If you're in Japan (which is the end goal here, let's be honest) then the fish in your village are carp. You may know them as koi, too.
A carp is called a koi (こい) in Japanese. We've used that word before so I hope you know it by now. A koi is a koi, you know?
Currently there are no similar looking kanji which exist in the WaniKani learning system