When Fishy Joe is talking to Fry and Bender, he mentions that he has a Fishy Joe's on every planet in the known universe. So, why wasn't there a Fishy Joe's on the poppler plannet?
RESPONSE: There isn't a Fishy Joe's on the Popplers' planet because it wasn't yet discovered by humans.
Evidence of this:
-Bender states in the beginning of the episode, they were "a billion miles from nowhere."
-Leela had to look at her wrist device to analyze the type of planet, so she probably didn't know the planet beforehand.
-No one seemed to have seen or known what a Poppler was before they brought them to Earth, so it is likely that no human had discovered or been to the Poppler planet before Leela, Fry, and Bender.