In Isaac Asimov's Robot/Empire/Foundation series of novels, the Langano Sector was an administrative division of the Galactic Empire. Its capital was presumably the planet Langano. The only planet known in the sector is Salvan, which was famous in the Empire for its geckoes. Presumably, geckoes were a rarity in the Empire, since they did not help humanity particularly much, and only those creatures that were useful were brought by humanity into space.