Acara pairing- weird situation

[Plec123]

Looking for some input here.

I've got a 125 gallon with some mixed SA cichlids including an adult female Aequidens diadema, 6" xingu II pike, 6" Caquetaia spectabilis, and a juvenile Mesoheros gephyrus. Other tankmates are a few hoplo cats and some silver dollars.
Months ago I tried adding several small male A. diadema to get the big female to pair with one eventually, and it did not go well. We salvaged the last living male and put him in QT for a few months, and now that he's bigger (5-6") we put him back in the 125 today.

He immediately tried to take shelter behind the big female, and after some flared fins she calmed down. She hasnt tried to chase or bite him since we re-added him, and is occasionally bumping up against him or staying very close to him. In fact, she is chasing off any other fish that comes near him. Mostly the Caquetaia.

We went out tonight and came back a few hours after dark to find the male acara a little beat up, but still in the same cave as the female with the female not showing any aggression. Guessing the spec got some good shots at him while we were gone.

This seems pretty wild because I've never heard of fish pairing so rapidly And it seems like she took a liking to him right away. Even more bizarre because she would not tolerate his presence when he was initially added months ago.

Anyone know what to make of this? I'm kind of nervous that she's gonna snap and try to kill him again, but if they're gonna pair off I'll definitely get rid of the other aggressive tankmates to give them a chance.

 

[neutrino]

With the variability in individual fish, pairs, tank circumstances (including tank mates), etc., I wouldn't make (or trust) a dogmatic prediction, but:

I have wild Aequidens metae. I started with 4 total, 2 males, 2 females. During something like 3 years I put them in different tanks and combinations, depending on what else I was doing with my tanks, and they readily paired up, no matter which male/female I put together (which surprised me a little bit). Eventually I kept 2 of them, had them separated for several months, put them back together and again they immediately paired up. It's not uncommon at all for male acara to be hard on females, some of them very much so, and I see a little of it with these, but nothing serious. That said I keep them with Geos and Heros; having something else in the tank can help with aggression between a pair.

How close in size are they now? My expectation would be that the larger the male grows the more he'll hold his own with your female, and most likely turn the tables and be the more dominant of the two eventually. But cichlids don't always follow the norms for a species or do what you expect them to.

 

[jjohnwm]

Fish are weird...and cichlids are especially weird fish. It's pretty much impossible to foretell with any degree of accuracy what they will do, because they themselves don't know. And, as stated above, a lot of things can influence how they act and interact, not the least of which is how old they are...and what kind of mood they happen to be in on any given day.

I have two adult pairs of Cichlasoma dimerus; purchased 6 of them as 1-inchers and raised up together. They lived in a 8 x 3 foot tank, with numerous other cichlids and non-cichlids, and two pairs quickly formed and bred several times in said tank, although the young were not removed and soon vanished. Last summer those two pairs were placed outside in a 6-foot diameter stock tank, where they established territories, got along quite well and bred successfully...although one or both pairs were confirmed fry cannibals and almost no young were saved.

After a winter spent together back inside in the 360-gallon, they went out again this summer, into the same 6-foot stock tank. Three days later it was observed that one of the males had been very badly beaten. I assumed the culprit was the other male (no other tankmates), so I removed them all and gave each pair their own smaller stock tank, about 4 x 3 feet. The male healed up quickly and completely; both pairs produced decently large spawns...and both pairs ate every GD one of the young!

It's stuff like this that keeps me from being a very devoted cichlid fan...

 

[Plec123]

How close in size are they now? My expectation would be that the larger the male grows the more he'll hold his own with your female, and most likely turn the tables and be the more dominant of the two eventually. But cichlids don't always follow the norms for a species or do what you expect them to.

The female is fully grown. Around 9".
The male is around 5".
The two of them loosely follow each other around. Occasionally, the female will brush against the male or just bump into him. She's around 5 years old and never had a mate so maybe she's feeling him out.

He is very wary of any aggressive behavior from tankmates as he was beaten half to death a while back and kept solitary for months to heal up and grow a bit.

Almost all the aggression seems to be from the C. spectabilis. Even though the male has been defending himself fairly well, I may remove and sell off the spec anyway to give this potential pair a better chance.