'Fish' is the plural of 'fish' (it doesn't change) and you'd normally always use it as such.

When pluralising many kinds of fish, you can say 'fishes' if you'd like.

Ex:

I ate six fish.

I caught six fish in the river.

All the fishes in the ocean.../All the fish in the ocean...

Help, please!

Can I say "fishes"? or it's always used in singular "fish"?

For example: I have many fishes at home or I have many fish at home?

I like to eat all kind of fish or I like to eat all kind of fishes?

Thanks!!!!

When talking about eating, you can only say fish - I eat different kinds of fish; I like to eat all kinds of fish.

While it is acceptable to say fishes as the plural of fish, it isn't common at all and more often than not you will hear the word fish for singular and plural.

Some nouns have identical singular and plural.For eg. animals like bison, buffalo,deer,fish,moose,pike, sheep.......

Nearly all kinds of fish have no separate plural form (though there are exceptions—such as rays, sharks or lampreys). As to the word fish itself, the plural is usually identical to the singular, although fishes is sometimes used, especially when meaning "species of fish".