Dominant Apistogramma Swim issues

Magnos · May 28, 2026

So i have had this happen a few times. (Especially with heavy line breed apistos). So I get 2 males 2 females. One of the males starts showing the usual signs of being the dominant male (longer finnage, brighter colors). Then after a few days he starts sticking to the bottom and having to fight really hard to get to the top of the tank and swims to the top to eat and sinks immediately once he catches something. Which points to swim bladder issues. All 3 of the other fish show no signs of this. So I removed that male and put him in my hospital tank. Once I removed him after a week the other male starts showing signs of dominance and after a few days he starts having the same issue.
It was Apistogramma Macmasteri gold/white morph. This was about a year ago and the females are still fine. Any insight into this i couldn't find anything when i searched.

GaryE · May 28, 2026

Guesses only, but I kept and bred a lot of Apistogramma, so educated guesses. A. macmasteri were one of my favourites.

I'll venture a guess one of the females didn't like either male. It's females who make the choice in that group, and if they deem a male to be useless and he doesn't swim away, they hit them pretty hard. I've seen male cacatuoides that attacked fry killed with a single blow, rammed where the gills meet underneath.

A hard hit can damage the swim bladder.

I never put two males together, and if the tank wasn't large, kept to a single female. Two pairs means two tanks, in how I kept and bred them. I found the territoriality to be much less like that, and the fish seemed calmer. I rarely lost them to scrapping. But when I was raising juveniles in groups and one began to strut, things happened fast.

Theory two is the fish were harbouring a bacterial infection, and the stress of sale/shipping/new quarters combined with the stress of asserting dominance let the pathogen take over. The females, not needing to push out the finnage, colour and size, were less stressed.

@anewbie has a lot of Apistogramma experience, and may be able to suggest other possibilities.

Magnos · May 28, 2026

So when a male becomes dominant he is using more energy and feels more stress so the bacteria was able to win against his immune system?

Magnos · May 28, 2026

Is it like Ich? Present but muted until stress is introduced?

anewbie · May 28, 2026

Magnos said:
So when a male becomes dominant he is using more energy and feels more stress so the bacteria was able to win against his immune system?

I believe what Gary said is the female has injured the male. It isn't a disease. What size is your aquarium ?

While i can't tell you it was the female who attacked him it is clear that the damage is physical and not disease - simply removing him wouldn't cure him if he was ill though stress can lead to greater chance of getting sick - curing takes a bit longer.

If your tank was less than a 40b there is virtually no chance of these 4 fishes having worked out in a pleasing way.

Usually it is the male who harrasses but if the female is mature and the male is a bad potential partner the table might be switched; though i've seen the female aggression more often with pair forming species like nijjensi. In any event having two males in a small box of a polygamous species is a bad idea unless the species is very docile.

OldFishKeeper · May 28, 2026

GaryE said:
Guesses only, but I kept and bred a lot of Apistogramma, so educated guesses. A. macmasteri were one of my favourites.

I'll venture a guess one of the females didn't like either male. It's females who make the choice in that group, and if they deem a male to be useless and he doesn't swim away, they hit them pretty hard. I've seen male cacatuoides that attacked fry killed with a single blow, rammed where the gills meet underneath.

A hard hit can damage the swim bladder.

I never put two males together, and if the tank wasn't large, kept to a single female. Two pairs means two tanks, in how I kept and bred them. I found the territoriality to be much less like that, and the fish seemed calmer. I rarely lost them to scrapping. But when I was raising juveniles in groups and one began to strut, things happened fast.

Theory two is the fish were harbouring a bacterial infection, and the stress of sale/shipping/new quarters combined with the stress of asserting dominance let the pathogen take over. The females, not needing to push out the finnage, colour and size, were less stressed.

@anewbie has a lot of Apistogramma experience, and may be able to suggest other possibilities.

This is why I moved on to German Blue Rams and Red Breast Acara. Dwarf cichlids with better "personalities"

!

anewbie · May 28, 2026

OldFishKeeper said:
This is why I moved on to German Blue Rams and Red Breast Acara. Dwarf cichlids with better "personalities" !

Well rams are pair forming as are l. dors; BUT don't be fooled rams can be super aggressive - i had a couple in a 120 (4 random ones) and one of the females decided she owned the entire tank. Of course sometime they are content to just ahve their little spot esp when breeding so there is a wide variance but they can be extremely aggressive (she was not partner or breeding at the time - she just had an attitude).

OldFishKeeper · May 28, 2026

anewbie said:
Well rams are pair forming as are l. dors; BUT don't be fooled rams can be super aggressive - i had a couple in a 120 (4 random ones) and one of the females decided she owned the entire tank. Of course sometime they are content to just ahve their little spot esp when breeding so there is a wide variance but they can be extremely aggressive (she was not partner or breeding at the time - she just had an attitude).

Well, in as much as attitudes are not just restricted to fish (wink), some apistos are known not to share parenting duties.

anewbie · May 28, 2026

OldFishKeeper said:
Well, in as much as attitudes are not just restricted to fish (wink), some apistos are known not to share parenting duties.

