In Pokemon FireRed you can't, but in Pokemon leafgreen you can get it then trade it to Pokemon firered.
NO you cant but you can in leafgeen
Super Rod in "Canalave City"
use good rod on route 19
Poliwhirl → Poliwrath, Shellder → Cloyster, Staryu → Starmie and Eevee → Vaporeon
lombrea, evee, poliwhirl, shellder, and staryu. some of these can only be found in firered and leafgreen so you will need to trade. that's all I can think of.
Staryu are not available in firered you will need a leafgreen version to trade you one.
A Staryu, and Starmie
you can't. you have to trade to get it.
NO you cant but you can in leafgeen
It's one of the starter pokemon.
eevee and staryu
Super Rod in "Canalave City"
You can't catch staryu in firered only in leafgreen or ruby or sapphire or emerald.
use good rod on route 19
Slowpoke is a LeafGreen exclusive, along with Staryu, Pinsir, Bellsprout and Sneasel.
leaf green only
Staryu is a water type Pokemon. In Pokemon FireRed, it is possible to find lots of Staryus in the Seafoam Islands.