It really depends more on the your perspective which is usually based visually on size rather than age. Approximately any swordtails less than ¾ “ would be perceived as fry and any larger than that would be considered Juvies, once they are mature enough to begin or start dropping fry Young Adult Size and Larger Fish would be considered Breeder Show Stock.
What Are the Water Conditions and Parameters For Livefins Aquastock?
I raise these particular fish in a greenhouse in a 55 gallon breeder tank with some endlers and the water stays quite warm. 82 – 86 degrees this time of year. The pH is 7.6, source is unfiltered Florida well water which filters though a limerock aquifer, kH is quite high. The TDS measures 390. I raise plants with them, so the tank has Florida sandy soil as substrate and is heavily planted along with scuds, daphnia and cyclops cultured within same tank. This lessens aggression between males. I would not recommend placing all 3 of these in a bare tank or without females and lots of retreat area for the sub dominant males.