Moorish Idol - Take 2
 

As many know, due to unforeseen circumstances, I had to essentially abandon my tank for nearly a month. In that month, my very healthy and long kept MI was lost.
I've obtained another, in great shape, apparently net caught, and within 24 hours has been caught nibbling PE mysis.

Looking for any other tips and tricks people have had luck with in getting these guys eating well.
I have someone scouring the beach for sponge, I have some in my sump, will be picking up some clams from the seafood dept today. Nori is loaded in clip.

Anything I haven't thought about?

And just to be clear, this is a "how to feed a finicky fish" thread, not an invite to discuss morality in fish keeping :) TIA for keeping it on track.

I haven't kept a MI, but there are two at the LFS here that are eating PELLETS. Wtf?!

My last one ate everything. Pellets, nori, mysis, anything that would fit in it's mouth. I know of another member here that just got one that eats pellets already.

Nice. I never saw one eating pellets at an LFS only 2 days landed though. They be gooders. I wish my tank was big enough for a MI. It's one of my holy grail fish.

Unfortunately they're very tough. My last one was in the LFS display for over a year, very fat. I'm not happy it died (with my other big fish) during my absence

Many years ago, I had one outgrow my tank and I only fed it mostly Ocean Nutrition flake, which isn't available here anymore, with the occasional nori and Mysis and freeze dried plankton to supplement it. But I'm sure New Life Spectrum is all you need and some supplement.

Its been a while since I mentioned it on the forum, but here goes. The Idol is the most highly oxygen demanding fish I've ever kept. Angels were my 2nd most highly oxygen demanding fish I've kept. When I've unplugged my aerator/skimmer, after some time I would see the Idol laying on the sand gasping unable to swim, while the other fish are fine (including tangs and angels). It would slowly recover after I turned the skimmer back on. Would have loved to have recorded this on video for people. After my Idol was adopted, one time I left the skimmer unplugged overnight (with only powerheads and aquaclear providing circulation/aeration), the next morning, my well established angel was dead. All else was fine. I just couldn't get enough o2 into my tank (for high oxygen demanding fish) without an air diffuser such as the protein skimmer (I had powerheads and aquaclears going only). It was repeatable as it would happen once or twice more in future years every time I forgot to plug my skimmer back in overnight. It was always the angels, and nothing else, and always found dead the next morning after they were established for a long time. I had a DO meter and found that my morning DO levels were very low even with the skimmer on so without the skimmer running at night, it was just clearly lethal to the fish that require the most oxygen which happens to be the Idol (which luckily was adopted by someone before I had my mishaps) followed by my dwarf angels. Sorry, I know you don't want to discuss anything but diet here but I've been silent on this for a few years already. :) I'm not planning to write about this topic too often so I thought I would try to get this in here. My feeling is that the diet requirement is a bit overrated and I know people will disagree with me. But I'm pretty confident I could keep another one and not be too concerned about the diet and it will outgrow my tank again. Given what I said, I agree that this makes the Idol hard to keep due to its high maintenance and low tolerance for mistakes and should be left to advanced aquarists. :)

Interesting observation.

As Sam and I have discussed offline, I agree. This is what killed my MI and larger angels.

I also agree, based on the one I had, that the diet isn't something magical. It was healthy, fat, active and showed no fear. Ate anything offered, in double portions.

Mine is currently showing down on some PE mysis, and I'm about to add some banana. (Ya, I know....)

Banana not going over huge, but nibbling. He has started eating pellets though, so off to a good start.

Add some cheap brown zoas as a great treat that they can graze on all day without worry of polluting the tank with food decomposition. If they don't find it right away as a food source, they will eventually. Not needed but will be a good treat to give them something natural to graze on while waiting for their next meal.

Sam, the tank is full of brown zoas, no interest at all.

No worries, it took mine maybe 5 to 6 months to figure it out. :) Then they were gone in short time.

This guy won't be in this tank that long :) Not putting brown zoas in my DT

Just a frag Brad...what harm could it do?? ;)

I said as I added a plug of blue cloves :)

I actually have a couple already that came on my rock. But I have zoa rocks in my QT for food if anything wanted them.

I guess this thread will be more of a progress thread on the MI. So far, 24 hours after intro to the tank, he (and his anthias buddies) are savagely eating PE mysis. The MI is also gorging on NLS pellets. I'm hopeful!

All fish seem somewhat less interested in food today. Still eating, but spitting out the mysis. Hmm.

My experiences with these fish were similar to that of the copperband butterfly...

Even when I could get them to eat, they would seem to slowly wither away.


I always assumed they had some specific specialized dietary needs that could not be met by mysis or LR foraging.

The long term one I had seemed to do fine on it's diet, I suspect that O2 content of the water plays a significant role. I guess diet is a popular theory on their poor success, so we'll see how it goes.

My tanks are always open top with an open sump in a room that is vented outside.

I would never imagine I had low oxygen in my system.

Interesting theory.

I wonder if you could say the same for a copperband?

I thought my tank had lots of O2, but I had turned the pumps down, thinking the lower setting plus return pump plus skimmer would do the job, and lost my 3 larger fish. MI first, then the 2 angels. Low O2 is the only answer I have..

Makes sense Brad. Your sump with the protein skimmer was highly oxygenated but that oxygenated water was not coming back into your main tank fast enough because of the reduced return flow. Night time deaths of the highest O2 demanding fish would result when DO levels drop at night. For most the easier to keep and less demanding fish, this would not be a problem.

