Pseudomugil luminatus aggression?

[PlantedAri]

Probably excessive backstory: I got 12 pseudomugil luminatus 2 months ago. My tank is heavily planted and I also have 6 amanos. I didn't quarantine the pseudomugils because they were the first fish in my tank, but they settled in well and seemed fine until a month and a half later when I noticed one of my amanos munching on a dead fish. I hoped it was a fluke since they all seemed fine otherwise, but then a few days later I was down to 9 fish. I never found the carcasses because of aforementioned dense planting and my shockingly efficient amanos and snails. I also noticed a few fish trying to peck at the eggs one of the amanos was carrying - even just an hour after being fed.

 

This led me to my first theory: that the amanos were somehow culpable. Work got busy and I noticed that one of the amanos had laid her eggs, so I hoped that would be the end of it, but a couple days ago I once again noticed an amano 'disposing' of a fish carcass. I'd even counted 9 fish that same morning, so one of them had died during the 8ish hours I was at work. I've been watching the tank more closely and I noticed the largest male has been chasing everyone around. (I've attached a video of said chasing.) Throughout all this I've been testing the water and I'm at 0ppm ammonia/nitrite/nitrate, and my water hardness and buffer hasn't changed from what I can tell via testing strips. I haven't spotted any strange scale, appetite, or swimming issues otherwise.

 

 

Basically, should I assume this male is to blame for my other pseudomugils gradually disappearing? Any other ideas/things I should look for or check?

 

[Guppysnail]

What size tank? Is that red root floater clump the only clump hanging down in the water.  
I had the same aggression death issue with my first group. Mine was aggression because I watched it happen. Mine were 10 in a 10 gallon. A larger tank and several spaced out floating spawning mops so each had their own spawn territory fixed it. 
also Amano are predatory especially if hungry they go after small fish. 

[T. Payne]

I've kept and bred luminatus for years and never had any serious aggression issues that resulted in the death of a fish. I've kept them in aquariums from 10 to 29 gallons.

[PlantedAri]

On 8/4/2024 at 5:55 PM, Guppysnail said:

What size tank? Is that red root floater clump the only clump hanging down in the water.  
I had the same aggression death issue with my first group. Mine was aggression because I watched it happen. Mine were 10 in a 10 gallon. A larger tank and several spaced out floating spawning mops so each had their own spawn territory fixed it. 
also Amano are predatory especially if hungry they go after small fish. 

20 gallons, there's another clump of red root floaters and then quite a bit of water lettuce and frogbit hanging down too. Here's a photo of the whole tank:

Hmm very good to know about the Amanos. Honestly I'd thought the algae, plant matter, and leftover fish food would do it for them, so maybe I need to be more intentional about feeding them.

On 8/4/2024 at 6:23 PM, T. Payne said:

I've kept and bred luminatus for years and never had any serious aggression issues that resulted in the death of a fish. I've kept them in aquariums from 10 to 29 gallons.

How did the less serious aggression issues resolve?

[T. Payne]

Mostly just males flaring and displaying. Always kept more females than males as well.

[Guppysnail]

On 8/4/2024 at 8:23 PM, PlantedAri said:

I need to be more intentional about feeding them.

Add protein rich food for them. 

[mynameisnobody]

They are very short lived fish. Most pseudomugils are annuals meaning they have a lifespan of about a year, give or take. 

[beastie]

Last year i bought 10 fish to a 13 gallon i think (54liters) and since they were mature, i asked for 5 males 5 females. I lost one due to too cold water change, they hate it , but can't say i observed any aggression. They flare, they chase, they flare AND jump (heard the thud as the males hit the glass).

I still have the ten from last July, have few babies and now way less planted tank then yours. I even had them with other fish and snails, no issues. I would blame the amanos

[T. Payne]

On 8/4/2024 at 8:56 PM, mynameisnobody said:

They are very short lived fish. Most pseudomugils are annuals meaning they have a lifespan of about a year, give or take. 

Never experienced this, I have some luminatus over 4 years old. I've kept and bred 4 different species of blue eyes and have never experienced a short life span of a year or close there to. Maybe that was due to poor genetics. My fish are fed live bbs daily, a quality flake and quality pellets. 

[Woowala]

My dominant luminatus male was ridiculously aggressive as well.  Conditions were not ideal (3m 3f in a 10 gal, not enough plants, no spawning mops) so that likely contributed.  Never had amanos so can't comment on that.

I would add a mop or two at either end of the tank, or remove the dominant male to another tank for a few weeks before reintroducing.

[mynameisnobody]