Betta fish grow to be an average of 2 inches from head to the beginning of the tail.
a long time
No.
Because, if they are in a small cage the Betta will stop growing. But, the organs will keep growing and the fish will die a long and painful death.
you don't
A body length of around 2.5 inches is a well grown male.
A betta fish is anywhere from 1 to 2 inches.
Betta fish can be from 2 to 4 inches long when fully grown.
Yes a betta fish will grow back lost scales with time and clean water.
No
Betta fish grow paler and less active when they are sick or old.
The average is 1.5 inches
it depends on how small the bowl is betta fish usually dont grow larger then 3 or 4 inches