I dont understand the different between fish and fishes
there are many fish in the sea
there are many fishes in the sea
fishes= many kinds of fish right
there are always many types in the fish so should fishes be corect?
It is fairly unusual to use the word 'fishes'. You should use 'fishes' only if you specifically want to refer to types of fish, usually in a very specific location. To me, your sentence seems a little too general to use 'fishes'.