Blue acara sexing and size

[Lysol]

I have these 2 eba and I've never kept any acaras before theese 2 therefore I don't know how to sex them... Also as you might notice there is one that is smaller.... Is this due to hierarchy? The difference seems a little too much

 

[Lysol]

Forgot to attach

 

[Jexnell]

There is no outward way to sex these guys, they look the identical. You will have to take them out to vent, or wait till they gets frisky and naturally drop down for use.

From the side males look like a V

Females look like a U

 

[ryansmith83]

When they’re full grown, males tend to be a little larger, with a more slender body shape and a steeper forehead. Females will be shorter and fuller with a less steep forehead. The differences are subtle if you’ve never sexed them before but you can start to see it after you’ve kept them a while.

Electric blues are slightly smaller than wild-type blue acaras, growing to 4 - 5” while the normal ones can make it to 6” or so.

 

[duanes]

Below is a video of wild caught Acara's (Andinoacara coerleopunctaus) guarding a spawn, to help show gender differences in the Andinoacara genus.
Note as Ryan pointed out, the male is the larger of the two, and his profile is steeper, yet his body is more streamlined.
The female, a bit boxier in body shape, and when guarding fry, her melanin type colors are darker.
If it is your intention to have yours spawn, I would pick up a few more to allow them a variety of partners to select from.
In my tank below, there are a dozen, and the pair have taken over about 1/3 of the 180 gallon footprint as their spawning territory.
Flashlight Andinoacara fry

 

[BurbeyTanks]

One thing I have noticed between my Male and Female, even though they are not full grown, is that my Male has orange edges to his anal and pelvic fins. On Females if this is present it will be a more dull yellow color. Anybody else find this as an accurate way to sex them?