If I turned off my skimmer tonight and only leave my powerheads and an aquaclear running, tomorrow I will wake up with dead dwarf angels but no problems with everything else in my tank including tangs. Happened every time.

Brad, mine wasn't eating anything for a few days until I started putting some garlic extract in the pe mysis, it had a couple of nibbles and after a few feeds it definitely perked up his appetite. Now I am not sure if it had internal parasites or not but the garlic extract acted as immune system and appetite booster. It is now also eating large amounts of purple nori.

Sam, correct. Skimmer is good, but flow back to tank is pretty low. I'm going to rig a small Tunze to agitate the surface at night when pumps are lower

Interesting point on the dissolved oxygen level. I will have to keep that in mind.

Yeah, that's my biggest fear too. I recently bought and installed a Penn-Plax battery-operated backup air pump so I don't lose fish during power blackouts. Sorry to hear about your MI....

I only lost fish, could have been a lot worse!!

smaller mysis? my fish won't eat the heads....:rolleyes:

Anyone have any research on this or is the current theory based solely on 2 board members shared conversation and experience?

Seems like if proven and not common knowledge, should be a pretty important piece of information for the hobby.

I think this is all we have. I haven't read anything else about it anywhere. Assuming enough O2 is present, are they still super difficult? Probably..

My DT has flow enough for surfing across the surface, so we'll see where I end up in this trial.

Haha. I'm tempted to buy a Moorish Idol, put it in my tank, turn off the skimmer for about 2 hours during the day, take a video of the MI dying while all other fish are active, then turn the skimmer back on to see it recover just so I don't have to keep on about it. :) I've seen it 2 or 3 times before.

Sam, I'm a believer. However, that doesn't mean there aren't other factors. I'm hoping that with my "surf tank", I'll have no troubles. He's eating well and seems well settled, so we will see.

Yes, other factors goes without saying. But healthy fish all dying during the night (and the fish which I know would be the first to suffocate) while others have no problems. Also, all else constant except for the flow of oxygenated water back to the display tank.

On my tank, I also had surface ripples from powerheads and aquaclear running when the skimmer was off. Not enough.

Back to food. Looking back, in additional to zoas, mine also devoured: Hydnophora, Candy Cane, and Moon corals.

Maybe I'll look for some of these

Back to DO:

My own DO measurements support a lot of what was discussed here in this article: The Need to Breathe, Part 3: Real Tanks and Real Importance

It's a long article but I'll just briefly post a little bit of it here.

http://reefkeeping.com/issues/2005-08/eb/index.php

Tank 1: "Clownfish Tank"


Test 1: Circulated with powerheads and no skimmer: Morning DO saturation: 16%

Test 2: Aerated with protein skimmer: Lowest DO saturation: 81.2%

Same tank but aerated with airstone: Brought DO saturation up from 51% to 87% in 30 mins.


"
Tank 1 Discussion
The ten-gallon tank containing clownfish has been set up as an unskimmed system with what I consider to be an average stocking density of organisms for a tank of its size. I had assumed (wrongfully) that oxygen was maintained at high levels through the use of two powerheads that agitated the water's surface. However, once the lights went out and photosynthesis stopped, oxygen levels dropped quickly from a high of 78.7% of saturation to a hypoxic low of 16% of saturation. The levels were apparently low enough that each night, the clownfish would leave their anemone and adopt a position just under the water's surface directly above a powerhead. Out of concern, I then monitored the changes in oxygen levels at night using an airstone. Oxygen rose quickly and dramatically. At that point, I added a skimmer to the tank, with the result that oxygen is now maintained at much higher levels, ranging from a high of 130% of saturation to a low of 81.2% of saturation. However, it is only when the lights come on that oxygen reaches saturation or becomes supersaturated. It is notable that there appears to be a period early in the day when oxygen levels are maximal, with a depression to slightly subsaturated levels over the course of the afternoon. Also notable is a slight, but noticeable, drop in oxygen immediately after feeding. This measurement has been made repeatedly and is consistent.
"


"-Aquaria can and do become hypoxic at night and such a state may pose a risk to hypoxia-intolerant organisms.

-Aquaria can and do become saturated or supersaturated with oxygen during the day, and this is a result of oxygen resulting from irradiance of photosynthetic organisms. In no case was saturation or supersaturation measured without photosynthesis.

-Airstones and skimmers appear to be a very effective means of oxygenating small water volumes.

-Powerheads and recirculating pumps do not appear to greatly increase the oxygen saturation state of seawater aquaria.
"

So, thinks to himself, Apex must make a DO meter, right?? Ya, Google the price on that one!! lol

$700? Sell more frags instead of dumping them onto your lawn.

And another 100 for the module. US. So near a grand. I'll just keep the pumps pumping :) I'm years away from frags lol

Ok, just note that powerheads (nor external hang on back filters) really don't oxygenate the water much according to the article and my own tests and results. You really need to break the water surface with really violent splashes that would really make a mess or for ease, just use the skimmer/airstone

If there's a place to rent DO meters on the Island (In Burnaby, there's Hoskin Scientific) you could find out what your morning DO is with your pumps dialed down to its minimum and compare to when it is running at its max. Just take your angels and MI out of the system when you are testing for minimum levels and keep them in other oxgenated tanks (sump?). Although keep into consideration that the levels in the display tank would be a bit lower once those demanding fish are put back in.