Aggressive Male Cacatuoides

[rollj1]

Hi,

This is my first post!

I've been using this excellent forum as a source of reference as I have just started keeping Apisogramma cacatuoides in my Amazon Biotope tank.

I purchased a trio of them last weekend, 1 male and 2 females. All with excellent colourings and perfect! They are still very small, and the male is no more than an inch long, the 2 females slightly smaller.

The tank is 60litres in size, has a fine sand substrate and is decorated with redmoor root, java fern, moss balls and I've placed some pieces plastic piping in there for caves/shelter until I can find a suitable, more fitting solution.

Tank mates are 4 small Sterbai Cory cats and a couple of cherry red shrimp from an old tank for now. That's it.

PH: 7.6
Amonia: 0
Nitrite: 0
Nitrate: circa 20ppm
Temp: 26 degrees


The male seems to have paired with one of the females, yet chases and flares his fins almost constantly towards the other female. I noticed last night that he may have nipped her rear fins and this is upsetting me. I deliberatey purchased 2 females so as to split any agression from the male out and all I seem to have done is make life for one of the females miserable. She seems fine at the moment and is still showing a good yellow colouration, but is hiding behind the filter much of the time.

Is this common behaviour? Any ideas on how to get around this and give the other female a break? I was thinking of adding a small group of dither fish at some point, would that help?

Thank you in advance.

John.

 

[Mike Wise]

This behavior is common in tanks that are too small and too open, visually, for a trio. Another possibility is the harassed female is not a female, but a young male. Right now you best option is to add more visual barriers to the tank and add a piece of floating pipe at the top as a refuge.

 

[rollj1]

This behavior is common in tanks that are too small and too open, visually, for a trio. Another possibility is the harassed female is not a female, but a young male. Right now you best option is to add more visual barriers to the tank and add a piece of floating pipe at the top as a refuge.

Thank you for your reply Mike. I'll try to add some more plants and pipe at the top. Apologies if this is a silly question, but you mention one of the females could actually be a male. Visually she looks identical to the other female, but I have noticed she has some orange colouration to her tail fin. Is this normal for females? The male looks very different indeed to the other 2 as you would expect.

It might also be worth mentioning that one of the females (the one who is left alone) has more of a black spot than a line on her side, which I believe indicates spawning? Would this be another possible cause as to why the male is showing aggression?

 

[Mike Wise]

Since your fish are small (young), there is a good chance that your harassed female is either a juvenile or a sneaker male. Both resemble females to a large degree. Females of domestic color strains of A. cacatuoides often show some of the colors commonly seen on males. This is why most people (me included) have such problems sexing small specimens.

The pattern on your other female indicates dominance, willingness to breed, or breeding/brood dress. It really depends on the color of the body. It gets brighter yellow and darker black with each successive state.

 

[rollj1]

Since your fish are small (young), there is a good chance that your harassed female is either a juvenile or a sneaker male. Both resemble females to a large degree. Females of domestic color strains of A. cacatuoides often show some of the colors commonly seen on males. This is why most people (me included) have such problems sexing small specimens.

The pattern on your other female indicates dominance, willingness to breed, or breeding/brood dress. It really depends on the color of the body. It gets brighter yellow and darker black with each successive state.

Thanks again for your reply Mike.

Since my last post I have added more planting to the tank and also added a shoal of Ember Tetras as dither fish. This has distracted the male and the dense planting has helped, but I still see him chasing the other female around - that is, if it is a female and not a male or sneaker fish as you say. If this fish is actually a male, how long would it be before she/he developed the larger fins and different colouration? Or, if the other male is present will it always remain looking like a female? Would it help if I removed this suspect female from the tank and re-introduced her at a later date?

 

[Mike Wise]

Well, sneaker males can remain small and more female-like in appearance for most of their life if kept with a dominant male. I suggest that you put this fish in a separate tank and see if it develops into a male.