Who is Supaari VaGayjur from The Sparrow and what is their importance?

Supaari is a Jana'ata species, the native and sentient being on planet Rakhat. He is a rich and successful trader and the third born in his family. According to the Jana'ata tradition as a third born, Supaari is not allowed to reproduce unless given special permission or under special circumstances. He has become bored with his wealth and starts searching for a way to get permission to start a family. Supaari is the first Jana'ata to encounter the humans due to his close relationships with the Runa species.