Emperor not changing

brad

Active member
A little over a year ago, I bought a juvenile emperor. It has grown and seems healthy, but hasn't shown the start of adult colors. Is it healthy? I don't mind the juvenile colors but expected a change by now. This fish has also scared me twice by disappearing for days and I thought it was dead, only to turn up healthy, eating and behaving normally. Fish is in a 270 which may be too small for an adult but just fine right now.
 
A 270 is plenty large enough for a Emperor long term. How large is your emperor, they don’t start to change until the 5” or so mark.
 
a 270 will be fine for an Emperor. Usually, they start changing when they are 1 - 2 years old. One of my current Emperors has been with me since Jan 2017, its almost fully changed to its adult colors. The other one has been with me since Aug 2017 and is kinda changing, it still has the juv colors but the circles are starting to go away. I would not worry about it to much.
 
Now that I look, I think he is changing, although not the way I expected. Fish are hard to photograph:
emperor.jpg


He is still dark blue, almost black with fading lighter to white near the dorsal fin. I expected this lighter color spreading downwards would be the first sign of a change. Instead, some of his white lines are changing pattern and becoming yellow, while other white lines look exactly the same. This is even harder to photograph, as the fish is capable of changing the color of the yellow lines slightly but not the white ones.

Anything special to do with him during the transition, such as diet? Will what he eats now determine how nice his final pattern is? He ate all my aiptasia and much plenty of LPS and lots of sponges and small stuff on the rocks - actually quite a lot of food from the reef. Beyond that, he is just eating a variety of dried and convenient fish food.
 
Perfectly normal. Just keep feeding. They can grow about 3 inches per year and IME slow down at the 9 inch mark. They turn at different sizes.
 
A client of mine had a 4 inch juvi emperor in a tank I serviced. The type of person that really didn't love fish and didn't care much for my preaching about offering a variety of foods for the health of the fish. He only fed one type of pellet food for the two years he had the fish. Over the course of the first year it changed to adult colors. It turned into the ugliest emperor I have ever seen. The colors were so dull that he ended up giving it away.
IMO it is vital to give this fish a varied diet; mixed frozen, fresh seafood as well as pellets and nori. This will give it the best chance to color up to it's full potential.
 
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