(not from the net!)
I never kept Moorish idols in my stateside tanks, due to their reputation as being very difficult to keep. However, I moved to Micronesia where the Idol is very common. So, I put 6 of them in a 380 L tank with live rock and live corals. I've had them for 3 years now and they keep growing, so I had to return 3 of them to the ocean. I caught all my idols next to a sewage dump where the water quality is atrocious. This just shows that they are tough fish, but travel very poorly. Therefore, I've had my fun, and will not try to keep them when moving back to the US.
My Moorish Idol has been with me for nearly 18 months. I bought him when he was really small. He was eating when I got him. He eats frozen brine, mysis, marine green, ocean plankton, squid and prawns. He is living with my coris wrasse, picasso trigger and snowflake eel at the moment but I am going to move them out shortly into a bigger reef tank. Then the MI will be living with my seahorses again. He originally lived with them until he grew quite large, and then I transfered him to the reef. I was not going to add him to the reef while he was so little. My MI grazes all day. They need a constant source of food.
Growing up on the south coast of NSW, Australia, I always looked forward to the warm summer months that would carry the larvae of barrier reef fish down thousands of kilometres from the GBR. These fish settled on our temperate reefs and were quite contrasting to the temperate fish, in colour and appearance. Chaetodons, surgeons, various angels and heniochus and moorish idols would be the most common. One particular year I counted a school of 200 moorish idols. These fish, once caught, seemed to do well. Within hours they were eating an open mussell. I have had a group of 6 of these moorish idols in a 1500 L reef tank. The oldest one I have had for 9 years and the others between 7 and 2 years. My tank has rich growths of ulva algae, as well as various caulerpa species. The MI's graze all day, and I supplement the food with nori, mussell, mysis shrimp and frozen prawn. They are bold feeders and boss around my conspicuous angel. I believe my success lies in the fact that transport was only half an hour from capture to aquarium and the fish were all juveniles, without a preferred diet. I recommend them if they have good weight on them and they are feeding.
I live in the Micronesia Islands. Guam to be more specific. I can take you to a reef here that houses hundreds and hundreds of MI's. With all these comments combined they are all correct. The Idol does not do well during transportation. A small bag from you LFS will probably kill him. I highly recommend you pay for the fish, have the store quarantine him till you can see him eat, and then transport him in a large container back to your home for a dedicated acclimation period of at least one hour. If you are close to a population of these, then you can hand catch them at night with very little effort, using a dive light and a small soft net. This is how I do it and they will be eating again the next morning, even though they are in a small quarantine bucket for a few days. Keep in mind though that there are no true replacements for the Moorish Idol, for they belong to no species but themselves. Good Fish keeping.
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