Well a good start is making sure his/her tank is clean and doesn't have lots of leftovers at the bottom of the tank (this will prevent it from getting sick), Feed it a healthy and rather popular food (if the betta doesn't like the food he will spit it out or not eat), keep the Betta in a tank by himself (this will lower stress) and a very important thing to do is make sure there is enough in his tank to keep him busy/happy.
Betta fish grow paler and less active when they are sick or old.
If they are not too old and the female is ready, then they will mate.
A nine month old betta is already full grown, so yes.
A betta normally only lives 2-3 years, so it would be around 70 years old in "betta years".
A Male Betta will grow to about 2.5inches of body length and a Female will grow to about 2 inches of body length. A Betta is fully grown at about 6 to 8 months a Betta is very old at 30 to 36 months.
the size of it's fins and body
'I'm not 2 sure !
Signs of old age in betta fish may include decreased activity levels, slower movement, faded coloration, fin deterioration, and reduced appetite. It is important to monitor your betta fish closely for any changes in behavior or appearance as they age.
They can live up to 3 years.
There are half moon betta, delta betta, round tail betta, long tailed betta, crown tailed betta, king betta, and others I don't know of yet.
Most likely. I would wait until the little betta is around 3 cm (3/4 inch) Make sure the betta's are the different sex because two males will fight (often until death)
A betta fish's color may fade due to stress, poor water quality, inadequate diet, or old age. It is important to ensure a clean and suitable environment for your betta to help maintain its vibrant colors.