Fish Poo

[rleechb]

Apologies for the unflattering title.


Anyways, I've been hearing quite a bit about fish poo being coral food? Is there any validity to this? If so, why, and how does fish poo differ as a coral food from prepared food, such as mysis in a blender/oyster eggs/etc? I was always under the impression that fish poo = nitrates/phosphates = coral death?

 

[esco]

tagging along to learn about fish poo

 

[twon8]

in the same way animal poo is food for plants, the zoox in the corals do need some nitrates and phosphates, but there is other stuff also, such as already broken down mysis, other food. plus bacteria, maybe magnesium if you feed a lot of nori, and im sure a whole lot of other stuff that im not aware of. this is all a guess on my part, so dont' present it as fact.

 

[rleechb]

yeah, i can understand small amounts of nitrates and phosphates possibly being beneficial to feeding zoox, but if those are present in the water column (magnesium as well), then what's the point of "fish poo"? How is partially digested mysis any better than fresh mysis? Given that fish poo is good food for sps, would it be prudent to simply bottle some fish excrement, and dump it into the tank?

 

[twon8]

well partially digested would be broken down some, as sps can't consume an entire mysis. i suppose you could just dump poo into the tank but why wouldnt you just have a few fish in there?

 

[rleechb]

Well, how is partially digested better than a mysis shrimp blended into consumable fragments?

I actually have plenty of fish in my tank, but my curiosity is jogged a bit. If you have a few fish in your tank, would you really benefit from adding a few more to increase poo volume? How would that be any better than adding a consumable form of coral food such as oyster eggs?


I'll get off my soapbox now...

 

[twon8]

<a href=showthread.php?s=&postid=8490830#post8490830 target=_blank>Originally posted</a> by rleechb
Well, how is partially digested better than a mysis shrimp blended into consumable fragments?



I actually have plenty of fish in my tank, but my curiosity is jogged a bit. If you have a few fish in your tank, would you really benefit from adding a few more to increase poo volume? How would that be any better than adding a consumable form of coral food such as oyster eggs?


I'll get off my soapbox now...

well i don't think they have blenders in the ocean..., but digestion breaks down food chemically, not just from mastication: ie, carbs into sugars, protiens into amino acids, and i have seen some people adding amino acids to their sps tank, so there is at least some thinking in that direction.
beyond that, i think variations in each of our systems preclude any certainty in any "is this better than this way" conjectures.

i feed oyster eggs and frozen rotifers but i also have a lot of fish and feed very often.

 

[Sk8r]

some experts [and I'm sorry I'm horrid at names, and can't cite the article] believe that bristleworms are an important intermediate step in this cycle, that they break down fish poo so that it can be reduced to chemical elements by the sandbed bacteria, and so that it can be absorbed by coral polyps just as it floats around as microdust.

 

[rleechb]

Ah. Good stuff. That makes more sense. I didn't notice much on the "fish poo = coral food" theory until recently, where I've seen multiple threads cite this tidbit. So I guess fish poo isn't exactly all good, as whatever is broken down into usuable sustenance for the coral is also coupled with organics which ultimately lead to higher nitrates/phosphates. It'd be interesting to see any articles on this.


Sheesh, it's really tough trying to discuss this topic when every other word in these posts is "poo".

 

[twon8]

but nature has dealt with the poo on the coral reefs for eons, and while there are substances that may be detrimental to one organism, im sure there is something that has evolved to take advantage of the waste, such as the bristeworms sk8r mentioned. also the wealth of pods in my system and thousands of stomatellas and nassarius snails that have bred themselves into my tank help out with the waste. i really only notice the poo in my tanks at feeding time when the fish get excited and clear themselves out in preparation.

 

[rleechb]

<a href=showthread.php?s=&postid=8491131#post8491131 target=_blank>Originally posted</a> by twon8
but nature has dealt with the poo on the coral reefs for eons, and while there are substances that may be detrimental to one organism, im sure there is something that has evolved to take advantage of the waste, such as the bristeworms sk8r mentioned. also the wealth of pods in my system and thousands of stomatellas and nassarius snails that have bred themselves into my tank help out with the waste. i really only notice the poo in my tanks at feeding time when the fish get excited and clear themselves out in preparation.

I'm not sure if making a comparison between the ocean and a reef tank is really that valid. While there might be a lot of bristleworms/stomatella/etc. in one's reef tank, that reef tank is still a closed system. These organisms might be able to help out with the waste, but there has to be a threshold to reach where the bad stuff in fish waste becomes detrimental to our corals. I also only notice the poo in my tank when it's being actively excreted, but that doesn't mean it's not there.