Keeping The Mysterious Moorish Idol

4FordFamily

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Keeping The Mysterious Moorish Idol

Moorish Idols. Impossible to keep. Better left in the wild, right? Anyone that has been in this hobby for nearly any length of time has read things like this or can at least recognize this iconic fish. Many of us grew up seeing this majestic fish in photos and documentaries. Whether seen schooling in Hawaii or casted as "Gill", the wise Moorish Idol from the beloved Disney Pixar film "Finding Nemo", this fish is quite desirable in the hobby. Sadly, The vast majority of these fish do not survive past a few months in the home aquaria.

But is it really true that these fish are best left in the ocean and impossible to keep? Well, like any sweeping statement this is untrue -- but the overall (intended) message is largely correct; this fish is NOT for the beginner or intermediate fish keeper. For the devoted, experienced hobbyist that is willing to cater to its' needs it can in fact be kept "successfully".

idol.png

Photo by R2R member @Bubblewood

I will begin by mentioning my experience with Idols. I have kept two over the past three years which is hardly a "success" if I am being honest. My first idol lasted two years before getting an eye infection. As fragile as idols are, unlike my prior fish to become "cyclops", he did not cope nor adapt. I noticed the infection too late and what was once the healthiest eater in the tank began his signature Moorish Idol downward spiral. They are notorious for "randomly" dying after a few weeks or months and randomly refusing to feed (permanently). I have quarantined and treated several (thus getting them to eat successfully) for local reef clubs on several occasions. I think I've quarantined 12 now, 11 successfully. My friends that have kept these fish for a couple years or more also follow the same "formula" to come. Important to note that an idol should live 10+ years in captivity to be truly declared a success, in my opinion. I believe I will get there.

For most people that have attempted Idols, it generally ends one of two ways.

1. You bring home your beautiful new fish and despite your efforts you cannot get the fish to eat. Slowly the fish wastes away and dies. You become frustrated.

2. You bring home your idol and you are lucky enough to get it to eat. Despite a healthy appetite, it seems to continue to lose weight and waste away. Perhaps it doesn't lose weight but after a few weeks or months the fish drops dead. This is often due to feeding the wrong foods, not enough food, and parasites. I will discuss all of these things.

So what do you do? In my opinion there are three primary factors that can lead to success for the experienced hobbyist with a well established tank.

1) Start with a healthy specimen. This may sound like common sense but even seasoned hobbyists have difficulty identifying a healthy specimen from one not so healthy. To make matters worse, most LFS keep fragile fish in low amounts of copper which will mask the presence of parasites but will not rid the fish of them.

Avoid fish that have spots, "dustings", torn fins, discoloration, erratic swimming or breathing, or are otherwise thin. An idol that has a clearly visible spine (not to be confused with the lateral line) is almost always a goner by that point. At this point of fasting they rarely if ever begin feeding. As a result, it is best to buy a fish that is already eating and feed it what it ate at the LFS. Buy a very fat idol whenever possible as this gives you the best chance of success. Consider the extra weight as extra time you have to get the fish to feed. In general, a thick fish is also a sign of an overall healthy specimen, though not commonly found after going through the distribution system.

My two idols were purchased from NYAquatic and Live Aquaria's Divers Den. I trust these sources and they do a fine job but there may be others.

1.jpg

Photo by R2R member @foxvalleypcgeek

2) Provide a disease-free environment. This is a fish that will need to go in to a tank where every fish has been properly quarantined AND treated for ich/velvet/flukes as a precaution before addition. The idol will also obviously need to be treated using the same regimen. There are many fish in this hobby that may tolerate "ich management" practices whereby you do not quanrantine or treat fish prior to addition. The Moorish Idol is NOT one of these fish. In today's environment disease is more prevalent than ever and this practice is probably the single most common reason for people exiting the hobby and fish deaths.

Although your fish may not show symptoms, if you do not properly quarantine and treat they are carriers that have built up a resistance to parasites. This will become starkly obvious when adding fish like Moorish Idols, powder blue tangs, achilles tangs, other acanthurus tangs, or other fragile species.

The deck is already "stacked" against you with this fish, the last thing you need is another stressor/factor weighing down your chances of success. With idols, weight is everything. With ich or other parasites present, too much energy will be spent fighting these infestations off and eventually they starve and die. They have very high metabolisms and need lots of calories to be retained to thrive. This is a great segway in to the next factor.

