Would catalina gobies become prey for the octopus? A pair would be nice in there. Can't you get a fishing license?
I think that catalina gobies would probably be easy prey for an octopus, since they like to hold still a lot, but I don't know for sure.
As for the fishing license:
California law says that if you have a fishing license you can catch fish, but even then, you can't take them home alive. The reason for the law is that they don't want people to put native a fish in their home aquarium, and then later decide to release it back in to the ocean. It would be easy for the local fish to catch an exotic parasite or disease in a tank filled with critters from all over the tropical world, and then, if released, infect the local fish population. It's a really good reason, I think, although it does limit what I can have in my tank.