Plural of fish

The noun fish is an uncountable (mass) noun as a Word for a food substance.

• The possessive form is fish's.

The noun fishes is a plural noun as a Word for two or more creatures.

• The plural possessive form is fishes'.

Examples:

This fish's source is the north Atlantic. (singular)

The tiny silver fishes' glint in the sunlight looked like a pool of jewels. (plural)