Territorial fish vs dominance

[DYIguy]

I find that when researching fish and compatability the term of being territorial comes up a lot. I think it's used loosely to just say that a fish is likely to show dominance in the wholw hierarchy of the system or over similar fish. Granted there are fish that are very territorial, but I find that most ( in my tank ) think less about territory ( or ignore it altogether) and more about who's boss-

 

[radiata]

An Aggressive and/or Dominant and/or Territorial fish tends to be a fish that in the wild is protecting their feeding territory from interlopers that happen to have the same dietary requirements that they have. This, in terms of our tanks, means that a fish (such as a tang) that needs a territory of fifty square meters of reef floor to harvest enough food to sustain itself, will harass any fish with a similar dietary requirement that suddenly arrives in its territory, to the point where it is driven out of said needed territory. The defending fish doesn't know that the size of the territory that it needs has been limited by the size of your tank. It has just been programmed to drive the new fish out of the fifty square meters it owns, tank or no tank.