That is mostly species oriented though mass produced ones are likely to be worse parents then those that are hobby bred. The key difference is related to how long the fry are kept with the parents after all they have to go to school while with the parents.

Btw one of the big problems with domestic bred fishes is that the line breeding to produce specific strong colours make it more difficult for the fishes to talk to each other - and when they can't settle their disagreement verbally they resort to fists.

OldFishKeeper · May 28, 2026

I would be interested in reading the scientific study supporting this...

anewbie · May 28, 2026

Sadly 'this' is not descriptive - however a 30 second search finds among many others this article:

Paternal care in a fish: epigenetics and fitness enhancing effects on offspring anxiety - PMC

In many animals, including humans, interactions with caring parents can have long-lasting effects on offspring sensitivity to stressors. However, whether these parental effects impact offspring fitness in nature is often unclear. In addition, ...

pmc.ncbi.nlm.nih.gov

and another 30 second search finds this article:

Cichlids | Calgary Aquarium Society

So i saved you 60 seconds though neither article might cover the 'this' you referenced.

There are of course better articles esp for the first topic but i was too lazy to reference those.

GaryE · May 29, 2026

All I have is anecdotes, but I think from years with these fish that the instincts are there, but they need to be triggered. It's rather like imprinting for birds. It may be the same with us.

When I started I had a naive view that rare fish could be sold, and I stole a few spawns to get maximum numbers. I learned that the hobby fears new and rare pretty quickly, and I switched to allowing parents to raise babies for as long as the broodcare operates. It worked better, and I saw what I considered to be a difference between stolen fry and parent raised fry in terms of the next generation's broodcare.

Rams are interesting, because to me, GBRs are severely behaviourally modified compared to the wild ones I've kept twice. They are insipid fish compared to the wild sparkplugs. The colour jumps out more in the domestic product, but whether the genes for colour also trigger behaviour, or whether breeders have consciously or unconsciously selected for calmer fish, who can say? There are so many breeders and so many fish involved.

Fancy form angels have often been awful parents compared to wild forms. The latter are harder to spawn, but care levels are consistently good.

I've had broodcare trouble the few times I kept Apistogramma cacatuoides orange flash or double/triple red. but never had any issues with wild caught individuals. I used to have excellent access to wild caught Apistos.

I have little interest in numbers, beyond wanting enough broodstock to continue for as many generations as I can. I enjoy fish behaviour, and dwarf Cichlids (mainly African rainforest ones for me over the past 20 years - no more Apistos) are great for that. But they do raise questions. Good.

OldFishKeeper · May 29, 2026

GaryE said:
All I have is anecdotes, but I think from years with these fish that the instincts are there, but they need to be triggered. It's rather like imprinting for birds. It may be the same with us.

When I started I had a naive view that rare fish could be sold, and I stole a few spawns to get maximum numbers. I learned that the hobby fears new and rare pretty quickly, and I switched to allowing parents to raise babies for as long as the broodcare operates. It worked better, and I saw what I considered to be a difference between stolen fry and parent raised fry in terms of the next generation's broodcare.

Rams are interesting, because to me, GBRs are severely behaviourally modified compared to the wild ones I've kept twice. They are insipid fish compared to the wild sparkplugs. The colour jumps out more in the domestic product, but whether the genes for colour also trigger behaviour, or whether breeders have consciously or unconsciously selected for calmer fish, who can say? There are so many breeders and so many fish involved.

Fancy form angels have often been awful parents compared to wild forms. The latter are harder to spawn, but care levels are consistently good.

I've had broodcare trouble the few times I kept Apistogramma cacatuoides orange flash or double/triple red. but never had any issues with wild caught individuals. I used to have excellent access to wild caught Apistos.

I have little interest in numbers, beyond wanting enough broodstock to continue for as many generations as I can. I enjoy fish behaviour, and dwarf Cichlids (mainly African rainforest ones for me over the past 20 years - no more Apistos) are great for that. But they do raise questions. Good.

Whatever the result is, my main reason for keeping cichlids is the entertainment factor watching the parents raise their young.

The GBR and Red Breast Acara have the added benefit of smaller size aquariums making it easier and cheaper to keep them. They are also colorful.

GaryE · May 29, 2026

That's the key thing. "stealing" fry is an industrial trick. Watching fish is a great hobby!

anewbie · May 29, 2026

OldFishKeeper said:
Whatever the result is, my main reason for keeping cichlids is the entertainment factor watching the parents raise their young.

The GBR and Red Breast Acara have the added benefit of smaller size aquariums making it easier and cheaper to keep them. They are also colorful.

For others reading this i will say l. dors (red breast acara) are a much more robust and gentler fish even when spawning than gbr - the only real disadvantage is they are a bit larger and of course looks which is a personal thing.

Also be aware that domestic l. cuvies are usually blue form of l. dors and not actually l. curives. IMHO the blue form of dors are pretty darn nice (there are 3 or 5 colours in nature; not human induced bred) - i only know of one colour form of l. cuvies.

These are my domestic dors sold as as cuvies: