look on www.supercheats.com go to consoles:ds game:pokemon platinum and look for the action replay codes link and they will be there w/ many others
At a pokemart
On Pokemon Platinum, Carvanha can be caught in the Great Marsh.PLEASE NOTE: REQUIRES SUPER ROD.
fish with the super rod at the pokemon league
You can go to super cheats .com and search Pokemon platinum
You can receive a Super Rod from a fisherman in the Fight Area on Pokemon Platinum, Diamond and Pearl.
use codes
The Pokemon Platinum guide book says you get it at Pastoria City with a super rod hope i helped
Use a super rod.
Almost any where with a super rod
Fire
You can fish with a super rod
Pastoria City and Pokemon League, use super rod