Age of maturity

[Bilbo]

I should know this so sorry for the newbie question.

At what age usually does a male agassizi start showing his true patterns and fin shape?
I have had a fish in the past that I thought had either been a sleeper male or had had a sex change at over 2 1/2 years old (See here)

Next generation.
These fish are now over 15 months old with no obvious sex differences except for the dominant female going bright yellow and looks like she is spawning.

 

[Mike Wise]

Being cold blooded, a fish doesn't have a 'maturity date'; it depends on external environmental factors: temperature, food, water quality. In an aquarium most apistos are sexually mature around 9 months of age. With pushing (and depending on the species) it can be as soon as 5-6 months. Immature males can often be recognized by 3 months of age. Some males - again, depending on their environment - might never show their "secondary sexual charateristics" (color, finnage, size) until environmental factors change. Females are much harder to sex when young. Young or sneaker males often look like females. As females age, however, many can develop more masculine features.