If you want the dogface that badly, I'd find a bigger tank (at least a 125 gallon). Otherwise, I'd go with a Canthigaster valentini. Just as cool looking, but not quite the threat that a dogface puffer would be because it stays smaller in size. If you were to stick a hawkfish with a puffer, you could do it as long as the hawkfish was in the genus Paracirrhites or Amblycirrhites (i.e.-something like a Forster's or Blood Red Hawkfish, which are larger and semiaggressive in their own right) instead of the Long-nosed. If you want to stick with a 75 gallon set-up, I'd go with Blue Devil Damsels or one of the many members in the genus Pomacentrus (such as coelestis, pavo, and alleni, among others) which are highly colorful and aggressive enough to fend for themselves, but not big enough to do a whole lot of damage, a pair of Clark's Clownfish (or also a Percula, Ocellaris, or Cinnamon), any one of the puffers in the genus Canthigaster (i.e.-valentini, solandri, etc.), and to add a flash of color and more brazen behavior, I'd go with the flame hawkfish instead of the long-nosed. Both are hardy, but the flame is both less secretive and more colorful than the long-nosed. If you want to upgrade size to a 125 gallon or larger and go to a more aggressive community with the same families of fish, I'd recommend the more aggressive damsels (i.e.-those in the genera Abudefduf and Neoglyphidodon and Dascyllus trimaculatus-AKA the three-spot domino damsel, among others), a pair of Maroon Clownfish (Premnas biaculeatus), one of the larger and more aggressive hawks, like the aforementioned Blood Red and Forster's Hawfishes, and your Dogface Puffer (Arothron nigropunctatus). It's a good thing that you only want the Dogface. Any other Arothron, and you'd have to have a very large tank to support an even more aggressive fish-only community. The bottom line to a question like this is simple: what do you want to accomplish with your tank? You have to prioritize what you want if some of your objectives conflict. Do you want the dogface puffer more, or do you want to keep your size tank without the added expense of upgrading to a bigger size more? Simply put, you can have similar types of communities with each size tank, but the 75 gallon can only accomodate certain species of fish in such a type of community because of size constraints and concerns over aggression due to space constraints. If you want the dogface more, you need to upgrade your tank size and choose tankmates that have a corresponding increase in both size and aggression. If I were you, I'd stick with your 75 gallon setup with less expense, and go with the community that could fit with it, but then again, that's just me. The point is that you want to research your options, and the fact that you appear to be doing that is a good thing. Oh...notice that I said nothing about the tang. There's a reason for that. Hippo tangs prefer to be kept in groups of 3 or more if at all possible. Three tangs alone would fully stock your 75 gallon tank. Furthermore, your dogface puffer would do a number on hippo tangs if you wanted to upgrade sizewise, and the hawks I mentioned for that size tank might also do unspeakable things to hippo tangs. If you were to add a tang to those types of communities, you'd want to upgrade to at least 150 gallons and add one of the more aggressive types of tangs, such as Zebrasoma veliferum, desjardini, or xanthurum (the Sailfin, Red Sea Sailfin, or Purple Tangs, respectively) for the more aggressive community, or stick the group of hippo tangs in with the bunch that I suggested for your 75 gallon community in a 150 gallon tank. Hope this helps.
Brad