342EB544-75F3-40FA-8322-8F2F6C2E8C3D.jpeg
ED6410CC-1303-4B0F-8E2F-8342C025C2B4.jpeg

Two idols I am currently quarantining (but will not be kept together if they both make it). They’re eating red nori, fresh mussels, live blackworms, and occasionally frozen offerings soaked in garlic and selcon. Updated 11/2017

3) Diet is critical. In the wild, Moorish Idols dine on sponges, algae and other marine plants, and even some corals (such as polyps). Many have written that they feel that high quality pellets such as "Spectrum pellets" are the secret to idol
success. I have never fed any of my idols these foods so I cannot comment. Like many angels, sponges are largely omitted from their diet in the home aquaria and are actually a very important staple. Hikari and Ocean Nutrition both have a frozen "angel formula" that contains sponge. Fresh mussels can also help them begin eating in captivity - break in half and leave in tank for 6 hours. Even more important than sponge and often ignored is nori. As I said, the key to idol success is to have a thick, well-fed fish. This can obviously be difficult if they do not eat. Red nori is the often overlooked staple of their diet and in my personal opinion is the single most important food for your idol. Nori is important because they can get a lot of calories and girth. Also, grazing throughout the day seems to be soothing for a fish that grew accustomed to this in the wild. Since stress can be such a killer, reducing stress is a good idea. In my opinion, leaving nori for them serves a dual purpose. Mine get equal amounts of red and green nori. For finicky eaters, try rubber banding nori to a small rock so it can best resemble wild feeding habits at first.

My fish all get a mixed smorgasbord of a dozen or so frozen foods (including lots of angel formula) that are mixed, strained, and soaked in selcon. I add garlic guard when I am trying to tempt new fish to eat as well. They also have access to nori for most of the day, whatever amount that requires.

For the struggling idol try fresh mussels, live blackworms and live brine. These can tempt even the most finicky or hesitant eaters. Blackworms are also a very nutritional food and should be fed to marine fish regularly.

Other Factors

1. Moorish Idols do not prefer to be kept in pairs. This is often perpetuated on forums I suspect in part because people see videos or photos of them schooling in the wild. However, many fish such as the powder blue tang school frequently in the wild but do not get along or have enough room in the home aquaria for this behavior.

2. Moorish Idols should have access to enough nori that it is gone by about midday or longer. This allows them to graze for about half of the day.

3. Idols, in my experience, are not particularly sensitive to medications. I've successfully treated about a dozen with copper at high dosages without issue. It's best to get them eating healthily before treating if possible. If visible disease is present then begin treating as soon as possible.

4. Idols should not be kept with aggressive fish as stress can be a quick killer. They are relatively fragile fish. When stressed they tend to stop eating and this is typically a death sentence as they don't generally begin eating again after they have decided to quit. My idols have been with large angels, a couple tangs, and large wrasse which seems contrary to my suggestion. My angels are not very aggressive and have respected both idols. However, I do not recommend anyone do as I have. If aggression were to become a factor I have two other tanks I could move the idol to without issue.

5. Moorish Idols prefer at least 5 feet of swimming room with 6+ being ideal. They can cover vast distances in the wild and to reduce stress a larger more established tank will be best.

Please do not attempt this fish if you cannot commit to the above suggestions. Can you succeed without all of them? Sure, but your chances will be greatly reduced and another treasure of the ocean may be wasted.

Happy reefing!
 
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melypr1985

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This is great! Thanks for a great read!
 

Daniel@R2R

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Great work, sir!!
 
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4FordFamily

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Black Pearl

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Great article, had two and one died a few days after receiving it, the one that survived has been in the tank 4 months now, and is eating well. I feed nori, the purple and green, I've got some red that I will try again, initially it didn't go over to well, also feeding New Life Spectrum pellets, which he loves. now that I've read your article, I have a new choice in his diet regime. I'll be adding the Ocean Nutrition Angle formula
 
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4FordFamily

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Great article, had two and one died a few days after receiving it, the one that survived has been in the tank 4 months now, and is eating well. I feed nori, the purple and green, I've got some red that I will try again, initially it didn't go over to well, also feeding New Life Spectrum pellets, which he loves. now that I've read your article, I have a new choice in his diet regime. I'll be adding the Ocean Nutrition Angle formula
Post photos!

Red nori's attractiveness to fish I believe is more due to color than actual nutrition, at least in the hobby. This seems especially true of my Hawaiian fish (such as the idol and Achilles tangs).
 

