Well, at first glance it is not easy to differ the genders, especially if the respective dealers themselves often
unable to do so. Added to that the fisches in the pet shop mostly very young and very frightened. A distinction is
mostly impossible. Not until the Puffers are larger and they feel comfortable at least some of the males can be recognized.
Basically the puffers reach sexually mature after approximately 5 Month. Gender-related behaviour like courtship behavior can be observed before.
There are four optical characteristics where you can fix the difference, these differences are:
1st The different color, which shows only Dwarf Puffers that feel comfortable.
2nd The body shape, usually with larger animals to be distinguished.
3rd The dark longitudinal line along the belly of male Dwarf Puffers.
4th The wrinkles behind the eyes with larger males

These picture shows the coloration of a full-grown male. It is characterized by yellowish abdomen (belly) and the back of brownish
color. Clearly, one sees the "wrinkles" behind the eyes.
"Eva" is just doing her favorite activity, looking for Food. Her back is bright with black spots and you can see her nearly white belly well.
Although a Ram cichlid (Microgeophagus ramirezi) is between the figures, on the top left you still can see a male with the
dark longitudinal line along the belly. This line depends on the mood and is only to see at the "the lords of creation."
Right below, the female shows in contrast the typical almost white belly, which is something roundish body shape and the bright coloration.


If the males are old enough and in the mood, the dark longitudinal line on the bellies of males can not be be overlooked. This line can be seen earliest in the 12th week.