you can know by their tail their tail the female's tail is not big and large.The males on the other hand have big luxurious tail.
In order to know if a Silver Arowana is male or female, you need to look at the size of the fish. The male fish are bigger in size.
What exactly is a fish coin?
flowron
the rosy red fish is the boy.
If the fish is male it will be bright and colourful, if it is female it will be quite dull
male is huge and grey female is colurful
A girls cap is bigger and the boys cap is smaller
the female beta fish is "plainer" than the male as where the male is a darker shade near the face and lighter shade near the tail.
Male guppies have color in their tails,females never have color.
they females are brighter and the males are paler
The males have a red tail.
If it tries to pinch you it's a female if it's calm and doesn't pinch you it's a male