Sexing Aequidens diadema

[Plec123]

I've had a large female Aequidens diadema for some time, and have struggled immensely in finding a male. I found a sub-adult at the lfs and vented it in the shop, and it appeared to be male, so i bought it... but now I'm not so sure. I've heard that the males have a steeper profile but slender build overall. As you can see below, the big girl is pretty stocky, and the smaller one is slimmer, though that might just be because it's a wild caught fish.... I tried getting some side pictures of the genital papilla on each fish, particularly the little one. Do you guys think i found another female, or does this fish look male?
Pics 1 and 2 are the 5" one, pic 3 is the big female, and pic 4 is both fish.

Apologies for the messy tank, just rescaped and fed them.

 

[kno4te]

Gourami Swami duanes

 

[duanes]

I don't have enough personal experience with this species to comment, I would suggest tagging ryansmith.

 

[Plec123]

ryansmith83 any thoughts?

 

[neutrino]

Ime except for size (males end up larger) not much difference. Males can be pretty chunky-- or not, depends on the individual. Mature males with pristine fins have a longer dorsal fin that curls around the caudal a bit, but the difference is not dramatic and you may not see it in immature males or if their fins are less than pristine, so it's not necessarily reliable. I haven't seen a profile difference that I'd call a reliable indicator. Compounding this, they can vary some by catch location, so what I've seen may not match someone else.

Your photo of the tube looks a bit ambiguous to me, my guess would be male, but I'd feel more confident seeing it in person and you may get varying opinions on that.

 

[duanes]

Above is a great answer, I have found that all the acaras that I've kept of the "Aequidens, Cichlasoma, even Andinoacara" are difficult to tell apart, unless you catch them in the act spawning.
They were all lumped into Aequidens not that long ago anyway.

Much like the Cichlasoma dimerus above, cranial profile, and fin trailors are of minimal help.
And (for example) take the Andinooacara above, I kept about 3 years, when out of spawning mode its almost mpossible to make an accurate gender determination.

Above Male left female right
Below a female

The best method to get pairs from these cichlids for me, has been to been to get 6 to 8 (or preferably even more) and let them figure the logistics out.
When acquiring my group od C dimerus, I started with about 10 or so.

 

[ryansmith83]

I was never able to tell mine apart until they hit maturity. Males ended up over 8” while females stayed 5 - 6”, and the females dropped their tubes when they started furiously digging nests in the sand. While doing this, they turned a dramatic dark color with blue-purple iridescent faces.

I did find the males to be more long and slender while females were more short and chunky, though the difference was slight and only something I could tell when looking at the group as a whole. I’m sure as the males got older and the growth slowed they’d probably also get chunky if fed well.

 

[Plec123]

I was never able to tell mine apart until they hit maturity. Males ended up over 8” while females stayed 5 - 6”, and the females dropped their tubes when they started furiously digging nests in the sand. While doing this, they turned a dramatic dark color with blue-purple iridescent faces.

I did find the males to be more long and slender while females were more short and chunky, though the difference was slight and only something I could tell when looking at the group as a whole. I’m sure as the males got older and the growth slowed they’d probably also get chunky if fed well.

Really appreciate your detailed answers. Honestly, that behavior is the main reason why I believe the big one is female. She has calmed down a lot, but she went through a phase where she was almost black and digging pits constantly. I tried to buy 4 to grow out when i only had a 75 gallon, but they just tore each other up and I ended up getting rid of them.

I guess we will see how things go as this one grows. Hopefully the big one doesnt get too aggressive now that she's in a 6ft tank.

 

[neutrino]

Ime they vary in temperament. Some can be hard on each other, some males are rough on females, some males are territorial and feisty even with larger fish, while others are fairly mild ime. I've seen something similar with others who have them, varying experiences, even as singles in a SA community.

Ime they pair readily and it's possible to match a female with a gentler male if you have one, in other words ime it's possible to try a female with different males and it may work out better than just letting the most dominant male choose the female-- which is a little different from some cichlid species that may not pair readily or where it's best to let pairs form on their own in a group and leave it at that. Otherwise it's kind of "the luck of the draw" with them. Ime even with a milder male there will be some aggression toward the female but not more than she can handle, not so much as she gets roughed up. That's my experience, anyway.

But all of that's with a larger male than female. Don't know about having a larger female with a younger male. I suspect, as above, it will depend on the individuals. Of course, as the male approaches adult size things can change.

 

[jully76]

nice one...