Just a Few Fish Mod 1.7.10
If you got tired of there being no simple fish entities for the vanilla fish items, this is a mod for you. There are many other mods out there that add fish mobs, but none of them did it quite the way you wanted (or had a zillion other mobs and other content in the mod too), and this is a little fish mod that adds some simple fish entities.
Download link: Just a Few Fish Mod 1.7.10