The noun fish is a considered the singular and plural form, although fishes is accepted by some. The possessive form is fish's for the singular or plural. Example sentences:
My fish's name is Oscar.
Marlin, Dory, Nemo, and Gill are the fish's names in the movie 'Finding Nemo'.
You could use '...the fishes' names in the movie...', it would be pronounced the same but it is not a universally accepted form.
the fish has gills
Fish is my best delicatessen..
In some cultures, jawless fish are a delicacy.
the fish was born demented.
I have deca fish! I ran a triangulation
I flayed the fish, for example.
Some fish have caudal fins.
Noun: That fish was extremely heavy. Verb: How do you know how to fish?
i gave a denomination to my pet fish today
If water is unpolluted, fish thrive in it.
The cormorant sought fish in the blue ocean.
And the fish got flushed away