How man gobies could you fit in a 40 breeder?

[Crepe]

Out of curiosity has anyone ever kept many species of gobies in one area? I know that if you get similarly colored gobies there may be competition but what exactly is the general rule for bottom dwelling gobies?

Also are there any top dwelling sw fish?

 

[mysticeel]

clowns hang out wherever their home is...so they can be top dwelling...