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Since the clown tang has been removed from the tank, M's streamer has gotten longer. He was very thin when I first got him and it took about five days before he would eat. he first started eating pellets, but they had to be pre soften and I had to feed with a Skimz Coral feeder so the pellets would kinda roll in the flow across the front bottom of the tank , he would follow and pick them off the bottom, totally ignored them if they were in the water column. eventually he settled in and now eats any and everything feed to the tank
 

Paul B

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4FordFamily, thank you for that article, I am sure it will help a lot of people. It is unfortunate that Idols have such a bad reputation of dying in so short a time as they are a very common fish. They are all over the South Pacific and all the Hawaiian Islands. As a matter of fact I just went diving in Hawaii and they are probably the most common fish there. I have spent quite a lot of time with them underwater and like you said, they live on sponges. In Tahiti, sponges are the only thing I have seen them eat and in Hawaii there is a "mulm" growing on all the rocks that they constantly pick at. They swim large circles around the reef looking for their food and their mate eventually follows them to eat the same food from the same place. Looking at my log book I see I have kept a few Moorish Idols even then in the 70s which is surprising because at that time those types of fish had virtually no chance of living in a tank. My last Idol lived five years which is a failure, but for an Idol, it is pretty good. I think I found their secret. Here in New York I can collect a brownish sponge that grows just under the surface on wooden docks. It is very common and easy to collect. I couldn't keep it alive but it freezes well and my Idol would practically jump out of the water for the disgusting stuff.
Every day my Idol got a little sponge and I devised a feeder which was essentially a dish at the bottom of my tank with a tube to the surface. On top of the tube was a funnel and over that was an automatic food dispenser that dispensed fish oil soaked pellets 3 or 4 times a day which went into the dish. The Idol would circle the tank constantly and on every pass check out the dish for pellets.
My tank is 6' long which I feel is too small for a full grown Idol so I won't get another one. But I feel that now, with al I have learned by swimming with them and discovering a local food source for them I "think" I could keep one for 10 years. But I will probably unfortunately never find out. :D
I took this off of Bora Bora in Tahiti.



This was one of the outer Hawaiian Islands, I think it was Lanai



Here is a page from my log book. It is a shame they sold Moorish Idols in those days as none of us could have kept them alive for very long at that time.
 
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tj w

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I too noticed that while in Kauai the MI was one of the most prevalent fish found. They all picked off the rocks all day a long with a lot of orange shoulder and convict tangs.
 

Paul B

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tjw, that is true. Hawaiian Islands are covered in this growth that looks like a combination of dying algae and detritus and Moorish Idols seem to love the stuff.
In the rest of the South Pacific that stuff does not appear so the Idols live off this sponge. I noticed them eating a lime green sponge there and it is all I ever saw them eat. They search for the stuff in huge 90 yard circles.
This is Hawaii and what they pick on.


This is also Hawaii but here, the urchins picked the rocks clean as you can see them everywhere.


If you look very close here in Tahiti, you can see one lone Idol at the bottom of the picture.

 

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Thanks for the article ,so far mine has been well .loves the garlic laced seaweed and really goes after the fish eggs I sprinkle in the tank for the zooanthens .interesting about liking company .i hesitate to buy another had a bad experience with the copperband butterfly .if I find another the same size I might consider though.
 
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4FordFamily

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4FordFamily

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Thanks for the article ,so far mine has been well .loves the garlic laced seaweed and really goes after the fish eggs I sprinkle in the tank for the zooanthens .interesting about liking company .i hesitate to buy another had a bad experience with the copperband butterfly .if I find another the same size I might consider though.
I would avoid keeping two together personally, I've had it not end well. Three or more perhaps. I qt'd 4 together once and they did alright. Very temporary though
 

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Great article!! Well written and interesting to read. I think it would be great to post 2 sticky threads in the 'New to Saltwater Tanks' forum like
'Fish for Beginners to Avoid " that has a List with links to articles like this and other challenging fish.
"A Stocking List Plan - What to plan before you add any fish". This could describe what a stocking plan is. It could cover the importance of owner skill level. fish compatability and the order in which fish are added. Have link to @mdbannister's thread on Deciding if a fish is right for you? " on this thread so they can be guided.
I suggest this because many newbies seem to post after making impulse buys. Many LFS don't ask questions for newbies to make wise fish selections. R2R can ask those questions.
I think this might help excited newbies realize they should utilize great resources like @mdbannister 's thread & articles like these.
 
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