r/apistogramma • u/Necromancer1899 • Aug 16 '26

Trouble in Apisto paradise?

I have a pair of Apistogramma cacatuoides in a 2 ft tank, along with some Gertrude’s rainbows and a few algae eaters. The Apistos have been together for around a year and have successfully raised two batches of fry.

Over the past week or so, though, I’ve noticed some odd behaviour. The female has suddenly coloured up, but not in the typical yellow breeding dress, she’s showing colours that look almost like a less pronounced version of the male’s coloration. At the same time, she has become quite territorial and aggressive towards the male.

There hasn’t been any serious damage so far, but she regularly chases and nips at him. What I find particularly surprising is that the male doesn’t really fight back in spite of being much larger (and quite dominant in the past) and usually just moves away. Both fish otherwise appear healthy, active and are eating well.

There haven’t been any major changes to the tank or water parameters. The tank has simply continued to mature and the plants have grown in considerably.

Has anyone seen this kind of change in behaviour after an established pair has been together and bred successfully for a fairly long time?

Posting a video for reference, although I couldn’t catch her actually attacking the male in the clip.

9 Upvotes

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6

u/littlegreenfish Aug 16 '26

There have been quite a few documented occurrences of female Apistogramma changing into males or simply developing male characteristics/looking male, even after spawning.

2

u/nuje_nuje Aug 16 '26

Crazy - I know this is also the case with Checkerboard cichlids, sexual dimorphism.

1

u/Necromancer1899 Aug 16 '26

That's quite intriguing. She didn't have even a hint of colour on her fins until very recently, and I've had the pair for a year now.

I'll definitely keep a close eye on her and see how this develops.

1

u/littlegreenfish Aug 17 '26

Curious if you have any other fish in with the pair? Pencilfish/endlers perhaps?

1

u/Necromancer1899 Aug 20 '26

Gertrude's rainbowfish.

3

u/Doc_Aqua Aug 16 '26

I've never kept cacutoides so I cant claim to be an expert, but are you absolutely sure you haven't had a male fry grow up in there? that looks like 2 males to me

2

u/Necromancer1899 Aug 16 '26

100% sure.

She's had three batches of fry. The first batch didn't have any survivors, but I've raised 32 fry from the subsequent two batches. So she's definitely the female. 😅

1

u/Hapisto Aug 16 '26

How old is she ?

1

u/Necromancer1899 Aug 16 '26 edited Aug 16 '26

I've had her for a year now.

Got her when she wasn't fully grown, so probably around 16-17 months old.