding against light only without removing them from the system to be fed. In that case you would need one system, and a fully seprate holding tank for feeding purposes only. You could not feed them directly in the same tank where they will be housed, as the food will break down and add nutrient level to the water. If that happens you are really testing one of the other test options, depending on how the system is set up.