Fighting fish are territorial and can be very aggressive, they will kill other fish if you put them in the same tank.
Other fishes
because a fish can breath underwater and a whale cant its a mammal
The "flaring" of the gills is simply a way for the fish to look larger and more threatening. It is both defensive and aggressive behavoiur.
Angelfish, fighting fish and other bigger fish would. They would do it more often too if the guppy looked weak or less strong than other guppies.
yes. but you might want to do some research on what fish can go in the same tank with fighter fish (Bettas). I have 10 other fish with my betta and so far he has only killed 1 platy over the holidays when my nan was looking after the fish. :)
Basically, no. There are no fishes that doesn't live out of the water. :D
The Fishes...
No, fighting fish (Bettas) are only interested in fighting with other fighting fish.
yes blue fighter fish eat other fish and bites them slowly untill they die
maybe you can put a non-aggressive fish that if physically provoked by the fighting fish it can defend itself. or fast moving fish like goldfish so it can outrun the fighting fish. when feeding your fishes they usually move quick, putting their mouths above water. however, the betta doesn't. and they can get easily annoyed when other fish bump them. so,I recommend the angelfish.
Other reef fishes.
Will fish. The verb 'fishes' is the third person, singular, present of the verb to fish. He fishes; She fishes; It fishes. Examples of the third person, singular, future tense of the verb: He will fish; She will fish; It will fish.