Thanks Mottoro. You're 100% correct!
#1 - I think is male, he hides alone under this driftwood and once tried to enter the alpha male's cave but ended up fighting.
#2 - I believe is also male, he lays next to the two females but he has long odontodes.
#3 - is female, she sits close to #5.
#4 - I think is male, he is really small but hides inside the second cave. I'm not sure if the alpha male knows this.
#5 - is female, she sits behind the alpha male's cave and lays next to #3 all the time.
Sorry - I was not sure as many people told me different things. It is very difficult to sex Hypan. zebra
At least I have some females, now wait for some breeding.