Size of SPS prey in the wild?
- Thread starter dixiedog
- Start date
dave willmore
New member
My contribution to this is far from solid or scientific, but I'd think that calanoid copepods would be a primary food. I'd also offer the observation that most polyped feeders are opportunists which will grab any prey in their size range that isn't strong enough to tear the polyps. In our aquariums I think rotifers are one substitute that is a weak swimmer and nutrituous if you gut load them. The other primary candidates are the pelagic offspring of worms in your sand, the benthic copepods on your algae and pelagic nauplii from the amphipods in your rocks, but you probably know all about these zooplankton substitutes already.
Sorry I can't be more scientific than these generalities.
Sorry I can't be more scientific than these generalities.
der_wille_zur_macht
Team RC
Here's some reading for you:
http://www.reefkeeping.com/issues/2002-07/eb/index.php
Every time I think I understand coral eating habits, something happens that changes my perception. Last week I watched an acro capture and (apparently) eat a whole adult brine shrimp (from a chunk of Rod's Food). I target fed the same acro with another piece of brine the next day and it did it again. Nothing I've read suggests that they'd eat something this large.
http://www.reefkeeping.com/issues/2002-07/eb/index.php
Every time I think I understand coral eating habits, something happens that changes my perception. Last week I watched an acro capture and (apparently) eat a whole adult brine shrimp (from a chunk of Rod's Food). I target fed the same acro with another piece of brine the next day and it did it again. Nothing I've read suggests that they'd eat something this large.
dave willmore
New member
That's a good article. It doesn't provide the level of scientific breakdown that dixiedog may be looking for, but then again neither did my post. But I think the article points out that even if we could get a scientific breakdown it couldn't be replicated in our tanks.
My approach will be to dose the tank with a constant supply of live enriched plankton and hope that a settlement chamber with sump pump can still keep nutrient levels low. If it fails I will go with the inert feeding methods that are currently in vogue.
And I still haven't answered dixiedog's question.
My approach will be to dose the tank with a constant supply of live enriched plankton and hope that a settlement chamber with sump pump can still keep nutrient levels low. If it fails I will go with the inert feeding methods that are currently in vogue.
And I still haven't answered dixiedog's question.
der_wille_zur_macht
Team RC
Now I'm going to take the thread way off topic. Do you have culture plans in mind yet as far as what and how you're going to grow enough of the right plankton?
dave willmore
New member
Yes, but we're in danger of hijacking dixiedog's thread and I hope he doesn't take offense. Here is the short version: I have 4,000 gallons of sump to split between rotifers, artemia and calanoid copepods. I feed veggie juice, phyto and DIY selco, then push screens together for concentration, then pump them directly to the display tank or indirectly through a feeding tube of phyto. Low density culture with high water volume gives more stability (fewer crashes).
It's not as complicated as it sounds, the sumps are conical so a bottom pump removes brownwater while dosing pumps feed the zooplankton tanks. I'm leaning toward an apex for the timing, automation is the key. A peristaltic type of pump will be used on the zooplankton. Rotifers are the best candidate because of their reproductive capabilities, but variety is the spice of life.
Dixiedog, sorry about this. But hopefully the rotifer part will grow your sps corals the way you need. Rotifers are not nutritious without enrichment, which fouls the water. So the solution is large culture vessels, auto feeding and auto nutrient removal. If you value your time an automated large culture is actually cheaper than small hand batches.
It's not as complicated as it sounds, the sumps are conical so a bottom pump removes brownwater while dosing pumps feed the zooplankton tanks. I'm leaning toward an apex for the timing, automation is the key. A peristaltic type of pump will be used on the zooplankton. Rotifers are the best candidate because of their reproductive capabilities, but variety is the spice of life.
Dixiedog, sorry about this. But hopefully the rotifer part will grow your sps corals the way you need. Rotifers are not nutritious without enrichment, which fouls the water. So the solution is large culture vessels, auto feeding and auto nutrient removal. If you value your time an automated large culture is actually cheaper than small hand batches.
ousnakebyte
New member
"SPS" corals is very general - almost too general. Are you talking primarily Acropora? Montipora? Pocillipora? Porites? Seriatopora?
I'm not aware of any studies detailing prey size, per se, but for most shallow-water acropora, I belive cyclopeez is fine in terms of size, especially feeding at night when the polyps are much more extended. For montipora, perhaps it's a bit large.
Keep in mind that not only prey size but also flow rate will determine what and how much your corals can capture. It's a bit dated, but here is a study from 1998 talking about that:
Sebens, K.P., S. P. Grace, B. Helmuth, E. J. Maney Jr. and J. S. Miles. 1998. Water flow and prey capture by three scleractinian corals, Madracis mirabilis , Montastrea cavernosa and Porites porites, in a field enclosure. Marine Biology. 131 (2), 347-360.
Cheers
Mike
I'm not aware of any studies detailing prey size, per se, but for most shallow-water acropora, I belive cyclopeez is fine in terms of size, especially feeding at night when the polyps are much more extended. For montipora, perhaps it's a bit large.
Keep in mind that not only prey size but also flow rate will determine what and how much your corals can capture. It's a bit dated, but here is a study from 1998 talking about that:
Sebens, K.P., S. P. Grace, B. Helmuth, E. J. Maney Jr. and J. S. Miles. 1998. Water flow and prey capture by three scleractinian corals, Madracis mirabilis , Montastrea cavernosa and Porites porites, in a field enclosure. Marine Biology. 131 (2), 347-360.
Cheers
Mike
dave willmore
New member
That's a great study. How do you transfer the results to our tanks? I'm not sure how rotifer swimming strength (cpature avoidance) compares to copepods but I'd think rotifers are weaker swimmers. And the study told me that at slower water flows the polyps weren't "blown out of form".
Taking it a step further, coral capture efficiency shouldn't matter as much as the length of the feeding time. In other words, if we put a million rotifers in a tank of a million polyps, we just need time. At 5% efficiency the corals need pumps turned off for 20x more time than at 100% efficiency, but in a closed system each polyp would get a rotifer eventually.
It looked to me like still water had the highest ratio of prey items captured for time unit, but I'm not sure. Is this what others found from the bar graphs on flow rate?
dixiedog
New member
Primarily Acropora. Sorry, should have mentioned that!
For some reason I didn't get auto-subscribed to this thread so I didn't know there were any responses until just now! Looks like I have some reading to do.
Guys, feel free to take the discussion any direction you want, it'll drift back around. :beer:
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