How large sould 3 week old Betta fry be?

[Liz Sagara]

My Betta fry are 3 weeks old (August 1st) how large should they ideally be? Here's some questions.

1. How big should they ideally be?
2. Should they already be breathing air?
3. Is it true that the males develop quicker?

 

[Liz Sagara]

http://www.youtube.com/watch?v=mm2MQb0yd-g Is this normal for 3 week old fry? The largest of them is half an inch.