If you have more fish, you should put the catfish into another tank. Or you could just get rid of it.
No
Because it want's to eat it.
Provided the tank is large enough and the catfish is a tropical species there should be no problems.
Some fish that can be kept with a betta include neon tetras, corydoras catfish, and ghost shrimp. It is important to choose tank mates that are peaceful and won't nip at the betta's fins.
It depends on the Betta's personality. I WILL live on its own in peace because there solitary animals. But they CAN live with Otto catfish, Cory catfish, African dwarf frogs, Zebra danios, Ghost shrimps, Cherry shrimps and Kulhi loachs. I would recommend no Guppies, Goldfish, other Bettas, Kois, Goramies, Rosy Barbs, Hermit crabs or turtles
By not adding other fish? You'll be surprised that in most cases its the betta who is the victim. Betta is such slow swimmer and they have large fin, which makes them perfect target for fin nippers. Although, you can add bottom feeders such as Corydoras catfish into the same tank as a betta, they do not occupy the same level.
The best fish to have in a tank with a betta fish are peaceful, non-aggressive species like neon tetras, corydoras catfish, or ghost shrimp. Avoid fin-nipping fish or those that may compete for food or territory with the betta.
You should feed your betta 3-4 times a week.
None. The 1 gallon bowl is already too small for the betta by itself.
Betta's are super Territorial once they see another one they go for the kill and one they do their is no stopping it they stop until one is dead even with cory catfish's the will kill anything ( fish) in my book their the king of the world ( and by world i mean tank) so i wouldn't even risk it weather male or female a betta is a betta
A nine month old betta is already full grown, so yes.
I believe you mean Betta fish. No, it should be fine. You can treat you Betta fish by giving them bloodworms!