Uaru Cichlid Uaru amphiacanthoides sex?

Hi,
I was wondering if it is possible to sex these 4 uaru? what to look for when sexing them? Was looking online for information and can't seem to find much on uaru cichlids. Around how big are they sexually mature? uaru 3 is the smallest of the group of 4. I'm hoping for a pair within the 4 and all 4 are almost always together. Any help would be appreciated thanks!
I was wondering if it is possible to sex these 4 uaru? what to look for when sexing them? Was looking online for information and can't seem to find much on uaru cichlids. Around how big are they sexually mature? uaru 3 is the smallest of the group of 4. I'm hoping for a pair within the 4 and all 4 are almost always together. Any help would be appreciated thanks!