Size: Male Glofish tend to be larger than female Glofish, but this is not always a reliable indicator.
Body Shape: Male Glofish usually have a more slender body shape, while female Glofish have a more rounded body shape.
Coloration: Female Glofish tend to be brighter in color than male Glofish. However, this is not always the case, and some male Glofish can be quite brightly colored.
Behavior: Male Glofish tend to be more aggressive than female Glofish, especially during breeding season. Male Glofish may also display territorial behavior, such as chasing away other fish from their territory.
It is important to note that these are just general guidelines, and there may be some exceptions. The best way to determine the gender of a Glofish is to consult with a qualified aquarium expert.