Male Siamese Fighting Fish (bettas) are highly territorial. In the wild, if a male betta encountered another betta they may choose to squabble over territory. However, it is more likey that the weaker male would leave to avoid getting him hurt. If the body of water is too small for both males to hold territories (ie. anything less than about 1000 gallons) they will fight, sometimes to the death. This behavior is not difficult to replicate in a small aquarium - add water, add two male bettas, sit back and watch. In some Asian countries, betta fighting is an actual sport, like cock fighting, and people go to watch and bet on it. The Asian fighting bettas are very well cared for, but unfortunately European and American copycats do not care for their bettas as well. Please don't make bettas fight. It's natural behavior and if you do not know exactly what you are doing (ie selecting evenly matched stock, choosing the right fighting strain, removing the fish at the right moment to avoid serious injury and treating them afterwards) do not exploit their instincts for your own entertainment. It is cruel to do so.
they look like this, with their gills sort of sticking out.
Look under its skirt
They are spawning.
fish are fish
Male betta fish tend to be very aggressive. They are best alone unless theres a special type of specie they can get along with. They like to have personal space. And as using fighter fish you probably refer to Siamese fighting fish which is betta fish
Fish
Dolphins look like dolphins and why would they look like a fish when they are a mammal?
There are thousands of species of fish and they all look different from one another in some way. Seawater fish look like fish as do freshwater fish.
You provide the male fish with optimum water conditions for its species. He will care for the eggs (ova) and look after them until they are free swimming.
The fish they stole were Japanese Fighter Fish
they look like fish.
Like a hokie fish