Tilapia
arowana
Inside their Abdomen and after giving eggs they keep eggs on Leafs.
Bettas and goldfish
it eats their young/it keeps in their mouth
Arowanas are one.
Breathing.
no ... when fish are borned thay has a bag that is full of eggs and when it grows another fish comes and kiss in the mouth and breakes the bag ,the eggs come out and grow .
Arowanas are mouth breeders, that is, the male will carry the fertilized eggs in his mouth and protect the young once they hatch. See the link below for a good overview of this fish's reproductive habits.
Catfish : a father sea catfish keeps the eggs of his young in his mouth until they are ready to hatch . Frog : the male Darwin frog hatches his eggs in a pouch in his mouth .
fighting fish
When a male betta fish puts the eggs in his mouth, he is engaging in a behavior known as mouthbrooding. This occurs after he fertilizes the eggs, and he will carry them in his mouth to protect them from predators and ensure their safety until they hatch. The male will typically keep the eggs in his mouth for several days to a couple of weeks, depending on the species and environmental conditions, before releasing the fry into the surrounding water. This behavior helps increase the survival rate of the young fish.
There are several, Chichlids, Apogonidae, Ariidae, Jawfishes, Osteoglossids and Gourami