From Bulbapedia, the community-driven Pokémon encyclopedia.

Trovita Island
ユズ島 Yuzu Island
Info
Region	Orange Islands
Anime debut	Misty Meets Her Match!
Gym info
Gym	Trovita Gym
Leader	Rudy
Badge	Spike Shell Badge
Challenge	Attack test, 3-on-3 Pokémon battle
Location of Trovita Island in the Orange Islands.

Trovita Island (Japanese: ユズ島 Yuzu Island) is a small isle off the western coast of Mandarin Island South in the Orange Archipelago. Trovita Island is surrounded by large rocks that were formed millions of years ago when the island rose out of the ocean. The Spike Shell Badge reflects this unique island trait.

Trovita Island is home to the third member of the Orange Crew, Rudy and his sister Mahri. The Trovita Gym is a large stadium.

Its English name comes from the thin-skinned trovita orange. Its Japanese name comes from the Japanese citrus fruit known as the yuzu (柚). The citron is the English equivalent.