Any.
None are recommended if the Betta is a male.
yes betta fish have to live alone or one will kill the other.
Male betta fish are typically aggressive and territorial, so they are best kept alone in a tank to prevent fighting with other fish.
Yes it can
Just one male betta, but you should consider a proper betta set up which can have 2 to 2.5 gallons for the one fish.
Provided you remember the 1 inch of fish to 1 gallon of water rule yes Betta splendens (Fighter) and Apistogramma ramirezi (Ram) will be OK together.
Some male betta fish are not as aggressive as others.
Just watch how they interact and if the betta is being aggressive isolate him. Bettas can be with other fish as long as the betta is a different color and there arent any fish with similar fins.
male
Yes. Betta Fish do change their coloer every now and then. Or if you have a male, he will change his coloer if hes chaseing a female Betta Fish. Or if he sees another male Betta Fish.
NO!!! Lizards should only be kept with other lizards of their own species. Some kinds of lizards are fine by themselves. Waste from the lizard is poisonous to fish. Also, Lizards do not need a lot of water, where would the fish go? Lizards don't swim. The lizard would eat the fish. Male betta fish are best housed by themselves, or in a 10 gallon or bigger tank with neon tetras, or other gentle community fish. Also, never house a male betta with another male betta, or a female betta. They will fight until their death. Females can be kept together. Three do fine in a ten gallon tank. NEVER put bettas with fish that have long flowing or colorful fins, the betta will mistake it for another betta and kill it.
yes