At what age / size will cichla develop their hump?

[itsKRUDD]

I dont know the exact spelling for it, but what age / size will it start to show? Im sitting on my couch and look over and my one cichla looks different so I run over and sure enough what i thought was a "her" because of the size difference sure looks like HE is developing a hump. He's coming up on 1 year old now, I think in the next month or so, and I'd say is roughly 10 inches?? Its hard to tell their size since I dont want to pull them out to measure. I use a 8 inch sticker on the tank to tell, and theyre clearly larger than the sticker.

Their blue has been really prominant in their tails recently as well, also showing a lot of orange under neath their body.

Could it be?

 

[itsKRUDD]

Also, generally speaking, is one (male or female) usually larger?

 

[sevank21]

It's nuchel hump. And usually around sexual maturity so appx 12"

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[itsKRUDD]

They're roughly 10-12 inches, from that picture what do you think? Is it possible? I've never noticed this before. Im going to do a good sized water change this evening to see if I can promote some more growth out of it.