Sure do.
The only non-giant fish I could find is this:
Barracuda (M): Str 11, Dex 17, Con 10, Int 1, Wis 12, Cha 2
Dropping it to Small yields Str 7, Dex 19, Con 8, Int 1, Wis 12, Cha 2
...and to Tiny yields Str 3, Dex 21, Con 8, Int 1, Wis 12, Cha 2
Compare to...
Tiny lizard: Str 3, Dex 15, Con 10, Int 1, Wis 12, Cha 2
Small octopus: Str 12, Dex 17, Con 11, Int 2, Wis 12, Cha 3
So maybe...
Tiny Salmon: Str 3, Dex 21, Con 10, Int 1, Wis 12, Cha 2
Small Salmon: Str 7, Dex 19, Con 10, Int 2, Wis 12, Cha 2
How big a salmon are we shooting for?