That goby will get waaayyyy too big for that tank. and anyone who says the bichir will eat the goby has no idea how big they grow and how fast they get that big. My jade goby hit 12" in 8 months.
I will agree with that if the Goby is a chubby one the Delhezi might not be able to but I've had Bichirs take down Yellow Labs that were fatter then them.i think a 6-7 inch delhezi wouldn't be able to get it down their throat. a 3-4" jade goby is pretty fat. I had my jade goby in with my 10" ornates when he was 4", and he was much too fat for the ornates to eat. The jade goby quickly outgrew the two ornates.