Attempting pairing of Singapore Angelfish

[iamwhatiam52]

The two Singapore Angelfish (Chaetodontoplus mesoleucus) in my tank do not seem to be "pairing up" and after 3 months the larger one still chases the smaller one. There is no serious aggression or pursuit, but the larger darts toward the smaller and it zips behind the rock for a moment.

Do they need more time, or is it unlikely they will ever be a pair?

Here are the other relevant details:

180 gal mixed up reef, lots of hiding places.
First one introduced 6 months ago, now 2"
Second introduced 3 months ago, now 2 3/4"
Both are fat and sassy, but a bit shy
Other fish, 3 1/2" yellow tang, pair of argi, flame angel occasionally face off with both, but no significant aggression or chasing

[tcmfish]

They aren't like clowns where they will sit side by side all day long, and your tank may or may not be deep enough for them to spawn, but that is usually when you see pair behavior. They will spawn during the twilight hours, so if you have a period where only the actinic lights are on, that would be it. Does the smaller one seem fatter or more round in the midsection right before the vent?

[iamwhatiam52]

Does the smaller one seem fatter or more round in the midsection right before the vent?
Not that I can see.


While spawning would be nice (the argi do at times), I am more concerned about compatibility. My hope would be that they are not aggressive or territorial toward one another.

[jhawkor]

They are still quite small, maybe they just need more time to mature into a pair?

[tcmfish]

The behavior seems normal, the only thing I noticed is that yeah they are small, but I definitely would have introduced a smaller one later, not a bigger one.

[iamwhatiam52]

Thanks for the information.

I definitely would have introduced a smaller one later, not a bigger one.
My first one was pretty small at the time and I was afraid that an even smaller one would get harassed to death by the resident. I figured a bigger one would have a better chance of holding its own against the established one. Problem is that he held his own and then some.

[tcmfish]

With angels at least dwarfs and probably larger ones it is better to add a smaller one to the established one because the established one is male usually after being alone, and if you introduce a larger one chances are it will be male too. Who knows when singapores reach sexual maturity but it is always good to rule on the safe side. That is why I would have added a smaller one because the first one may have been turning male, I doubt at that size though thats the only thing. I also doubt your newest one is male yet either but who knows like I said earlier.

[iamwhatiam52]

With angels at least dwarfs and probably larger ones it is better to add a smaller one to the established one because the established one is male usually after being alone, and if you introduce a larger one chances are it will be male too. Who knows when singapores reach sexual maturity but it is always good to rule on the safe side. That is why I would have added a smaller one because the first one may have been turning male, I doubt at that size though thats the only thing. I also doubt your newest one is male yet either but who knows like I said earlier.


Wish I knew this before! I hope I don't have two males, or if I do that the are very open minded.

Is turning male a one way street for angels?

[jhawkor]

Wish I knew this before! I hope I don't have two males, or if I do that the are very open minded.

Is turning male a one way street for angels?

I believe so, for most species anyway. I know C. ferrugata was observed changing from male back to female but I don't think larger angels can.

[iamwhatiam52]

Bump.

I was hoping one of the other resident angel fish nuts might know more.

It would be helpful if someone knows, or could steer me to someone who might know at what size they become sexually differentiated since the suspicion is that both might already be male, and that it is irreversible.

I want to be as sure as possible before removing one. None of my other tanks are large enough to keep one long term, and I'd hate to give one to someone unless they had a great home for it.

[stunreefer]

I agree with Tim regarding "normal behavior". If they're not causing major damage, just give them time.

[LargeAngels]

I usually add larger to smaller. It takes a while for them to turn into males (IME.)

I also think that behavior is normal. I still see that everyday with some of my pairs, even the ones that do spawn.